diff options
| author | nfenwick <nfenwick@pglaf.org> | 2025-04-29 09:21:28 -0700 |
|---|---|---|
| committer | nfenwick <nfenwick@pglaf.org> | 2025-04-29 09:21:28 -0700 |
| commit | ead546f4dbca120fa72ce1839a5b0aed3c91227b (patch) | |
| tree | 5c75cc5266e826d60cd875bac94009a559462dc7 /75985-h | |
Diffstat (limited to '75985-h')
| -rw-r--r-- | 75985-h/75985-h.htm | 9904 | ||||
| -rw-r--r-- | 75985-h/images/cover.jpg | bin | 0 -> 95341 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p006.jpg | bin | 0 -> 68003 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p008.jpg | bin | 0 -> 70660 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p011.jpg | bin | 0 -> 68485 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p013.jpg | bin | 0 -> 42028 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p020.jpg | bin | 0 -> 31428 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p022.jpg | bin | 0 -> 82697 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p023a.jpg | bin | 0 -> 80120 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p023b.jpg | bin | 0 -> 36720 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p023c.jpg | bin | 0 -> 35300 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p024a.jpg | bin | 0 -> 58376 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p024b.jpg | bin | 0 -> 27563 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p024c.jpg | bin | 0 -> 11985 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p025a.jpg | bin | 0 -> 30108 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p025b.jpg | bin | 0 -> 17954 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p025c.jpg | bin | 0 -> 38928 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p047.jpg | bin | 0 -> 77039 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p048.jpg | bin | 0 -> 57236 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p049.jpg | bin | 0 -> 58447 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p050a.jpg | bin | 0 -> 63368 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p050b.jpg | bin | 0 -> 128469 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p058.jpg | bin | 0 -> 88483 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p063.jpg | bin | 0 -> 80000 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p067.jpg | bin | 0 -> 49225 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p068.jpg | bin | 0 -> 71379 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p069.jpg | bin | 0 -> 77134 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p070.jpg | bin | 0 -> 125436 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p077.jpg | bin | 0 -> 84366 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p078.jpg | bin | 0 -> 99131 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p080.jpg | bin | 0 -> 74870 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p081.jpg | bin | 0 -> 76687 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p083.jpg | bin | 0 -> 52514 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p084a.jpg | bin | 0 -> 57398 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p084b.jpg | bin | 0 -> 181482 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p085a.jpg | bin | 0 -> 37206 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p085b.jpg | bin | 0 -> 53874 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p091.jpg | bin | 0 -> 160516 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p098.jpg | bin | 0 -> 61708 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p099.jpg | bin | 0 -> 35259 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p100.jpg | bin | 0 -> 48851 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p102.jpg | bin | 0 -> 66000 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p104.jpg | bin | 0 -> 45213 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p110.jpg | bin | 0 -> 61658 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p115.jpg | bin | 0 -> 42079 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p116.jpg | bin | 0 -> 81963 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p117.jpg | bin | 0 -> 62705 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p119.jpg | bin | 0 -> 69748 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p122.jpg | bin | 0 -> 45213 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p124.jpg | bin | 0 -> 42561 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p128.jpg | bin | 0 -> 53134 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p129.jpg | bin | 0 -> 38854 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p130.jpg | bin | 0 -> 31534 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p131.jpg | bin | 0 -> 78704 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p135.jpg | bin | 0 -> 142424 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p139.jpg | bin | 0 -> 36004 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p146.jpg | bin | 0 -> 45873 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p147.jpg | bin | 0 -> 207625 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p159.jpg | bin | 0 -> 40844 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p160.jpg | bin | 0 -> 62634 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p176.jpg | bin | 0 -> 29124 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p183.jpg | bin | 0 -> 46340 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p194.jpg | bin | 0 -> 44392 bytes | |||
| -rw-r--r-- | 75985-h/images/i_p196.jpg | bin | 0 -> 67735 bytes |
64 files changed, 9904 insertions, 0 deletions
diff --git a/75985-h/75985-h.htm b/75985-h/75985-h.htm new file mode 100644 index 0000000..4dd3a07 --- /dev/null +++ b/75985-h/75985-h.htm @@ -0,0 +1,9904 @@ +<!DOCTYPE html> +<html lang="en"> +<head> + <meta charset="UTF-8"> + <title> + Handbook of Anæsthetics | Project Gutenberg + </title> + <link rel="icon" href="images/cover.jpg" type="image/x-cover"> + <style> + +body { + margin-left: 10%; + margin-right: 10%; +} + + h1,h2,h3,h4,h5 { + text-align: center; /* all headings centered */ + clear: both; + font-weight: normal; +} + +h2 {font-size: 110%; } + +h3 {font-size: 90%; } + +h4 {font-size: 90%; } + +h5 {font-size: 90%; } + +.subhed { display: block; margin-top: 1em; font-size: 80%; font-weight: normal; } + +p { + margin-top: .51em; + text-align: justify; + margin-bottom: .49em; + text-indent: 1.2em; +} + +.p0 {margin-top: 0em;} +.p1 {margin-top: 1em;} +.p2 {margin-top: 2em;} +.p4 {margin-top: 4em;} + +.p-min {margin-top: -.5em;} + +.p-indent {text-indent: 3em; } + +.p-index {text-indent: 8em; } + +hr { + width: 33%; + margin-top: 2em; + margin-bottom: 2em; + margin-left: 33.5%; + margin-right: 33.5%; + clear: both; +} + +hr.tb {width: 45%; margin-left: 27.5%; margin-right: 27.5%;} +hr.chap {width: 65%; margin-left: 17.5%; margin-right: 17.5%;} + +div.chapter {page-break-before: always;} + +ul { list-style-type: none; } +li.i1 { + text-indent: -2em; + padding-left: 2em; +} +li.i2 { + text-indent: -2em; + padding-left: 3em; +} + +table { +margin: auto; +width:auto; +border: 0; +border-spacing: 0; +border-collapse: collapse; } + +td { +padding: 0em .2em 0em 2.5em; +border: .1em none white; +text-align: left; +text-indent: -2em; } + +th.chap { +font-weight: normal; +font-size: x-small; +text-align: right; +padding-left: 1em; } + +th.pag { +font-weight: normal; +font-size: x-small; +text-align: right; +padding-left: 2em; } + +td.chn { +text-align: right; +vertical-align: top; +padding-right: 1em; } + +td.cht { +text-align: left; +vertical-align: top; +padding-left: 1.5em; +text-indent: -1em;} + +td.cht1 { +text-align: left; +vertical-align: top; +padding-left: 3em; +text-indent: -1em;} + +td.chtr { +text-align: left; +vertical-align: top; +padding-left: 1.5em; +text-indent: -1em; + border-right: 1px solid black;} + +td.chtrl { +text-align: left; +vertical-align: top; +padding-left: 1.5em; +text-indent: -1em; + border-right: 1px solid black; + border-left: 1px solid black;} + +td.chtrb { +text-align: left; +vertical-align: top; +padding-left: 1.5em; +text-indent: -1em; + border-right: 1px solid black; + border-bottom: 1px solid black;} + +td.chtrbl { +text-align: left; +vertical-align: top; +padding-left: 1.5em; +text-indent: -1em; + border-right: 1px solid black; + border-bottom: 1px solid black; + border-left: 1px solid black;} + +td.pag { +text-align: right; +vertical-align: bottom; +padding-left: 2em;} + + td.ctr { + text-align: center; + text-indent: 0em; + padding-left: 0em; + vertical-align: top; } + + td.ctrtrbl { + text-align: center; + text-indent: 0em; + padding-left: 0em; + padding-top: 1em; + padding-bottom: 1em; + vertical-align: top; + border-top: 1px solid black; + border-right: 1px solid black; + border-bottom: 1px solid black; + border-left: 1px solid black; } + + td.ctrtrb { + text-align: center; + text-indent: 0em; + padding-left: 0em; + padding-top: 1em; + padding-bottom: 1em; + vertical-align: top; + border-top: 1px solid black; + border-right: 1px solid black; + border-bottom: 1px solid black; } + + td.ctr1trb { + text-align: center; + text-indent: 0em; + padding-left: 0em; + padding-top: 1em; + padding-bottom: 1em; + vertical-align: middle; + border-top: 1px solid black; + border-right: 1px solid black; + border-bottom: 1px solid black; } + + td.ctrrl { + text-align: center; + text-indent: 0em; + padding-left: 0em; + vertical-align: top; + border-right: 1px solid black; + border-left: 1px solid black; } + + td.ctrr { + text-align: center; + text-indent: 0em; + padding-left: 0em; + vertical-align: top; + border-right: 1px solid black; + } + + td.ctrrbl { + text-align: center; + text-indent: 0em; + padding-left: 0em; + vertical-align: top; + border-right: 1px solid black; + border-bottom: 1px solid black; + border-left: 1px solid black; } + + td.ctrrb { + text-align: center; + text-indent: 0em; + padding-left: 0em; + vertical-align: top; + border-right: 1px solid black; + border-bottom: 1px solid black; + } + +td.right { +text-align: right; +vertical-align: top; +padding-left: 2em;} + +td.rightr { +text-align: right; +vertical-align: top; +padding-left: 2em; +padding-right: 1em; + border-right: 1px solid black;} + +td.right1 { +text-align: right; +vertical-align: top; +padding-left: 2em; +padding-right: 2em;} + +td.right2 { +text-align: right; +vertical-align: top; +padding-left: 2em; +padding-right: 1.2em;} + +td.rightrb { +text-align: right; +vertical-align: top; +padding-left: 2em; +padding-right: 1.2em; + border-right: 1px solid black; + border-bottom: 1px solid black;} + + +.pagenum { /* uncomment the next line for invisible page numbers */ + /* visibility: hidden; */ + position: absolute; + left: 92%; + font-size: small; + text-align: right; + font-style: normal; + font-weight: normal; + font-variant: normal; + text-indent: 0; +} /* page numbers */ + +.blockquot { + margin-left: 5%; + margin-right: 10%; + font-size: 90%; +} + +.hangingindent { + padding-left: 2em ; + text-indent: -2em ;} + +.xs { font-size: x-small;} + +.sm { font-size: small;} + +.lg { font-size: large;} + +.xl { font-size: x-large;} + +.smaller {font-size: 90%; } + +.center {text-align: center; + text-indent: 0em;} + +.right {text-align: right;} + +.r2 {text-align: right; + margin-right: 2em;} + +.smcap {font-variant: small-caps;} + +.allsmcap {font-variant: small-caps; text-transform: lowercase;} + +.gesperrt +{ + letter-spacing: 0.2em; + margin-right: -0.2em; +} + +em.gesperrt +{ + font-style: normal; +} + +/* Images */ + +img { + max-width: 100%; + height: auto; +} + +.figcenter { + margin: auto; + text-align: center; + page-break-inside: avoid; + max-width: 100%; +} + +/* Footnotes */ +.footnotes {border: 1px dashed;} + +.footnote {margin-left: 10%; margin-right: 10%; font-size: 0.9em;} + +.footnote .label {position: absolute; right: 84%; text-align: right;} + +.fnanchor { + vertical-align: super; + font-size: .8em; + text-decoration: + none; +} + +/* Transcriber's notes */ +.transnote {background-color: #E6E6FA; + color: black; + font-size:small; + padding:0.5em; + margin-bottom:5em; + font-family:sans-serif, serif; +} + + </style> +</head> +<body> +<div style='text-align:center'>*** START OF THE PROJECT GUTENBERG EBOOK 75985 ***</div> + + +<h1>HANDBOOK OF<br> +<span class="gesperrt">ANÆSTHETICS</span></h1> + +<p class="center p2 xs">BY</p> + +<p class="center">J. STUART ROSS, M.B., <span class="smcap">Ch.B.</span>, F.R.C.S.E.</p> + +<p class="center xs">LECTURER IN PRACTICAL ANÆSTHETICS, UNIVERSITY OF EDINBURGH;<br> +HONORARY ANÆSTHETIST EDINBURGH DENTAL SCHOOL;<br> +ANÆSTHETIST, DEACONESS HOSPITAL; INSTRUCTOR<br> +IN ANÆSTHETICS, EDIN. ROYAL INFIRMARY</p> + +<p class="center p2 lg">With an Introduction</p> + +<p class="center xs">BY</p> + +<p class="center">HY. ALEXIS THOMSON, C.M.G., M.D., F.R.C.S.E.</p> + +<p class="center xs">PROFESSOR OF SURGERY, UNIVERSITY OF EDINBURGH</p> + +<p class="center sm p1">AND CHAPTERS UPON</p> + +<p class="center lg">Local and Spinal Anæsthesia</p> + +<p class="center xs">BY</p> + +<p class="center">WM. QUARRY WOOD, M.D., F.R.C.S.E.</p> + +<p class="center xs">LATELY TEMPORARY ASSISTANT SURGEON, EDINBURGH ROYAL INFIRMARY</p> + +<p class="center sm p1">AND UPON</p> + +<p class="center lg">Intratracheal Anæsthesia</p> + +<p class="center xs">BY</p> + +<p class="center">H. TORRANCE THOMSON, M.D., F.R.C.S.E.</p> + +<p class="center xs">ANÆSTHETIST TO THE LEITH HOSPITAL</p> + +<p class="center p4 sm">EDINBURGH<br> +E. & S. LIVINGSTONE, 17 TEVIOT PLACE<br> +1919</p> + +<div class="chapter"> +<h2>CONTENTS</h2> +</div> + +<table class="smaller" style="max-width: 50em"> + <tr> + <th class="chap">CHAP.</th> + <th></th> + <th class="pag">PAGE</th> + </tr> + + <tr> + <td class="chn"></td> + <td class="cht smcap">Introduction by Professor Alexis Thomson</td> + <td class="pag"><a href="#Page_ix">ix</a></td> + </tr> + + <tr> + <td class="chn"></td> + <td class="cht smcap">Preface</td> + <td class="pag"><a href="#Page_xi">xi</a></td> + </tr> + + <tr> + <td class="chn">I.</td> + <td class="cht smcap">Physiological Action of Anæsthetic Drugs</td> + <td class="pag"><a href="#Page_1">1</a></td> + </tr> + + <tr> + <td class="chn">II.</td> + <td class="cht smcap">Shock and Anæsthesia</td> + <td class="pag"><a href="#Page_5">5</a></td> + </tr> + + <tr> + <td class="chn">III.</td> + <td class="cht smcap">Asphyxia or Anoxæmia</td> + <td class="pag"><a href="#Page_15">15</a></td> + </tr> + + <tr> + <td class="chn">IV.</td> + <td class="cht smcap">Methods of Anæsthetising</td> + <td class="pag"><a href="#Page_28">28</a></td> + </tr> + + <tr> + <td class="chn">V.</td> + <td class="cht smcap">The Clinical Observation of the Patient</td> + <td class="pag"><a href="#Page_31">31</a></td> + </tr> + + <tr> + <td class="chn">VI.</td> + <td class="cht smcap">The Preparation of the Patient</td> + <td class="pag"><a href="#Page_42">42</a></td> + </tr> + + <tr> + <td class="chn">VII.</td> + <td class="cht smcap">Nitrous Oxide</td> + <td class="pag"><a href="#Page_46">46</a></td> + </tr> + + <tr> + <td class="chn">VIII.</td> + <td class="cht smcap">Nitrous Oxide and Oxygen</td> + <td class="pag"><a href="#Page_60">60</a></td> + </tr> + + <tr> + <td class="chn">IX.</td> + <td class="cht smcap">Ether</td> + <td class="pag"><a href="#Page_74">74</a></td> + </tr> + + <tr> + <td class="chn">X.</td> + <td class="cht smcap">Intratracheal Ether</td> + <td class="pag"><a href="#Page_96">96</a></td> + </tr> + + <tr> + <td class="chn">XI.</td> + <td class="cht smcap">Chloroform</td> + <td class="pag"><a href="#Page_109">109</a></td> + </tr> + + <tr> + <td class="chn">XII.</td> + <td class="cht smcap">Ethyl Chloride</td> + <td class="pag"><a href="#Page_122">122</a></td> + </tr> + + <tr> + <td class="chn">XIII.</td> + <td class="cht smcap">Mixtures of Nitrous Oxide and Ethyl Chloride</td> + <td class="pag"><a href="#Page_128">128</a></td> + </tr> + + <tr> + <td class="chn">XIV.</td> + <td class="cht smcap">Mixtures of Chloroform and Ether</td> + <td class="pag"><a href="#Page_134">134</a></td> + </tr> + + <tr> + <td class="chn">XV.</td> + <td class="cht smcap">Sequences</td> + <td class="pag"><a href="#Page_137">137</a></td> + </tr> + + <tr> + <td class="chn">XVI.</td> + <td class="cht smcap">The Accidents of Anæsthesia</td> + <td class="pag"><a href="#Page_140">140</a></td> + </tr> + + <tr> + <td class="chn">XVII.</td> + <td class="cht smcap">The Sequelæ of Anæsthesia</td> + <td class="pag"><a href="#Page_151">151</a></td> + </tr> + + <tr> + <td class="chn">XVIII.</td> + <td class="cht smcap">Posture of the Patient</td> + <td class="pag"><a href="#Page_157">157</a></td> + </tr> + + <tr> + <td class="chn">XIX.</td> + <td class="cht smcap">The Choice of the Anæsthetic</td> + <td class="pag"><a href="#Page_162">162</a></td> + </tr> + + <tr> + <td class="chn">XX.</td> + <td class="cht smcap">Local Anæsthesia</td> + <td class="pag"><a href="#Page_171">171</a></td> + </tr> + + <tr> + <td class="chn">XXI.</td> + <td class="cht smcap">Spinal Anæsthesia</td> + <td class="pag"><a href="#Page_193">193</a></td> + </tr> + + <tr> + <td class="chn"></td> + <td class="cht smcap">Appendix</td> + <td class="pag"><a href="#Page_201">201</a></td> + </tr> + + <tr> + <td class="chn"></td> + <td class="cht smcap">Index</td> + <td class="pag"><a href="#Page_209">209</a></td> + </tr> +</table> + +<div class="chapter"> +<h2>LIST OF ILLUSTRATIONS.</h2> +</div> + +<table class="smaller" style="max-width: 50em"> + <tr> + <th class="chap">FIG.</th> + <th></th> + <th class="pag">PAGE.</th> + </tr> + + <tr> + <td class="chn">1.</td> + <td class="cht">Shock (Grey and Parsons)</td> + <td class="pag"><a href="#i_p006">6</a></td> + </tr> + + <tr> + <td class="chn">2.</td> + <td class="cht">Shock (after Crile)</td> + <td class="pag"><a href="#i_p008">8</a></td> + </tr> + + <tr> + <td class="chn">3.</td> + <td class="cht">Diagram to Illustrate Anoci-Association (after Crile)</td> + <td class="pag"><a href="#i_p011">11</a></td> + </tr> + + <tr> + <td class="chn">4.</td> + <td class="cht">Apparatus for Lane’s Saline Infusion</td> + <td class="pag"><a href="#i_p013">13</a></td> + </tr> + + <tr> + <td class="chn">5.</td> + <td class="cht">Diagram of the Vicious Circle of Asphyxia</td> + <td class="pag"><a href="#i_p020">20</a></td> + </tr> + + <tr> + <td class="chn">6.</td> + <td class="cht">Hewitt’s Mouth Props</td> + <td class="pag"><a href="#i_p022">22</a></td> + </tr> + + <tr> + <td class="chn">7.</td> + <td class="cht">Bellamy Gardner’s Mouth Props</td> + <td class="pag"><a href="#i_p023a">23</a></td> + </tr> + + <tr> + <td class="chn">8.</td> + <td class="cht">Phillips’ Modification of Hewitt’s Artificial Air-way</td> + <td class="pag"><a href="#i_p023b">23</a></td> + </tr> + + <tr> + <td class="chn">9.</td> + <td class="cht">Silk’s Nasal Tubes</td> + <td class="pag"><a href="#i_p023c">23</a></td> + </tr> + + <tr> + <td class="chn">10.</td> + <td class="cht">Tongue Forceps and Glossotilt</td> + <td class="pag"><a href="#i_p024a">24</a></td> + </tr> + + <tr> + <td class="chn">11.</td> + <td class="cht">Apparatus for Opening Clenched Jaws</td> + <td class="pag"><a href="#i_p025a">25</a></td> + </tr> + + <tr> + <td class="chn">12.</td> + <td class="cht">Frame for Adapting Vertical Cylinders to Foot Use</td> + <td class="pag"><a href="#i_p047">47</a></td> + </tr> + + <tr> + <td class="chn">13.</td> + <td class="cht">Nitrous Oxide Cylinders (upright and angle)</td> + <td class="pag"><a href="#i_p048">48</a></td> + </tr> + + <tr> + <td class="chn">14.</td> + <td class="cht">Complete Nitrous Oxide Apparatus</td> + <td class="pag"><a href="#i_p049">49</a></td> + </tr> + + <tr> + <td class="chn">15.</td> + <td class="cht">Barth 3-way Nitrous Oxide Tap</td> + <td class="pag"><a href="#i_p050a">50</a></td> + </tr> + + <tr> + <td class="chn">16.</td> + <td class="cht">Hewitt’s Wide-bore Nitrous Oxide Valves</td> + <td class="pag"><a href="#i_p050b">50</a></td> + </tr> + + <tr> + <td class="chn">17.</td> + <td class="cht">Ash’s Modification of Paterson’s Nasal Gas</td> + <td class="pag"><a href="#i_p058">58</a></td> + </tr> + + <tr> + <td class="chn">18.</td> + <td class="cht">Hewitt’s Apparatus for Nitrous Oxide and Oxygen</td> + <td class="pag"><a href="#i_p063">63</a></td> + </tr> + + <tr> + <td class="chn">19.</td> + <td class="cht">Diagram to Illustrate Action of Hewitt’s and Teter’s Gas-Oxygen +Methods</td> + <td class="pag"><a href="#i_p067">67</a></td> + </tr> + + <tr> + <td class="chn">20.</td> + <td class="cht">Details of Clark’s Expiratory Valve</td> + <td class="pag"><a href="#i_p068">68</a></td> + </tr> + + <tr> + <td class="chn">21.</td> + <td class="cht">The Clarke Gas-oxygen Apparatus</td> + <td class="pag"><a href="#i_p069">69</a></td> + </tr> + + <tr> + <td class="chn">22.</td> + <td class="cht">Marshall’s Sight-feed Gas-oxygen Apparatus</td> + <td class="pag"><a href="#i_p070">70</a></td> + </tr> + + <tr> + <td class="chn">23.</td> + <td class="cht">Clover’s Ether Inhaler, with Nitrous Oxide Attachment</td> + <td class="pag"><a href="#i_p077">77</a></td> + </tr> + + <tr> + <td class="chn">24.</td> + <td class="cht">Clover’s Inhaler, Diagram of a Vertical Section</td> + <td class="pag"><a href="#i_p078">78</a></td> + </tr> + + <tr> + <td class="chn">25.</td> + <td class="cht">Hewitt’s Wide-bore Ether Inhaler</td> + <td class="pag"><a href="#i_p080">80</a></td> + </tr> + + <tr> + <td class="chn">26.</td> + <td class="cht">Ormsby’s Ether Inhaler</td> + <td class="pag"><a href="#i_p081">81</a></td> + </tr> + + <tr> + <td class="chn">27.</td> + <td class="cht">Bellamy Gardner’s Mask and Ether Dropper</td> + <td class="pag"><a href="#i_p083">83</a></td> + </tr> + + <tr> + <td class="chn">28.</td> + <td class="cht">Four Photographs to Illustrate the Administration of Open +Ether</td> + <td class="pag"><a href="#i_p084a">84–5</a></td> + </tr> + + <tr> + <td class="chn">29.</td> + <td class="cht">Shipway’s Warmed Ether Apparatus</td> + <td class="pag"><a href="#i_p091">91</a></td> + </tr> + + <tr> + <td class="chn">30.</td> + <td class="cht">Diagram of Intratracheal Apparatus</td> + <td class="pag"><a href="#i_p098">98</a></td> + </tr> + + <tr> + <td class="chn">31.</td> + <td class="cht">Electric Blower for Intratracheal Method</td> + <td class="pag"><a href="#i_p099">99</a></td> + </tr> + + <tr> + <td class="chn">32.</td> + <td class="cht">Kelly’s Intratracheal Apparatus</td> + <td class="pag"><a href="#i_p100">100</a></td> + </tr> + + <tr> + <td class="chn">33.</td> + <td class="cht">Shipway’s Intratracheal Apparatus</td> + <td class="pag"><a href="#i_p102">102</a></td> + </tr> + + <tr> + <td class="chn">34.</td> + <td class="cht">Hill’s Direct Laryngoscope</td> + <td class="pag"><a href="#i_p104">104</a></td> + </tr> + + <tr> + <td class="chn">35.</td> + <td class="cht">Diagram of Blood-pressure Curves Obtainable with Chloroform</td> + <td class="pag"><a href="#i_p110">110</a></td> + </tr> + + <tr> + <td class="chn">36.</td> + <td class="cht">Vernon Harcourt’s Percentage Chloroform Inhaler</td> + <td class="pag"><a href="#i_p115">115</a></td> + </tr> + + <tr> + <td class="chn">37.</td> + <td class="cht">Chloroform Mask</td> + <td class="pag"><a href="#i_p116">116</a></td> + </tr> + + <tr> + <td class="chn">38.</td> + <td class="cht">Chloroform Drop Bottles</td> + <td class="pag"><a href="#i_p117">117</a></td> + </tr> + + <tr> + <td class="chn">39.</td> + <td class="cht">Junker’s Chloroform Apparatus</td> + <td class="pag"><a href="#i_p119">119</a></td> + </tr> + + <tr> + <td class="chn">40.</td> + <td class="cht">Tube of Ethyl-Chloride</td> + <td class="pag"><a href="#i_p122">122</a></td> + </tr> + + <tr> + <td class="chn">41.</td> + <td class="cht">Ethyl-Chloride Inhaler</td> + <td class="pag"><a href="#i_p124">124</a></td> + </tr> + + <tr> + <td class="chn">42.</td> + <td class="cht">Guy’s Gas and Ethyl-Chloride Inhaler</td> + <td class="pag"><a href="#i_p128">128</a></td> + </tr> + + <tr> + <td class="chn">43.</td> + <td class="cht">Details of Guy’s Inhaler</td> + <td class="pag"><a href="#i_p129">129</a></td> + </tr> + + <tr> + <td class="chn">44.</td> + <td class="cht">Diagram of Gas-Oxygen Method Introduced by Dr Guy and the Author</td> + <td class="pag"><a href="#i_p130">130</a></td> + </tr> + + <tr> + <td class="chn">45.</td> + <td class="cht">The Guy Ross Gas-Oxygen Instrument</td> + <td class="pag"><a href="#i_p131">131</a></td> + </tr> + + <tr> + <td class="chn">46.</td> + <td class="cht">Rendle’s Cone</td> + <td class="pag"><a href="#i_p135">135</a></td> + </tr> + + <tr> + <td class="chn">47.</td> + <td class="cht">Clover Inhaler adapted for the Ethyl Chloride-Ether Sequence</td> + <td class="pag"><a href="#i_p139">139</a></td> + </tr> + + <tr> + <td class="chn">48.</td> + <td class="cht">Two Photographs illustrating Sylvester’s Artificial Respiration</td> + <td class="pag"><a href="#i_p146">146–7</a></td> + </tr> + + <tr> + <td class="chn">49.</td> + <td class="cht">Sitting-up Posture for Operations upon the Head and Neck</td> + <td class="pag"><a href="#i_p159">159</a></td> + </tr> + + <tr> + <td class="chn">50.</td> + <td class="cht">O’Malley’s Posture for Intra-nasal Surgery</td> + <td class="pag"><a href="#i_p160">160</a></td> + </tr> + + <tr> + <td class="chn">51.</td> + <td class="cht">All-metal Syringe for Infiltration Anæsthesia</td> + <td class="pag"><a href="#i_p176">176</a></td> + </tr> + + <tr> + <td class="chn">52.</td> + <td class="cht">Infiltration of the Brachial Plexus</td> + <td class="pag"><a href="#i_p183">183</a></td> + </tr> + + <tr> + <td class="chn">53.</td> + <td class="cht">Needle and Syringe for Spinal Analgesia</td> + <td class="pag"><a href="#i_p194">194</a></td> + </tr> + + <tr> + <td class="chn">54.</td> + <td class="cht">Position of the Patient for Spinal Analgesia</td> + <td class="pag"><a href="#i_p196">196</a></td> + </tr> +</table> + +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_ix">[ix]</span></p> + +<h2>INTRODUCTION.</h2> +</div> + + +<p>The securing of a safe anæsthesia during operations is more important +than ever before, partly because of the mere number of operations, +and partly because of the greater extent to which other operative +risks—hæmorrhage, shock and infection—have been overcome. The risk +from the anæsthetic is now so very small that the joint aim of the +surgeon and anæsthetist to abolish it altogether is not far from +being accomplished. The author of this volume has done a good deal to +accomplish this end, and it is a matter of congratulation that he has +now published an account of his methods, so that a larger circle may +benefit from his teaching and his experience.</p> + +<p>The author very properly goes further and maintains that anæsthesia +must not only be safe but must also be good; good anæsthesia is +absolutely vital to good surgery. Only a generation back many surgeons +professed to see no difference as to who gave the anæsthetic; at the +present day no one willingly embarks upon a difficult operation without +the aid of a skilled anæsthetist.</p> + +<p>In various parts of the book the author has very rightly laid great +emphasis upon the influence which the work of the surgeon has upon +that of the anæsthetist. The latter may learn much from an occasional +glance at the field of operation. He should not interest himself in the +details of operative procedure to the distraction of his mind from his +own responsibilities; but he can, in abdominal surgery, see for himself +whether the muscles<span class="pagenum" id="Page_x">[x]</span> are properly relaxed, and observe the state of +operation, so that he can when necessary deepen the anæsthesia in good +time, while not maintaining deep anæsthesia when a light one would +suffice. Finally, he can check his other sources of information as to +the condition of the circulation by noticing the force with which cut +arteries spout, the colour of the blood and the size of uncut veins.</p> + +<p>Like other branches of medicine, adequate study as well as practical +experience is required in order to master the art of administering +anæsthetics, and that a reliable manual of instruction is essential, +goes without saying; I feel on perfectly safe ground in recommending +this book as such both to the student and the practitioner.</p> + +<p class="r2 p-min">ALEXIS THOMSON.</p> + +<div class="chapter"> +<p><span class="pagenum" id="Page_xi">[xi]</span></p> + +<h2>PREFACE.</h2> +</div> + + +<p>This little book is an attempt to present to the student and +practitioner a condensed account of modern anæsthetic views and +practice. In choosing a general scheme I have tried to lay emphasis +upon the relation of anæsthesia to general medical science rather than +upon elaborate descriptions of anæsthetic apparatus and methods which +a few years hence may be superseded. I have therefore devoted the +first four chapters to an account of the various forces which modify +the physiology of the patient during an operation under a general +anæsthetic, in so far as we at present understand them. I trust that +they will prove not only a sound basis for the information given in +the rest of the book but also a help towards forming a judgment upon +new methods and appliances as and when they meet the attention of the +reader.</p> + +<p>In making a selection of drugs and appliances for description, I have +eliminated those which do not appear to me to have any real sphere of +usefulness.</p> + +<p>The account of nitrous oxide and oxygen has been given in some +detail. Both the profession and the lay public have arrived, through +the experiences of the war, at a more just appreciation of the +possibilities of this combination than was at all general before +the year 1914. At the present day, no one who proposes to engage in +anæsthetic work can afford to remain unpractised in its administration.</p> + +<p>I have an apology to make to my women readers. Throughout the book, +when speaking of the anæsthetist, I have presumed the male sex. Such +phrases as “his or her” and “he or she” are tedious and inelegant, and +their omission must not be taken as<span class="pagenum" id="Page_xii">[xii]</span> forgetfulness on the author’s part +that women frequently make very good anæsthetists.</p> + +<p>Professor Alexis Thomson has added to the many kindnesses I have +received at his hands by writing the Introduction which immediately +precedes this Preface, and I wish to express my sincere thanks to him +for such a valuable addition to the book.</p> + +<p>From Mr David Wallace, F.R.C.S.E., I have received much valuable help +and guidance in anæsthetic matters. It was largely due to his kindly +assistance and moral support that I was encouraged to persevere with my +early attempts to use nitrous oxide and oxygen in major surgery. The +hints which are given in connection with Genito-Urinary Surgery are +also derived from him.</p> + +<p>The chapters upon Local and Spinal Anæsthesia are entirely the work of +Mr Wood, to whom I must express my gratitude for the admirable way in +which he has done the work.</p> + +<p>I must also thank Dr Torrance Thomson most sincerely for his useful +contribution in chapter <span class="allsmcap">X</span>, which constitutes a complete +monograph upon Intratracheal Anæsthesia.</p> + +<p>To Dr Wm. Guy I am indebted for the photographs which appear in the +book, and I must express my sincere gratitude to him for the trouble he +has taken in the matter.</p> + +<p>Much thanks are also due to the following firms who have been kind +enough to lend illustrative blocks:—Messrs Claudius Ash & Co. Ltd., G. +Barth & Co., De Trey & Co., J. Gardner & Son, Allen & Hanbury’s Ltd., +Meyer & Phelps, Coxeter & Son, Down Bros., Ltd., Krohne & Sesemann, and +Mr J. H. Montague.</p> + +<p>Lastly, I must express my high appreciation of the courtesy which the +publishers have shown to me, and of their generosity in the matter of +illustrations.</p> + +<p class="r2 p-min">J. STUART ROSS.</p> + +<p class="sm p-min"><i>October 1919.</i></p> + +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_1">[1]</span></p> + +<p class="center xl"><b>Handbook of Anæsthetics.</b></p> +</div> + +<h2>CHAPTER I.<br> +<span class="subhed"><b>PHYSIOLOGICAL ACTION OF ANÆSTHETIC DRUGS.</b></span></h2> + +<p>Every anæsthetic drug has certain pharmacological peculiarities of its +own, but all have much in common, and it is to these common features we +shall first direct our attention.</p> + +<p>Reaching the blood stream by absorption from the lung alveoli, the drug +enters into loose combination with the red blood corpuscles; a small +proportion only is carried in the plasma. Within the corpuscles it +must of necessity displace a certain proportion of the oxygen normally +carried: this factor is of great importance only in the case of nitrous +oxide gas, which readily displaces the larger part of the normal oxygen +content. In the case of other anæsthetics, the same process occurs; but +to a less extent. Detailed figures of the extent to which the blood +gases are altered in various stages of chloroform anæsthesia will be +found in Appendix III.</p> + +<p>The actions of individual drugs upon the circulatory, respiratory, +and excretory systems differ so considerably that a small section +has been devoted to this subject in each of the chapters devoted to +nitrous oxide, ether, and chloroform respectively. One feature is, +however, dependent upon the <i>state of anæsthesia</i> rather<span class="pagenum" id="Page_2">[2]</span> than +the action of the particular drug, and that is a certain slight fall +of blood pressure. This phenomenon is seen even in natural sleep, and +is presumably due simply to lack of normal stimuli such as tactile, +visual, and auditory impressions which in the ordinary circumstances of +life, help to maintain the tone of the vasomotor system. That such a +fall is due to the <i>state</i> of anæsthesia admits of little doubt, +but the fact is not always easy to demonstrate since each of the drugs +themselves have a marked influence upon the B.P., which masks the pure +effect of the anæsthetic sleep.</p> + + +<h3><b>Action upon the Nervous System.</b></h3> + +<p>It is in this system, of course, that we look for the characteristic +action of anæsthetics, since if we had a choice, it is the brain +only which we should desire to influence by our drug. It used to be +said that anæsthetics paralyse the brain from above downwards, but +that is only approximately true. More correctly we may say that the +more highly developed parts of the brain are earliest affected, and +that those portions, such as the vital medullary centres, which man +shares in common with his humbler zoological relatives, maintain +their activity until the last. Moreover, it must be remembered that +before any brain centre succumbs, it passes through a preliminary +stage of <i>excitement</i>, varying in intensity with varying drugs +and also with different types of patients. Those who are accustomed +to administer to their nervous centres repeated large doses of such +nerve poisons as alcohol and tobacco, may show very evident signs of +this preliminary cerebral irritation during the process of induction +of anæsthesia; so do also the unhappy possessors of nervous systems +deranged from other causes such as epilepsy.</p> + +<p><i>The first centres to be attacked are those of thought and +perception.</i> The patient is incapable of coherent reasoning, and +loses touch to some extent with impressions from the outside world. +<i>Muscular sense and co-ordination next become affected.</i><span class="pagenum" id="Page_3">[3]</span> Although +still able to move the limbs or the head, movements are incoherent, and +if at this stage the patient were put upon his feet, he would stagger +as he does in alcoholic intoxication. By this time <i>sensation</i>, +both tactile and special, begins to be affected. The patient is no +longer cognisant of pain,—if cut he would at any rate not have a +remembrance of pain. <i>The special senses</i> are at this stage also +lost, one of the last to go being the auditory sense, a point which +is sometimes forgotten by those inclined to talk while anæsthesia is +being induced. <i>Muscle tone is the next function</i> to be lost, and +at this stage all movements on the part of the patient should cease +except those of respiration. <i>The reflexes</i> disappear at varying +stages: the spinal reflexes, <i>e.g.</i> the knee-jerks, disappear +fairly early, probably before muscle tone is entirely abolished, but +certain other reflexes persist to a later stage. Those which are of +most interest to the anæsthetist are the conjunctival, corneal, and +pupillary reflexes of which he will find full details in Chapter +<span class="allsmcap">V</span>.</p> + +<p>Lastly the <i>vital medullary centres</i>, respiratory, vasomotor, +and cardiac are overcome, and at this stage we have passed beyond the +stage of a proper anæsthesia into that of over-dosage. In passing it +may be observed that the level at which one endeavours to work is that +indicated by the loss of muscle tone and of some of the reflexes and +the full activity of the medullary centres, and that an anæsthetic is +good or bad according as it gives a wide or narrow margin between these +two events.</p> + +<p>Upon the <i>peripheral nerves</i>, anæsthetics have much less effect +than on the central nervous system. Faradisation of a <i>motor +nerve</i> will in the deepest anæsthesia still cause immediate +contraction of the muscles supplied by it, showing that the +conductivity of the nerve is unaffected. Of far more importance, +however, is the fact that the <i>sensory nerves</i> are not paralysed. +That pain is not felt by the patient is due simply to the loss of +function of the cerebral sensory centres; <i>injury to the nerve +still causes an impulse to be<span class="pagenum" id="Page_4">[4]</span> transmitted to the brain</i>. Since no +operative procedure can be carried out without more or less trauma +(injury) to sensory nerves, we may picture the brain of the patient +undergoing a surgical operation while under a general anæsthetic, +as being constantly bombarded by sensory stimuli, which though not +consciously appreciated by the sleeping patient, are yet capable of +producing reflex effects of a definite character, the importance of +which to the work of the surgeon and anæsthetist it is difficult to +exaggerate, and of which a condensed account will be found in the +succeeding chapter.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_5">[5]</span></p> + +<h2>CHAPTER II.<br> +<span class="subhed"><b>SHOCK AND ANÆSTHESIA.</b></span></h2></div> + +<p>Under this short and convenient title, the author proposes to discuss +all the changes observable in the patient’s condition, the causation +of which can be traced to the procedure of the surgeon. The use of +the term <i>shock</i> was at one time, and by some teachers still is, +restricted to a definite clinical condition. The patient was described +as lying pallid and almost pulseless, with dilated pupils, cold +sweating skin, and gasping, irregular respirations. In the view more +generally taken to-day, that is but the extreme and final manifestation +of a syndrome, which any patient who suffers trauma (whether inflicted +accidentally or by the surgeon) exhibits in a greater or less degree, +and from which general anæsthesia protects a patient to a very limited +extent only.</p> + +<p>Professor Crile, to whose work we owe so much of our knowledge on this +subject, has said, “In general anæsthesia, part of the brain only is +asleep.” Though consciousness is abolished, many parts of the brain +are quite capable of responding to <i>centripetal impulses</i> passed +to the brain through sensory nerves injured by the knife. A full +account of the changes demonstrated by Crile in some of the cells of +the grey matter of the brain as a result of such stimuli, and of the +interpretation put upon these by their discoverer, is not suitable +for a text-book of anæsthesia. It is sufficient to say that such +changes have been discovered, and that their occurrence as a result +of trauma is not prevented by inhalational anæsthesia. Such changes, +though of the utmost interest scientifically, cannot be demonstrated +clinically, and it is<span class="pagenum" id="Page_6">[6]</span> to alterations of <i>blood pressure</i> and +of <i>respiration</i> that we must look for clinical evidence of the +effects of <i>shock stimuli</i>.</p> + + <div class="figcenter" id="i_p006" style="max-width: 473px"> + <img + class="p1" + src="images/i_p006.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 1.</span>—Shock—Blood pressure of a dog undergoing +laminectomy under general anæsthesia (Grey and Parsons.)</p> + <p class="p0 center smaller">(<i>Reproduced by kind permission of the Authors.</i>)</p> + </div> + +<p>With every incision by the surgeon, sensory nerve twigs are of +necessity injured. The fibres found in sensory nerves are, it will +be remembered, either pressor, or depressor—that is, stimulation of +them, causes either an increase or decrease of the blood pressure, +the depth and frequency of respiration being usually affected in the +same direction as the B.P. That such changes do commonly occur is +easily recognised by clinical observation. The veriest beginner in +anæsthesia soon learns to expect a deeper, quicker respiration and a +stronger pulse as soon as the operation has begun. These changes have +been studied experimentally upon animals and upon the human subject by +the use of the sphygmomanometer: Fig. 1, drawn from Grey & Parson’s +Arris and Gale Lectures of 1912,<span class="pagenum" id="Page_7">[7]</span> shows a tracing from a dog undergoing +laminectomy under general anæsthesia, and gives a good idea of the +early evidences of shock.</p> + +<hr class="tb"> + +<p>We may condense the results of much work on this subject under the +following headings:—</p> + +<div class="blockquot"> + +<p>(<i>a</i>) Most stimuli from the field of operation cause a +sharp rise of blood pressure, followed by a sharp fall.</p> + +<p>(<i>b</i>) Successive stimuli delivered quickly one after +another add their effects together, the total result being +considerably greater than from one severe trauma.</p> + +<p>(<i>c</i>) After a time, the pressor effect of stimuli begins +to lessen: the animal or patient “wears out,” and finally no +pressor result can be obtained by the most massive stimulation: +the curve of B.P. steadily falls: the condition of full surgical +shock is produced.</p> + +<p>(<i>d</i>) The tearing or pulling of tissues produces more +powerful stimuli than the use of a sharp knife, and, therefore, +brings on the full condition of shock more rapidly.</p> + +<p>(<i>e</i>) Stimuli from some tissues cause much more reflex +effect upon the organism than from other less sensitive +structures. This is well exemplified when an abdominal section +is in progress. Incision of skin causes immediate response in +deepened respiration and higher B.P.: division of the fascia +very little effect. If the muscle is divided by the knife, again +little reflex effect is noticeable, but if it be stretched and +split by the fingers, the response is powerful. The parietal +peritoneum, however delicately handled, is one of the most +sensitive structures in the body, and, unless the patient is +fully under at the stage either of opening or closing this +layer, actual breath-holding or straining will occur. On the +other hand, incision or suture of the hollow viscera will cause +practically no response however light the anæsthesia, provided<span class="pagenum" id="Page_8">[8]</span> +these structures, and their connections with the parietes, are +not pulled upon.</p> + +<p>(<i>f</i>) Stimulation of certain selected areas, of which the +spermatic cord is a well-known but by no means the only example, +results in an almost immediate fall of blood pressure with +little or no preliminary rise. In the operating theatre, we +sometimes see faintness or syncope arising quite suddenly during +operations in such regions. This subject is explained more fully +in Chapter <span class="allsmcap">XVI.</span> under the term “Reflex Syncope.”</p> +</div> + + <div class="figcenter" id="i_p008" style="max-width: 655px"> + <img + class="p1" + src="images/i_p008.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 2.</span>—Combined blood pressure chart showing +the average of a number of experiments.—A—Under nitrous +oxide and oxygen. B—Under ether. At each spot marked +x, a trauma (burning of the paw) was inflicted. (After +<span class="smcap">Crile</span>.)</p> + </div> + +<div class="blockquot"> + +<p>(<i>g</i>) While no general anæsthetic protects absolutely +from shock stimuli, some anæsthetics give more protection than +others. Nitrous oxide is the most effective in this respect,<span class="pagenum" id="Page_9">[9]</span> +its powers being two and a half times greater than that of +ether: chloroform is even less effective than ether (<i>see</i> +Fig. <a href="#i_p008">2</a>).</p> + +<p>(<i>h</i>) The claim made by the older generation of surgeons +that shock could be prevented by the use of a <i>deep</i> +anæsthesia, and that the occurrence of any “Reflex syncope” was +always a sign of too light an anæsthesia cannot be made good. At +the same time, it must be admitted that too light an anæsthesia +does increase the likelihood of shock. <i>Prolonged deep</i> +anæsthesia, on the other hand, produces by itself a condition +indistinguishable from shock, with the single exception of +nitrous oxide gas.</p> + +<p>(<i>i</i>) Operative shock is predisposed to by several factors +of which the following are the most important:—</p> + +<p class="p-indent">1. Hæmorrhage before or during operation.</p> + +<p class="p-indent">2. Sepsis.</p> + +<p class="p-indent">3. Fear.</p> + +<p class="p-indent">4. Prolonged starvation.</p> + +<p>5. Certain diseases, especially hyperthyroidism +(exopthalmic goître).</p> +</div> + + +<h3><b>Theories of Shock.</b></h3> + +<p>So far as we have touched in the above upon theory, it has been theory +which receives general acceptance and which accords with known clinical +facts. When we come to discuss <i>the reason why blood-pressure falls +in shock</i>, we are in more debatable country.</p> + +<p>Crile’s original view was that the upstroke seen in such charts as +shown in Fig. 1 are caused by reflex vaso-constriction, and that the +final fall of B.P. was due to exhaustion of the vaso-motor centre. +This view he does not seem to have modified as a result of his later +discovery of degenerative changes in certain cells of the grey matter +of the brain.</p> + +<p>Other workers, J. D. Malcolm in this country, and Yandell<span class="pagenum" id="Page_10">[10]</span> Henderson, +of Yale, U.S.A., maintain an opinion diametrically opposite. In their +view, in fully developed shock, the vessels are in vaso-constriction, +and the circulation is arrested from undue internal resistance to blood +flow.</p> + +<p>A third explanation of lowered B.P. has been offered, and while its +significance is not understood, there is fairly general agreement as +to its validity. This factor is a <i>reduction in the total blood +volume</i>—an oligæmia. No one has as yet demonstrated to what region +or organ the missing blood volume has retreated.</p> + + +<h4 class="smcap">Yandell Henderson’s Acapnic theory of Shock.</h4> + +<p>Acapnia is a condition in which the CO<sub>2</sub> content of the blood and +tissues has been brought to too low a level. Those who climb mountains +suffer from it, and so do those who breathe rapidly and heavily for a +prolonged period. Carbon dioxide is necessary for the vigour of the +respiratory centre, of which it may be termed the natural regulator. +Moreover, the heart and the great veins which empty into it require a +certain proportion of CO<sub>2</sub> in the blood.</p> + +<p>Admittedly, patients inhaling anæsthetics do on occasion breathe too +deeply. Sometimes they do so voluntarily before losing consciousness, +sometimes reflexly as a result of such a manœuvre as stretching the +sphincter ani. Do they thereby bring their CO<sub>2</sub> down to a level which +does serious harm and which can be considered a cause of collapse under +anæsthesia? Henderson says they can and do: most other workers deny the +possibility.</p> + + <div class="figcenter" id="i_p011" style="max-width: 526px"> + <img + class="p1" + src="images/i_p011.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig 3.</span>—Diagram (after <span class="smcap">Crile</span>) to illustrate +anoci-association. In “A” the trauma is inflicted on the leg, +and the brain being wholly unprotected, considerable shock +is suffered. In “B” the brain is protected by inhalational +anæsthesia from the effects of fear, etc. In “C” the sensory +nerves from the seat of trauma are blocked by novocaine, and the +brain also protected by inhalational anæsthesia. Theoretically +no shock is suffered.</p> + </div> + + +<h3><b>Prevention and Treatment of Shock.</b></h3> + +<p>There are many theories of shock but only one anti-shock technique +which will bear examination. Founding upon his own theory, Crile about +1913 elaborated his <span class="allsmcap">ANOCI-ASSOCIATION</span> method of which the +following are the leading features (<i>see</i> Fig. <a href="#i_p011">3</a>):—</p> + +<p><span class="pagenum" id="Page_11">[11]</span></p> + +<div class="blockquot"> + +<p>(<i>a</i>) <i>Prevention of fear.</i>—Every member of this team +is taught the all-important art of so dealing with the patient +that no unnecessary fear is allowed to remain in his mind. +That art does not consist in endless repetition of the phrase, +“Do not be frightened,” but rather in each so bearing himself +or herself before the patient that he may gradually acquire +the conviction that he is surrounded by careful, kindly, and +skilful persons who are doing for him what they do for<span class="pagenum" id="Page_12">[12]</span> hundreds +of others, and doing it with an expectation of his early and +complete recovery so certain that they do not need to put it +into words unless definitely questioned. Such an art is not +acquired in a day, and some unhappy few are so constituted that +they can never acquire it.</p> + +<p>As a further preventative of fear, and also for other reasons +explained in Chapter vi., the patient receives a dose of morphia +(⅙th grain, with ¹⁄₁₂₀th grain atropine, hypodermically) three +quarters of an hour before operation. Some surgeons go further, +and give a sedative the night before operation. Veronal gr. +viii. is the favourite prescription of Prof. Alexis Thomson of +Edinburgh.</p> + +<p>(<i>b</i>) The sensory nerves are “blocked” by infiltration +with novocain. By the systematic use of local in conjunction +with general anæsthesia, the harmful stimuli from the area of +operation are prevented from reaching the brain. For the details +of this measure, the reader is referred to Chapter xx.</p> + +<p>(<i>c</i>) The anæsthetic of choice in Crile’s practice is +nitrous oxide and oxygen (<i>see</i> Chapter vii.).</p> +</div> + +<p>The whole of this technique has not been generally adopted as a +routine, but nevertheless the teachings of Crile have greatly +influenced the mind and practice of most surgeons and anæsthetists. +Traces of that teaching are to be found everywhere in the organisation +built up during the Great War to save as many as possible of the lives +of badly smashed men. At no previous time in the history of surgery was +the problem of shock so pressing, and a brief resumé of the methods +adopted is here set down, as an example of how shock should be dealt +with.</p> + + <div class="figcenter" id="i_p013" style="max-width: 299px"> + <img + class="p1" + src="images/i_p013.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 4.</span>—Lane’s apparatus for subcutaneous +infusion of saline solution.</p> + </div> + + +<h3><b>Treatment of Shock among the Casualties of the War.</b></h3> + +<p>The first essentials demanded were the most careful organisation, +the provision of equipment far in advance of most home civilian<span class="pagenum" id="Page_13">[13]</span> +hospitals, and of surgical teams specially trained to a high level of +excellence. Upon recovery from the field, the injured man received +at the <span class="smcap">Advanced Dressing Station</span>, such first aid dressing +as was necessary, and a substantial dose of <i>morphia</i>. When the +latter had had time to take effect, the case was passed back to the +Field Ambulance (where he received his first dose of antitetanic +serum), and from there to the <span class="smcap">Casualty Clearing Station</span>. +During every stage of the journey, he received as much <i>warm fluid +nourishment as possible</i>. Arrived at the C.C.S., the severe case was +passed first into the <span class="smcap">Resuscitation Ward</span>. This department,<span class="pagenum" id="Page_14">[14]</span> +under the charge of a specially trained M.O., concentrated largely +upon two measures—the thorough <i>warming</i> of the patient, +and the replacing as far as possible of the fluids lost to him by +hæmorrhage and shock. The warming in many C.C.S.’s was effected by +electric radiant heat baths. The fluids were replaced either by way of +infusing blood from another patient, or by the use of <i>gum saline +solution</i>. Introduced into a vein, the action of this solution +persists for a much longer period than that of ordinary saline, being +less easily lost by osmosis through the capillaries into the tissues. +From the resuscitation ward, the patient passed to the <span class="smcap">Operating +Theatre</span>. Though the full technique of anoci-association was +not always possible, the maxims which Crile had sought to inculcate +into the practice of surgery influenced the work of surgeons and +anæsthetists very profoundly. Nitrous oxide and oxygen was used for all +the severely shocked cases, and infiltration with local anæsthetics +where feasible and necessary.</p> + + +<h3><b>Subcutaneous Infusion of Saline.</b></h3> + +<p>For those who do not feel bound to adopt the Crile technique this is a +simple measure which does much to minimise shock in prolonged abdominal +operations. Saline infusion into a vein is so rapidly excreted that its +influence is very fugacious, but if the fluid be introduced under the +skin during the period of operation it is slowly absorbed as required +by the blood. Sir Arbuthnot Lane is a strong advocate of this measure.</p> + +<p>Fig. 4 shows a suitable apparatus. The needles are thrust into the +loose areolar tissue under the breast, one on each side, and a pint or +more of fluid is <i>slowly</i> run in from the reservoir.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_15">[15]</span></p> + +<h2>CHAPTER III.<br> +<span class="subhed"><b>ASPHYXIA OR ANOXÆMIA.</b></span></h2></div> + +<p>Some degree of asphyxia is a common complication of inhalational +anæsthesia: indeed some small degree of it is almost unavoidable. It +is hardly too much to say that the difference between a good and a bad +anæsthetist is that the one recognises and deals with asphyxia in its +early stages, while the other allows it to assume serious proportions +before he becomes aware of its existence. The man who only realises +that asphyxia is present when the patient is deeply cyanosed and has +ceased to be able to draw any air at all into his chest may know much +of the physiology of anæsthetic drugs, and be well up in complicated +anæsthetic apparatus, but knows nothing of the proper practice of +anæsthesia.</p> + +<p>Asphyxia arises during anæsthesia from several causes. In the first +place, the drug which the patient is inhaling and absorbing into the +blood, turns out from his red corpuscles a corresponding quantity +of oxygen. While this is only seen in its extreme form in the case +of nitrous oxide gas, it is a factor acting even in the case of +other anæsthetics. Secondly, during deep anæsthesia, the respiratory +centre may be somewhat depressed, and the force and frequency of the +respiratory act diminished. Thirdly, the respiratory passages may be +partially or wholly occluded from <i>mechanical</i> causes. This is far +the most important type of asphyxia, being the most common, the most +fatal, and the most easily prevented.</p> + + +<h3><b>Common Causes of Mechanical Asphyxia.</b></h3> + +<p>(1) <span class="smcap">Clenching of the Jaws</span> arises not uncommonly during +anæsthesia, being specially frequent towards the end of the induction<span class="pagenum" id="Page_16">[16]</span> +period. Since a very large proportion of individuals have nasal +passages insufficient in bore to carry the full volume of respired air, +respiration must be obstructed if the jaws are clenched.</p> + +<p>(2) <span class="smcap">Falling Back of the Lower Jaw and Base of the Tongue over the +Epiglottis.</span>—This is always liable to happen after the muscles are +deeply relaxed.</p> + +<p>(3) <span class="smcap">Mucous or Blood or a Foreign Body is Drawn by Inspiration into +the Air Passages.</span>—Changes of position of the head may release +mucous which has been gathering in some parts of the mouth or pharynx. +For instance, if the head has been lying on the side for some time, a +pool of mucous or saliva commonly gathers in the most dependent cheek, +and unless this is mopped out before the head is brought into the +mesial position, this pool will be suddenly tipped backwards, and very +probably drawn into the larynx. Again, in operations upon the nasal or +oral cavities, blood is always liable to be inspired, and not a few +teeth have found their way into the air passages in the practices of +dental surgeons who do not take precautions against this accident.</p> + +<p>(4) <span class="smcap">Spasm of the Adductors of the Vocal Cords</span> is one of the +most common and most baffling incidents in anæsthesia. It announces +its presence by the commencement of <i>laryngeal stridor</i>, a +high-pitched crowing noise, which is as annoying for the surgeon and +anæsthetist to hear as it is detrimental to the progress of a smooth +anæsthesia. Inspired mucous or blood almost invariably sets it up, and +the two conditions of fluid in the larynx and narrowing of the glottis +from approximation of the cords, add their effects together, with +resulting obstruction of a high degree.</p> + +<p>Laryngeal stridor, however, frequently occurs even when no fluid +has been inspirated. It may be set up as a reflex from the area +of operation. Dilatation of the sphincter ani, and removal of the +prepuce in circumcision, are two common examples of this. It is also +undoubtedly sometimes caused by giving too strong a vapour<span class="pagenum" id="Page_17">[17]</span> during the +latter part of the induction stage. Stridor unfortunately sometimes +occurs from no obvious cause at all, or to speak more correctly, from +causes which are at present not known to us. It is the author’s belief +that one of these causes may prove to be <i>morphia</i> given as a +preliminary to inhalational anæsthesia. In his experience, stridor +has been more frequent with morphia than without, particularly if +chloroform be the anæsthetic chosen. Beyond that he cannot at present +go.</p> + +<p>(5) <span class="smcap">Pressure upon the Air Passages of Neoplastic or Inflammatory +Swellings in the Neck.</span>—In such cases any obstruction which may +exist before induction will probably become intensified during the +process, and a complete arrest of respiration is not uncommon. Large +goîtres are the most common type of neoplasm to give trouble, and all +acute inflammatory conditions in the neck which extend towards the +trachea are notorious for their tendency to give cause for anxiety +during anæsthesia.</p> + + +<h3><b>The Physiology of Asphyxia.</b></h3> + +<p>An animal, subjected to asphyxia, either mechanically or otherwise, +shows the following signs:—</p> + +<div class="blockquot"> + +<p>(<i>a</i>) <i>Increase of the force and frequency of the +respiratory movements of chest and abdomen.</i> Even though +there be a complete mechanical obstruction, increased efforts +to breathe will still be made for some moments, although air no +longer passes in and out of the chest.</p> + +<p>(<i>b</i>) There is a considerable rise of blood pressure owing +to a high degree of vaso-construction.</p> + +<p>(<i>c</i>) The pupils dilate.</p> + +<p>(<i>d</i>) Generalised convulsions.</p> + +<p>(<i>e</i>) The animal succumbs finally from cardiac failure. +No heart muscle can continue to function properly if supplied +by the coronary arteries with venous blood. Moreover, the +heart<span class="pagenum" id="Page_18">[18]</span> pump has to act against the greatly increased peripheral +resistance induced by vaso-constriction. It must therefore be a +matter of time only when the strongest and healthiest heart will +cease to contract under the abnormal conditions of asphyxia.</p> +</div> + +<p>There are in asphyxia, two alterations in the blood-gasses, <i>i.e.</i> +lack of oxygen and increase of CO<sub>2</sub>. The action of these two +conditions have been differentiated by experimental work (Starling, +Kayala, Jerusalem), and one can say definitely that the excess of +CO<sub>2</sub> is the cause of the increased activity of the respiratory +efforts, and that the remaining phenomena are due to oxygen starvation. +This point is of some importance in considering anæsthetic methods +in which re-breathing (breathing in and out of a bag) is practised. +The use of such methods has often been thoughtlessly condemned as +“poisoning the patient with his own CO<sub>2</sub>.” Within the limits usually +practised, a re-breathing method does not involve any such risk, +provided oxygen starvation does not occur. This point is referred to +again in Chapter iv.</p> + + +<h3><b>Clinical Signs of Mechanical Asphyxia in the Anæsthetised Subject.</b></h3> + +<p>The classical signs of asphyxia above described are hardly to be +expected in the operating theatre, but essentially the condition +of the patient who develops respiratory obstruction while under an +anæsthetic is similar to that produced experimentally in animals in the +laboratory. The changes most easily observed are as follows:—</p> + +<div class="blockquot"> + +<p>(1) <i>Alteration of the colour.</i>—Cyanosis shows itself +earliest in the lips, and the lobules of the ears,—later the +whole face becomes dusky.</p> + +<p>(2) <i>Dilatation of the pupil</i>, which ceases to respond to +the stimulus of light.</p> + +<p><span class="pagenum" id="Page_19">[19]</span></p> + +<p>(3) <i>The respiratory movements increase in depth and +frequency.</i>—The chest and abdominal walls heave forcibly; but</p> + +<p>(4) <i>The volume of air passing in and out of the glottis is +diminished.</i>—In complete obstruction, of course, none passes +at all. In passing we may draw the moral that persistence of +chest movements is no proof of the passage of air in and out +of the chest: that can only be proved by hearing the movement +of air through glottis and mouth or nose, or feeling it on the +delicate skin of the back of the observer’s hand.</p> + +<p>(5) <i>True convulsions are not seen</i>, unless we may consider +the jactitation of deep N<sub>2</sub>O anæsthesia as such (see Chapter +<span class="allsmcap">VII.</span>). Nevertheless, there are obvious and most +valuable signs of asphyxia to be found in the muscular system +often quite early. These consist in the incidence of <i>muscular +rigidity</i>, which is frequently observed first in the +muscles of the abdominal wall. A surgeon performing laparatomy +will notice at once the occurrence of this phenomenon, than +which hardly anything can complicate and delay his task more +effectively. The anæsthetist who knows his work will, upon +hearing from the surgeon a complaint as to the rigidity of +the abdominal wall, devote his attention first to securing a +perfectly free air-way before deciding that a deeper anæsthesia +is required.</p> +</div> + + <div class="figcenter" id="i_p020" style="max-width: 527px"> + <img + class="p1" + src="images/i_p020.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 5.</span>—Vicious circle of asphyxia.</p> + </div> + + +<h3><b>Prevention and Treatment of Asphyxia.</b></h3> + +<p>Once asphyxia, especially mechanical asphyxia, has begun, it almost +invariably tends to get worse. The engorgement affects among other +venules, those which run under the mucous membrane of the respiratory +tract, still further obstructing the passage of air. The muscular +rigidity, moreover, soon manifests itself in the<span class="pagenum" id="Page_20">[20]</span> adductors of the +vocal cords and the muscles which close the jaws: the patient has +thus entered into a “vicious circle,” Fig. 5. It is evident that the +prevention of the earliest signs of asphyxia is to the anæsthetist a +matter of vital interest. The cardinal points to watch are as follows:—</p> + +<div class="blockquot"> + +<p>(1) Keep the neck of the patient as far as possible in a natural +position, <i>i.e.</i> do not either flex or extend the head +unduly upon the body unless the nature of the operation demands +such an unusual position.</p> + +<p>(2) Maintain a free passage for air either through the nose or +the mouth.</p> + +<p><span class="pagenum" id="Page_21">[21]</span></p> + +<p>(3) Keep the lower jaw in good position throughout the +administration.</p> + +<p>(4) Avoid turning the face from the lateral to the dorsal (face +up) position unless essential. If it has to be done, be careful +first to mop out any “pool” from the dependent cheek.</p> + +<p>(5) Deal as effectively as possible with the earliest appearance +of laryngeal stridor.</p> +</div> + +<p>Let us see how in a normal case, these rules can be applied. With +the patient lying (or, in exceptional circumstances, sitting) in a +comfortable position, the shoulders and head raised above the rest of +the body and the face looking upwards (or straight forwards, in the +case of the sitting patient), the anæsthetic is begun slowly, and the +patient encouraged to take his time and to breathe naturally. At this +stage the jaw needs no support, the muscles being neither relaxed by +deep anæsthesia, nor spastic from asphyxia. With the advent of muscular +relaxation, the head is turned to one side, that which is opposite to +the side on which the surgeon will be working, being usually chosen. +We must now determine whether the patient can breathe best through the +mouth or the nose, and make sure that the channel chosen is as free as +possible. In the majority of cases it will be found that respiration is +oral, and that all that is necessary is to support the lower jaw by a +finger hooked into the depression just below the symphysis mentes. The +hands of the anæsthetist, therefore, take up a position from which in +nine cases out of ten they will never require to be moved.</p> + +<p><i>The hand of the side toward which the patient’s face is turned</i> +supports the jaw and keeps the face-piece or mask adapted to the face. +The middle finger is pressed into the space below the symphysis mentis, +and <i>exercises traction forwards and a little upwards</i>, thus +preventing the jaw from slipping backwards; the<span class="pagenum" id="Page_22">[22]</span> index finger lies +along the lower part of the mask, maintaining adaptation between it +and the chin; the thumb bears on the mask higher up, keeping its upper +part pressed against the bridge of the patient’s nose, and also serving +as a <i>point d’appui</i>, or fulcrum, from which the jaw traction +by the middle finger can conveniently be exercised. This grip once +learnt is not fatiguing to the hand, and is in the author’s opinion one +of the essential points for the beginner to master (<i>see</i> Fig. +<a href="#i_p084b">28<span class="allsmcap">C</span></a>, page 85).</p> + +<p><i>The opposite hand</i> holds the drop bottle, if the method in use is +an open one, the wrist resting upon the uppermost side of the patient’s +head.</p> + + <div class="figcenter" id="i_p022" style="max-width: 595px"> + <img + class="p1" + src="images/i_p022.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 6.</span>—Hewitt’s dental props.</p> + </div> + +<p>Fig. 28<span class="allsmcap">C</span> shows this grip in operation, while Fig. 28<span class="allsmcap">D</span> +shows the alternative frequently adopted. This alternative has various +disadvantages. It covers up a larger part of the patient’s face than +the method recommended, and it tends to tilt the mask sideways. The +little finger is supposed to be hooking forward the jaw by pressing +behind its angle, but such a method is very fatiguing if in use for +more than a few moments.</p> + +<p>In a proportion of cases, it is found that a free air-way cannot be +maintained by these simple measures. Upper or lower teeth<span class="pagenum" id="Page_23">[23]</span> (or both) +may be missing and traction upon the lower jaw only closes the mouth +the more firmly. In most of these cases, the difficulty can be met by +the use of the <i>dental prop</i>. These are made in various sizes and +shapes, of which the best known are Hewitt’s and Bellamy Gardner’s +(<i>see</i> Figs. <a href="#i_p022">6</a> and <a href="#i_p023a">7</a>). The latter are made of aluminium and are +of small size only. They are the most convenient for cases with teeth +both in the upper and lower jaw, but who suffer from a receding lower +jaw not easily kept forward unless the prop is used as a rocker, as it +were, upon which it can be slid forward. Hewitt’s props are of plated +metal, with lead on the cups, to avoid injury to the teeth. They are +made in five sizes, of which the middle and larger are very convenient +for cases in which one or both rows of teeth are missing.</p> + + <div class="figcenter" id="i_p023a" style="max-width: 618px"> + <img + class="p1" + src="images/i_p023a.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 7.</span>—Bellamy Gardner’s Dental Props.</p> + </div> + + <div class="figcenter" id="i_p023b" style="max-width: 417px"> + <img + class="p1" + src="images/i_p023b.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 8.</span>—Phillips’ modification of Hewitt’s +artificial airway.</p> + </div> + +<p>For cases entirely without teeth, and in which a large flabby tongue +is prone to fall back over the epiglottis, the mouth tube (Fig. 8) is +very convenient. The rubber shank lies along the top of the tongue, the +metal end lies between the gums. As originally introduced by Hewitt, +the air-way was circular in cross section, but the flattened model +figured is a distinct improvement. It was introduced by Dr Phillips.</p> + + <div class="figcenter" id="i_p023c" style="max-width: 525px"> + <img + class="p1" + src="images/i_p023c.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 9.</span>—Silk’s nasal tubes.</p> + </div> + +<p>Occasionally one decides to facilitate nasal rather than oral<span class="pagenum" id="Page_24">[24]</span> +breathing, and if the natural passages are inadequate, recourse may be +had to the passage of a short piece of drainage tube of the calibre of +a number 10 catheter, and about 3 inches in length. With such a tube +in one or both sides of the nose, reaching from anterior to posterior +nares, nasal respiration is usually possible even in much obstructed +noses (Silk). (Fig. 9.)</p> + + <div class="figcenter" id="i_p024a" style="max-width: 213px"> + <img + class="p1" + src="images/i_p024a.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 10</span><span class="allsmcap">A.</span>—Bellamy Gardner’s +tongue-clip.</p> + </div> + + <div class="figcenter" id="i_p024b" style="max-width: 204px"> + <img + class="p1" + src="images/i_p024b.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 10</span><span class="allsmcap">B.</span> Ring tongue forceps.</p> + </div> + + <div class="figcenter" id="i_p024c" style="max-width: 150px"> + <img + class="p1" + src="images/i_p024c.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 10</span><span class="allsmcap">C.</span> Glossotilt.</p> + </div> + + <div class="figcenter" id="i_p025a" style="max-width: 600px"> + <img + class="p1" + src="images/i_p025a.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 11</span><span class="allsmcap">A.</span>—Boxwood wedge for opening +jaws.</p> + </div> + + <div class="figcenter" id="i_p025b" style="max-width: 228px"> + <img + class="p1" + src="images/i_p025b.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 11</span><span class="allsmcap">B.</span>—Wedge for opening jaws.</p> + </div> + + <div class="figcenter" id="i_p025c" style="max-width: 220px"> + <img + class="p1" + src="images/i_p025c.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 11</span><span class="allsmcap">C.</span>—Mouth gag.</p> + </div> + +<p>If proper and timely use be made of one or other of these simple +devices, the use of the <i>tongue forceps</i> is rarely necessary.</p> + +<p><span class="pagenum" id="Page_25">[25]</span></p> + +<p>Occasionally, however, it may be required, and a suitable appliance +should always be at hand for an emergency. Fig. 10 shows two types. The +little clip of Mr Bellamy Gardner is preferable to the ring type, the +passage of the spike through the tongue substance producing less after +pain, than the bruising following the use of the other instrument. The +third drawing in Fig. 10 is of an<span class="pagenum" id="Page_26">[26]</span> instrument not much known outside +Edinburgh; it is called a glossotilt, and is intended to lever forward +the base of the tongue, as an alternative to nipping the tip of the +organ with forceps, and has, in the opinion of some, various advantages.</p> + +<p>Before using either mouth prop or tongue forceps, it is occasionally +necessary to use some mechanical means to lever open a tightly clenched +jaw. The earlier one interferes in a case of mechanical asphyxia, the +less necessity will exist for the use of such means. Fig. 11 shows two +well-known mouth gags, and also a box-wood wedge, the use of which is +less liable to injure teeth than a metal instrument. If a gag is used, +the blades when closed should lie the one behind the other, not side +by side. This ensures a minimal thickness to be inserted between the +tightly clenched teeth.</p> + + +<h3><b>Treatment of Laryngeal Stridor.</b></h3> + +<p>This is of necessity difficult since the causation of the condition +is in many cases obscure. <i>The error</i> common to most beginners, +and to many who would resent such a title being applied to them, is +to regard the appearance of stridor as an indication to <i>deepen +the anæsthesia</i>. Whether the cause lie in local irritation of +the laryngeal mucous membrane or in some stimulus from the area of +operation, the condition is presumably always essentially a reflex +spasm of the adductors of the vocal cords, but it is a <i>reflex which +may persist even in an anæsthesia so deep that the vital medullary +centres are in peril</i>.</p> + +<p>The preventive treatment consists chiefly in following the other rules +set forth above for the prevention of asphyxia with such faithful care, +that the patient never enters into the vicious circle of asphyxia of +which stridor is so prominent a feature. Patience in the induction +stage—the avoidance of <i>forcing</i> the anæsthetic upon the +patient—is a safeguard not to be forgotten.</p> + +<p>Once the condition has arisen, it saves time to <i>withdraw the<span class="pagenum" id="Page_27">[27]</span> +anæsthetic</i> altogether, and to allow the patient to breathe nothing +but fresh air. Brisk friction of the lips with a rough towel often +does good, presumably by setting up a “cross reflex.” In severe cases, +a most valuable measure is the inhalation of pure oxygen, a cylinder +of which should always be at hand in the operating theatre. Even an +obstructed air-way will convey enough undiluted oxygen to reduce the +venosity of the blood, and so cut across the “vicious circle.”</p> + +<p>So much for the treatment of the early stages of asphyxia, the more +advanced stages constitute one of the “accidents of anæsthesia,” and +are dealt with in Chapter <span class="smcap">xvi</span>.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_28">[28]</span></p> + +<h2>CHAPTER IV.<br> +<span class="subhed"><b>METHODS OF ANÆSTHETISING.</b></span></h2></div> + +<p>Certain terms such as “open method,” “closed method,” etc., are used in +describing different systems of anæsthetising, and it will save time +later if these are now defined.</p> + +<p>The <span class="smcap">Open Method</span> is one in which the drug is dropped or +poured upon a fabric stretched on a mask which does not lie in close +apposition to the face. If the student will experiment with such a +mask as Schimmelbusch’s, he will find that by no effort can he make +its whole circumference touch his face at the same time. Anæsthetics +vapourised from such masks must of necessity be inhaled freely diluted +with fresh air. These masks are only suitable for use with chloroform.</p> + +<p>The <span class="smcap">Perhalation Method</span>.—This term is not used often, but +it is the most strictly correct name to give to the process commonly +called “open ether.” If the student will examine Bellamy Gardner’s open +ether mask (Fig. 27) he will find that it is deliberately shaped to lie +over its entire circumference in close apposition to the face of the +average patient. In actual use it is well however to make sure of this +apposition by the use of a ring of gauze as shown in Fig. 28<span class="allsmcap">A</span>. +Upon the mask is stretched gauze of a thickness just as great as will +permit free respiration to take place through its layers. The whole +bulk of the respired air must pass <i>through the fabric</i>, none +escaping between the face and mask.</p> + +<p>The term “<span class="smcap">Semi-Open</span>” is applied to various methods now rarely +seen. One of the best known of these was the anæsthetic cone, still +used by a few for C.E. mixture (<i>see</i> Fig. <a href="#i_p131">45</a>).</p> + +<p><span class="pagenum" id="Page_29">[29]</span></p> + +<p>The term “<span class="smcap">Closed Method</span>” is applied to one in which the +patient breathes in and out of a closed bag. The Clover and Ormsby +inhalers are “closed” instruments. With this method the patient rapidly +uses up the oxygen of the contained air, and accumulates considerable +CO<sub>2</sub>; life could not be sustained for any long period of time under +such a system. Oxygen must be supplied from time to time by permitting +say one breath in five to be taken from the fresh air instead of from +that in the bag. Alternatively, oxygen from a cylinder may be supplied +by an accessory pipe into the inhaler.</p> + +<hr class="tb"> + +<p>This method is also referred to as the <span class="smcap">Re-Breathing Method</span>.</p> + +<hr class="tb"> + +<p>The <span class="smcap">Valved Method</span> is used only with “gas” or “gas-oxygen.” +The facepiece fitting accurately, the patient draws all the volume of +his inspiration from the inhaler: his expirations he propels through +a valve, into the general atmosphere of the room. If nitrous oxide +unmixed with oxygen is being given, the patient suffers from oxygen +starvation even more rapidly and completely than in the re-breathing +method. During the induction period of gas anæsthesia, such oxygen +starvation is practised deliberately, and if not pushed too far is +harmless. It cannot, however, be continued for more than a brief space +of time. The admixture of oxygen to the vapour being breathed entirely +abolishes this unfavourable feature of the valved method.</p> + +<p>There is, however, another consequence of the use of “valves” which +is unaffected by the addition of oxygen. Reference has already been +made to <i>Yandell Henderson’s acapnic theory</i>, and if under +any form of anæsthesia the patient can be reduced to a condition +<i>of CO<sub>2</sub> starvation</i>, it will be when the valved system of +administration is in operation for a prolonged period. As a matter of +experience, patients breathing “on the valves” do often exhibit shallow +respirations and slight pallor which is rapidly and very strikingly +remedied by turning to the rebreathing method. One<span class="pagenum" id="Page_30">[30]</span> can hardly doubt +that the improvement is due to a gradual re-accumulation of carbon +di-oxide in the blood and tissues.</p> + +<p>Two other terms referring not to the type of inhaler but to the method +of supplying the drug, are in use.</p> + +<p>By the <span class="smcap">“Drop” Method</span>, we mean one in which the anæsthetic is +supplied in a steady series of drops. The flow may be quick or slow, +but it always arrives on the mask in isolated drops of uniform size. +Such a method demands more constant attention than the next to be +described, but it is capable of yielding that even uniformity of vapour +strength so desirable in open methods.</p> + +<p><span class="smcap">The Douche Method</span> is unfortunately far more commonly used by +those whose attention has never been drawn to the significance of the +difference between the two. Supplies of the drug rendered, say, every +twenty seconds cannot possibly give an even vapour strength.</p> + +<p>“<span class="smcap">Single Dose</span>” methods are of use chiefly in dental surgery. +The patient is charged up with the anæsthetic, and the operator has to +begin his work as soon as the mask is withdrawn from the face, ceasing +as soon as the patient shows any signs of recovering consciousness of +pain.</p> + +<p>Single dose anæsthetics are in a class by themselves. In order to +achieve success with them, special experience on the part of the +administrator and mutual confidence between operator and anæsthetist +are essential.</p> + +<p>The period of anæsthesia available to the operator which any particular +“single dose” anæsthetic may be expected to yield is obviously a matter +of the first importance, and the table given in Chapter <span class="smcap">xix</span>. +will be found helpful in this connection.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_31">[31]</span></p> + +<h2>CHAPTER V.<br> +<span class="subhed"><b>THE CLINICAL OBSERVATION OF THE PATIENT.</b></span></h2></div> + + +<h3><b>Stages of Anæsthesia.</b></h3> + +<p>Anæsthesia has been divided into four clinical stages corresponding +to the degrees to which the nervous system has been affected. The +boundaries between these stages are often ill-defined, but the +terminology has some value as facilitating description.</p> + +<p><span class="smcap">The First Stage</span> lasts from the commencement of inhalation up +to the time when volitional self-control is lost by the patient.</p> + +<p><span class="smcap">The Second Stage</span> in the older text-books was said to be +characterised by struggling, shouting, and breath-holding. With a +patient not addicted to alcohol and with the anæsthetic skilfully +administered, this description is unduly lurid.</p> + +<p><span class="smcap">The Third Stage</span> is that of full surgical anæsthesia.</p> + +<p><span class="smcap">The Fourth Stage</span> is that of over-dosage.</p> + + +<h3><b>The Ocular Reflexes in Anæsthesia.</b></h3> + +<p>These give such valuable assistance to the anæsthetist that it will be +well to define and describe them as a preliminary. They are three in +number.</p> + +<p><span class="smcap">The Conjunctival Reflex</span> is best elicited by drawing the +upper lid upwards from the eyeball and retaining it in that position +with one finger, while with another finger the ocular conjunctiva is +lightly touched in the area of the inner canthus. If the anæsthesia is +very light, both lids attempt to approximate<span class="pagenum" id="Page_32">[32]</span> and close the palebral +fissure. The upper lid may slip down from under the retaining finger +and come into its proper place, while the lower lid is elevated. At +a deeper level of anæsthesia there is not complete action of the +orbicularis but merely of a certain part of it, so that all that is +observed is a <i>twitch inwards of the lower lid</i>. Even this form of +the reflex disappears before the corneal reflex.</p> + +<p><span class="smcap">The Corneal Reflex</span> is elicited by pushing up the upper lid by +one finger and with the pulp of the <i>same</i> finger lightly brushing +the centre of the cornea as soon as it is exposed, when we feel or see +the upper lid come back into position with a sharp definite twitch. +The examining finger must be slipped smartly out of the way as soon as +the cornea has been touched. Even in deep anæsthesia, a trace of this +reflex can usually be elicited if the little manipulation be properly +performed.</p> + +<p>The conjunctival and corneal reflexes are frequently confused in the +mind of the student. The most common mistake made is to pin the upper +lid firmly somewhere in the region of the bony roof of the orbit, +to dab the eye far too vigorously, and to believe that no reflex is +present because no movement of the upper lid takes place. In the first +place, the upper lid cannot move if it is rigidly held against a bony +plate: in the second place, it is wholly unnecessary to inflict upon +the cornea more than the lightest of touches. Both these reflexes +are to be used with great discretion, undue frequency and excessive +vigour of touch being alike capable of setting up serious inflammatory +reaction.</p> + +<p><span class="smcap">The Pupillary Light Reflex</span> is elicited by shutting off light +from <i>both</i> pupils for ten to twenty seconds and then smartly +withdrawing the protecting fingers and allowing as strong a light as +possible to fall on to the eye. The response of the ciliary muscle +should <i>always</i> be present; its absence is a certain indication of +something wrong: some sluggishness may be permissible under<span class="pagenum" id="Page_33">[33]</span> ether, but +even that is suggestive of trouble if chloroform is the anæsthetic.</p> + +<p>The use of a preliminary hypodermic of morphia tends to make the pupil +somewhat smaller than normal, and to elicit the light reflex it may be +necessary to cut off illumination for a somewhat longer period than +if no morphia had been given. Nevertheless with a little care, the +light reflex should always be capable of demonstration even in the +morphinised subject.</p> + + +<h3><b>The Observation of a Normal Case.</b></h3> + +<p>In the case of nitrous oxide and of ethyl chloride, the patient passes +through the various stages very rapidly, and the picture of anæsthesia +as induced by either of these two is therefore best described +separately. The following may be taken, therefore, as an account of +what is to be observed in the patient inhaling ether or chloroform, +unless a specific reference is made to one of the other anæsthetics.</p> + +<p><span class="smcap">First Stage.</span>—The first sign that some effect is being +produced in the patient is usually the appearance of the movements of +<i>swallowing</i>; the hyoid and thyroid can be felt or seen to be +moving in conjunction with the muscles of deglutition. During this +stage, the patient being still to some extent under volitional control, +there should be no other movement noticed. The eyes are usually closed +and the colour normal; the respiration may be hurried by excitement, +but judicious handling of the patient will do much to minimise this.</p> + +<p><span class="smcap">The Second Stage</span> is really entered when volitional control +is lost. It may be characterised by struggling and shouting by the +patient, even if the anæsthetic is properly administered; but with a +healthy patient and a good anæsthetist, all that usually occurs in +the way of movement by the patient is some rigidity of the limbs and +a slight attempt, perhaps, to lift the head from the pillow or a limb +from the couch. The breathing tends during the first part<span class="pagenum" id="Page_34">[34]</span> of this +stage to be light and is rarely entirely regular: slight pauses occur, +usually after an inspiration, less commonly after expiration. Serious +“holding of the breath” (after an inspiration) rarely occurs save in +the type of patient who is also struggling; if it does occur to a +degree which causes any blueness of the patient’s face (cyanosis), it +usually calls for the removal of the anæsthetic for a moment until +normal breathing has been resumed.</p> + +<p>The colour of the face rarely departs much from normal during the +second stage, unless cyanosis from breath-holding intervenes.</p> + +<p>The eyes are usually opened, as the second stage progresses, and the +eyeballs tend to rotate slowly in every plane. The pupils are usually +large, but react sharply to light. Both conjunctival and corneal +reflexes are brisk.</p> + +<p><span class="smcap">The Onset of the Third Stage</span> is marked by the appearance of +muscular relaxation. Any limb which the patient may have been holding +rigidly up sinks down on to the couch, and it will be found that if an +attempt be now made by the anæsthetist (as it should be) to turn the +head of the patient to one side or another, the muscles of the neck no +longer resist.</p> + +<p><i>The respiration</i> also alters in type, losing its tendency to +lightness and irregularity, and becomes full, deep, and regular. In +open ether anæsthesia particularly, expiration commonly assumes a +“blowing” type very characteristic, and which to the trained ear is of +itself an indication that full surgical anæsthesia is present or at any +rate not far distant.</p> + +<p><i>The colour</i> varies somewhat with the anæsthetic in use. With +ether it is usually somewhat higher than normal, and a trace of +blueness may be present if the method is the “closed” one. Anything +more than a trace, however, must be regarded as abnormal, whatever the +method or anæsthetic may be. With chloroform the colour is perhaps a +little paler than that normal to the individual.</p> + +<p><span class="pagenum" id="Page_35">[35]</span></p> + +<p><i>The eyelids</i> are usually half open, and the eyeballs at rest +looking forward and slightly downwards. An extreme rotation downward +may usually be taken as a sign of very deep anæsthesia. <i>The +pupil</i> is, as already said, always active to light, but its actual +size varies with the anæsthetic used. With ether, particularly “closed” +ether, it may be large (4–5 millimetres): with open ether, preceded by +morphia, about 3–4 millimetres: a good chloroform anæsthesia usually +exhibits a pupil of only 2–3 millimetres, and if morphia has also been +given, it may be pin-point in size. Too much emphasis must not be +placed, however, upon the mere size of the pupil; that may vary within +wide limits without necessarily indicating serious abnormality. The +essential point is that the light reflex shall be brisk. A pupil of 5 +millimetres reacting sharply to light may be of no special moment: one +of that size immobile to light would cause real anxiety.</p> + +<p><i>The conjunctival reflex</i> usually disappears fairly early in +the third stage: if briskly present, the anæsthesia is certainly a +light one, and probably insufficient for an abdominal section. <i>The +corneal reflex</i> if properly taken in the way already described can +usually be elicited throughout the third stage. In an anæsthesia deep +enough for abdominal section it is, of course, not brisk, but we may +say generally that its entire absence is <i>presumptive</i> evidence +of a very deep anæsthesia—probably undesirably deep. It must not be +forgotten that some local causes such as drying of the surface of the +cornea may cause it to disappear, and in case of doubt it is sometimes +worth while to wash out the eye with a little saline solution. If after +doing so the anæsthetist still finds the reflex not present he should +be on his guard. Provided, however, that the light reflex is still +present and colour and respiration satisfactory, he need not consider +that the patient is in any immediate danger.</p> + +<p>Broadly speaking, then, the third stage, the stage which is called for +by the requirements of major surgery, is characterised by<span class="pagenum" id="Page_36">[36]</span> (1) full +regular respirations; (2) colour not much removed from normal; (3) +moderate sized pupil, larger in the case of ether than chloroform; (4) +conjunctival reflex faint or absent; (5) corneal reflex just present, +or, in a deep third stage, just absent; (6) light reflex present: +these may be regarded <i>as the signs of fully developed surgical +anæsthesia</i>.</p> + +<p>The absolute beginner may be so completely out of his reckoning as +to mistake the quietude of the later part of the first stage for the +appearance of the third stage. For the prevention of so gross an +error as that, the reader need only be referred to a patient study +of the foregoing. But even a man with considerable experience may +frequently be in doubt exactly as to <i>how far through the third +stage his patient has passed</i>. He may have attained a level which +will permit an incision to be made into the skin without movement on +the part of the patient, but not one which would relax the abdominal +muscles sufficiently for the peritoneum to be opened without eliciting +considerable resistance from the abdominal muscles. In such moments +of doubt, the author is accustomed to request the surgeon to make his +skin incision, and <i>observe the effect which this trauma has upon the +depth, frequency, and regularity of respiration</i>. This furnishes a +most valuable guide to the depth of anæsthesia. In a third stage of +very light degree, the respiratory rhythm will be interrupted and the +breath held for a second in inspiration. Apart from any other sign, +that may be taken as an index that the anæsthesia is very light—too +light to permit of opening the peritoneal cavity. In a very deep +anæsthesia the respiration is little affected by the skin incision, +while at a moderate and more desirable level the respiration is +quickened and deepened, but unaffected in the regularity of its rhythm.</p> + +<p><span class="smcap">The Fourth Stage is Stage of Over-Dose.</span>—This stage is, of +course, never entered voluntarily. Its earliest signs are loss of all +tone in the muscles of expression, complete loss of corneal<span class="pagenum" id="Page_37">[37]</span> reflex, +a widely dilated pupil <i>insensitive to light</i>, and a type of +respiration which though definitely weakened may show occasional deep +gasps. Circulatory failure and cessation of respiration from failure of +the medullary centre are the closing phenomena of overdose.</p> + + +<h3><b>The Circulation in Anæsthesia.</b></h3> + +<p>It will be perhaps noticed that in the foregoing, no reference has +been made to the examination of the pulse. This is not an oversight on +the part of the author. It is perfectly true that under any anæsthetic +not complicated by an asphysical element, the blood pressure falls as +the drug takes effect, and that in the case of chloroform the fall is +often quite considerable. Such a fall can be appreciated by the skilled +finger, but only by concentrating upon that examination a degree of +attention which necessarily detracts from the administrator’s available +energy for the observation of other signs which are of equal value, and +can be more rapidly and certainly appreciated and appraised.</p> + +<p>It is nevertheless essential to assure oneself during the whole +progress of an anæsthesia that the circulation is in a satisfactory +condition. Two obvious guides to this are the colour of the patient’s +face and the force with which cut arteries spout. As regards the colour +in circulatory failure, one would naturally expect a pallid face, and +this indeed is the rule. It must not be forgotten, however, <i>that +cyanosis may sometimes be cardiac in origin</i>. Cases do sometimes +occur when a bluish tinge is seen on the lips, ears, and nostrils, +apart from any obvious cause of oxygen starvation. In these we may +reasonably suspect that the right heart is failing, and take measures +accordingly.</p> + +<p>Another valuable index to the state of the circulation is the “skin +reflex,” that is, the speed with which the circulation returns to an +area of the skin which has been pinched. The student should train his +eye by occasionally pinching the lobule of the<span class="pagenum" id="Page_38">[38]</span> patient’s ear and +observing first the white area so produced, and later the rate at +which, in a normal case, the healthy colour returns.</p> + + +<h3><b>Abnormal Phenomena in Anæsthesia.</b></h3> + +<p>It is not intended to furnish here any account of matters more suitably +treated under the “Accidents of Anæsthesia,” which are fully described +in Chapter xvi., but merely to draw the attention of the student to +certain departures from the normal course of anæsthesia which are +encountered with varying frequency, to ascribe them as far as possible +to their true causation, and indicate methods of prevention.</p> + +<p>The abnormalities fall into two classes, those connected with the +nervous and muscular systems, and those in which respiratory changes +are evident.</p> + + +<h4 class="smcap">Motor and Nervous System.</h4> + +<p><i>Clonus or tremor</i> sometimes appears in one or more limbs, even +the trunk being affected in severe cases. Ether is practically the +only anæsthetic under which the tremor ever appears, and the condition +is often spoken of as “ether tremor.” It rarely appears in the female +subject, being almost limited to powerfully built young men. Coming +on towards the end of the second stage, it frequently persists in the +deepest of third stages, and in bad cases there is usually no option +but to change over to chloroform—always supposing that the tremor will +interfere with the work of the surgeon. If it will not, the condition +calls for no active treatment, since it is in itself not dangerous.</p> + +<p><i>Movements recalling to the observer the condition of athetosis +seen in the limbs of hemiplegics</i> are occasionally seen in the +anæsthetised patient. The fingers of a hand may be slowly moved, or one +or other shoulder may be shrugged. The exact cause of these movements +is obscure. They occur in all types, both sexes, and at all ages; they +are not necessarily asphyxia though a trace of asphyxia seems sometimes +to conduce to them. They persist for<span class="pagenum" id="Page_39">[39]</span> some time after the third stage +has been entered, and ultimately disappear without any obvious cause +other than the passage of time. It is rare for them to continue more +than five or ten minutes after full anæsthesia has been induced. Their +practical importance lies purely in this, that the inexperienced +anæsthetist observing some muscular movements still persisting, may +take them as an infallible sign that anæsthesia is not complete, and +may deliberately take his patient to a deeper level. If in doubt, +the anæsthetist must, of course, consult all the other recognised +guides, such as the eye reflexes, but once he has seen these movements +in a case, and had demonstrated to him <i>their slow, rhythmical +character</i>, he is not likely to be misled on a future occasion.</p> + +<p><i>Muscular rigidity</i> has been mentioned already in Chapter iii. +When it persists in a patient in whom other signs suggest that a full +anæsthesia has been produced, the anæsthetist will usually find that +attention to the air-way, and perhaps a whiff of oxygen, will remedy +the trouble.</p> + + +<h3><b>Respiratory Abnormalities.</b></h3> +<p><i>Shallow breathing</i> or even slight temporary arrests of +respiration arise frequently. During the induction stage they may be +due to:—</p> + +<div class="blockquot"> + +<p>1. Apnœa or acapnia following voluntary excessive breathing.</p> + +<p>2. Using morphia before chloroform.</p> +</div> + +<p>At a later stage, it may be due to:—</p> + +<div class="blockquot"> + +<p>1. Acapnia following excessive breathing excited reflexly from +the seat of operation.</p> + +<p>2. Direct reflex inhibition of the respiratory centre. +An example of this is seen sometimes when the bladder is +over-distended by lotion.</p> + +<p>3. Impending vomiting.</p> +</div> + +<p><span class="pagenum" id="Page_40">[40]</span></p> + +<p><i>Moist sounds</i> not uncommonly appear. The student’s general +knowledge of medicine will enable him to decide whether the fluid is +likely to be in the pharynx, larynx, trachea, or bronchi. If in one +of the first two named, it will suffice to swab out the throat and +encourage the patient to cough. If, however, moisture is evidently +present in the trachea or bronchi, the condition is one calling for +considerable care and judgment. It arises more commonly with ether than +with chloroform. Much will depend upon how much longer the surgeon +requires to finish his operation. If only a few minutes more are +required, nothing is necessary but to cut down the amount of ether +being given to the minimum possible. If, however, the surgeon has +still a good deal to do, the safest thing is to withdraw the ether and +substitute chloroform or a mixture. Be it clearly understood, however, +that such a change over is not devoid of risk. If it is to be made, it +must be done early, before the patient is cyanosed and almost drowned +in his own secretion. In a neglected case where cyanosis has already +appeared, there will be no option but to interrupt the operation, +empty the chest by encouraging coughing, and to aid the process +by compressing the patient’s chest during expiration. Thereafter +chloroform may be given, but with the greatest care.</p> + +<p><i>Gasping and sighing</i> are not common phenomena but when they +occur, call for close notice from the anæsthetist. Excluding, of +course, such occurrences in the first stage, before volitional control +has been lost, they may be <i>usually but not invariably ascribed +to overdosage or to the appearance of definite surgical shock</i>. +Whenever they are noticed, therefore, it behoves the administrator to +overhaul the patient thoroughly, to consult the eye reflexes, the skin +reflex, and the pulse, and not to rest until he is assured that there +are no other signals of danger to be found.</p> + +<p><i>Stertor and stridor.</i> The first of these is caused by flapping +of the soft palate. It is a noise low in pitch, resembling ordinary +snoring. Indicating as it does that the palatal and therefore<span class="pagenum" id="Page_41">[41]</span> probably +other muscles, are relaxed, it may if moderate in volume usually be +taken as a favourable sign. If it becomes very loud, however, the +probability is that the base of the tongue has fallen back; cyanosis +will begin to appear, but will immediately be remedied by pulling +forward the jaw or in extreme cases, using the tongue forceps.</p> + +<p><i>Stridor</i> is a high-pitched sound produced by approximation of the +vocal cords. It has already been dealt with in Chapter iii.</p> + + +<h3><b>False Anæsthesia.</b></h3> + +<p>This term has been applied to a condition often seen in children, +and occasionally in adults. It is almost limited to chloroform: the +author has never seen a genuine case when ether has been in use. It +appears very quickly after inhalation has begun: the muscles are +relaxed, the respirations quiet and regular, the conjunctival reflex +sluggish. A very marked feature is the excessive smallness of the +pupil. Obviously then, the condition much resembles a true third stage, +but if the operation be begun, the mistake will very rapidly be made +evident, for the patient will at once move and cry out. In essence, the +condition is simply one of ordinary sleep. It can be recognised by its +appearance after a period of inhalation too brief for the induction +of true anæsthesia, by the very small pupils and the lightness of the +respiration. It will be a waste of time to permit the condition to +continue, as the lightness of the respiration delays the taking in of +a dose of the anæsthetic sufficient to induce a proper third stage. +The remedy is simple,—rub the lips and face smartly with a towel or +the hand, when respiration will at once deepen and the pupil dilate. +Thereafter, the induction should proceed normally.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_42">[42]</span></p> + +<h2>CHAPTER VI.<br> +<span class="subhed"><b>PREPARATION OF THE PATIENT.</b></span></h2></div> + +<p>For all but short anæsthesias conducted chiefly by nitrous oxide, the +intestinal tract of the patient must receive careful preparation. In +doing this, one must avoid excessive starvation and purgation, both of +which tend to increase shock.</p> + +<p>We will suppose that the operation is timed for 10 a.m. on Tuesday +morning. On Monday morning the patient receives an aperient which +may be varied a little to suit his taste and habits. If he has no +preference, there is nothing better than an ounce of castor oil. During +the rest of Monday, he has a light diet: fish and milk pudding in the +middle of the day, a little soup at night. The aperient should operate +before 9 p.m. When that is over, the patient retires to bed. During the +day he may be allowed to move about his room a little, but should not +undertake any exertion.</p> + +<p>If there be excessive nervousness, or a natural tendency to insomnia, +sulphonal gr. 15 or veronal gr. 8 may be given early in the evening, to +ensure a night’s rest.</p> + +<p>About 6 a.m. on Tuesday morning, a large soap and water enema is given, +and when this has operated, a cup of tea or a little soup or Bovril may +be taken. Thereafter nothing should be given by mouth.</p> + +<p>The early forenoon is the time of choice for any operation, but if +an afternoon time be of necessity chosen, the patient should not be +starved throughout the forenoon. A repetition of the early morning meal +may be allowed about 11 a.m.</p> + +<p><span class="pagenum" id="Page_43">[43]</span></p> + +<p>In cases such as gastro-enterostomy, where the alimentary tract will be +opened, the preparation must be a little more stringent. It is usual +to allow no solids at all the day before. A saline enema may be given +an hour or two before operation, when the soap and water has been +evacuated.</p> + + +<h3><b>Preliminary Hypodermic Medication.</b></h3> + +<p>This great improvement in anæsthesia was practised many years ago by +a few surgeons, but it was only when open ether assumed its present +position of pre-eminence that it was widely adopted.</p> + +<p>The present routine is to give morphia gr. ⅙, atropine gr. ¹⁄₁₂₀ to +adult patients three quarters of an hour before operation. It has the +following <i>advantages</i>:—</p> + +<div class="blockquot"> + +<p>(1) The nervous fears of the patient give place to a feeling of +bien-être.</p> + +<p>(2) The secretions of saliva and of mucous from the respiratory +mucous membranes are limited.</p> + +<p>(3) A little less inhalational anæsthetic is required.</p> + +<p>(4) The after vomiting is lessened, and probably the liability +to inflammatory respiratory complications also reduced.</p> +</div> + +<p>The <i>disadvantages</i> can be met by proper care and dosage. They are +as follows:—</p> + +<div class="blockquot"> + +<p>(1) Morphia <i>plus</i> chloroform depresses the respiratory +centre at an early stage of anæsthesia. Respiration becomes +infrequent and shallow, and cyanosis appears before the patient +is really sufficiently anæsthetised for the purposes of the +surgeon.</p> + +<p>(2) The larger the dose of morphia, the more troublesome is this +premature failure of respiration.</p> +</div> + +<p><i>The moral</i> is obvious: give the small doses above recommended<span class="pagenum" id="Page_44">[44]</span> +and induced with mixtures weak in chloroform, or better still with +ether only (see page <a href="#Page_86">86</a>).</p> + +<p>Some years ago, before these facts were appreciated, there was a +fashion for giving very large doses of preliminary narcotics. The +combinations most favoured were as follows:—</p> + + +<h4 class="smcap">Scopolamine-morphine.</h4> + +<p>Scopolamine is a form of hyoscyamine and is itself a powerful narcotic. +Two or sometimes three doses of the mixed drugs were given at intervals +of an hour, the last half an hour before operation. Scopolamine gr. +¹⁄₂₀₀, morphia gr. ⅛ was the usual formula: some surgeons added a dose +of atropine or strychnine with the idea of stimulating the respiratory +centre.</p> + +<p>The patients went to the operating or anæsthetising room so drowsy +that they were unaware of their surroundings, and afterwards had no +recollection of the actual beginning of the inhalation. So humane a +method naturally attracted a good deal of attention, but the serious +depression of the respiratory centre which seems inevitable in the +method has gradually caused it to disappear from the practice of +most surgeons and anæsthetists. At the present day, it is only to +be recommended in midwifery practice; to the drowsy semi-conscious +condition produced, the name of <i>Twilight Sleep</i> has been given.</p> + + +<h4 class="smcap">Omnopon and Omnopon-scopolamine.</h4> + +<p>Omnopon is composed of a mixture of several of the alkaloids derived +from opium; the makers claim that it produces less after malaise than +morphia alone. It may be given before anæsthesia in doses of ⅙–⅓ gr., +either alone or combine with a small dose of scopolamine. It gives +quite good results if not pushed to excess.</p> + + +<h4 class="smcap">Heroin Hydrochloride</h4> + +<p>This comparatively modern sedative is used by some surgeons in +preference to morphia. A dose of ¹⁄₁₂ gr. is quite sufficient,<span class="pagenum" id="Page_45">[45]</span> three +quarters of an hour before operation. Atropine should always be +combined with it.</p> + +<hr class="tb"> + +<p>To young children, morphia should not be given, but atropine may be +given freely. A child of twelve months tolerates a dose of ¹⁄₂₀₀ gr. +quite well: one of six years, will take ¹⁄₁₅₀ gr.</p> + +<p>In ages ranging from 12 years upwards, greatly reduced doses of morphia +may be given. No child under 15 years requires more than ¹⁄₁₂ gr. of +morphia at most.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_46">[46]</span></p> + +<h2>CHAPTER VII.<br> +<span class="subhed"><b>NITROUS OXIDE.</b></span></h2></div> + +<h3><b>Special Physiology.</b></h3> + +<p>Upon the nervous system, nitrous oxide acts like other anæsthetics, +but the stages of anæsthesia are passed through so rapidly that a +second stage can hardly be distinguished. It is rare for struggling or +excitement to be manifest, unless air or oxygen be admitted at the same +time, when the effect which led Humphrey Davy more than a century ago +to apply to nitrous oxide the name of “laughing gas” is very evident +indeed.</p> + +<p>Upon the other systems of the body, nitrous oxide has little if any +effect in itself. The essential point to remember in connection with +nitrous oxide administered unmixed with air or oxygen is that there +is an <i>inevitable element of asphyxia</i>. The larger part of the +oxygen normally carried by the red blood corpuscles is eliminated +and replaced by N<sub>2</sub>O: oxygen starvation is therefore of necessity +present. In other words, the “vicious circle of asphyxia” (<i>see</i> +Fig. <a href="#i_p020">5</a>) is entered, and muscular spasm is bound ultimately to appear. +Moreover, the blood pressure rises very materially as a result of the +lack of oxygen. That no harm results to the normal healthy patient +from this rise is due to the fact that the gas does not in itself +poison the heart muscle, which can therefore stand up to the extra +strain of working against higher resistance, so long as the process +is not carried to extremes. A heart muscle weakened by the action of +chloroform would give out at once if exposed to such a test.</p> + +<p><span class="pagenum" id="Page_47">[47]</span></p> + + +<h3><b>Apparatus.</b></h3> + +<p>Nitrous oxide is supplied by the makers as a fluid condensed in iron +bottles or cylinders, and only becomes gaseous upon being released from +them. In passing from the fluid to the gaseous state, heat is of course +lost, and it will be noticed that the end of the cylinder which is in +use becomes rapidly crusted over with frost. Ice, moreover, forms in +the small channel at the head of a cylinder, and is apt from time to +time to block it.</p> + +<p>The cylinders are of various sizes and designated after the numbers +of gallons of gas which they will supply: 25 is the smallest size, 50 +or 100 are more usual; anything up to 500 is occasionally met with in +hospital practice. Moreover the cylinders are of two types, called +respectively <i>vertical</i> (for use in the upright position), and +<i>angle</i> for use in the horizontal position (<i>see</i> Fig. <a href="#i_p048">13</a>).</p> + + <div class="figcenter" id="i_p047" style="max-width: 650px"> + <img + class="p1" + src="images/i_p047.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 12.</span>—Frame for adapting vertical cylinders +to foot use.</p> + </div> + + <div class="figcenter" id="i_p048" style="max-width: 430px"> + <img + class="p1" + src="images/i_p048.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 13a.</span>        <span class="smcap">Fig. 13b.</span></p> + <p class="p0 center smaller">Two types of N<sub>2</sub>O cylinders.</p> + <p class="p0 center smaller">A. Vertical (or ordinary).        B. Angle.</p> + </div> + +<p>The cylinders are fixed in frames of various types of which examples +are seen in Figs. <a href="#i_p048">13</a> and <a href="#i_p049">14</a>.</p> + +<p>Upon each cylinder, of whatever size or type, will be found a label +stating its weight when full and empty, the difference<span class="pagenum" id="Page_48">[48]</span> representing +the weight of the contents when the bottle is full. For instance, in +the case of the 50-gallon cylinder the weight of its full charge is 15 +ounces. Weighing the cylinder is the only certain means which we have +to estimate how much of the charge remains. The student will readily +appreciate therefore that once a cylinder has been used at all there +is always a risk of the supply of gas from it running out during an +administration. It is<span class="pagenum" id="Page_49">[49]</span> for this reason that cylinders are habitually +used in couples, one of which is always supposed to be quite full. To +this one it is well to attach a label marked “full,” and care must be +taken to replace at once a cylinder known to be empty. In this way we +always have upon the frame one cylinder partly and another entirely +full.</p> + + <div class="figcenter" id="i_p049" style="max-width: 308px"> + <img + class="p1" + src="images/i_p049.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 14.</span>—Complete N<sub>2</sub>O apparatus, showing +twin cylinders, supply pipe, 2-gallon bag, 3-way tap, and face-piece.</p> + </div> + +<p><span class="pagenum" id="Page_50">[50]</span></p> + +<p>By whatever makers the cylinder is supplied it will be found that the +thread upon the outlet pipe is the same, and the metal nipple figured +in Fig. 14 will fit it. To the distal end of the nipple, a rubber tube +is attached which leads to a rubber bag usually of 2 gallons capacity.</p> + +<p>The remainder of the apparatus may be of several types.</p> + +<p>Fig. 15 shows the ordinary <i>Barth three-way</i> tap with facepiece; +the indicator on the tap has three possible positions designated on +the dial as “Air,” “Valves,” and “No Valves.” If the tap is pointed +backwards towards the bag at the position marked “air” the end of the +bag is closed and the patient is breathing air only. With the tap in +the middle position of “valves,” the inspiration of the patient will +draw gas from the bag, but the expiration closes the valve which is now +in operation at the orifice of the bag, and will open the expiratory +valve which conducts the expired air into the general atmosphere. In +the third position of “no valves” the patient breathes both in and out +of the bag.</p> + + <div class="figcenter" id="i_p050a" style="max-width: 592px"> + <img + class="p1" + src="images/i_p050a.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 15.</span>—Barth 3-way N<sub>2</sub>O tap.</p> + </div> + + <div class="figcenter" id="i_p050b" style="max-width: 538px"> + <img + class="p1" + src="images/i_p050b.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 16.</span>—Hewitt’s wide-bore gas valves.</p> + </div> + +<p>Fig. 16 shows the Hewitt type of inhaler. The calibre of the orifices +through which respiration takes place is greater than in the Barth +three-way tap, and to that extent this type of valve<span class="pagenum" id="Page_51">[51]</span> is to be +preferred. Although differently arranged exactly the same possibilities +are present in it.</p> + +<p>The <i>facepiece</i> is sometimes made of celluloid with an inflatable +rubber edging. The object of this type of facepiece is that the +colour of the lips may be appreciated by the anæsthetist during the +administration. The preferable plan is to make the whole facepiece of +rubber with an inflatable border. Such a facepiece made by a good maker +will last many years, and is much more stable and reliable than its +celluloid competitor.</p> + + +<h3><b>The Care of the Nitrous Oxide Apparatus.</b></h3> + +<p>This is a matter of considerable moment, particularly to those who do +not use their apparatus every day. After use, the valves, facepiece, +and bag should be disconnected from each other, all moisture wiped away +from the bright parts, and the bag hung up with its open end downwards, +and preferably in a warm room. If re-breathing has been extensively +practiced it is well to wash the bag out with some carbolic lotion +before hanging it up. The rubber valves in the valvepiece are liable +to lose their elasticity, particularly if kept in a cold place after +becoming damp. From time to time the valve piece should be taken to +pieces, the valves carefully dried in front of a warm fire and powdered +over with a little talc.</p> + + +<h3><b>Administration.</b></h3> + +<p>Most commonly nitrous oxide is administered to a patient sitting in a +chair. Care should be taken that the respiration of the patient shall +not be obstructed by tight clothing round the throat or chest, and +that the head and neck are neither unduly flexed nor extended upon the +shoulders. The patient should not have any solid food for two hours +before the anæsthetic. At the last moment he should be instructed to +empty his bladder. Artificial dentures if present should be removed, +and, if the anæsthetic is being given for the purpose of the extraction +of a<span class="pagenum" id="Page_52">[52]</span> tooth, it will be necessary before applying the facepiece to +insert between the teeth a dental prop. (See Fig. <a href="#i_p022">6.</a>) Standing to the +left and slightly behind the patient the anæsthetist’s first step is to +secure good apposition between facepiece and face. This is best done by +working from above downwards: that is to say, secure first a good fit +at the bridge of the nose, and then approximate the remainder of the +rim of the facepiece to the cheeks and lower jaw. During this stage the +indicator of the tap is kept at “Air.”</p> + +<p>Working with the left foot the administrator now opens the head of one +of the cylinders with the foot key. It is wise first to have loosened +this with a hand key, and leave it just “on the swing,” otherwise +one’s boots are apt to suffer! Gas is allowed to flow into the bag +until it is partially, but by no means tightly distended. The patient +is instructed to breathe naturally and easily, and during the whole +process the anæsthetist should converse with him in a quiet easy way. +The tap is now turned to “valves” and the patient begins to inspire +the gas, a supply of which is allowed to flow steadily from cylinder +into bag. After a few breaths of the gas, when the sensibilities of +the patient are a little dulled, it is wise to allow the gas to flow +a little more freely and to distend the bag. This exercises upon the +patient a slight <i>positive pressure</i>, which has been proved +both experimentally and practically to increase the rapidity of the +absorption.<a id="FNanchor_1" href="#Footnote_1" class="fnanchor">[1]</a> The valves are left in operation for some thirty or +forty seconds, after which time the supply of gas should be cut off +and the tap be pushed over to the position of “no valves” for further +twenty seconds. This should be ample to secure full gas anæsthesia.</p> + +<p><i>The phenomena</i> seen in nitrous oxide anæsthesia are so different +from those of any other that a few words must be said about them. +Within a few seconds of the inhalation beginning, the colour of<span class="pagenum" id="Page_53">[53]</span> the +patient shows evidence of the presence of the gas in his blood. The +normal complexion changes first to a dull pink, and very rapidly to the +definite blue of cyanosis. The <i>eye symptoms</i> are of the utmost +value. Very early the pupil begins to dilate, and the eyeball tends +during the first twenty or thirty seconds to rotate as if the patient +were looking for some object in his field of vision. In full anæsthesia +the eyeball, however, comes to rest, usually pointed downwards. The +pupil is widely dilated, the conjunctival reflex is almost or even +entirely abolished, but the corneal reflex is still brisk. <i>The +respiration</i> tends to become steadily deeper and more frequent, and +in the later stages stertor at least, if not stridor usually develops. +<i>The muscles</i> under ordinary nitrous oxide anæsthesia are rarely +entirely relaxed, but the limbs hang motionless, and it is only if an +attempt be made to move them into some abnormal position, that one +appreciates the persistence of muscular tone.</p> + +<p>A phenomenon peculiar to nitrous oxide anæsthesia is observed in its +deepest stage. Designated as <i>jactitation</i>, it consists in a +tremor beginning in the limbs, but spreading from them to the trunk if +its development is allowed to proceed. It is a finer movement than that +described under “ether tremor” (page 38), and wholly different in type +from the athetosis referred to on page 38. Jactitation is almost wholly +an asphyxial phenomenon, and is therefore definitely an indication +that the process of oxygen starvation has been carried as far as is +permissible.</p> + +<p><i>The signs of fully developed nitrous oxide anæsthesia</i> then are:—</p> + +<div class="blockquot"> + +<p>1. Deep regular snoring respirations.</p> + +<p>2. Dilated pupils.</p> + +<p>3. Rotation of the eyeball downwards.</p> + +<p>4. Loss of conjunctival but persistence of corneal reflex.</p> + +<p>5. A colour of the skin definitely blue, but not blackish blue.</p> + +<p>6. The commencement of jactitations.</p> +</div> + +<p><span class="pagenum" id="Page_54">[54]</span></p> + +<p><i>The signs of overdose</i> are:—</p> + +<div class="blockquot"> + +<p>1. An enormously dilated pupil not re-acting to light.</p> + +<p>2. Loss of corneal reflex.</p> + +<p>3. A blackish blue colour.</p> + +<p>4. Jactitations fully developed.</p> + +<p>5. Failing respirations.</p> +</div> + +<p>The final arrest of respiration in nitrous oxide anæsthesia is usually +painfully sudden. Upon the respiratory side the only warning is one or +two gasps, and even that is sometimes absent. The paralysed pupil and +the jactitations are the most useful signs of overdose.</p> + +<p>The above, then, may be taken as an account of what one expects to see +in a normal gas anæsthesia during the induction stage. For the great +majority of cases, nitrous oxide is given for the purpose of rendering +painless the extraction of a tooth, and it is, in this large class of +case, the induction stage only which need be considered. It requires +only some fifty to sixty seconds to bring the patient to the stage +described under the heading “fully developed anæsthesia” and when that +has been attained, the mask may be removed and the operation begun. +From the moment of removal of the mask, however, it must be noted that +the patient begins to breathe fresh air and to eliminate the N<sub>2</sub>O. +The period of anæsthesia available to the surgeon or dentist during +which he must perform the operation, is therefore very small. In thirty +seconds the patient has frequently recovered sufficiently to begin +to feel pain, and it is rare to secure more than forty-five or fifty +seconds by the use of a single dose of nitrous oxide.</p> + + +<h3><b>Nitrous Oxide and Air.</b></h3> + +<p>If the nature of the operation does not necessitate the removal of the +mask from the face, it is possible to maintain nitrous oxide anæsthesia +for some considerable time. The exact length of that time varies a good +deal with two factors—the type of patient and<span class="pagenum" id="Page_55">[55]</span> the experience of the +administrator. Heavily built muscular patients are not easily dealt +with by prolonged gas anæsthesia (unless with admixture of oxygen as +explained in chapter viii.) Of far greater importance, however, is the +other factor. The student can easily be taught to give a single dose +of gas for the extraction of a tooth, or the momentary incision of an +abscess. He will, however, be wise to secure a good deal of practice in +that class of work before attempting to prolong gas anæsthesia for more +than a minute or two.</p> + +<p>With reasonable skill and experience and the utmost care, it is, +however, perfectly possible to prolong nitrous oxide anæsthesia for +periods of five, ten, or even fifteen minutes in the average healthy +patient. As soon as the signs of full anæsthesia appear, the valve +tap is pushed back to “air” for the space of one inspiration and +one expiration, and then at once pushed back to “no valves.” By +this manœuvre, one inspiration of air is permitted to the patient, +whose colour at once shows amelioration, or at any rate no further +progression of cyanosis. The admission of air is repeated every third, +fourth, or at most fifth respiration. After the first minute or so +of this cycle of events, it is obvious that the contents of the bag +will be composed of a mixture of nitrous oxide, air, and CO<sub>2</sub> in +proportions quite impossible to calculate. It is therefore best to +push the indicator to “valves,” and allow the bag to be emptied by the +suction of the patient’s inspirations. The cylinder head is then opened +by the turning of the foot-key, and the bag filled again with gas. The +cycle of “air” and “no valves” is then begun again for another minute +or so.</p> + +<p>It must be understood that by this process, it is not to be expected +that an ideal anæsthesia can be produced. Some movement of the patient +will not improbably take place when sensitive structures are cut or +handled by the surgeon, and at no time will the muscles be entirely +relaxed. Such an anæsthesia is therefore only suitable for a limited +class of case, but does admirably for,<span class="pagenum" id="Page_56">[56]</span> say, opening an abscess, +exploring its interior, and removing from it a sequestrum or an easily +found foreign body. During his service in Macedonia the author had not +at his disposal any of the appliances later to be described under the +heading of nitrous oxide and oxygen, and found “gas and air” a most +useful form of anæsthesia for the requirements of military surgery as +seen in a Base Hospital, under active service conditions.</p> + + +<h3><b>Contra-indications to the Use of Pure Nitrous Oxide Gas.</b></h3> + +<p>In the healthy subject, there is no safer anæsthetic than nitrous oxide +when administered properly and limited to its proper province.</p> + +<p>From the account given of the physiological action of the gas it will, +however, be obvious to the student that in a limited class of case its +use is not permissible. Such cases fall into two categories.</p> + +<p><i>Firstly, cases in which an asphyxial element already exists will +have their condition greatly aggravated by the substitution of N<sub>2</sub>O +for the oxygen in their blood.</i>—Already caught in the vicious +circle of asphyxia, nitrous oxide would but push them deeper into the +vortex. Examples of such cases are patients suffering from tumours or +inflammatory swellings in the neck which are pressing upon the air +passages. In passing, one may note that it might be the desire of the +surgeon to submit an individual case falling into this group to the +operation of tracheotomy for the immediate relief of the condition. The +short space of time required for this little operation might well tempt +the unwary to choose nitrous oxide as the anæsthetic, and in point of +fact such an error of judgment has more than once been made with fatal +results.</p> + +<p><i>Secondly, no patient suffering from any condition which will be +aggravated by a sudden rise of blood pressure, should be submitted to +nitrous oxide undiluted by oxygen.</i>—Examples of such conditions are +cases of <i>dilated right heart</i> with weakened cardiac musculature.</p> + +<p>Such hearts could not be expected to work against a peripheral<span class="pagenum" id="Page_57">[57]</span> +resistance suddenly raised, say, from 120 mm. of Hg, to 180 or even +200 mm.—figures well within the possible in deep gas anæsthesia. +Similarly, so great an increase of pressure would be dangerous to +a patient suffering from an <i>aneurysm</i>, or from <i>extensive +arterio-scelorosis</i> with high blood pressure.</p> + +<p>It will be noted that the above warnings are limited to the use of pure +nitrous oxide, that is, N<sub>2</sub>O unmixed with oxygen. The extent to which +the dangers referred to can be met by the admixture of oxygen in the +manner to be described in the next chapter is largely a matter of the +skill and experience of the administrator.</p> + + +<h3><b>Nasal Methods.</b></h3> + +<p>The object of using this route is to be able to continue the +administration throughout the period in which the dentist is doing his +work. The essentials of a suitable apparatus are:—</p> + +<div class="blockquot"> + +<p>1. A malleable nosepiece which can be closely adapted to the +nose.</p> + +<p>2. Two supply pipes from bag to nosepiece.</p> + +<p>3. Some means of admitting air to the stream of gas.</p> + +<p>4. A two-gallon bag.</p> + +<p>5. A supply of gas.</p> + +<p>6. A mouth cover with an expiratory valve only.</p> +</div> + +<p>The patient is instructed to breathe in through the nose, but to +expire through the mouth. The gas is supplied under some pressure and +the mouth cover ensures that no air is inspired by that route. Some +patients find it easier to conduct both inspiration and expiration +through the nose, and for their benefit an expiratory valve is also +provided in the nosepiece. After unconsciousness has supervened, nearly +all patients begin to-and-fro nasal breathing. The mouth cover may then +be removed, and if it be desired to economise gas, the expiratory valve +in the nosepiece may be thrown out of action.</p> + +<p><span class="pagenum" id="Page_58">[58]</span></p> + + <div class="figcenter" id="i_p058" style="max-width: 406px"> + <img + class="p1" + src="images/i_p058.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 17.</span>—Ash’s Modification of Paterson’s +Nasal Gas</p> + <p class="p0 sm"><span class="smcap">Description</span>:—A—Nose-Cap Attachment with Stopcock for Air +and Gas, and with Inspiratory and Expiratory Valves and Shutter. +B—Nose-Cap. C—Sliding Clip on India-rubber Tubings. D—Bifurcated +Mount. E—Bag Mount. F—Gas Bag Compressor. G—Gas Bag. H—India-rubber +Tubing. MC—Mouth Cover. This is fitted with an expiratory valve, and +should be used at the same time as the Nose-Cap. By using the two +together patients are more quickly anæsthetised than they would be if +only the Nose-Cap were used, and the Nitrous Oxide is economised.</p> + </div> + +<p><span class="pagenum" id="Page_59">[59]</span></p> + +<p>Air must be admitted in limited quantity through the tap after +the first thirty seconds or so; by a judicious regulation of this +mechanism, anæsthesia may be prolonged for five or ten minutes. +Facility with nasal gas comes only after some considerable practice.</p> + +<p>Fig. 17 shows Ash’s No. 3 Patented Nasal Inhaler, which admits of +Air or Gas being administered either by the Naso-Oral Method, or by +to-and-fro nasal breathing. <i>Air</i> only is admitted when the +Shutter A is open and turned to the right as far as it will go. +<i>Nitrous Oxide</i> is admitted when the Shutter A is open and turned +to the left as far as it will go, and the patient will breathe it +in-and-out through the nose. <i>For the Nasal Oral Method</i>, close +Shutter A and turn it to the left as far as it will go. This will cause +the patient to inhale through the nose and exhale through the mouth.</p> + +<p>Nasal attachments are provided with most of the gas-oxygen apparatuses +mentioned in the next chapter. With them good results can be obtained +with much greater ease.</p> + +<p>For a more detailed account of nasal methods, the student is referred +to works devoted entirely to Dental Anæsthesia.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_60">[60]</span></p> + +<h2>CHAPTER VIII.<br> +<span class="subhed"><b>NITROUS OXIDE AND OXYGEN.</b></span></h2></div> + +<p>The account given in the previous chapter of anæsthesia by nitrous +oxide and air will have convinced the student that it is a somewhat +inelegant method with a limited sphere of usefulness. The reason is +obvious. In atmospheric air, oxygen exists only in the proportion +of about one to four of nitrogen. To sustain life it is therefore +necessary to admit to the anæsthetic mixture an amount of air which +leaves too little room for the anæsthetic factor—nitrous oxide. If, +however, pure oxygen be used, the nitrous oxide is diluted to a much +less degree, and far better results are obtained.</p> + +<p>The exact scope for gas-oxygen anæsthesia cannot at present be defined +with certainty. The work of Crile, and the experience of the war have +done much to enlarge it. We may say that the following are definite +indications for its use:—</p> + +<div class="blockquot"> + +<p>(1) Minor operations lasting 5–15 minutes, particularly if +performed on out-patients.</p> + +<p>(2) Operations of any variety upon the subjects of severe shock.</p> + +<p>(3) Operations upon patients suffering from acute sepsis.</p> + +<p>(4) Operations repeated upon the same subject at short intervals.</p> +</div> + +<p>As regards (3) and (4), the lack of toxic properties in nitrous oxide +gas, and the rapidity with which it is eliminated, give it a tremendous +advantage over ether or chloroform. To men with shattered bones and +extensive damage to soft tissues, badly infected with sepsis, who +required repeated opening up of pockets, changing of gauze packs, etc., +the advantage of gas-oxygen over ether was<span class="pagenum" id="Page_61">[61]</span> evident, and was easily +appreciated by the patients themselves during the late war.</p> + +<p>There are, however, certain <i>drawbacks</i> to the method which must +be appreciated—</p> + +<div class="blockquot"> + +<p>(1) The necessary plant is heavy, bulky, and costly; it cannot +be easily transported.</p> + +<p>(2) The running cost is high as compared with ether or +chloroform.</p> + +<p>(3) It has been said by some that gas-oxygen can only be given +by an expert. That is a statement too extreme, in the author’s +opinion. Certainly, of all anæsthetics it is the most difficult +to give successfully. Adequate study and proper teaching by an +expert are required, but given these two helps, any one can soon +learn to administer gas-oxygen for minor surgery. Considerably +more experience is, however, necessary before the beginner +should give it for an abdominal section.</p> +</div> + + +<h3><b>Apparatus.</b></h3> + +<p>A good gas-oxygen apparatus is necessarily rather complicated. The +machines in the market are numerous, and of the most diverse external +appearance. Certain broad principles, however, underlie all the +machines, and it is to be hoped that some one of them will before long +become practically the standard. Once that is effected, hospitals and +nursing homes could be expected to provide them. So long as every +anæsthetist asks for a different machine, they certainly never will do. +A good machine must provide means for the following:—</p> + +<div class="blockquot"> + +<p>(1) <i>An even flow</i> of both gases under perfect control.</p> + +<p>(2) <i>A percentage of Oxygen</i> in the mixture rising at the +will of the administrator from 2 to 15 or 20.<a id="FNanchor_2" href="#Footnote_2" class="fnanchor">[2]</a> To meet this +requirement it is not necessary that any indicator should be<span class="pagenum" id="Page_62">[62]</span> +provided which shows with mathematical precision what percentage +of oxygen is being given. The colour of the patient tells us at +once if too much or too little oxygen is being supplied, and all +we need in the apparatus is some mechanism whereby we can tell +approximately to what extent we are increasing or decreasing the +percentage.</p> + +<p>(3) <i>Positive Pressure.</i>—If the pressure at which the +gases are supplied to the patient can be raised a little above +that of the ordinary atmosphere, absorption is increased and a +deeper anæsthesia produced. In the author’s view, this is an +essential point in a good instrument.</p> + +<p>(4) <i>Re-breathing.</i>—To supply the whole volume of gases +required for inspiration during a long operation is costly and +quite unnecessary. Yet that is what is being done if the whole +administration is conducted upon the “valvular” principle. +Moreover, a prolonged inhalation upon the valves tends to remove +a great deal of CO<sub>2</sub> from the patient’s blood and tissues +(<i>see</i> Chap. <span class="allsmcap">IV</span>.). Periods of partial or complete +re-breathing do much to deepen respiration, and reduce the cost +of the anæsthetic.</p> + +<p>(5) <i>Warming the Gases.</i>—While not essential, this is +certainly an advantage.</p> + +<p>(6) <i>Addition of Ether Vapour to the mixture.</i>—Gas-oxygen +even well given is hardly capable of reducing to quiescence +very robust people, unless the oxygen percentage is kept to an +undesirably low level. The merest trace of ether vapour as an +adjunct is a great assistance during the stages of the operation +where very sensitive structures such as the parietal peritoneum +are being handled. The more experienced the anæsthetist, the +less will he require such assistance.</p> +</div> + +<h3><b>Hewitt’s Apparatus.</b></h3> + +<p>This, with the exception of one designed by Dr Guy and the author, +and described on page 130, is the only machine with any<span class="pagenum" id="Page_63">[63]</span> pretence to +portability by hand. It does not satisfy all the requirements above +referred to, but the fact that it was the first practicable means +introduced in this country to give gas-oxygen entitles it to full +description. (<i>See</i> Fig. <a href="#i_p063">18</a>.)</p> + + <div class="figcenter" id="i_p063" style="max-width: 390px"> + <img + class="p1" + src="images/i_p063.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 18.</span>—Hewitt’s gas oxygen apparatus.</p> + </div> + +<p>Essentially it consists of the following:—</p> + +<p><span class="pagenum" id="Page_64">[64]</span></p> + +<div class="blockquot"> + +<p>(1) A supply of nitrous oxide and oxygen in separate cylinders. +Hewitt’s own stand held two of nitrous oxide and one of +oxygen.<a id="FNanchor_3" href="#Footnote_3" class="fnanchor">[3]</a></p> + +<p>(2) Rubber pipes of supply for each of the two gases. For +convenience, it is sometimes arranged that one of these shall +run inside the other.</p> + +<p>(3) Two 2-gallon bags. Nitrous oxide is led into the one, oxygen +into the other. The mouth of <i>each</i> bag is guarded by an +inspiratory valve.</p> + +<p>(4) The mixing chamber. Upon the surface of this are marked +successively: “Air,” “N<sub>2</sub>O,” “O<sub>2</sub>, 1 2 3 4 5 6 7 8 9 10.” +As the indicator is pushed from “air” to “N<sub>2</sub>O,” the patient +begins to inhale nitrous oxide only, but as it travels into the +numerals 1, 2, etc., a proportion of oxygen is added.</p> + +<p>Immediately below the mixing chamber is the <i>expiratory +valve</i>.</p> + +<p>(5) Lastly, there is the <i>facepiece</i>, identical with that +used for pure nitrous oxide.</p> +</div> + +<p>It would be fallacious to suppose that the numerals 2, etc., on the +dial represent accurately the percentage of oxygen yielded by the +instrument when the indicator points to one of these figures, nor +did Hewitt ever make such a claim. What the figures do represent is +a number of holes in the wall of the mixing chamber, opposite to the +aperture from the oxygen bag, which are uncovered one by one as the +indicator moves over. The amount of oxygen which enters into the mixing +chamber is regulated by the number of these holes uncovered, and also +by the tension of the oxygen bag. If the figure on the dial is to be +even a rough index of the actual percentage of oxygen present in the +mixture, it is necessary<span class="pagenum" id="Page_65">[65]</span> to keep the tension reasonably constant, +<i>i.e.</i> to regulate the flow of oxygen from the cylinder by +manipulation of the foot key. In a brief administration for, say, +a dental case, this is not necessary. It is sufficient to fill the +oxygen bag once, and then turn off the supply. If, however, a long +administration is required, a constant flow of oxygen of just the +requisite amount must be secured.</p> + + +<h3><b>Administration.</b></h3> + +<p>Put the lever at “air,” and fill up each bag to an equal and moderate +degree of distention. Adapt the facepiece accurately to the patient’s +face, and then push the lever to “N<sub>2</sub>O”. After a few inhalations, +move to 2 of oxygen; regulate the flow of nitrous oxide from the +cylinder so that the N<sub>2</sub>O bag remains slightly distended. Gradually +move the indicator along the numerals until the figure 6 or 8 is +reached at the end of about a minute or a minute and a half. Women and +children require more oxygen than men. The former are easily cyanosed; +if the latter are fed too generously with oxygen, they are apt to +become excited. Take as your guide to the amount of oxygen required the +colour of the patient, the type of respiration, and the size of the +pupil.</p> + +<p>The <i>colour</i> aimed at can only be learnt by experience, but is +best described as a dull pink.</p> + +<p><i>The Type of Respiration.</i>—Too little oxygen leads to stertor and +even stridor; too much oxygen, to a light almost noiseless respiration, +which to the experienced ear is the certain precursor of a stage of +excitement. Such a stage is clear evidence of too much oxygen having +been given.</p> + +<p><i>The pupil</i> should not be dilated to anything like the degree +seen with undiluted nitrous oxide. A moderate distention only is to be +desired.</p> + +<p><i>Full Anæsthesia</i> should be reached in 100–120 seconds. It is +marked by:—</p> + +<p><span class="pagenum" id="Page_66">[66]</span></p> + +<div class="blockquot"> + +<p>(1) Dull pink complexion; (2) full respiratory movements with +a stertor not exceeding that of gentle snoring; (3) eyeballs +rotated downwards; (4) moderately dilated pupils; (5) loss of +conjunctival reflex; (6) corneal reflex present but not very +active.</p> +</div> + +<p>If the object be the removal of a tooth, the mask may now be removed, +and the dentist may rely upon a period of anæsthesia somewhat longer +than that furnished by pure nitrous oxide. He ought to secure +approximately one minute in which to do his work.</p> + +<p>Anæsthesia by this apparatus may however be prolonged for an +indefinite time if desired. In order to maintain the patient in the +condition described above, it will be necessary gradually to increase +the supply of oxygen. For this purpose Hewitt added to his mixing +chamber a supplementary oxygen supply giving 10 or 20 volumes of +oxygen. As a matter of fact, all the necessary supply can be got +through the original ten holes <i>if the tension in the oxygen bag +be increased</i>. The regulation of all this requires, of course, +considerable practice and experience.</p> + +<p>The signs upon which we rely for warning that the supply of oxygen is +insufficient to keep the patient safe, are chiefly the colour of the +face, which must not pass from dull pink to blue, and the size of the +pupil.</p> + + <div class="figcenter" id="i_p067" style="max-width: 750px"> + <img + class="p1" + src="images/i_p067.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 19.</span>—Diagrams to illustrate action of (A) +Hewitt (B) Teter gas oxygen apparatus. Note that in A the mouths of +both bags are guarded by valves of inspiration, while in B the oxygen +bag only possesses it.</p> + </div> + + +<h3><b>Deficiencies of Hewitt’s Apparatus.</b></h3> + +<p>These are chiefly two:—</p> + +<div class="blockquot"> + +<p>(1) There is no means of producing <i>positive pressure</i>. Any +attempt to distend the nitrous oxide bag beyond a certain point +simply leads to escape of the gas through the mixing chamber and +out of the expiratory valve even during inspiration. To this +defect especially must we attribute the fact that an anæsthesia +deep enough for abdominal section is difficult to secure with +the Hewitt instrument.</p> + +<p><span class="pagenum" id="Page_68">[68]</span></p> + +<p>(2) There is no means of securing <i>re-breathing</i>. The whole +administration must of necessity be conducted “upon the valves.” +This latter fault is remedied by the modification introduced by +<i>Burns</i>, who took away the inspiratory valve from the mouth +of the N<sub>2</sub>O bag, and fitted a cap over the expiratory valve +which could be rotated so as to throw the valve out of action. +The author first met this modification at a Base Hospital in +France, and found it a great improvement upon the original +instrument. It is, however, only an imperfect attempt to adopt +Teter’s chief principle.</p> +</div> + + +<h3><b>The Teter and Allied Machines.</b></h3> + +<p>The rapid spread of nitrous oxide and oxygen anæsthesia in the +U.S.A. brought forward a number of machines of which Teter’s was the +forerunner; the other well-known machine of the group is the Clarke. +They differ in principle from the Hewitt apparatus in that they permit +re-breathing and the use of positive pressure. Diagrammatically, the +two are contrasted in Fig. 19.</p> + + <div class="figcenter" id="i_p068" style="max-width: 583px"> + <img + class="p1" + src="images/i_p068.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 20.</span>—Details of the Clarke Expiratory +Valve. In the position of the lever marked “open” the valve lifts +easily and widely, and the breathing will be purely valvular: in the +position marked “half open,” the valve lift is diminished, and the +breathing is partly valvular, partly to-and-fro. In the position +“closed” re-breathing only is possible.</p> + </div> + +<p>The key to Teter’s advance is his removal of the inspiratory valve from +the mouth of the nitrous oxide bag, and his substitution for Hewitt’s +rubber expiratory valve, of a <i>rigid</i> valve, the lift of which +can be diminished or entirely abolished, at will (<i>see</i> Fig. +<a href="#i_p068">20</a>). By damming, as it were, the flow from the expiratory valve, the +administrator can oblige the patient to practise a certain amount of +re-breathing, and, if he keeps up a free flow of the gases, he<span class="pagenum" id="Page_69">[69]</span> can +develop a pressure in the nitrous oxide bag definitely exceeding that +of the atmosphere.</p> + +<p>Teter also introduced into his apparatus a means to warm the gases, and +to add a little ether vapour to the mixture when required.</p> + + <div class="figcenter" id="i_p069" style="max-width: 326px"> + <img + class="p1" + src="images/i_p069.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 21.</span>—The Clark gas oxygen machine.</p> + </div> + +<p>The Clarke machine is similar in principle to the Teter, but makes a +strong point of the intimate mixture of the two gases produced in the +mixing chamber which occupies the centre of the apparatus (Fig. 21).</p> + +<p><span class="pagenum" id="Page_70">[70]</span></p> + +<p>In both these machines, it will be observed, the two bags for N<sub>2</sub>O +and O<sub>2</sub> respectively are attached to the stand, and the mixed gases +are led to the patient by a pipe of wide bore. When re-breathing +occurs, it must therefore be up and down this pipe, but the width of +the bore seems to obviate any disadvantage which theoretically might be +expected from this form of respiration.</p> + + <div class="figcenter" id="i_p070" style="max-width: 474px"> + <img + class="p1" + src="images/i_p070.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 22.</span>—Marshall’s sight-feed gas-oxygen +apparatus. Of the two glass bottles the one to the left is the +sight-feed, that to the right the ether chamber.</p> + </div> + +<p>In the experience of the author and of many other anæsthetists, very +good results can be obtained from either of these machines.</p> + + +<h3><b>Sight Feed Machine.</b></h3> + +<p>In the author’s opinion, machines based upon this principle are likely +to take a prominent place in the future of gas-oxygen.<span class="pagenum" id="Page_71">[71]</span> Fig. 22 +explains the simple mechanism. Each gas is led through a tube dipping +into water contained in the sight feed mixing chamber. The ends of +the pipes are open, and on the sides of each pipe also are a number +of holes. If the pressure at which either gas is delivered is small, +bubbles will be seen ascending towards the surface of the water from +the upper holes only. The greater the pressure, the further down the +pipe does the gas carry before all of it escapes through a hole, and +one can therefore get an accurate estimate of the pressure from the +number of holes through which the bubbles are seen escaping.</p> + +<p>Upon the surface of the water, the two gases meet and enter into +mixture and are conveyed away by the third pipe which, of course, does +not dip into the water.</p> + +<p>Once the eye of the anæsthetist is trained to its use, this is a very +simple means of gauging the relative proportions of oxygen and nitrous +oxide which are being delivered, and manipulation of the cylinder heads +combined with visual inspection of the sight feed enable one to strike +the right proportions very easily. The nitrous oxide is usually kept at +a constant pressure sufficient to ensure bubbles, not only from all the +side holes, but also a few from the open end of the tube. The oxygen +pressure is begun at the point where there is a little bubbling from +the top hole only, and is gradually increased until there is a full +supply from two holes, occasionally a little even from a third.</p> + +<p>Messrs Coxeter have recently brought out two sight feed machines +designed by Mr Leonard Boyle and Dr Geoffrey Marshall, of which the +latter is shown in Fig. 22. This apparatus may be put up in either +portable form or a larger type for use in hospitals. An ether chamber +is provided for use when necessary in either type.</p> + +<p>As originally introduced, the remainder of the apparatus consisted +simply of an ordinary two gallon bag, Barth 3-way tap, and rubber +facepiece. With such an appliance, it is not possible<span class="pagenum" id="Page_72">[72]</span> to secure +“positive pressure, a point which the author brought to the notice +of the makers. Messrs Coxeter are willing to supply a facepiece and +expiratory valve which obviate this defect, being supplied with a mica +expiratory valve the lift of which can be controlled. There should be +no inspiratory valve.</p> + + +<h3><b>Administration of Gas-oxygen for the purposes of Major Surgery.</b></h3> + +<p>The patient is prepared with the same scrupulous care as if ether +or chloroform is to be administered. Half an hour before operation, +morphia gr. ⅙ and atropine gr. ¹⁄₁₀₀ are given hypodermically. The +anæsthetist before beginning administration, must look over the +apparatus most carefully and satisfy himself that every part of it is +in perfect order, and that a sufficient supply of both gases is at hand.</p> + +<p>The inhalation is begun by the use of nitrous oxide alone, given “on +the valves,” and at no great pressure. After a few breaths, oxygen +is added very guardedly, the proportion being steadily raised during +the first two minutes: after that point, a further increase will not +be necessary until several more minutes have elapsed. The pressure at +which the mixture is being given is also steadily increased and should +reach the maximum permissible within a few minutes. A useful plan +is to allow the flow of gases to remain constant, but to close the +expiratory valve at frequent intervals for about forty to sixty seconds +at a time. During this period of complete re-breathing the tension in +the supplying bag will of course rise, falling again slightly when the +expiratory valve is allowed once more to come into action. As soon as +the tension falls appreciably, the valve is again closed down.</p> + +<p>It is wise, particularly in one’s early days, to give a trace of ether +vapour during the latter part of the induction stage, and to maintain +it until the operation is well under way. Once the<span class="pagenum" id="Page_73">[73]</span> anæsthetist is +satisfied that the narcosis is proving deep enough for the purposes +of the operation, the ether may be shut off and will probably not be +required again.</p> + +<p>Remember that <i>depth</i> of anæsthesia can be secured in three +ways—(1) cutting down the oxygen percentage; (2) increasing the +tension of the mixed gases; (3) adding a little ether. Of these, No. 1 +is most undesirable, and if carried to the least excess over a period +of more than a minute or two may lead to an accident. No. 3 is the +means for the beginner to rely upon, until he learns the judicious +and skilful use of No 2. The anæsthetist who is learning the method +of anæsthesing must resolve that nothing shall tempt him to overstep +the stage of dull pink colour, and moderate pupils. If with gas-oxygen +alone, he cannot get a satisfactory anæsthesia without resorting to +oxygen starvation, let him not be ashamed to turn on his ether.</p> + +<p>Abdominal relaxation sufficiently complete to permit the surgeon to +explore the abdominal cavity with ease, is not readily secured by +gas-oxygen in a patient of robust type. Fortunately, it is the weakly +or the severely shocked who really <i>need</i> this form of anæsthesia, +and in them abdominal relaxation is fairly easily obtained.</p> + +<p>Professor Crile, as has already been explained, does not rely upon +the inhalational anæsthetic alone. He infiltrates each layer of the +parietes with novocain, thus producing a local anæsthesia. If this +method be faithfully carried out by the surgeon, a most complete +relaxation of the muscles can be secured.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_74">[74]</span></p> + +<h2>CHAPTER IX.<br> +<span class="subhed"><b>ETHER.</b></span></h2></div> + +<p>The drug commonly known as ether and otherwise described as ethylic +ether or sulphuric ether, has a chemical formula (C<sub>2</sub>H<sub>5</sub>)<sub>2</sub>O. +It is a transparent colourless fluid with a specific gravity of ·720 +to ·723. A brand much used in the States has an S.G. of ·713 only, a +point which is greatly emphasised by its supporters, who claim that it +volatises quicker and therefore is more powerful in action. The author +has in actual practise not found much difference between this brand and +any good British one.</p> + +<p>Ether is highly inflammable and volatilises readily at ordinary +room temperatures. Its boiling point is 96° to 98° Fahr. Whether +evaporating from a fabric such as gauze, or from bulk in a jar, ether +cools very rapidly, and the fall in temperature soon reduces the +ease of its volatisation. This point is of some practical importance +in anæsthetics, and some years ago the author made a number of +observations, hitherto unpublished, with a view of ascertaining some +definite facts in this connection. His results will be found in +Appendix <span class="allsmcap">I</span>.</p> + +<p><i>Ether vapour</i> is heavy—two and a half times heavier than air. +It therefore tends in a room to flow towards the floor, and to remain +for some time unmixed with the general atmosphere. Since it is highly +explosive, this constitutes a definite danger if any naked light or +open fire is present. Everyone who handles ether should bear in mind +these physical peculiarities of its vapour.</p> + +<p>Ether is affected by prolonged exposure to bright sunlight, and also by +prolonged bubbling through it of air, nitrous oxide, or oxygen. Ether +which has been subjected to any of these<span class="pagenum" id="Page_75">[75]</span> measures should be inspected +before being put back into reserve, and if any brown discoloration +is noticed, it should either be sent to the hospital laboratory for +redistillation, or presented to the theatre sister for use as a +cleaning agent. Such contributions are always gratefully received.</p> + +<p>Most of the ordinary impurities of ether are acid in reaction, while +ether itself is absolutely neutral. Any specimen which turns litmus +paper red should be sent to the laboratory for examination.</p> + + +<h3><b>Sources of Supply.</b></h3> + +<p>Ethylic alcohol may be prepared either from ethyl alcohol or from +methylated spirits. In the former case it carries, however, the cost +of the duty imposed upon potable spirit, and since perfectly good +anæsthetic ether can be prepared from the latter source, it is waste of +money to use the more expensive article.</p> + + +<h3><b>Physiology.</b></h3> + +<p>Ether acts upon the nervous system like other anæsthetics: as compared +with chloroform, however, the stage of excitation of each centre +before its paralysis is apt to be marked. There is, therefore, in some +subjects, a greater tendency to struggle; healthy subjects properly +handled do not show much evidence of irritation of the cerebrum. All, +however, show some evidence of stimulation of the respiratory centre, +which is not prolonged. <i>Prolonged deep and rapid respiration under +ether is due to other causes than the action of the drug itself.</i> It +is of course seen in “closed ether,” but the active agent is excess of +CO<sub>2</sub>, not ether.</p> + +<p>The working margin of safety in ether, <i>i.e.</i> the stage between +loss of spinal reflexes and the poisoning of respiratory centre is much +wider than in chloroform.</p> + +<p>Some experiments of Waller made many years ago showed that upon nerve +tissue, ether acts much less powerfully than chloroform: in the +proportion, he found, of one to seven or eight.<span class="pagenum" id="Page_76">[76]</span> These laboratory +results have received entire confirmation by later workers who have +estimated the actual vapour strength required of either drug to produce +or maintain anæsthesia. Roughly, to induce anæsthesia, we require 2 per +cent. chloroform, or 16 to 18 per cent. of ether (<i>see</i> Appendix +II.).</p> + + +<h3><b>The Circulation.</b></h3> + +<p>The first effect of ether is a temporary stimulation of the heart, +which beats more rapidly and more strongly, thus raising the blood +pressure. This effect is not very prolonged; like all other drug +stimulation, it is followed by depression. In the healthy subject +properly anæsthetised, such depression is very moderate in degree, and +in a normal administration it is probable that the heart, after the +first few minutes, is acting very much at its normal speed and force. +Ether is, however, a marked vaso-dilator, and the net result upon blood +pressure is a slight fall after the first few minutes.</p> + +<p>If the method in use is “closed,” the pressure remains slightly raised +for some considerable time, usually throughout the administration. The +slight anoxaemia induces a vaso-constriction; and the CO<sub>2</sub> excess, in +the view of Henderson (<i>see</i> page <a href="#Page_10">10</a>), maintains a good return of +venous blood to the heart and a satisfactory cardiac output. For a note +of certain blood changes resulting from ether and other anæsthetics +(<i>see</i> Appendix III.).</p> + + +<h3><b>Respiratory System.</b></h3> + +<p>In addition to the effect upon the medullary centre already referred +to, ether effects the respiratory tract more profoundly than other +anæsthetics. The mucous membranes are irritated, and in some cases +there is a great outpouring of mucous. Though usually limited to the +upper part of the tract (nose, pharynx, and trachea), the irritation +sometimes extends deeply into the chest, affecting even the small +bronchioles. These unpleasant effects of<span class="pagenum" id="Page_77">[77]</span> ether are in the great +majority of cases, quite transient: after the first ten minutes no +addition to the secretions is noticed. In a minority, however, the +effect persists, the whole chest is filled with moist sounds, and +persistence with the drug is impossible.</p> + +<p><i>The kidneys</i> are always slightly irritated by ether, and if they +are or recently have been subject to inflammatory disease, a very acute +exacerbation is apt to follow the use of the drug. In the healthy +kidney this is not to be feared, nor does it seem to be an appreciable +danger where one kidney is sound, even if the other is the seat of +gross organic disease necessitating its drainage or removal.</p> + + <div class="figcenter" id="i_p077" style="max-width: 277px"> + <img + class="p1" + src="images/i_p077.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 23.</span>—Clover’s ether inhaler, with nitrous +oxide attachment.</p> + </div> + + +<h3><b>Methods of Administration.</b></h3> + +<p>Many methods have been tried, but those which at present hold the field +are—</p> + +<div class="blockquot"> + +<p>(1) Closed Ether.</p> + +<p>(2) Open Ether, more properly called the Perhalation Method.</p> + +<p>(3) The “Vapour” Method.</p> + +<p>(4) The Rectal Method (Gwathmey’s oil-ether).</p> + +<p>(5) The Intratracheal Method, described separately in Chapter +<span class="allsmcap">X</span>.</p> +</div> + +<p><span class="pagenum" id="Page_78">[78]</span></p> + + <div class="figcenter" id="i_p078" style="max-width: 495px"> + <img + class="p1" + src="images/i_p078.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 24.</span>—Diagram of a vertical section through +the middle of Clover’s Inhaler. A. shows the ether dome; B. Central +tube removed from apparatus.</p> + </div> + + +<h4>(1) <b>Closed Ether.</b></h4> + +<p>The two inhalers originally brought out for this were Clover’s in +London, and Ormsby’s in Dublin. At a later date Hewitt’s “wide bore” +modification of the Clover was introduced.</p> + +<p>(<i>a</i>) <i>The Clover instrument</i> (see Fig. <a href="#i_p077">23</a>)<a id="FNanchor_4" href="#Footnote_4" class="fnanchor">[4]</a> consists +of a face-piece, a dome-shaped ether chamber, and a one-gallon bag, +usually attached to the top of the ether chamber by a <b>T</b>-shaped +tube. The details of the method by which the amount of ether inhaled +by the patient is graduated are best appreciated by unscrewing the<span class="pagenum" id="Page_79">[79]</span> +milled head at the top of the dome, and withdrawing the tube which runs +through it (<i>see</i> Fig. <a href="#i_p078">24</a>). In the tube will be found two slots, +one about half an inch above the other, and each extending for half the +circumference of the tube. Between these two slots the tube is divided +by a diaphragm. In any case, therefore, air passing up or down the tube +must pass in and out of these slots.</p> + +<p>Now turn to the tubular space left in the dome piece, and examine +visually and with the finger its interior. On the one side of its +middle will be found two slots leading into the circular ether chamber +which occupies a large part of the dome. On the other side will be +found a small cavity, as deep from above downwards as the two slots +combined, but <i>not</i> communicating with the ether chamber. It is +obvious that with the tube inside, if this cavity is opposite the slots +in the tube, air will pass up the tube out of one slot and back into +the other, without coming into contact with the ether at all. If on the +other hand the slots in the tube are opposite the slots in the ether +chamber, the air passes over the surface of the contained ether, and +volatises some of it.</p> + +<p>Intermediate positions of the tube give a condition where part only +of the air passes over the ether. The indicator attached to the tube, +combined with the figuring “O, one, two, three, full,” to be found +on the outside of the base of the dome, shows at any moment what +proportion of the air is passing into the ether chamber.</p> + +<p>To use the instrument, fill the metal measure provided with ether, +withdraw the stopper from the ether chamber, and pour in the ounce +and a half of ether which the measure contains. Replace the stopper, +and blow through the tube to expel any ether vapour which may have +appeared in it. Leave the rubber bag at first unattached: the patient +will feel more comfortable if during the first minute the top of the +tube is open. With the indicator at 0 adapt the face-piece to the face +and allow<span class="pagenum" id="Page_80">[80]</span> the patient to breathe up and down the tube. By rotating +the dome, ether is then gradually turned on, until the figure two +is reached in the first minute. The indicator is then slipped back +nearly to zero for a second, and the rubber bag slipped on during +an <i>expiration</i>: it must be moderately inflated to supply the +requisite volume of air for respiration.</p> + + <div class="figcenter" id="i_p080" style="max-width: 379px"> + <img + class="p1" + src="images/i_p080.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 25.</span>—Hewitt’s wide-bore ether inhaler.</p> + </div> + +<p>The rotation of the dome is again begun and the indicator is made to +travel away from the zero, until at the end of about five minutes, it +reaches “full.” After the first few minutes, it will be necessary to +give an occasional breath of fresh air, otherwise an undesirable degree +of cyanosis will result, but it must be done with great discretion, or +struggling will ensue. At the end of about five minutes, anæsthesia +should be fully established. A<span class="pagenum" id="Page_81">[81]</span> little extra ether is then poured +into the chamber, the indicator pushed back to about “two” and the +administration continued. One breath of fresh air is given in every +three or four. Spells may be given with the bag off altogether, but +during such periods the indicator will require to be advanced a little, +and refills of ether provided more frequently than would be necessary +if the bag were on.</p> + + +<h5><b>Hewitt’s-wide-bore.</b></h5> + +<p>The principle of this is identical with that of the Clover, but the +channels being wider, there is less mechanical interference with the +ingress and egress of air. The actual construction differs also, in +that to turn on the ether, instead of rotating the dome, one moves the +indicator (<i>see</i> Fig. <a href="#i_p080">25</a>). The instrument certainly gives results +a little better than those obtainable by the Clover, but it is heavier, +and rather more bulky.</p> + + +<h5><b>Ormsby’s Inhaler (<i>See</i> Fig. <a href="#i_p081">26</a>).</b></h5> + +<p>This consists of a facepiece, a cage made of wire or thin steel slips +and containing a sponge; and lastly, a one gallon bag which fits +over the cage. In the face-piece is an air vent, which can be either +entirely closed, partially or entirely opened.</p> + + <div class="figcenter" id="i_p081" style="max-width: 298px"> + <img + class="p1" + src="images/i_p081.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 26.</span>—Ormsby’s Inhaler. The cage for the +sponge does not show in the figure, it projects upwards from the +bag-mount, and is therefore enclosed in the bag.</p> + </div> + +<p>To use the instrument, take out the sponge and warm it either by +wringing it out of hot water, or better by leaving it a few minutes on +the top of a hot steriliser. Push it back into the<span class="pagenum" id="Page_82">[82]</span> cage, open the air +vent fully, and holding the inhaler upside down, pour on to the sponge +a measure full (about half an ounce) of ether. Tell the patient to +inhale deeply, and then catch the resulting expiration in the bag by +quickly adapting the facepiece to the face at the appropriate second.</p> + +<p>After a few seconds, begin to close the air vent, when it will be +found that the bag begins to wax and wane with each expiration and +inspiration respectively. After the first three minutes, the inhaler +must be removed, more ether poured in, the air vent opened again +partially, and the inhaler again applied to the face. After full +anæsthesia is induced, the air vent may constantly be left partially +open.</p> + +<p><i>N.B.</i>—It must be observed that the air vent is not valved: it is +merely an opening through which part of the respired air may pass in +and out without going near the ether sponge.</p> + +<p>In actual practice, the induction stage of closed ether is almost +invariably assisted by using either nitrous oxide, or a small dose of +ethyl chloride as a preliminary: these methods are described in Chapter +<span class="allsmcap">XV</span>.</p> + +<p>The question now arises, what <i>scope</i> is to be assigned in modern +anæsthesia, to closed-ether methods. Formerly a large proportion of +anæsthesias, long or short, were conducted by the closed method, and +while the greater number of anæsthetists no longer utilise them to the +same extent as formerly, they may still be regarded as of the utmost +value in a limited class of cases. They are speedy in action, powerful +enough to overcome the most refractory patient, and with reasonable +skill very safe. On the other hand, the anæsthesia obtained is not +of the most desirable type. There is a great deal of salivation and +mucous secretion from the respiratory mucous membranes; the respiratory +movements are deeper than in open methods, from the excess of CO<sub>2</sub> +present in the blood, and this leads to a good deal of heaving of +the abdominal wall, which may<span class="pagenum" id="Page_83">[83]</span> be most troublesome to the surgeon +if he is opening or closing that cavity. Moreover, after their use +more headache, malaise, and vomiting occur than after open-ether, and +perhaps a little more tendency to bronchitis or pneumonia. For these +reasons, many anæsthetists and surgeons now object to their use in +abdominal surgery, though some still adhere to them for the induction +stage, passing to the open method when the patient is once well under.</p> + + +<h4><b>(2) Open Ether.</b></h4> + +<p>As already explained the strictly accurate term for this is +Perhalational Ether, but so cumbersome a terminology stands small +chance of general acceptance.</p> + + +<h5><b>Apparatus.</b></h5> + +<p>The essential points in a proper outfit have already been explained +(<i>see</i> page <a href="#Page_28">28</a>) and are all well met by the mask and ether dropper +introduced by Mr Bellamy Gardner (<i>see</i> Fig. <a href="#i_p083">27</a>). The mask is +covered with from twelve to sixteen layers of gauze, and lies on the +gauze ring, shown in the Fig. <a href="#i_p084a">28</a><span class="allsmcap">A</span>, which completes the fit +between face and facepiece. The dropper fits into the ordinary six +ounce dispensary bottle: the long arm dips into the ether, the short +one allows air to enter the bottle to replace the ether used. A dropper +can also be improvised by<span class="pagenum" id="Page_86">[86]</span> using a cork with slots cut at each side +and with a gauze or wool wick inserted along one of these. The author +finds these uncertain in their action, however: with Gardner’s dropper, +a steady flow of <i>drops</i> of ether slow or fast as required, can +always be obtained once the student has acquired the knack of using the +appliance.</p> + + <div class="figcenter" id="i_p083" style="max-width: 650px"> + <img + class="p1" + src="images/i_p083.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 27.</span>—Bellamy Gardner’s (<span class="allsmcap">A</span>) open +ether mask; (<span class="allsmcap">B</span>) ether dropper.</p> + </div> + + <div class="figcenter" id="i_p084a" style="max-width: 402px"> + <p class="p1 center smaller"><span class="smcap">Fig. 28.</span></p> + <img + class="p0" + src="images/i_p084a.jpg" + alt=""> + <p class="p0 center smaller"><i>A.</i>—Open ether. Ready to begin.</p> + </div> + + <div class="figcenter" id="i_p084b" style="max-width: 367px"> + <img + class="p1" + src="images/i_p084b.jpg" + alt=""> + <p class="p0 center smaller"><i>B.</i>—Open ether. Condensing towel in position.</p> + </div> + + <div class="figcenter" id="i_p085a" style="max-width: 401px"> + <img + class="p1" + src="images/i_p085a.jpg" + alt=""> + <p class="p0 center smaller"><i>C.</i>—Open ether. Correct method of holding mouth and jaw.</p> + </div> + + <div class="figcenter" id="i_p085b" style="max-width: 467px"> + <img + class="p1" + src="images/i_p085b.jpg" + alt=""> + <p class="p0 hangingindent smaller"><i>D.</i>—Open ether. Alternative method of holding mask. The +towel and gauze have been removed so as to show the tilting of +the mask which this method is liable to cause.</p> + </div> + +<p>To Mr Bellamy Gardner’s outfit, the author adds a folded towel, pinned +at one corner, so as to form a short cone. The base of this cone +embraces the mask and face; through its upper apperture the anæsthetic +is dropped on to the mask. The cone can be rotated into the position +most convenient for this purpose in any given position of the patient’s +head (Fig. 28).</p> + + +<h5><b>Problems of the Induction Period.</b></h5> + +<p>Open-ether is not a powerful anæsthetic, just not powerful enough for +one to be sure that one can induce full anæsthesia with it alone, in a +powerful subject. The reason for this is shown in Appendix II, and may +be here condensed by explaining that some 18 per cent. to 20 per cent. +of ether vapour is required to induce anæsthesia, while it is not easy +to get more than 14 per cent. off an open mask. How is this situation +to be met?</p> + +<p>Reference has already been made to one solution of the problem. <i>A +closed ether method may be used for induction</i>, and this practice is +widely used. The author does not often adopt this course, fearing that +the undesirable features of closed ether may persist even after the +change to an open method has been made.</p> + +<p>Another possibility even more widely favoured is to use <i>chloroform +as the inducing agent</i>, and only to turn to ether when full +anæsthesia is obtained. To this plan the author is strongly opposed. It +exposes the patient to the risks of the induction stage of chloroform +which are much greater than those of the later stages. Moreover, to +develop the full advantages of open-ether, a preliminary hypodermic +of morphia is essential, and the<span class="pagenum" id="Page_87">[87]</span> drawbacks of chloroform <i>plus</i> +morphia are elsewhere mentioned (page 43).</p> + +<p>The use of a <i>mixture of chloroform two parts, ether three parts</i>, +presents the same disadvantage, but in a degree so much smaller that +in powerful or alcoholic patients, the author believes this to be the +method of choice (<i>see</i> Chapter xiv.).</p> + +<p><i>Dr Silk</i> has recently suggested another plan. He has sought to +make open-ether easy for the non-expert with a view of encouraging the +wider use of so valuable a method. For this purpose he advocates the +admixture of one part of chloroform in thirty-two of ether (a dram of +chloroform in four ounces of ether). This is to be given in exactly the +same way as perhalational ether, and will, Silk says, give a type of +anæsthesia, and a degree of safety, identical with those of pure ether. +The author’s experience with Silk’s mixture is too limited to enable +him to offer any opinion upon its merits.</p> + +<p>Lastly, there remains the plan of using <i>ether as the main inducing +agent</i>, but assisting its action by the intermittent and most +guarded addition of small quantities of C<sub>2</sub>E<sub>3</sub> mixture. This is +the author’s “stock” method; but in teaching it to students, too +much emphasis cannot be laid upon the small quantities of chloroform +mixture required or <i>permissible</i>. <i>As a consequence of the +perhalational method here advocated, every drop of chloroform which +appears on the mask will when volatilised, give a very much higher +percentage of CHCL<sub>3</sub> vapour in the inspired air, than the same +quantity exhibited on the ordinary open chloroform mask.</i> Once the +student has grasped this essential fact, ordinary care and intelligence +will enable him to guard against a danger which is only existent if +unappreciated.</p> + + +<h5><b>The Administration.</b></h5> + +<p>For many of the hints given in this section the author is<span class="pagenum" id="Page_88">[88]</span> indebted to +Dr W. J. Ferguson of New York, and Dr Hornabrook of Melbourne.</p> + +<p>Success in inducing with open-ether is attained only by attention to a +number of small details. The student who thinks that some of these are +too trifling for his notice is usually the man who informs you that +induction by open-ether is impossible, the fact really being that he +has not taken the trouble to learn, or has never had proper tuition. +The following are the points demanding attention:—</p> + +<div class="blockquot"> + +<p>1. Always give a dose of morph-atropine or other narcotic, half +to three-quarters of an hour beforehand.</p> + +<p>2. See that the patient is comfortable on the table. Prop up his +head and shoulders a little with pillows. In powerful subjects +Hornabrook tilts the whole table down at the foot-end, for a few +degrees.</p> + +<p>3. Adhere strictly to perhalation and to the drop method. You +will never induce with open-ether if the whole volume of the +respired air does not pass through the gauze.</p> + +<p>4. Chat to the patient as long as consciousness can possibly +persist. Tell him he is doing very well. Don’t shout complicated +instructions at him as to how to breathe: it annoys and muddles +him.</p> + +<p>5. When the gauze ring and the mask are in position, allow one +or two drops of ether to fall on the mask, then pause: in a few +seconds the mild ether vapour so formed will soothe the upper +respiratory tract, and prepare it for the stronger vapours yet +to come. This does not waste time—it saves it.</p> + +<p>6. When the administration is again begun, attend closely to +the rate of dropping. At first not more than one drop in three +or four seconds is wanted. The full rate of dropping cannot be +attained for at least ninety seconds.</p> + +<p>7. Give no mixture for the first ninety seconds; thereafter some +five to ten drops every half minute or every twenty seconds<span class="pagenum" id="Page_89">[89]</span> +according to type of patient. Have the mixture bottle handy so +that no time is wasted in changing bottles. Stop the addition of +mixture as soon as full anæsthesia is attained.</p> + +<p>8. Slip the folded towel over the mask and tuck its base well +round the chin and face. Do this only after the first two +minutes have elapsed.</p> + +<p>9. As soon as the neck muscles are relaxed, turn the patient’s +head over to one side, and let the hands assume the position +described in Chapter iii. and illustrated in Fig. 28<span class="allsmcap">C</span>.</p> + +<p>10. The student is warned to discourage the too early attentions +of the nurse or house-surgeon. These officials are naturally +anxious to “get the patient ready for the Chief” and are +apt to start “cleaning up” before the patient has lost all +consciousness. A man who is doing his level best to go to sleep, +derives neither pleasure nor profit from a wholly unexpected dab +of ice-cold methylated spirit upon his umbilicus.</p> +</div> + +<p>By the use of the method here advocated, induction is singularly easy +and successful in good subjects. The struggling stage is either not +represented at all, or appears only in the form of the lifting of +a limb and a slight occasional pause or catch in respiration. Full +anæsthesia is often announced audibly, by the commencement of a gentle +“blowing.” Once it is heard, the anæsthetist may rest assured that a +workable level of anæsthesia is either present or not far off.</p> + + +<h5><b>Amounts of Ether required.</b></h5> + +<p>If the above instructions are followed, the amount of ether required +is not excessive. Anæsthesia is attained after the use of about 1½ to +2 ounces of ether and one or two drams of mixture. The next forty to +fifty minutes demand about another four or five ounces of ether; no +mixture at all. Some practice, is required before these small figures +are attained. The more practice, the less ether is required.</p> + +<p><span class="pagenum" id="Page_90">[90]</span></p> + + +<h3>III.—<span class="smcap"><b>Vapour Anæsthesia.</b></span></h3> + +<p>In a sense, all forms of ether anæsthesia are vapour methods, but +in all the forms so far described, the patient has to vapourise the +drug for himself: in a true vapour anæsthesia this is done for him, +and the mixture of air and ether vapour propelled towards him. One +of the keenest advocates of this method is Dr Gwathmey, of New York. +He lays great stress also upon the necessity of warming the vapour, +claiming that this measure will prevent the loss of heat to the patient +incidental to the warming up in the air passages of the cold vapour +usually supplied by other methods; but the results of the laboratory +experiments upon which Gwathmey founded his case are inapplicable to +the human subject, in that they were performed upon dogs and cats, +which lose heat largely from the mouth and air stream. Man is not a +hairy animal, and transacts most of his thermolysis through the medium +of his skin. None the less, warming the vapour of ether has value since +the process removes some of the irritant effects so marked in the case +of cold ether vapour.</p> + + +<h4><b>Apparatus for the Vapour Method.</b></h4> + +<p>In 1913, Karl Connell described such an apparatus, which was then in +use at the Roosevelt Hospital, New York. The ether was vapourised by +dropping it into a warm chamber. Air was pumped into the chamber, and +carried the ether vapour in known percentage, and at known pressure as +shown by gauges. Such mechanism is ideal, but would certainly be rather +costly. Its great value was that it informed us with certainty what +proportions of ether in the atmosphere were necessary to induce and +maintain anæsthesia (<i>see</i> Appendix II.).</p> + +<p>A simple mechanism was brought out shortly afterwards by Dr Shipway, of +Guy’s, and is known as Shipway’s warmed Ether.</p> + +<p>It consists essentially of the following parts (<i>see</i> Fig. <a href="#i_p091">29</a>):—</p> + +<p><span class="pagenum" id="Page_91">[91]</span></p> + +<div class="blockquot"> + +<p>(1) A small hand bellows (B).</p> + +<p>(2) An ether bottle, with tube for delivery of air stream +dipping deeply into the fluid: the exit tube of course does not +dip in. The bottle stands in a metal pan in which water at about +75° Fahr. is to be placed (E).</p> + +<p>(3) A thermos flask (W) in which is a metal tube (U). The +etherised air passes along this tube, and picks up heat from its +walls. The thermos is filled with water at about 180° Fahr.</p> +</div> + + <div class="figcenter" id="i_p091" style="max-width: 512px"> + <img + class="p1" + src="images/i_p091.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 29.</span>—Shipway’s warmed ether vapour +apparatus.</p> + </div> + +<div class="blockquot"> + +<p>(4) A mask upon which a towel or gauze is to be stretched: the +rubber tube bringing the air and ether is brought through the +covering material and delivers the anæsthetic vapour in the +region of the mouth.</p> + +<p><span class="pagenum" id="Page_92">[92]</span></p> + +<p>(5) Additional to the above, there may be added a small +chloroform bottle (C). In specimens of the instrument containing +this convenience, there has, of course, to be a regulating tap +(T) at the head of the ether bottle, which will divert more or +less of the air stream towards the chloroform.</p> +</div> + +<p>This little machine, somewhat resembling a cruet stand in its +appearance was widely used in France. Owing to the kindness of +the Edinburgh Red Cross Committee, one was provided for the Base +Hospital with which the author proceeded to Salonika, where he used +it extensively. The impression of it formed by himself and others +was that it was peculiarly easy to maintain with it a steady level +of anæsthesia. It had, however, no claim to banish post-anæsthetic +bronchitis and pneumonia, of which in spite of much anxious care and +thought, a fair number of cases were seen during the winter time +(<i>see</i> page <a href="#Page_151">151</a>).</p> + +<p>In using the machine, it is necessary to remember that from the +physical point of view, one is providing from the machine a small part +only of the total volume of air required by the patient.</p> + +<p>The bellows are quite small: one squeeze of the hand will not supply +more than about the equivalent in volume of one or two fluid ounces. +The larger part of the volume required by the patient has to be +obtained from the general atmosphere, so that the percentage of ether +which may be as high as 25 in the exit tube, will be greatly lowered by +the time it reaches the patient’s respiratory tract.</p> + +<hr class="tb"> + +<p>The actual strength of ether breathed by the patient will depend upon:—</p> + +<div class="blockquot"> + +<p>1. The force and frequency with which the pump is compressed. +(<i>N.B.</i> It is of course useless to pump during expiration).</p> + +<p>2. The depth of ether in the bottle.</p> + +<p><span class="pagenum" id="Page_93">[93]</span></p> + +<p>3. The temperature of the water bath in which the ether bottle +stands. The warm water should only be put in at the last moment +before starting, otherwise very strong ether vapour will collect +on the surface of the ether, and the first puff of the bulb will +expel a highly irritant vapour towards the patient.</p> +</div> + +<p>With specimens of this machine which have the addition of the +chloroform bottle, it is perfectly possible to conduct even the +induction stage of anæsthesia; a mere trace of chloroform vapour will +be sufficient. It is unnecessary to give detailed instructions for the +use of the machine. A preliminary consideration of the above physical +facts, together with a little cautious practice, will enable the +student rapidly to acquire facility with the method.</p> + + +<h3>IV.—<span class="smcap"><b>Rectal Etherisation.</b></span></h3> + +<p>For such operations as the removal of jaw or tongue there are obvious +advantages in being able to introduce ether vapour to the blood per +rectum, since the mouth and air passages are thereby left free for the +attention of the surgeon.</p> + +<p>Many years ago this was attempted by vapourising ether and propelling +the vapour through a tube high up into the rectum. This method was +abandoned, as it led to a good deal of inflammatory trouble afterwards. +Recently, Dr Gwathmey suggested a new method of utilising the rectal +route which has largely overcome this objection.</p> + + +<h4><b>Gwathmey’s Oil Ether Method.</b></h4> + +<p>This consists in passing into the rectum a mixture of olive oil and +ether. The bowel is first carefully washed out, and an hour before +operation, the patient receives a hypodermic of morphia, gr. ⅙; +atropine, gr. ¹⁄₁₂₀. A suppository of chloretone gr. v is also passed +into the rectum to act as a local sedative. Half-an-hour later, the +patient is put into the left lateral position, a soft catheter<span class="pagenum" id="Page_94">[94]</span> +attached to a funnel is passed some six inches up the rectum, and the +mixture of oil and ether poured into the funnel. It is wise to take at +least five minutes to introduce the whole dose.</p> + +<p>The following table shows the dosage required:—</p> + +<table class="smaller" style="max-width: 40em"> + <tr> + <td class="ctrtrbl">Age of Patient.</td> + <td class="ctrtrb">Strength of<br>Ether in<br>Mixture.</td> + <td class="ctrtrb">Quantity of Mixture required.</td> + </tr> + + <tr> + <td class="ctrrl">Under 6 years</td> + <td class="ctrr">50%</td> + <td class="chtr">One ounce to each 20 pounds body<br>weight (no preliminary morphia)</td> + </tr> + + <tr> + <td class="ctrrl">6 to 12 years</td> + <td class="ctrr">55% to 65%</td> + <td class="ctrr">Do.    do.</td> + </tr> + + <tr> + <td class="ctrrl">12 to 15 years</td> + <td class="ctrr">Do.</td> + <td class="chtr">One ounce to each 20 pounds body<br>weight (but use ¹⁄₁₂ gr. morphia)</td> + </tr> + + <tr> + <td class="ctrrbl">16 years and<br>upwards</td> + <td class="ctrrb">75%</td> + <td class="chtrb">One ounce to each 20 pounds body<br>weight with ⅙ gr. morphia as a<br>preliminary</td> + </tr> +</table> + +<p>In practice then, for the ordinary adult, one uses eight ounces of the +mixture, six ounces of which are pure ether. The oil and ether require +to be shaken together, but remain blended long enough for introduction.</p> + +<p>In five or ten minutes, the patient begins to feel a rather pleasing +numbness and tingling in the lower, and later the upper extremities, +and drops quietly to sleep in about twenty minutes. In a large +proportion of cases, it is necessary to deepen the anæsthesia by the +use of the open mask for a few minutes, but once a deep anæsthesia has +been thus obtained, the absorption from the rectum will balance the +loss in expiration and maintain a good anæsthesia for three quarters of +an hour at least.</p> + +<p>On return to bed of the patient, the nurse passes two tubes placed side +by side, as high into the rectum as she can; the end of a Higginson +syringe is inserted into one of them, and a considerable quantity of +soap and water is pumped gently into the bowel,<span class="pagenum" id="Page_95">[95]</span> escaping down the +second tube. The washing must be continued until all smell of ether +is removed. Finally the soapy water itself is washed away by a little +saline.</p> + +<p>Unless there be some pre-existing local inflammatory disease of the +rectum (in which case the method should not be used), there are no +unpleasant sequelæ after oil ether. The chief objection to the method +is the amount of labour thrown on the nursing staff, which is so +considerable as to bar it from adoption as a routine. This should not, +however, be allowed to prevent its use in the limited number of cases +in which it is strongly indicated. These are:—</p> + +<div class="blockquot"> + +<p>(1) Panic-struck cases who cannot face the ordeal of ordinary +methods.</p> + +<p>(2) Nose, throat, and tongue operations where intratracheal +ether is not available.</p> +</div> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_96">[96]</span></p> + +<h2>CHAPTER X<br> +<span class="subhed"><b>INTRATRACHEAL INSUFFLATION OF ETHER</b></span></h2></div> + +<p>Intratracheal insufflation consists in driving a current of air under +pressure, through a tube introduced by way of the mouth and larynx, +deeply into the trachea. The current of air which is continuous, +returns between the tube and the wall of the trachea, and escapes +through the mouth and nose.</p> + + +<h3><b>Certain Physical Considerations.</b></h3> + +<p>The work of Meltzer and Auer has demonstrated that this insufflation of +air into the trachea under adequate pressure ventilates the pulmonary +alveoli, and enables the normal diffusion of gases to be carried out +for many hours, independently of all respiratory movements. If the +air in its passage under pressure is made to pass through a chamber +containing ether, we are enabled to introduce into the pulmonary +alveoli, ether vapour of varying strength, and, by this means, to +maintain surgical anæsthesia.</p> + +<hr class="tb"> + +<p><span class="smcap">The Actual Process of External Respiration</span> consists in the +absorption of oxygen from the alveoli into the blood of the lung +capillaries, and the elimination of carbon dioxide from the lung +capillaries into the alveoli. The oxygen has to be brought from the +outside to the alveoli, and the carbon dioxide has to be conducted +from the alveoli to the outside. Between the outside and the alveoli +is the long airshaft, consisting of mouth and nose, pharynx, larynx, +trachea, bronchi and bronchioles. In natural respiration the conduction +of oxygen inwards, and of carbon<span class="pagenum" id="Page_97">[97]</span> dioxide outwards, is carried through +by a complicated pumping mechanism. In ordinary inhalation anæsthesia, +this mechanism is entrusted with the task of introducing ether vapour +into the alveoli.</p> + +<p>In intratracheal insufflation the work of this natural pumping +apparatus is taken over by an artificial mechanism. In considering the +justification for this, the following points are to be noted:—</p> + +<div class="blockquot"> + +<p>(1) The patient is unconscious—not naturally so as in +sleep—but unnaturally as the result of drugs; there is +therefore a probability that the elaborate natural mechanism +may not work smoothly—especially is there a danger that the +free airway may be interfered with. Intratracheal insufflation +obviates this danger.</p> + +<p>(2) By means of the artificial mechanism, air is brought with +some force to the mouth of the bronchi, and thus a more rapid +and more powerful diffusion of gases takes place.</p> + +<p>(3) The mechanism ensures the maintenance of a current of air +blowing forcefully from the trachea and larynx through the +pharynx, mouth and nose. This re-current continuous air-stream +effectively prevents the entrance of blood or any infectious +material into the bronchi and air cells, and thus the danger of +septic lung troubles is obviated.</p> + +<p>(4) In certain intrathoracic operations the normal respiratory +mechanism is deliberately interfered with. Intratracheal +insufflation by the constant maintenance of sufficient positive +pressure, prevents or regulates the collapse of the lung +which occurs when the thorax is opened, and thus obviates the +necessity for the somewhat elaborate positive and negative +pressure cabinets and masks which had been devised for +intrathoracic operations.</p> + +<p>(5) Incidentally it may be noted that intratracheal insufflation +of air provides us with an excellent means for performing<span class="pagenum" id="Page_98">[98]</span> +artificial respiration. Many instances have now been recorded +of its utility in this respect. Dr Elsberg records the case +of a patient who had taken morphia with suicidal intent, on +whom artificial respiration by this method was kept up for 12 +hours, without any respiratory movements taking place, recovery +ultimately ensuing.</p> +</div> + + +<h3><b>The Apparatus.</b></h3> + +<p>This consists of (<i>see</i> Fig. <a href="#i_p098">30</a>):—</p> + +<div class="blockquot"> + +<p>1. Instrument for producing air current (A).</p> + +<p>2. Ether chamber and various regulating taps (B).</p> + +<p>3. Device for warming vapour (C).</p> + +<p>4. Safety valve (D).</p> + +<p>5. Manometer (E).</p> + +<p>6. Intratracheal catheter, with rubber tubing linking up the +various parts of the apparatus (H).</p> +</div> + + <div class="figcenter" id="i_p098" style="max-width: 750px"> + <img + class="p1" + src="images/i_p098.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 30.</span> Diagram of intratracheal apparatus.</p> + </div> + +<p>1. <span class="smcap">The Air Current</span> is obtained either by means of an ordinary +glass-blower’s foot bellows, or an electric motor may actuate a +rotatory blower which produces a current of air. The blower may be made +to rotate at a speed varying from 50 to 1000 revolutions per minute +(<i>see</i> Fig. <a href="#i_p099">31</a>).</p> + +<p>The foot bellows is simple and inexpensive, and there is no reason why +it should not be efficient. The electrically rotated blower is more +efficient, ensures a smoother air current, and saves much labour.</p> + +<p><span class="pagenum" id="Page_99">[99]</span></p> + +<p>2. <span class="smcap">The Ether Chamber.</span>—Ether vapour may be produced by +either of two methods. Fig. 32 shows Kelly’s instrument where air is +blown over the surface of a considerable quantity of liquid ether. Dr +Meltzer<a id="FNanchor_5" href="#Footnote_5" class="fnanchor">[5]</a> maintains that the effectiveness of the etherization is +proportional to the diameter of the ether bottle. In this connection +it may be well to recall certain points pertinent to the subject of +etherization. A satisfactory etherization depends on the establishment +in the blood and tissues of an ether tension of definite strength. +Boothby<a id="FNanchor_6" href="#Footnote_6" class="fnanchor">[6]</a> states that this tension should correspond to about 15 per +cent. of ether vapour in the alveolar cells. “If when this tension has +been established, less than 15 per cent. ether vapour is administered, +outward diffusion occurs from the tissues and blood to the air and the +anæsthesia becomes lighter.”</p> + + <div class="figcenter" id="i_p099" style="max-width: 589px"> + <img + class="p1" + src="images/i_p099.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 31.</span>—Electric blower to supply current of +air for intratracheal anæsthesia.</p> + </div> + + <div class="figcenter" id="i_p100" style="max-width: 699px"> + <img + class="p1" + src="images/i_p100.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 32.</span> Kelly’s intratracheal apparatus.</p> + </div> + +<p><span class="pagenum" id="Page_100">[100]</span></p> + +<p>In an apparatus such as we are describing the strength of the ether +vapour depends on and is influenced by a variety of factors, among +which the following may be specially noted:—</p> + +<div class="blockquot"> + +<p>(<i>a</i>) <i>The diameter of the ether chamber.</i>—The larger +the diameter the stronger will be the ether vapour. The chamber +is generally kept two-thirds full: the less the empty space in +the chamber the stronger will be the vapour.</p> + +<p>(<i>b</i>) <i>The rapidity of the air-current.</i>—The larger +the amount of air passing over the ether the more rapid will be +the vapouration, with the result that the temperature of the +liquid ether will rapidly fall and the strength of the ether +vapour in the air will be correspondingly lowered.</p> + +<p>(<i>c</i>) <i>The temperature of the liquid ether.</i>—The +higher the temperature of the liquid ether the stronger will be +the percentage of ether vapour in the air. If the ether chamber +is placed in a bath of water which is maintained steadily at an +adequate temperature and if the rate of the air flow remains +constant, a constant strength of ether vapour will be given off. +It is well in this connection to remember that the<span class="pagenum" id="Page_101">[101]</span> boiling +point of ether is low and that a very high percentage of ether +vapour is readily obtained if the temperature in the water +bath is allowed to rise beyond 80°F. For further information +regarding ether percentages <i>see</i> Appendix I and II.</p> +</div> + +<p>Such an instrument as Kelly’s requires at its head a <i>regulating +tap</i>, movement of which is capable of diverting part of the air +stream direct to the patient without coming in contact with the surface +of the ether. In this way the maximum strength of vapour may be diluted +as and when required.</p> + +<p>In Fig. 33 is shown Shipway’s instrument. Here the drug is dripped +into a chamber, the floor of which is kept warm. The ether volatilises +at once and the vapour is carried away by the air stream passing +through the chamber. The strength of ether vapour in this instrument is +regulated solely by the rate of drip which is in complete control of +the administrator.</p> + +<p>Whichever method of making ether vapour is utilised the instrument +should be capable of producing a maximum at least of 15 per cent. to 18 +per cent., and means must be provided to reduce this percentage at will.</p> + +<p>3. <span class="smcap">Device for Warming Vapour.</span>—It is doubtful if the warming +of inspired or insufflated vapour has any appreciable influence on +the body temperature, but there is a fairly general consensus of +opinion that if the ether vapour is warmed there is less likelihood +of irritation of the respiratory mucous membrane. It is to be noted, +moreover, that in intratracheal insufflation the natural apparatus for +warming the inspired air is put out of action. This warming can be +effected by the simple device of carrying the tube through a chamber of +hot water after it emerges from the ether chamber.</p> + +<p>4. <span class="smcap">Safety Valve.</span>—Dr Meltzer insists very strongly on the +necessity of having a safety valve capable of controlling the maximum +pressure under which the air may enter into the<span class="pagenum" id="Page_102">[102]</span> intratracheal tube. By +a simple device, any excess of desired pressure will cause the air to +bubble through mercury and thus never reach the lungs. In this way any +possibility of accident from undue intrapulmonary pressure is obviated.</p> + + <div class="figcenter" id="i_p102" style="max-width: 549px"> + <img + class="p1" + src="images/i_p102.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 33.</span>—Shipway’s intratracheal apparatus.</p> + </div> + +<p>5. <span class="smcap">Mercury Manometer</span> to indicate the pressure in the tube in +m.m. of mercury. It has been experimentally established<a id="FNanchor_7" href="#Footnote_7" class="fnanchor">[7]</a> “that the +pressure in the trachea and in the bronchi is only a small fraction +of the pressure in the manometer outside of the body, and that the +intratracheal pressure grows<span class="pagenum" id="Page_103">[103]</span> considerably less with the decrease of +the diameter of the intratracheal tube.”</p> + +<p>6. <span class="smcap">Intratracheal Catheter.</span>—It is essential to have an +instrument of adequate rigidity which can be satisfactorily sterilized. +The ordinary coudé catheters, or the silk web white enamelled +cylindrical catheters, are suitable. The size should be selected from +a range of 18 to 25 French. It is preferable to err rather on the side +of a small than a large tube. An ordinary adult will require a tube of +about size 22 to 24, a plethoric alcoholic, on the other hand, might +need a 25.</p> + +<p>A tube of too large a calibre interferes with the free return of air +and spontaneous respiration soon becomes too slow. Expiration is +prolonged, active, and laboured, and after a few minutes, respiratory +movements may cease entirely. The only way to meet such a situation is +to withdraw the tube and insert a smaller one.</p> + +<p><span class="smcap">Technique of Administration.</span>—It is advisable in adults to +administer about three quarters of an hour before the operation, a +hypodermic injection of morphia (gr. ⅙) and atropine (gr. ¹⁄₁₀₀), or +of scopolamine (gr. ¹⁄₁₀₀) and morphia (gr. ⅙). The latter combination +is more efficacious in alcoholic subjects. In children, atropine alone +should be given.</p> + +<p>It is to be remembered that intratracheal insufflation of ether is a +method of maintaining not of inducing anæsthesia. Induction is carried +out in the ordinary way. When this has been done, the catheter is +passed.</p> + +<p>The introduction of the catheter does present some difficulty, but +this is largely overcome as skill and confidence are acquired with +practice. It may be carried out indirectly, or a view of the glottis +may be obtained by the aid of such an endoscope as Hill’s, and the +catheter inserted between the cords. The latter method is probably the +more satisfactory, but it is well to acquire the<span class="pagenum" id="Page_104">[104]</span> skill to pass the +catheter indirectly as in a certain small proportion of cases there are +obstacles to the use of the endoscope.</p> + +<p>To facilitate catherization the pharynx and epiglottic region may +be cocainized with a 5 per cent. solution before induction. Hill’s +endoscope (Fig. 34) is distally illuminated by a small electric lamp, +which is connected with a small pocket battery. A useful modification +of this has been devised by Mr Dott. In it, the catheter is passed +along a separate compartment, so that the view of the glottis is +undisturbed. The point of the catheter comes into view at the distal +extremity of the endoscope and can be guided between the cords into the +trachea.</p> + + <div class="figcenter" id="i_p104" style="max-width: 307px"> + <img + class="p1" + src="images/i_p104.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 34.</span>—Hill’s Direct Laryngoscope.</p> + </div> + +<p>It is essential before attempting intubation, that there should be +thorough relaxation. The lower jaw should be so slack that a gag is not +required. The head is then placed in the occipito-shoulder position, or +is allowed to hang over the end of the table. The tongue is controlled +by forceps, and the endoscope passed slowly along its dorsum until the +epiglottis comes into view. The point of the endoscope is then passed +sufficiently far below the tip of the epiglottis to ensure that it will +not slip; too deep insertion must be avoided. The endoscope being held +in the left hand, the hyoid bone is lifted up by a tilting movement of +the hand. The glottis is thus brought into view. The catheter stiffened +by<span class="pagenum" id="Page_105">[105]</span> means of a probe is then passed through the glottis into the +trachea and the endoscope withdrawn. The bifurcation of the trachea in +the adult is at a distance of about 26 cm. from the incisor teeth. The +catheter should be marked accordingly, and inserted to a point just +short of this. The probe is then withdrawn, and connection made with +the air current.</p> + +<p>It occasionally happens that unexpected difficulty is met with on +attempting to pass the catheter by direct vision. The larynx may be so +fixed that the glottis does not readily come into view; or in the case +of an intraoral neoplasm the view may be obstructed by the presence of +blood. In such cases the catheter can be introduced by the indirect +method. The middle finger of the left hand is passed along the dorsum +of the tongue until the epiglottis is felt. The index finger is then +used to guide the point of the catheter to the glottis through which +it is then passed. No undue force must be used. A stilette should be +inserted into the catheter which should be moulded almost to a right +angle at its terminal third. If the stilette is withdrawn when the +point of the catheter is over the mouth of the glottis, the instrument +will, as a rule, slip easily into the trachea.</p> + +<p>Occasionally the tube passes into the œsophagus. With care and adequate +relaxation such a mistake should not occur, but the possibility of it +should be kept in mind. If the operator will abstain from attempting to +pass the catheter until such time as he has a satisfactory view of the +glottis, mistakes of this kind will seldom occur. The essentials are a +good illumination and an adequate relaxation.</p> + +<p>Mild glottic spasm may supervene on the passage of the catheter but +this rapidly passes off. At first the degree of concentration of the +vapour should be low or irritation will result, evidenced by spasm and +coughing. The strength of the vapour is gradually increased until the +necessary concentration is attained. The pressure should vary according +to the requirements of the<span class="pagenum" id="Page_106">[106]</span> case and should range between 10 mm. to 25 +mm. Hg. The safety valve must be set so as to make any pressure above +this impossible.</p> + +<p>In the majority of cases the course of anæsthesia is smooth and +uneventful; the colour remains a rosy pink, the pulse is good, and the +respirations quiet and regular. It is undesirable that the respiratory +movements should be abolished altogether; their presence indicates that +neither the central nor the peripheral respiratory mechanism is being +overdosed with ether.</p> + +<p>Theoretically, the constant plus-pressure in the lungs might be +thought to interfere with the circulation in the large veins, and +in the pulmonary vessels themselves. It is therefore well to reduce +the pressure in the catheter to zero every minute by opening the tap +provided for the purpose for a second or two.</p> + +<p>At the conclusion of the operation, before withdrawing the catheter +it is well to flush out the lungs with air so as to remove any ether +vapour that is present. In a certain number of cases, notably in +big alcoholic subjects, difficulty may be experienced in securing +a sufficiently deep anæsthesia with good relaxation. It is seldom, +however, that patience and the careful introduction of a stronger +vapour will not suffice to overcome this. In alcoholic subjects, as +previously suggested, preliminary medication with scopolamine and +morphia will help. It really becomes a question, if one may put it +so, of coaxing the unconscious patient to tolerate an ether vapour of +adequate strength.</p> + + +<h3><b>Advantages and Special Indications.</b></h3> + +<p>The general opinion of anæsthetists appears strongly to favour the view +that the absence of strain and the perfect æration in intratracheal +ether insufflation tend to lessen the shock of operation. The +post-operative history of patients also suggests that there is a +lessened liability to pulmonary complications as compared<span class="pagenum" id="Page_107">[107]</span> with cases +in which ether has been administered by other methods. Dr Elsberg<a id="FNanchor_8" href="#Footnote_8" class="fnanchor">[8]</a> +of New York in this connection writes: “The absence of any pulmonary +complications has led us to use this method of anæsthesia in all +patients in whom pulmonary complications were to be feared after an +anæsthesia or operation. Thus on all asthmatics, in patients with +chronic bronchitis and emphysema, in patients who require gastric +resection and the like, we no longer, during two years, have seen the +much dreaded post-operative pneumonia wherever intratracheal anæsthesia +was used.”</p> + +<p>In addition, there is ample evidence<a id="FNanchor_9" href="#Footnote_9" class="fnanchor">[9]</a> that the introduction of a +catheter into the trachea and its presence therein does not tend, +as might have been expected, to set up any irritation at the time +or predispose to subsequent trouble. Apart from these general +considerations, which suggest the advantage of a somewhat extended use +of intratracheal ether insufflation, the method has obvious advantages +in all operations about the mouth, such as those for excision of the +upper jaw, those undertaken for the removal of nasopharyngeal growths +and various plastic operations involving the nasal and buccal cavities. +In such cases the danger of aspiration of blood, mucus, etc., is +obviated and the anæsthetist is well out of the surgeon’s way, while at +the same time an even interrupted delivery of ether vapour is effected. +In operations for removal of glands in the neck the surgeon has the +field to himself, and is not hampered nor is his asepsis endangered by +the proximity of the anæsthetist’s mask.</p> + +<p>In such operations as laminectomy and nephrectomy the postural +difficulties with which the anæsthetist has to contend, and which also +tend to interfere with free respiration, are eliminated.</p> + +<p><span class="pagenum" id="Page_108">[108]</span></p> + +<p>The great advantage of the method in intrathoracic operations has +already been referred to.</p> + +<p>The introduction of intratracheal insufflation of ether was rendered +possible by the pioneer work of Drs Elsberg, Meltzer, and Auer. The +writer would like to acknowledge his indebtedness to their writings, of +which he has made free use.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_109">[109]</span></p> + +<h2>CHAPTER XI.<br> +<span class="subhed"><b>CHLOROFORM.</b></span></h2></div> + + +<h3><b>Physical Characteristics.</b></h3> + +<p>Chloroform is chemically trichlor-methane, CHCL<sub>3</sub>. It is a +colourless, transparent fluid, with a specific gravity of 1·491 at +17°C. Its vapour is even heavier than that of ether, approximately +four times heavier than air. It is not inflammable, but the action of +an open fire or naked flame tends to break it up into hydrochloric +acid and phosgene, both of which are highly irritant gases to all who +breathe them. The patient suffers, but since all the other occupants of +the theatre are also affected, warning is given before serious harm has +been inflicted.</p> + +<p>Chemically pure chloroform is a somewhat unstable product, but the +addition invariably made to it by the producers, of a trace of +alcohol, prevents any serious risk of decomposition in bulk. It should +be neutral in reaction and have an agreeable non-irritating odour: +departure from the normal in either respect indicates the possibility +of the presence of acids or aldehydes, and the necessity for referring +a specimen to the laboratory.</p> + +<p>Like ether, chloroform may be obtained from pure ethyl alcohol or from +methylated spirits, and the remarks made in the chapter upon ether +apply to the case of chloroform also. A third source of supply is +acetone, from which perfectly good chloroform can be produced.</p> + + +<h3><b>Physiology.</b></h3> + +<p>Chloroform is an irritant to the skin and mucous membranes. A drop left +on the skin and covered over with impermeable<span class="pagenum" id="Page_110">[110]</span> material will produce a +deep and painful blister. A drop falling into the eye, if not instantly +washed away, produces a very powerful inflammatory reaction, and many +eyes have been totally lost from carelessness in this respect. Such +incidents are of course actionable, and heavy damages may be given.</p> + + <div class="figcenter" id="i_p110" style="max-width: 615px"> + <img + class="p1" + src="images/i_p110.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 35.</span>—Diagrammatic representation of +various blood pressure curves obtainable with chloroform.</p> + <p class="p0 hangingindent smaller">Line ABA′ represents curve desired in normal chloroform administration.</p> + <p class="p0 hangingindent smaller">Line ABCB′ represents gradual overdosage.</p> + <p class="p0 hangingindent smaller">Line ABCC′ represents recovery by inversion.</p> + <p class="p0 hangingindent smaller">DD′ represents syncope from vagal inhibition: in its course, one +attempt of the heart to “escape” is shown.</p> + </div> + +<p>The special peculiarities of the action of chloroform upon the nervous +system have already been emphasised in the account<span class="pagenum" id="Page_111">[111]</span> given of the +physiology of ether (see page <a href="#Page_75">75</a>). Its action upon the <i>circulatory +and respiratory systems</i> has been the subject of many researches, +and of much embittered controversy. The literature is therefore +very extensive, and the account of it must be severely condensed. +The following may be taken as a brief resumé of present day opinion +(<i>see</i> Fig. <a href="#i_p110">35</a>):—</p> + +<div class="blockquot"> + +<p>(1) In every case of chloroform administration, there is a fall +of blood pressure.</p> + +<p>(2) If the drug be presented in weak concentration (less than 2 +per cent. vapour strength), the fall is gradual and even (line +AB).</p> + +<p>(3) If the same strength (say 2 per cent.) of vapour as produced +the above effect be prolonged unduly, the respiration will cease +at a time when blood pressure is still well above zero (line +ABCB′).</p> + +<p>(4) The fall of pressure is due to diminished force of cardiac +action, and at a later stage also to vaso-motor paresis.</p> + +<p>(5) The cessation of respiration is due partly to fall of +blood pressure in the vessels supplying the medullary centre; +partly to gradual poisoning of the centre itself by the drug. +That the fall of B.P. in the cerebral vessels is in itself one +explanation of the cessation of respiration, was proved many +years ago by Leonard Hill in his inversion experiments. Just +at the stage when respiration had ceased, the anæsthetic was +withdrawn, and the animal inverted into the head-down position. +The B.P. in the carotid at once began to rise, and natural +respiration was resumed (line A′BCC′).</p> +</div> + +<p>The above conclusions refer to chloroform given in moderate vapour +strength; other effects are produced if higher percentages are +administered:—</p> + +<p><span class="pagenum" id="Page_112">[112]</span></p><div class="blockquot"> + +<p>(6) With high concentration of chloroform vapour, the fall +of blood pressure is rapid, and is apt to become suddenly +precipitous (line DD′).</p> + +<p>(7) The cause of these sudden falls is inhibition of the +heart by over-activity of the vagus: cutting the vagi always +terminates the effect unless delayed so long that the animal is +dead: in an animal fully under atropine, these vagal actions +cannot be produced.</p> + +<p>(8) If the heart is inhibited by vagal action, the respiration +ceases at once, usually after one deep inspiratory sigh.</p> + +<p>(9) An inhibited heart may “escape” from vagal action before the +animal is dead: frequently, however, the inhibition persists and +the animal dies.</p> + +<p>(10) Struggling and breath-holding in the early stages of +induction cause sudden falls of blood pressure. Many observers +believe that these falls also are due to vagal activity, +others hotly deny this. All are united in believing that to +<i>press</i> chloroform upon a patient who is struggling and +holding the breath, is fraught with grave risk of causing sudden +syncope.</p> + +<p>(11) The abnormal irritability of the vagus above referred to is +a feature mainly of the induction stage, disappearing once full +anæsthesia is developed.</p> + +<p>(12) It is an undoubted clinical fact that there is a risk +of sudden arrest of heart’s action if the operation is begun +before the stage of full anæsthesia is reached. A reasonable +explanation of such accidents is furnished by supposing a reflex +inhibition acting through the vagal centre already rendered +hyper-sensitive by partial chloroformisation.</p> +</div> + + +<h3><b>Views of Goodman Levy.</b></h3> + +<p>This worker has demonstrated in animals that the heart is sometimes +thrown by chloroform into the condition of fibrillation—a delirium +of the cardiac muscle, from which recovery is rare. It<span class="pagenum" id="Page_113">[113]</span> occurs in +the early stage, before full anæsthesia has been reached, and is +predisposed to by the infliction of trauma. The practical outcome of +this is that the induction stage of chloroform should not be unduly +prolonged, and that the operation should not be begun until the third +stage is fully developed.</p> + +<p>So far as the author understands the views of Dr Levy, his explanation +of chloroform syncope need not be taken as introducing any new +principle into the administration of the drug. Even those who lay most +emphasis upon the danger of using vapours of too high a percentage +strength would admit the force of Levy’s contentions. As usual, safety +lies in steering between two extremes.</p> + +<p>During his work on this subject, Levy further demonstrated that +the introduction into the circulation of <i>adrenalin</i> during +incomplete chloroform anæsthesia was very liable to induce fatal +cardiac fibrillation. He thus furnished the explanation of a number +of deaths which had occurred in the practice of nose and throat +specialists. Since the publication of Levy’s work, the rule has been +absolute that if <i>adrenalin</i> is to be used in a case requiring +chloroform anæsthesia, the adrenalin must <i>precede, not follow</i> +the anæsthetic.</p> + + +<h3><b>Administration.</b></h3> + +<p>Basing upon these views as to the action of chloroform, and upon the +lessons of practical experience, we may formulate definite rules for +giving the drug.</p> + + +<h4><b>General Principles for giving Chloroform.</b></h4> + +<div class="blockquot"> + +<p>(1) Give chloroform evenly, not spasmodically.</p> + +<p>(2) Increase the vapour strength of chloroform gradually from +zero until 2 per cent. or at most 2½ per cent. is reached at the +end of two or three minutes; maintain that strength until full +anæsthesia is obtained; thereafter, drop down to 1–1·5 per cent. +This will result in a B.P. curve corresponding to the line ABA′ +in the diagram (Fig. 35).</p> + +<p><span class="pagenum" id="Page_114">[114]</span></p> + +<p>(3) Be guided chiefly by the patient’s respiration. Chloroform +kills by stopping the heart, but in the immense preponderance +of cases, evidence of failure of respiration appears in ample +time to give warning of approaching circulatory failure. The eye +reflexes give confirmatory evidence of the depth of anæsthesia, +but the superlatively important thing is to <i>maintain a free +airway, and be sure the patient is using it</i>.</p> + +<p>(4) If serious struggling and breath-holding occur, withdraw the +anæsthetic until the patient “resumes normal.”</p> +</div> + + +<h3><b>Methods of Administration.</b></h3> + +<p>The logical application of such general principles would be to use an +instrument which gives a definite and known percentage of chloroform, +variable at the wish of the administrator. Many such machines have +been brought forward, and while none of them have obtained general +acceptance, a description of the best known instrument will be given, +as the reader may as a house-surgeon meet with it, and with a surgeon +who wishes it to be used.</p> + + +<h4><b>Vernon Harcourt’s Inhaler.</b></h4> + +<p>In principle, this is a “draw-over” instrument; the patient’s own +inspirations are the motive power. Passing over the surface of the +fluid drug, the inspired air picks up from it a known percentage of +vapour. The other system available for the construction of percentage +chloroform instruments is the “plenum”; in this the vapour is propelled +to the patient by a pump.</p> + + <div class="figcenter" id="i_p115" style="max-width: 234px"> + <img + class="p1" + src="images/i_p115.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 36.</span>—Vernon Harcourt’s Percentage +Chloroform Inhaler.</p> + </div> + +<p>In appearance, the inhaler resembles the letter T, with a rubber +face-piece attached to the lower end of the vertical limb (<i>see</i> +Fig. <a href="#i_p115">36</a>). The T portion itself is made of metal tubing of a definite +size in cross section. One end of the horizontal limb admits pure air, +the other, air which has passed over chloroform and picked up from it +a certain proportion of vapour. The proportion of the total inspired +volume of air which passes through each of the ends is<span class="pagenum" id="Page_115">[115]</span> regulated by +a lever seen at the junction of horizontal and vertical limbs, and +the exact percentage of chloroform being inhaled is indicated by a +series of numerals marked on the dial over which the lever moves. These +figures are correct provided:—</p> + +<div class="blockquot"> + +<p>(1) The chloroform receptacle is not shaken (this would greatly +increase the percentage).</p> + +<p>(2) The temperature of the chloroform is not allowed to fall +below 13° centigrade. To ensure that this cannot take place +without the knowledge of the administrator, two coloured beads +are thrown into the chloroform. At the desired temperature of +the chloroform (13°-15°C) the blue bead sinks to the bottom, +the red one nearly to the bottom. Below 13°C, the red bead also +touches bottom, and when this is observed, the chloroform vial +is warmed up in the palm of<span class="pagenum" id="Page_116">[116]</span> the hand. At the point 15°C, both +beads float, and the warming must then stop, or an undesirable +addition to the vapour strength yielded will occur.</p> +</div> + +<p>The face-piece is made of rubber, and must be closely adapted to the +face; in its side is seen the expiratory valve. Inspiratory valves are +present at each end of the horizontal limb.</p> + +<p>The great advantage of this instrument, to the author’s mind, is for +teaching or demonstration purposes. If the student <i>sees</i> the +lever gradually being moved over from ·2 to 2 per cent., then slipped +back to about 1·5 per cent. after full anæsthesia has been obtained, he +begins to appreciate what it is he is aiming at when giving chloroform +by the ordinary open method.</p> + + <div class="figcenter" id="i_p116" style="max-width: 584px"> + <img + class="p1" + src="images/i_p116.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 37.</span>—Schimmelbushch’s mask.</p> + </div> + + +<h4><b>Open Method.</b></h4> + +<p>The appliances requisite are:—</p> + +<div class="blockquot"> + +<p>(1) A mask. Schimmelbushch’s is the best known (Fig. 37): as +elsewhere explained, it does not accurately fit the face.</p> + +<p>(2) Material to stretch on the mask. The best is two layers of +domette or one of flannelette: surgical gauze is so<span class="pagenum" id="Page_117">[117]</span> light that +heavy drops of chloroform are apt to “spark” through it and burn +the skin of the face: lint rapidly becomes sodden; the drug +drips away from its edge instead of vapourising properly.</p> + +<p>(3) A good drop bottle, of which many varieties are marketted +(Fig. 38): it is essential that it should be capable of +producing definite <i>drops</i>: the old method of intermittent +“douching” of chloroform is to be condemned as violating the +first general principle for giving the drug.</p> +</div> + + <div class="figcenter" id="i_p117" style="max-width: 461px"> + <img + class="p1" + src="images/i_p117.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 38.</span>—Chloroform drop bottles.</p> + </div> + +<p>It is not possible by the open method to be mathematically accurate +with percentages, but the necessary appliances are simple, easily +transported, and practically always at hand. If the student learns to +use it, and while doing so <i>to think in percentages</i>, he will +achieve as good results as or better than he will with percentage<span class="pagenum" id="Page_118">[118]</span> +instruments. While he may not have in front of his eyes a dial which +shows the percentage graphically, observation of the patient will +inform him whether the percentage being given should be maintained, +raised, or lowered. The only remaining point for him to realise, then, +is how in practice such regulations of percentage strength can be +achieved by the open method. The strength of the vapour will depend +upon three factors:—</p> + +<div class="blockquot"> + +<p>(1) Nature of the material used on the mask.</p> + +<p>(2) Closeness with which the mask is adapted to the face.</p> + +<p>(3) Amount of chloroform exhibited on the mask.</p> +</div> + +<p>To ensure uniformity of result, two of these factors should be kept +constant, and the necessary increase or decrease of vapour strength +achieved by varying the third. Always use the same type and thickness +of material on the mask, and allow the mask to lie lightly on the face. +If the amount of chloroform is then regulated by a strictly “drop” +method, results of great uniformity may be obtained by the open method.</p> + + +<h4><b>The Junker Inhaler.</b></h4> + +<p>This instrument was originally introduced as an attempt to achieve a +percentage method. Air is pumped through a certain depth of chloroform +contained in a bottle, and the vapour brought to the patient in the +face-piece shown in Fig. 39. The calculations by which it was sought +to establish this as a reliable dosimetric or percentage method are of +no great value. From that standpoint the instrument has not achieved +success. It delivers to the patient a <i>small quantity of high +percentage vapour</i> which is diluted by a much larger quantity of +air inspired by the patient from the general atmosphere, and the final +percentage inhaled by the patient is therefore no more accurately known +to the administrator than in the open method.</p> + +<p>The instrument is, however, of considerable value for tongue and jaw +cases, where anæsthesia has to be maintained for some<span class="pagenum" id="Page_119">[119]</span> considerable +time after the mask with which anæsthesia has been induced has had to +be removed, to give access to the surgeon.</p> + + <div class="figcenter" id="i_p119" style="max-width: 522px"> + <img + class="p1" + src="images/i_p119.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 39.</span>—Junker’s Chloroform Inhaler showing hand +bellows, bottle and mask. Alternatively to the latter, the nasal +tube shown above, may be used.</p> + </div> + +<p>The Figure 39 shows the instrument as usually marketed. It consists +of:—</p> + +<div class="blockquot"> + +<p>(1) A hand-bellows.</p> + +<p>(2) Chloroform bottle. A mark cut on this shows the level to +which it is to be filled: if more than the proper quantity be +poured in, droplets of fluid chloroform are apt to be blown +along the exit tube, with dangerous results.</p> +</div> + +<p>For convenience and neatness, it is usual to make the exit surround +the inlet tube. The entering air bubbles through the chloroform, +and a stream of air and chloroform vapour passes out<span class="pagenum" id="Page_120">[120]</span> from the exit +tube.<a id="FNanchor_10" href="#Footnote_10" class="fnanchor">[10]</a> It is unnecessary to give a detailed account of the use of +the instrument, but the student must remember the following points:—</p> + +<div class="blockquot"> + +<p>(1) The amount of chloroform vapourised will depend on the +vigour of the pumping, the depth of fluid, and the temperature +of the chloroform. In order to achieve uniform results, it +is therefore necessary to keep up a steady but not excessive +pumping, to warm up the bottle occasionally by holding it in the +palm of a disengaged hand, and to watch that the level of the +chloroform does not fall too low.</p> + +<p>(2) The pumping should be timed to synchronise with inspiration: +a puff of vapour delivered during an expiration will be wasted.</p> +</div> + + +<h3><b>Advantages and Disadvantages of Chloroform.</b></h3> + +<p>The light portable appliances which are alone necessary for chloroform +anæsthesia, the comparative cheapness of the method, and the +<i>apparent</i> ease with which its administration may be conducted, +are all great temptations to its use. Those who feel the temptation +strong upon them are advised to remember the following quotation from +the writings of Professor Leonard Hill:—</p> + +<p>“Chloroform is a drug used by the young anæsthetist with the utmost +hardihood, and until he has had the misfortune in his practice to meet +with a death caused by it, he derides the danger of the drug, and +asserts that its safety merely depends on the care and skill of the +administrator. After losing his patient, he falls to descanting on the +unavoidable dangers of the drug, dangers which he is now the first to +maintain cannot be met by any degree of skill in administration.”</p> + +<p><span class="pagenum" id="Page_121">[121]</span></p> + +<p>The most distressing and probably the most common chloroform fatalities +are exemplified in administration given for the most trifling +conditions, such as opening abscesses or extracting teeth.</p> + +<p>In general, we use chloroform if for any reason ether is not +applicable. For examples of cases of this description, the reader is +referred to the chapter upon the choice of anæsthetics.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_122">[122]</span></p> + +<h2>CHAPTER XII.<br> +<span class="subhed"><b>ETHYL CHLORIDE.</b></span></h2></div> + +<p>Chemically this drug has the formula C<sub>2</sub>H<sub>5</sub>Cl. It is a colourless +fluid so volatile that it boils at ordinary room temperature. Its +vapour is highly explosive, and the fluid itself very inflammable. The +drug is supplied by the makers in small tubes with a metal end which +can be opened by pressing a little lever (<i>see</i> Fig. <a href="#i_p122">40</a>), varying +in type with the brands made by various makers. Two brands are sold +by each firm; one is chemically pure, intended for use as a general +anæsthetic; the other is not so pure, and is only sold for local +anæsthesia. Such a product is not suitable for inhalation.</p> + + <div class="figcenter" id="i_p122" style="max-width: 150px"> + <img + class="p1" + src="images/i_p122.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 40.</span>—Tube of Ethyl Chloride.</p> + </div> + + +<h3><b>Physiology.</b></h3> + +<p>The special points in the physiology of ethyl chloride may be briefly +summarised as follows:—</p> + +<div class="blockquot"> + +<p>1. After a trifling preliminary rise, the effect of the drug +is to lower the blood pressure appreciably. In the human adult +subject, this fall becomes appreciable when more than 3 c.c. +have been given; if the dose exceed 5 c.c. a fall of 30 to 40 +mm. of Hg. is probable,—occurring as it does within a period of +perhaps twenty or thirty seconds, such a fall cannot be regarded +as safe.</p> + +<p><span class="pagenum" id="Page_123">[123]</span></p> + +<p>2. The cause of this fall is diminished cardiac output from +weakening of heart muscle. The vagus though not paralysed, does +not appear to be unduly irritable, as it does with chloroform.</p> + +<p>3. The respiratory centre is at first perceptibly stimulated, +and respiration is therefore deeper and quicker than normal. The +stimulant effect rapidly passes away and gives place to a stage +of depression.</p> +</div> + +<p>In the majority of cases, death appears to take place from paralysis +of the respiratory centre, the heart still showing a little power of +contraction after respiration has ceased. There is therefore a fair +prospect of recovery if artificial respiration be resorted to promptly.</p> + + +<h3><b>Methods of Administration.</b></h3> + + +<h4 class="smcap">Open Method.</h4> + +<p>The extreme volatility of the drug has discouraged most anæsthetists +from giving it upon an open mask. Hornabrook, of Melbourne, advocates +this system, however. His mask fits the face accurately, and his whole +method is strictly perhalational. He uses some 4–6 c.c. of the drug +for a child, 6–8 c.c. for an adult, and achieves his anæsthesia in a +minute to a minute and a half. He also advocates open ethyl chloride +as a preliminary to open ether. For some twelve months, the author +adopted the method. At the end of that time he came to the conclusion +that while it greatly facilitated the induction stage of open ether, +it appeared to increase the after sickness. He therefore abandoned it, +though rather reluctantly.</p> + + +<h4 class="smcap">Closed Method.</h4> + +<p>This is the usual means employed. A variety of inhalers have been +produced on the market, one of which is shown in Fig. 41. Essentially +all consist of:—</p> + +<div class="blockquot"> + +<p>(<i>a</i>) A face-piece which must fit the face with reasonable +accuracy.</p> + +<p>(<i>b</i>) A one-gallon rubber bag attached to the mask by a +T-piece.</p> + +<p><span class="pagenum" id="Page_124">[124]</span></p> + +<p>(<i>c</i>) A glass vial, with numerals from 1 to 5 marked on the +outside to facilitate the measurement of the drug in c.c. Into +this the drug is squirted from the makers’ tube. The vial is +attached to the T-piece (or alternatively the bottom of the bag) +by a rubber tube.</p> +</div> + + <div class="figcenter" id="i_p124" style="max-width: 205px"> + <img + class="p1" + src="images/i_p124.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 41.</span>—Ethyl Chloride Inhaler.</p> + </div> + + +<h3><b>Administration.</b></h3> + +<p>To use such an inhaler, the glass vial is first detached from the +rubber tube, and the chosen dose of drug squirted into it. A<span class="pagenum" id="Page_125">[125]</span> child +of five or six will require 3 c.c., an adult up to 5 c.c.; this dose +should never be exceeded. The vial is then rapidly reconnected with +the inhaler. The face-piece is adapted to the face, care being first +taken to place between the teeth a mouth prop or a gag. This enables +one to get immediate access to the mouth when the inhaler is removed. +The patient is then told to breathe deeply once or twice. During the +inspiration the mask is lifted slightly, and the ensuing expiration is +then caught in the bag by pressing down the mask on to the face. To +volatilise the drug there are two alternative methods. In the one, part +or the whole of the dose is tipped into the rubber bag by elevating the +vial. A far better is the “Vapour” method, almost universally used in +Edinburgh owing to the advocacy of Dr Logan Turner. A tumbler is filled +with hot water, and the bottom of the glass vial is allowed first to +touch, and after a few seconds to be immersed in it. Some thirty to +forty seconds suffice to vapourise the whole of the dose.</p> + +<p>Ethyl chloride given by itself should always be administered to a +patient in the recumbent position. A dose sufficient to produce +anæsthesia without the aid of nitrous oxide or ether will not be safe +in the erect posture. The case is quite different where a small dose +only is given, to assist the action of nitrous oxide, or facilitate the +induction stage of ether.</p> + + +<h3><b>Signs of Anæsthesia.</b></h3> + +<p>Ethyl chloride is very rapid in its action, some sixty seconds +availing to produce quite a deep anæsthesia. <i>Respiration</i> is +at first deepened and quickened: as full anæsthesia is attained it +remains rather deeper than normal, and is accompanied usually by light +snoring. The colour should remain perfectly good: the pupils show +marked dilatation, the corneal reflex is abolished, and good muscular +relaxation is attained.</p> + +<p>With no anæsthetic is it so essential as with this, to become<span class="pagenum" id="Page_126">[126]</span> +acquainted with the type of respiration normally to be expected, and to +watch for any departure therefrom with cat-like vigilance. The other +danger signal is the pupil. It should be dilated, but a rim of iris +should still be perceptible.</p> + +<p>Once anæsthesia is established, the inhaler should be removed, and the +surgeon may begin his work. He will have for its completion some 80–90 +seconds against the 40–50 available after nitrous oxide. With ethyl +chloride there is a somewhat prolonged “analgesic” stage. The patient +is partly conscious and may even be phonating, but seems unconscious of +the infliction of pain unless very severe measures are being used.</p> + + +<h3><b>The Scope of Ethyl Chloride.</b></h3> + +<p>When first introduced, it was expected by enthusiasts that the +lightness and portability of the drug itself and of the necessary +inhaler, would enable ethyl chloride to oust nitrous oxide from its +recognised place in surgery and dentistry. These high expectations +have for several reasons not been fulfilled. In the first place, this +drug is essentially a “single dose” anæsthetic. Most authorities view +coldly all attempts to prolong anæsthesia by repeated or continued +administration. Secondly, ethyl chloride has a mortality rate very much +greater than nitrous oxide if doses sufficient in themselves to produce +anæsthesia are habitually used (<i>vide supra</i>). The introduction +of the “vapour” method has done much to mitigate the risks, but even +then, this anæsthetic cannot approach the high level of safety rightly +credited to N<sub>2</sub>O. Moreover, it leads to after vomiting much more +commonly than its rival.</p> + +<p>In many schools these considerations have been held so powerful that +ethyl chloride has been entirely abandoned. It is, however, a very +valuable drug for the following purposes:—</p> + +<div class="blockquot"> + +<p>(1) The removal of tonsils and adenoids. For this operation, +the speed with which the patient (usually a child) loses +consciousness, the pleasant type of anæsthesia and<span class="pagenum" id="Page_127">[127]</span> absence of +all serious asphyxial phenomena, and the rapid re-appearance +of the cough reflex when once the inhaler is removed, are all +strong recommendations.</p> + +<p>(2) As an adjuvant to gas, or gas oxygen (<i>see</i> Chapter +<span class="allsmcap">XIII.</span>).</p> + +<p>(3) As a help to the speedy and comfortable induction of “closed +ether” (<i>see</i> Chapter <span class="allsmcap">XV.</span>).</p> +</div> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_128">[128]</span></p> + +<h2>CHAPTER XIII.<br> +<span class="subhed"><b>MIXTURES OF NITROUS OXIDE AND ETHYL CHLORIDE.</b></span></h2></div> + +<p>Dr Guy, Dean of the Edinburgh Dental School, introduced some years +ago a method of giving ethyl chloride in mixture with nitrous oxide. +Guy’s objective was to utilise the many excellent features of the drug +without incurring the risks which are apparently inherent in it when +a dose sufficient in itself to induce full narcosis is used. Given in +mixture with gas, a much smaller dose suffices.</p> + + <div class="figcenter" id="i_p128" style="max-width: 229px"> + <img + class="p1" + src="images/i_p128.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 42.</span>—Guy’s inhaler for N<sub>2</sub>O and Ethyl +Chloride.</p> + </div> + +<p>His original apparatus is shown in Fig. 42, the details are shown in +Fig. 43. The horizontal limb of a 3-way gas tap is prolonged half an +inch. In each side of the prolongation is a hole. The bag mount has +in its side also one hole, which is connected by a universal ball and +socket joint, with the rubber tube to which the ethyl chloride vial is +attached. An indicator on the outside of the bag mount and a mark upon +the outside of the horizontal limb of the 3-way tap, serve by their +apposition or the reverse to show whether the ethyl chloride vial is in +direct continuity with the interior<span class="pagenum" id="Page_129">[129]</span> of the inhaler. For purposes of +description, Dr Guy calls these two positions, “in register” and “out +of register.”</p> + +<p>To use the instrument, the ethyl chloride vial is removed, and the side +pipe attached to a cylinder of nitrous oxide. The indicator of the +3-way tap is put at “air” and the bag mount “in register.” The bag is +then filled with gas by opening the head of the cylinder. The bag mount +is now put “out of register,” and the side tube disconnected with the +cylinder. The bag, being closed, remains full of gas.</p> + + <div class="figcenter" id="i_p129" style="max-width: 700px"> + <img + class="p1" + src="images/i_p129.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 43.</span>—Guy’s Instrument for Gas and Ethyl +Chloride. Details of valve piece and bag mount, showing side tube for +attachment of Ethyl Chloride vial.</p> + </div> + +<p>A suitable dose of ethyl chloride is now squirted into the vial. To +an adult, Dr Guy gives 3 c.c.: on no account is this dose exceeded: +children take 1½–2 c.c.—even adults often get less than 3 c.c. The +vial is now attached to the side tube again, and the inhaler is ready +for use.</p> + +<p>After application of the mask to the face, the 3-way tap is at once +pushed over to “no valve” and the patient rebreathes the gas in and out +of the bag for some six or eight respirations. The<span class="pagenum" id="Page_130">[130]</span> bag mount is now +turned round “into register,” and the ethyl chloride tipped into the +bag. In a further twenty-five seconds the mask may be removed and the +operation begun.</p> + +<p>The available period of anæsthesia is eighty to ninety seconds, +counting from the instant of the removal of the inhaler.</p> + +<p>This method was in use for some years at the Dental Hospital of +Edinburgh; no instance of danger to life was ever seen. With so small a +dose of ethyl chloride, the erect position necessary for the purposes +of dentistry is perfectly safe.</p> + + <div class="figcenter" id="i_p130" style="max-width: 447px"> + <img + class="p1" + src="images/i_p130.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 44.</span>—Diagram of the method introduced by +Dr Guy and the author for giving Nitrous Oxide and Oxygen, with or +without Ethyl Chloride.</p> + </div> + +<p>This inhaler, of course, will serve admirably for giving ethyl chloride +without gas, and the author habitually uses it for giving the drug by +the “vapour” method.</p> + +<p>In 1911, Dr Guy and the present author modified the method so as to +permit the use of oxygen with the nitrous oxide. The inhaler which +they then introduced serves also for nitrous oxide and oxygen, unaided +by ethyl chloride, and the author has by its means given gas-oxygen +to a considerable number of major surgical<span class="pagenum" id="Page_131">[131]</span> cases. He now, however, +limits its use to short anæsthesias, and uses a sight-feed or a Clarke +apparatus for long cases.</p> + + <div class="figcenter" id="i_p131" style="max-width: 236px"> + <img + class="p1" + src="images/i_p131.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 45.</span>—The Guy-Ross Inhaler for Nitrous +Oxide and Oxygen, with or without Ethyl Chloride.</p> + </div> + +<p><span class="pagenum" id="Page_132">[132]</span></p> + +<p>In Fig. 44 will be found a diagram showing the method by which the +oxygen is introduced. The 1-gallon oxygen bag is either attached +directly to a cylinder, or suspended on an upright as shown in Fig. +45. In either case, the bag is, before the administration, moderately +filled with oxygen: one bagful will suffice for a short anæsthesia, and +the supply of the oxygen from the cylinder is therefore turned off at +once. For long cases, of course, a small trickle of oxygen into the bag +is required to replace the gas used.</p> + +<p>In the outlet pipe from the oxygen bag is placed a ball syringe of 2 +ounces capacity. A valve in the pipe obliges the flow of oxygen to take +place in one direction only when the bulb is squeezed, viz. from oxygen +bag to inhaler.</p> + +<p>The remainder of the apparatus is identical with Guy’s original +inhaler, except that the bag is of 2-gallon capacity, and is perforated +at its base by a <b>Y</b>-tube, one limb of the fork bringing in the +nitrous oxide, the other the oxygen.</p> + + +<h3><b>Method of Use.</b></h3> + +<p>A few breaths of pure nitrous oxide gas are usually allowed “on the +valve.” Rebreathing is then instituted, and the addition of oxygen +begun. The amount required to each type of patient can only be learnt +with experience, but the average is one full compression of the bulb +every ten seconds. If anæsthesia is not complete at the end of one +minute, put the indicator to “valves” again, and allow the patient +nearly to empty the bag. Then push back the indicator to “no valves,” +and refill the bag with nitrous oxide by opening the cylinder with the +foot key. Some four to six compressions of the bulb are made while the +nitrous oxide is running in. The time will now have come to add the +dose of ethyl chloride if it be judged necessary at all. This will have +been placed in the vial before the administration is begun.<span class="pagenum" id="Page_133">[133]</span> After +emptying the ethyl chloride into the bag of the inhaler, anæsthesia +should be complete in twenty-five seconds.</p> + +<p>The same small doses of ethyl chloride are used as is the case with +Guy’s original method.</p> + +<p>After a little practice under supervision, students at the Dental +Hospital learn to use this method safely and well. No example of risk +to life has arisen after eight years’ daily experience.<a id="FNanchor_11" href="#Footnote_11" class="fnanchor">[11]</a></p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_134">[134]</span></p> + +<h2>CHAPTER XIV.<br> +<span class="subhed"><b>MIXTURE OF CHLOROFORM AND ETHER.</b></span></h2></div> + +<p>The mere addition of ether does not remove all the undesirable features +of chloroform anæsthesia. A heart poisoned by excess of CHCl<sub>3</sub> does +not respond to ether stimulation. Nevertheless, CE mixtures of varying +proportions have great value. The less lethal drug takes on part of the +work of the more dangerous one; it also keeps the respiratory centre +active. Viewing mixtures as dilute chloroform, it is also obvious that +there will be with them a greater margin of error in dosage, than with +the pure drug.</p> + +<p>Some chemical change takes place when the two drugs are mixed, for heat +is evolved; of the nature of this change we are ignorant.</p> + +<p>The first mixture introduced was known as ACE, and consisted of one +part absolute alcohol, two parts chloroform, and three parts ether. +Alcohol evaporates very slowly and if it be introduced at all it should +be in much smaller proportion. Schäfer’s mixture is one part alcohol to +nine parts chloroform. Neither of these mixtures is now much used. The +most useful combination is two parts chloroform and three parts ether, +and is known as C<sub>2</sub>E<sub>3</sub>. In special cases, one part of chloroform to +two parts ether may be better.</p> + + +<h3><b>Methods.</b></h3> + +<p><i>Cones</i> of varying type were at first extensively used for +mixtures. The best known is Rendle’s (Fig. 46). It is made of +celluloid, and is perforated at the top by a series of small holes +through which the anæsthetic is introduced. A sponge is packed<span class="pagenum" id="Page_135">[135]</span> into +the upper part of the cone, and a flannelette cover completes the +appliance. The objection to the use of this and kindred cones is that +since chloroform evaporates more slowly than ether, the more dangerous +drug is apt to collect in the sponge, completely altering the strength +of the vapour after a time. This fault is remedied to a large extent by +the open drop method now used.</p> + + <div class="figcenter" id="i_p135" style="max-width: 496px"> + <img + class="p1" + src="images/i_p135.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 46.</span>—Rendle’s Cone.</p> + </div> + + +<h4><b>The Open (Drop) Method.</b></h4> + +<p>For this the mask and ether dropper of Bellamy Gardner are admirably +suited (Fig. 27). A material less close than the gauze advocated for +open-ether is required. One layer of flannelette does very well, or +the cheap cotton towels which used to be known in Edinburgh as “penny +towels” in the pre-war period. The mask should fit the face with +reasonable accuracy: there is no reason why a gauze ring should not be +used to ensure this if the administrator is careful to adhere strictly +to a “drop” method.</p> + +<p>The bottle into which the dropper is inserted should be of different +<i>colour</i> to those in which pure ether is habitually carried. This +is a greater safeguard against a dangerous forgetfulness than a mere +label.</p> + +<p><span class="pagenum" id="Page_136">[136]</span></p> + +<p>As already said, the anæsthetic must be given by a strict “drop” +method. “Douching” at frequent intervals gives results far inferior.</p> + +<p><span class="smcap">The Type of Anæsthesia</span> is a compromise between that of +chloroform and open-ether. Respirations and colour are better than with +pure chloroform, not so good as with open-ether. The size of the pupil +is also intermediate.</p> + +<p><span class="smcap">Scope.</span>—As elsewhere explained there are many patients to whom +open-ether cannot well be given; the greatest number of these can take +a mixture perfectly and C.E. should certainly be chosen in preference +to pure chloroform when possible. For refractory cases, it serves +admirably as the inducing agent before the use of open-ether.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_137">[137]</span></p> + +<h2>CHAPTER XV.<br> +<span class="subhed"><b>SEQUENCES.</b></span></h2></div> + +<p>By a sequence we mean a method in which anæsthesia is partially or +wholly induced by one anæsthetic or one method, and maintained by +another. The methods mentioned in Chapter <span class="allsmcap">XIII.</span> as devised +by Dr Guy for dental purposes are examples which have already been +sufficiently described.</p> + + +<h3><b>C.E. Mixture—Ether Sequence.</b></h3> + +<p>Of the method of inducing anæsthesia by <i>C.E.</i>, and turning later +to <i>open-ether</i>, we have also already spoken. One thing remains to +be said in this connection. Learn to judge the appearance of the type +of patient who will require this alternative to open-ether induction, +and use the sequence to such patients from the beginning. Don’t start +off with open-ether, and find out in a few minutes that the patient +is too obstreperous. A change from mixture to ether is harmless, the +reverse process needs much care.</p> + +<p>The sequence of <i>C.E. to closed ether</i> was advocated by Hewitt as +a means of dealing with very alcoholic men, and for this purpose has +great merits. The mixture is given until the stage of struggling is +just about to commence, a point which experience enables one to fix +with considerable accuracy. The remainder of the induction is conducted +by a closed-ether inhaler, either the Hewitt wide-bore or preferably +the Ormsby. The ether indicator which stands at about one when the +inhaler is first applied, may be advanced very rapidly full ether +strength being attained within a minute or two.<span class="pagenum" id="Page_138">[138]</span> As soon as rebreathing +is begun with either of these instruments, it is very striking to watch +the rapid and apparently safe subsidence into anæsthesia of the most +troublesome patient. The struggling is cut short and greatly minimised +in violence, and a stage which under CHCl<sub>3</sub> might have presented some +considerable risk of secondary syncope, is thus eliminated.</p> + + +<h3><b>Nitrous Oxide and Ether Sequences.</b></h3> + +<p>This is a method greatly superior to the induction by closed-ether +described on p. 79. Instead of the 1-gallon bag of the Clover or Hewitt +instrument, the valve piece and 2-gallon bag of a gas apparatus are +attached to the head of the ether inhaler (Fig. 23, on page 77).</p> + +<p>Once the gas bag is inflated from the cylinder, the supply of gas may +be cut off. A few breaths of gas “upon the valves” are given, until the +bag is half empty; the valve tap is then pushed over to “no valves” and +rebreathing begun. Ether may be turned on a few seconds later, and the +strength of the vapour may be increased more rapidly. Three-quarter +strength of ether may be attained as a rule in ninety seconds. There is +very little likelihood of struggling in this method.</p> + + +<h3><b>Ethyl Chloride and Ether.</b></h3> + +<p>This is a valuable method for short operations, being easily portable, +speedy and safe in action, and fairly agreeable to the patient. Some +anæsthetists use this induction method as a prelude to open-ether.</p> + +<p>The Clover (or Hewitt wide-bore) instrument is interposed between the +face-piece and the T. of the ethyl chloride inhaler, as shown in Fig. +47. A small dose of ethyl chloride only is requisite; for an adult, 3 +c.c. is enough. This is vapourised over hot water in the usual way; a +very light anæsthesia is induced in some<span class="pagenum" id="Page_139">[139]</span> sixty seconds, and the ether +can then be turned on at a much quicker rate than if the induction be +conducted by that drug alone.</p> + + <div class="figcenter" id="i_p139" style="max-width: 548px"> + <img + class="p1" + src="images/i_p139.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 47.</span>—Clover’s Inhaler adapted for the +Ethyl Chloride-Ether sequence.</p> + </div> + + +<h3><b>Scope.</b></h3> + +<p>The gas-ether and ethyl chloride-ether sequences are most useful +methods. They are quick, safe, and powerful.</p> + +<p>Either may be used as “single dose” anæsthetic, the ether being pushed +quickly up to “full” and the inhaler then withdrawn. If, however, no +access to the mouth is required by the surgeon, ether anæsthesia may, +by occasional breaths of fresh air be prolonged for as long as desired.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_140">[140]</span></p> + +<h2>CHAPTER XVI.<br> +<span class="subhed"><b>THE ACCIDENTS OF ANÆSTHESIA.</b></span></h2></div> + +<p>The minor difficulties of anæsthesia have already been dealt with, +and if the instructions already given, particularly in Chapter +<span class="allsmcap">III.</span>, are faithfully carried out, incidents of real danger +will rarely occur. The soundest knowledge and the most conscientious +care will, however, never entirely rid anæsthesia of an element of +danger to life. The conditions now to be considered are:—</p> + +<div class="blockquot"> + +<p>(<i>A</i>) Vomiting.</p> + +<p>(<i>B</i>) Failure of respiration.</p> + +<p>(<i>C</i>) Failure of circulation.</p> +</div> + + +<h3><b>(A) Vomiting.</b></h3> + +<p>This always exposes an unconscious patient to the danger of inhaling +solid or fluid material into the larynx, with resulting asphyxia. If +the patient be tided through that immediate difficulty, he is liable to +develop an inhalational pneumonia subsequently.</p> + +<p>A healthy patient properly prepared should not vomit during the +induction stage, nor during the progress of the operation. If he +does, it means that the induction has been too slow, or that the +administration has been intermittent, and the patient has been +permitted to come to too light a level of anæsthesia during the +operation.</p> + +<p>During emergency operations where the patient’s stomach may be full of +food, the case is different. Such patients commonly vomit early in the +induction stage, and no skill can avert the incident.</p> + +<p>A patient suffering from intestinal obstruction, or from<span class="pagenum" id="Page_141">[141]</span> generalised +peritonitis has his stomach and intestines full of highly infective +fluid. Reverse peristaltic may set in merely as the result of the +inhalation, or later from handling the contents of the abdomen, and +the feculent fluid gushes up the œsophagus with little or no warning. +Since vomiting in these cases may occur even in deep anæsthesia, when +the cough reflex which is the normal sentry to the entrance of the +larynx, is abolished, the dangers of insufflation are very real indeed. +Personally, the author prefers to wash out the stomach before beginning +to induce anæsthesia in these cases, but some surgeons believe that the +shock of this procedure outweighs the advantages.</p> + + +<h4 class="smcap">Symptoms and Treatment of Vomiting.</h4> + +<p>In ordinary cases, vomiting is usually heralded by a definite train of +symptoms. Respiration becomes shallow, the colour a little pale and the +pulse rather small. The pupil dilates, but remains active to light, +indicating that the alteration of respiration and circulation is not +due to overdose.</p> + +<p>At the first appearance of such symptoms, a brisk rub of the lips and +thereafter an increase of the vapour strength of the anæsthetic will +often avert the impending vomiting by deepening the anæsthesia, but if +the possibility of this complication has occurred to the anæsthetist +too late for its prevention, the head must be turned well to one side, +and the other shoulder slightly elevated by a pillow, so that vomited +material will fall out of the mouth at once. When the actual act of +vomiting is over, no time must be lost in mopping out the mouth and +pressing on with the production of a deeper anæsthesia.</p> + + +<h3><b>(B) Respiratory Dangers.</b></h3> + +<p>These divide themselves into two groups:—</p> + +<div class="blockquot"> + +<p>(1) <span class="smcap">Mechanical.</span>—The respiratory movements continue, +but the ingress and egress of air is blocked.</p> +</div> + +<p><span class="pagenum" id="Page_142">[142]</span></p> + +<p><i>The symptoms and preventative treatment</i> have been referred to at +some length in Chapter <span class="allsmcap">III.</span>, and no further account of these +is therefore necessary. <i>The treatment of a complete blockage</i> of +the air passages which resist the measure there described, alone remain +to be mentioned. Of these, the only two effective are <i>artificial +respiration and tracheotomy</i> (or laryngotomy if preferred by the +surgeon). Forcible artificial respiration by the Sylvester method, +with the mouth gagged open and the tongue held forward by the tongue +forceps, is frequently successful in getting over even a complete +block, but the last resort of opening the air passage by the knife must +not be delayed until too late. In deciding such a point, considerable +judgment is of course called for.</p> + + +<h4>(2) <span class="smcap">Non-mechanical.</span>—Respiratory arrest.</h4> + +<p>This is usually seen in conjunction with a serious failure of the +circulation caused by over-dosage. Exceptionally, some act of the +surgeon sets up a reflex inhibition of the respiratory centre; the +circulation is at the same time depressed, but to a varying degree. +The cardinal <i>symptom</i> is arrest of all respiratory effort. The +<i>treatment</i> is best dealt with under the heading of circulatory +failure.</p> + + +<h3><b>(C) Circulatory Failure, or Syncope.</b></h3> + +<p>By the term syncope, we mean a more or less sudden failure of the +cardiac pump, as opposed to the form of circulatory failure seen in +surgical shock, where the condition is chiefly, though not wholly, one +of vaso-motor paralysis (<i>see</i> Chapter <span class="allsmcap">II.</span>).</p> + +<p>Syncope occurs under varying conditions which may for descriptive +purposes be divided into four classes. It is not, however, always +possible to decide with certainty into which class an individual case +should be placed.</p> + +<p>The <i>symptoms</i> common to all classes of syncope are:—</p> + +<div class="blockquot"> + +<p>(1) Pallor, and loss of all tone in the muscles, noticeably +those of expression. The pulse is weak or imperceptible.</p> + +<p><span class="pagenum" id="Page_143">[143]</span></p> + +<p>(2) Cessation of respiration.</p> + +<p>(3) Dilatation of the pupil, which ceases to react to light.</p> +</div> + +<p>The four classes above mentioned are as follows:—</p> + + +<h4>A. <span class="smcap">Primary Syncope.</span></h4> + +<p>This is peculiar to chloroform. With no other anæsthetic is it seen, at +any rate in the healthy subject. It arises during the induction period, +and is not necessarily preceded by any respiratory difficulty. There is +one big inspiratory gasp, sudden and extreme pallor, and the pupil goes +out to the rim in a few seconds. The only reasonable explanation of +such an incident is the occurrence of vagal inhibition (<i>see</i> page +<a href="#Page_112">112</a>). Its prevention therefore is a matter of the avoidance of a high +percentage of chloroform.</p> + + +<h4>B. <span class="smcap">Secondary Syncope.</span></h4> + +<p>This term is applied to a collapse arising as a secondary result of +embarrassed respiration. Though not peculiar to chloroform, it is +far more common with that drug than with any other (ethyl chloride +excepted). The most common time for the accident is towards the end +of the induction period. The patient has probably been struggling, +has clenched the jaws, and developed “mechanical” asphyxia. Violent +inspiratory efforts are still being made, and considerable cyanosis +develops. Either at the very moment when the respiratory difficulty +is overcome, or while it still persists, the colour suddenly alters +from blue to white, and the other symptoms of syncope rapidly appear. +The exact period required to transform a blue struggling patient with +heaving chest, into one with pallid face, and motionless chest and +limbs, varies greatly, for reasons furnished below.</p> + +<p>The most reasonable explanation offered of such an accident is that +given by Leonard Hill. The attempts to inspire through an air<span class="pagenum" id="Page_144">[144]</span> way +mechanically blocked cause an immense strain upon the heart muscle. The +flow of blood in the lung capillary is hindered, and the right side of +the heart becomes over distended with blood. Its musculature is further +damaged by the fact that the blood in the coronary vessels is deficient +in oxygen, and that a considerable dose of anæsthetic has already been +absorbed. There is the further fact, not mentioned by Hill, that during +the whole period of asphyxia the peripheral resistance is rising from +vaso-constriction. Under circumstances such as these, it is obvious +that <i>any</i> heart must ultimately succumb, <i>no matter what +anæsthetic is in use</i>. It is also obvious that with chloroform and +ethyl chloride, which are themselves heart poisons, secondary syncope +will happen much more readily than with ether or nitrous oxide, which +are not; and that a heart with diseased musculature will fail quicker +than a healthy organ.</p> + +<p>Secondary syncope is almost certainly the commonest fatal accident of +anæsthesia. The reason why this fact is not more widely recognised +arises from the natural instinct of any one who has suffered the misery +and ignominy of causing a death under an anæsthetic, to attribute +it to some cause beyond human control. The <i>essential</i> cause +of secondary syncope is failure to maintain a free air way, which +cannot be styled unavoidable. Two consolations may, however, honestly +be offered to the person who has acted as anæsthetist in a case of +secondary syncope. Firstly, it is, in certain types of cases, very +difficult indeed to maintain a free air way; and secondly, a heart with +muscle degenerated from fatty or other changes, may give out after very +little respiratory embarrassment.</p> + + +<h4 class="smcap">Syncope from Overdose.</h4> + +<p>This is a more gradual affair than the two foregoing; and has been +sufficiently dealt with in the chapter devoted to the Stages of +Anæsthesia (see p. <a href="#Page_36">36</a>).</p> + +<p><span class="pagenum" id="Page_145">[145]</span></p> + + +<h3 class="smcap"><b>C. Reflex Syncope.</b></h3> + +<p>Exceptionally, a patient not overdosed with anæsthetic, and not +suffering from any mechanical obstruction to respiration, has a sudden +attack of syncope during the progress of the operation. We here exclude +patients who are suffering from surgical shock; the condition arises +too rapidly for such an explanation to be accepted. Much speculation +has been expended upon these cases. One view is that some procedure of +the surgeon has set up a reflex inhibition of the heart through the +vagus; another, that the reflex has taken the form of sudden vasomotor +paresis. Levy would ascribe the condition to cardiac fibrillation. +It may well be that all cases cannot be met by one explanation. The +older surgeons stoutly maintained that reflex syncope could not arise +if the patient were properly under, and that it was in the practice +of those anæsthetists who were afraid of pushing the anæsthetic +sufficiently, that such accidents occurred. The author’s own belief +is that a <i>very</i> light chloroform anæsthesia does pre-dispose to +this accident, but that it may occur also at a deep, the very deepest +possible level. With an anæsthetic other than chloroform, it is +extremely rare—perhaps unknown.</p> + + +<h3><b>Treatment of Syncope.</b></h3> + +<p>This must be speedy to be of any avail. The following are the points +upon which to concentrate:—</p> + +<div class="blockquot"> + +<p>(1) <i>Withdraw the anæsthetic.</i></p> + +<p>(2) Make sure that the <i>air way is free</i>.</p> + +<p>(3) Begin <i>artificial respiration</i> by Sylvester’s method, +the movement of <i>expiration</i> being first performed +(<i>see</i> Fig. <a href="#i_p146">48</a>).</p> + +<p>(4) <i>Lowering of the head and shoulders</i> is usually to be +recommended. It is best done by tilting the whole table as if +for the Trendelenberg position.</p> + +<p>The lowering of the head attracts more blood to the<span class="pagenum" id="Page_146">[146]</span> carotid +artery and raises the blood pressure of the main vessel and +its cerebral branches (<i>see</i> Fig. <a href="#i_p110">35</a>). It must, however, +be remembered that it will also tend to empty the blood in the +veins of the lower extremities and abdomen into the right side +of the heart, and cases in which marked cyanosis has preceded +pallor, are probably suffering already from engorgement and +dilatation of the right heart. The tilting of the table should +in such cases be very moderate in degree, and should not be +persisted in if it seems to do no good. In no case, indeed, +should the tilting be extreme. An angle of more than 15 or 20 +degrees is as likely to do harm as good.</p> +</div> + + <div class="figcenter" id="i_p146" style="max-width: 484px"> + <img + class="p1" + src="images/i_p146.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 48a.</span>—Artificial respiration by +Sylvester’s method. Expiration.</p> + </div> + +<div class="blockquot"> + +<p>(5) Hot cloths may be placed over the precordial region, care +being taken not to burn the skin.</p> + +<p><span class="pagenum" id="Page_147">[147]</span></p> + +<p>(6) The only <i>drugs</i> likely to be of any avail are +atropine and strychnine, the former being used with the idea of +paralysing the terminations of the vagus in the heart muscle, +the latter as a cardiac tonic and a stimulant to the respiratory +centre. Some authorities have recommended the injection of +atropine by a long needle passed into the heart muscle, but +most are content to give either or both drugs hypodermically. +Really to paralyse the vagus, a very large dose of atropine is +required—about ¹⁄₃₀ gr. Strychnine should be given in a dose of +¹⁄₄₀–¹⁄₃₀ gr.</p> +</div> + + <div class="figcenter" id="i_p147" style="max-width: 465px"> + <img + class="p1" + src="images/i_p147.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 48b.</span>—Artificial respiration by +Sylvester’s method. Inspiration.</p> + </div> + +<div class="blockquot"> + +<p>(7) In cases where the right heart has certainly been +over-distended, the expedient of venesection has been tried. +Some six ounces may be withdrawn from the external jugular or +one of the veins of the arm.</p> + +<p><span class="pagenum" id="Page_148">[148]</span></p> + +<p>(8) As a last resort, <i>the heart may be massaged</i>. The only +practicable route is to open the abdomen (if not already done) +pass one hand under the left side of the vault of the diaphragm, +placing the other hand over the precordial region. Between the +two hands, the heart can first be thoroughly compressed to empty +its presumably flaccid and over-distended cavities, and then +lightly massaged. Several cases of recovery from this measure +are on record.</p> +</div> + + +<h3><b>Status Lymphaticus.</b></h3> + +<p>Before leaving the subject of accidents it may be well to allude +to this condition, which is also known as status thymicus, and as +lymphatism.</p> + +<p>It is met with mostly in the young, the commonest ages probably being +five to fifteen years. Certain pathological conditions have been found +in fatal cases, of which the most important are an enlargement of the +thymus gland, of various lymph glands, and of the tonsils, including +the naso-pharyngeal tonsil (adenoids). The heart muscle is frequently +degenerated. Of the cause of these abnormalities we are as yet in +doubt. There is some reason to believe that the condition tends to +disappear with advancing years, if the subject survive.</p> + +<p>The most outstanding clinical fact in connection with the disease +is its tendency to cause sudden death on very little provocation. A +fright, a sudden exertion, and above all an anæsthetic may cause sudden +and fatal syncope.</p> + + +<h4 class="smcap">Diagnosis.</h4> + +<p>Suspicion that the disease is present may be aroused in several ways. +The presence of enlarged tonsils and adenoids, combined with general +enlargement of lymph glands from no obvious cause, and a tendency +to faint, make a very suggestive picture. “Night-crowing” (a sudden +attack of laryngeal spasm,<span class="pagenum" id="Page_149">[149]</span> occurring at night, and often repeated +at intervals) also raises grave doubt. The diagnosis can only be +established with certainty by an X-ray photograph, when the great +enlargement of the thymus may be seen in the upper part of the chest.</p> + + +<h4 class="smcap">Anæsthetics in Status Lymphaticus.</h4> + +<p>Too frequently the condition has never been suspected, and a fatality +occurs from sudden syncope, usually during the induction period, but +occasionally during the progress of the operation. It would, however, +be fallacious to suppose that an anæsthetic is necessarily fatal even +to an undoubted case. If the drug (preferably ether) be given with +great care, and the operation done carefully at a level of anæsthesia +neither too light nor too deep, there is every reason to believe that +the danger can be, and often is, successfully averted.</p> + +<p>At the same time, it must be understood that in a known case, operation +should always be avoided or deferred if possible.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_150">[150]</span></p> + +<h2>CHAPTER XVII.<br> +<span class="subhed"><b>THE SEQUELÆ OF ANÆSTHESIA.</b></span></h2></div> + + +<h3><b>Respiratory System.</b></h3> + +<p>After operations performed under any form of anæsthesia, even spinal, +there is always a possibility of pneumonia or bronchitis. The +anæsthetic itself is not always to blame. The patient has suffered +trauma and is confined to bed, and may develop a hypostatic pneumonia +just as a person who has suffered from a fractured thigh so commonly +does, even though he has had no anæsthetic at all.</p> + +<p>It is probable that organisms, capable under certain circumstances of +causing inflammatory disease of the respiratory tract, are present +in a large proportion of apparently healthy people. Pneumococci and +streptococci of varying strains may be grown from nasal or pharyngeal +secretions of patients who suffer from catarrh of these regions, and +may reappear upon slight provocation even when prolonged treatment had +apparently banished them permanently. All that is required to start +an acute infection of lungs or bronchi, is some factor that depresses +vitality and lowers body resistance to the organism. And if in addition +use has been made of an inhalational anæsthetic such as ether, which +may cause an immediate and fairly acute congestion of the respiratory +mucous membranes, it is not to be wondered at that serious sequelæ +follow in a certain proportion of cases.</p> + +<p>Laboratory results go to show that ether lowers the opsonic index +of the blood to pneumococci and streptococci, but without placing +undue emphasis upon a mere isolated phenomenon such as<span class="pagenum" id="Page_151">[151]</span> that, it is +plain that the whole conditions of the patient after operation are +favourable to the occurrence of pneumonia or bronchitis, and that of +all anæsthetics ether is the most likely to be the determining factor.</p> + +<p>Experience gained during the war has thrown a certain amount of light +upon this subject. Post-anæsthetic bronchitis and pneumonia was +very prevalent among the wounded, far more so than among civilian +patients. It is, the author believes, reasonable to attribute this +fact to several causes. In the first place, the soldier’s life, +alternating between stuffy billets and wet trenches, predisposed him +to naso-pharyngeal catarrh of a fairly high degree of infectivity. +Enthusiastic press representatives might state that you could not take +cold so long as your feet and legs were always buried in half frozen +mud, but experience hardly bore out their golden promises. Again, the +soldier did not improve his catarrh by inveterate cigarette smoking. +Lastly, military hospitals were large institutions, some under canvas, +some in huts, some in buildings constructed for other purposes, and +rapidly altered to the urgent needs of the army. Of whatever type, +nearly all had one feature in common—many of the surgical wards were a +long (and draughty) way from the operating theatre.</p> + +<p>For the prevention of post-anæsthetic pneumonia, the author offers the +following tentative suggestions:—</p> + +<div class="blockquot"> + +<p>(1) See that the skin is kept covered up as much as possible +during the operation and that the patient is not exposed to +draughts during or after it. Rooms can, and should be, well +ventilated without cold draughts.</p> + +<p>(2) If a patient has an acute or sub-acute naso-pharyngeal +catarrh, treat it as fully as possible before operation by +sprays and gargles.</p> + +<p>(3) Do not use ether to patients who suffer or recently have +suffered from such conditions.</p> + +<p><span class="pagenum" id="Page_152">[152]</span></p> + +<p>(4) Give a hypodermic of morphia and atropine before operation +as a routine.</p> + +<p>(5) In so far as possible, let the patient’s shoulders and head +be raised by pillows during the early hours of convalescence.</p> + +<p>(6) Lastly, remember that while no care will absolutely banish +these dangerous sequelæ from our practice, the greater care +and skill shown by the anæsthetist, the less bronchitis and +pneumonia will appear among his patients. As regards ether, the +author believes that it is the strength of vapour used, more +than the duration of the anæsthesia, which counts. It is for +that, among other reasons, that he has for the induction period, +no hesitation in recommending a method whereby a small part of +the requisite ether strength is replaced by chloroform.</p> +</div> + + +<h3><b>Vomiting.</b></h3> + +<p>After an anæsthesia lasting more than a few minutes, it may almost be +regarded as normal for the patient to vomit once or twice. Usually this +occurs a few minutes after the administration has ceased. In the case +of nitrous oxide and oxygen, even this slight disturbance may not occur.</p> + +<p>The amount of vomiting which after this stage may be regarded as +normal is difficult to determine. The author took notes of some 300 +cases on this point. The details of his results are not suitable for +a text book, but, broadly speaking, it would appear that after an +operation of ordinary duration and severity, the vomiting returns on +the average some five or six times, and usually ceases on the evening +of the operation day. A limited number continue to vomit at intervals +until the early hours of the following morning. With nitrous oxide +and oxygen the vomiting is far less than the above, though even with +this anæsthetic quite severe emesis may occur. With closed-ether, the +trouble is very violent<span class="pagenum" id="Page_153">[153]</span> for a short time, large quantities of mucous +being ejected: it is probable that after the first two hours, it is no +more marked than after open methods. The use of morphia and atropine +before operation most certainly reduces the violence and duration of +this sequela.</p> + +<p>Prolonged more than twenty-four hours, the condition must be regarded +as definitely abnormal.</p> + + +<h4 class="smcap">Prevention and Treatment.</h4> + +<p>The adoption of open-ether preceded by morphia and atropine and due +skill and thought on the part of the anæsthetist, combined with proper +preparation of the patient, are the only means of prevention at our +command.</p> + +<p>The raised position of the head and shoulders during the recovery +stage undoubtedly tends to reduce the nuisance. It is a vexed question +whether to give or to withhold fluids after operation—and this matter +is of course in the hands of the surgeon, not the anæsthetist. In +certain cases, the author believes that it is worth while trying the +effect of a cup of fresh tea with very little sugar or milk. Even if +rejected in a few moments, the astringent effect of the infusion seems +to soothe the gastric mucous membrane, and give relief.</p> + + +<h3><b>Post-operative Acidosis.</b></h3> + +<p class="center">(Synonym—Delayed Chloroform Poisoning).</p> + +<p>In a limited number of cases, post-operative emesis assumes a grave +type, and definitely threatens life. Such cases began to be studied +in the early part of this century, and though our knowledge of the +condition is still incomplete, the student should be acquainted with +the present views held upon the subject.</p> + +<p>Clinically, the earliest symptom to raise suspicion, is the +reappearance of vomiting at a time when one would expect such trouble +to have abated, usually twenty-four or thirty-six hours<span class="pagenum" id="Page_154">[154]</span> after +operation. Within a few hours, the nature of the vomit changes from +the usual bilious stomach contents, and shows obvious evidence of the +presence of <i>altered blood</i>. The pulse and temperature begin to +rise, the countenance assumes an anxious look. A trace of jaundice is +usually present. The nervous system becomes affected as shown first in +restlessness, and later, delirium. Every degree of this condition is +possible, but a very large proportion of recognisable cases pass into +coma, and death supervenes within a few days, sometimes less.</p> + +<p>Investigation into such cases has shown that the essential underlying +condition is an acidosis closely allied to that seen in diabetic coma. +The breath has the peculiar sweetish aroma of acetone, and acetone, +diacetic acid, and B. oxybutyric acid successively appear in the urine.</p> + +<p>Post-mortem, the most striking change found is a profound fatty +degeneration of the liver, the cells of which are disintegrated as in +acute yellow atrophy.</p> + +<p>It is obvious from the foregoing that there is present a very +remarkable abnormality of metabolism. Mr Rendle Short, in his admirable +book, <i>The New Physiology in Surgical and General Practice</i>, gives +the following explanation of the condition:—</p> + +<p>“The physiological process of dealing with fat is to resolve it into +carbon di-oxide and water. If we make a pound of fat into tallow +candles and burn it, we shall obtain carbon di-oxide and water, and a +certain amount of heat will be evolved. If the pound of fat is eaten +and absorbed by a man or an animal, it will be burnt to the same end +products, and the same amount of heat will be given out. But in certain +circumstances, an abnormal mode of breaking down is followed, and +there are produced, first B. oxybutyric acid, then diacetic acid, and +finally acetone. If this takes place on a large scale, the conversion +into acetone fails to keep pace with the production of acids. Therefore +first acetone appears in the urine, then diacetic acid, and finally<span class="pagenum" id="Page_155">[155]</span> +oxybutyric acid; the last may rise rapidly to an enormous figure: 30, +50, or even 180 grams may be passed daily.”</p> + +<p>Later in the same chapter, Short propounds the question as to what are +the special circumstances in which the breaking down of fat deviates +from its normal course, and follows this dangerous route. The answer +is, he says, quite definite and decisive. When the tissues are unable +to obtain sugar from the blood, fat is broken down <i>via</i> these +dangerous acids to acetone, instead of to carbon di-oxide and water.</p> + +<p>Such an inability on the part of the tissues to obtain sugar arises +under several conditions:—</p> + +<div class="blockquot"> + +<p>(<i>a</i>) In diabetes, where sugar though freely present in +the blood cannot, for some reason still not clearly known, be +assimilated by the tissues.</p> + +<p>(<i>b</i>) In poisoning by salicylates.</p> + +<p>(<i>c</i>) In starvation, for obvious reasons. The supply of +sugar from the liver has been used up, and the patient, living +on his own fats, breaks them up abnormally.</p> + +<p>(<i>d</i>) In post-anæsthetic poisoning, for reasons which are +at present not clearly ascertained.</p> +</div> + +<p>Upon the theoretical side it is therefore not possible to say more than +that anæsthetics sometimes initiate this abnormal metabolic process. To +the question as to why and how they do so, we can as yet give no answer.</p> + +<p>Upon the practical side, we can, however, speak much more definitely. +Acidosis follows the use of ether very rarely indeed: after nitrous +oxide it is unknown. Chloroform has been the drug used in almost every +recorded case, while ethyl chloride has been responsible in a few +isolated instances. Young children are much more prone to suffer than +adults, though the author had a fatal case in a lady well over forty +years of age: he has also seen a case very nearly fatal in a soldier +aged twenty. This man<span class="pagenum" id="Page_156">[156]</span> was, a week after recovery from acidosis, +anæsthetised for half-an-hour with nitrous oxide and oxygen, without +exhibiting any signs of a return of his dangerous condition. Anæsthesia +repeated in the same subject after a short interval is more prone +to start the process than a first inhalation. Lastly, acute sepsis, +particularly in the young, is notorious for its liability to be +followed by acidosis.</p> + + +<h4 class="smcap">Prevention and Treatment.</h4> + +<p>The obvious moral of the foregoing is that chloroform should not be +administered to patients suffering from acute sepsis, particularly if +they be very young. Indeed, so common is a mild degree of acidosis +among children, some surgeons consider there is a definite risk in +giving chloroform to them at all unless special precautions are taken. +Chief among these are regular dosage for a day or two before operation, +with considerable doses of bicarbonate of soda and sugar, which is a +routine measure in some children’s hospitals.</p> + +<p>As regards curative treatment, much can be done if the gravity of the +condition is recognised early. The stomach is first washed out with +alkalis, and a substantial dose (one dram) of bicarbonate of soda left +in it. The same dose is repeated hourly by the mouth, if retained, or +per rectum. A useful addition to the alkaline treatment is dextrose, +also in teaspoonful doses. In grave cases, these drugs should be given +intravenously in saline solution.</p> + +<p>These measures combined with warmth, and ample fluids by mouth or +rectum, will often save life, but to be of any value they must be +begun early. Fulminating cases occur which succumb rapidly in spite of +treatment.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_157">[157]</span></p> + +<h2>CHAPTER XVIII.<br> +<span class="subhed"><b>POSTURE OF THE PATIENT.</b></span></h2></div> + +<p>The position in which the patient is lying is of as much importance to +the anæsthetist as to the surgeon. It is for the surgeon to say what +he wants and for the anæsthetist to realise how his own work will be +thereby affected.</p> + + +<h3><b>Dorsal Decubities.</b></h3> + +<p>This is the ordinary position and calls for no extended comment. The +pillows must be so arranged that at no spot is the body acutely flexed +or extended. Abdomen, thorax, neck, and head must all be roughly in a +straight line.</p> + +<p>Deep-chested subjects require a higher pillow than those with shallow +chests, otherwise the neck is bent back and respiration obstructed.</p> + +<p>The arms should either be folded and retained by a bandage or other +device over the chest, or extended so that the hands can be slipped +under the buttocks and retained there by the body weight. An arm which +is allowed to hang over the side of the table is likely to show next +day and for many months afterwards, the condition of drop-wrist from +musculo-spiral paralysis.</p> + + +<h3><b>Face-down Position.</b></h3> + +<p>This is an awkward position for the anæsthetist; there being a general +tendency to respiratory embarrassment. Put a pillow under the upper +part of the thorax, leaving the lower part and the abdomen as free as +possible. Let the head project from the pillow, so that the face can be +got at without undue rotation of the neck. The intratracheal method is +a great help.</p> + +<p><span class="pagenum" id="Page_158">[158]</span></p> + + +<h3><b>Lateral Position.</b></h3> + +<p>This may be called for either with or without the addition of a +sand-bag or inflatable air-pillow to push the loin upwards. In either +case, there is a tendency for the upper shoulder to fall forwards, the +position then assimilating itself to the face-down position. This is +best met by a support fixed to the table, upon which the upper arm may +be rested. Failing such a convenience, a sand-bag may be pushed in to +keep up the shoulder, or the assistance of a nurse may be required.</p> + + +<h3><b>The Trendelenburg Position.</b></h3> + +<p>Slight tilting of the head end of the table downwards is often useful +in assisting the return of bowel into the abdomen: in this position, +the patient usually takes the anæsthetic very well. It must not be +assumed until the third stage of anæsthesia is reached.</p> + +<p>For many gynæcological operations, however, the full Trendelenburg +position is required. Healthy subjects usually do quite well in it, but +stout persons not uncommonly show a good deal of cyanosis. At the close +of the operation it is essential to restore the table to the horizontal +<i>slowly</i>: the physics of the circulation are profoundly modified, +and if any serious degree of shock is present, rapid return to normal +may initiate a collapse.</p> + +<p>In the full position, the weight of the body should be taken by metal +supports attached to the table against which the shoulders may rest. To +hang the entire weight of the body upon the legs may cause a good deal +of after-suffering to the patient.</p> + + +<h3><b>The Sitting-up Position. (<i>See</i> Fig. <a href="#i_p159">49</a>.)</b></h3> + +<p>The object of this position is to diminish venous engorgement and +bleeding in operations requiring delicate dissection in the region of +the neck. Prof. Alexis Thomson introduced the position into Edinburgh +surgery: the author was at first rather nervous of<span class="pagenum" id="Page_159">[159]</span> it, but has found +that with proper precautions the patients do uncommonly well. Beyond +all doubt, the position is a great help to the work of the surgeon.</p> + +<p>Not every surgical table is capable of giving the full position without +the use of many pillows and sandbags. The head-piece of the table is +tilted up at an angle of about 75° or even 80°, and the patient pulled +up so that the flexion of the body occurs in the lumbar, not the dorsal +spine. A small sand-pillow is placed behind the neck so as to produce +slight extension. Another heavier one is placed under the thighs to +prevent the body slipping down. A slight tilt downwards towards the +head end may be given to the table as a whole with the same object.</p> + + <div class="figcenter" id="i_p159" style="max-width: 462px"> + <img + class="p1" + src="images/i_p159.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 49.</span>—Sitting-up posture for operations on +the neck.</p> + </div> + +<p>One should not in this position attempt to induce a deep chloroform +anæsthesia. Weak C.E. mixture at most, but better simply open-ether is +the method of choice. The induction is<span class="pagenum" id="Page_160">[160]</span> begun with the shoulders raised +to a modified degree, and the full position assumed in a light third +stage anæsthesia.</p> + +<p>Intratracheal ether combined with this position is an ideal anæsthesia +for the removal of goitre or extensive dissections in the neck for +enlarged glands.</p> + + +<h3><b>O’Malley’s Position for Nasal Surgery. (<i>See</i> Fig. <a href="#i_p160">50</a>).</b></h3> + +<p>The author became acquainted with this useful position while acting as +Anæsthetist at the Royal Herbert Hospital, Woolwich, where the Nose +and Throat Department was under the charge of Major O’Malley, F.R.C.S. +Major O’Malley was kind enough in a recent letter written by request to +refresh the author’s memory of the details.</p> + + <div class="figcenter" id="i_p160" style="max-width: 578px"> + <img + class="p1" + src="images/i_p160.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig. 50.</span>—O’Malley’s posture for intra-nasal +surgery.</p> + </div> + +<p>With the patient lying as shewn in the photograph, every part of the +interior of the nose can be easily inspected by the surgeon; the +elevation of the head and shoulders prevents undue bleeding, and +such hæmorrhage as does occur goes down the gullet, where it does no +particular harm, instead of into the larynx. The degree<span class="pagenum" id="Page_161">[161]</span> of flexion +of the head upon the neck is not so extreme as to interfere with +respiration.</p> + +<p>The details of O’Malley’s procedure are as follows:—</p> + +<p>The interior of the nasal cavities are packed with gauze soaked in +adrenalin and novocain a quarter of an hour before operation, and the +patient receives a very small dose of morphia and atropine immediately +before anæsthesis is induced; given in this way it does not complicate +the induction with chloroform to the same extent as if given earlier. +The patient lies with the top of the head level with the top of the +table, and the head and shoulders (including the upper two-thirds of +the shoulder blades) supported on the usual depth of pillow. Induction +is by chloroform or mixture; a very light third stage only is aimed +at. When it is attained the mouth is opened by a gag, and Phillip’s +Oral Airway inserted (<i>see</i> Fig. <a href="#i_p023b">8</a>). Strict oral respiration is +essential to success. If air is passing in and out of the nose, blood +is spluttered all over the surgeon, seriously interfering with the +harmony of the proceedings. Junker’s chloroform bottle is ready, and +the end of the supply pipe is passed into one of the side holes in the +air way.</p> + +<p>The head of the table is now elevated to an angle of 45°, and a small +sand pillow slipped behind the occiput. The gauze is removed from the +nose, and the operation can be performed with great comfort.</p> + +<p>The circulation of the patient needs careful watching for the first +minute or two after the table head has been elevated, but thereafter +there is usually no special cause for anxiety. The area of operation +is locally anæsthetised by the action of the novocain and a light +chloroform sleep only is required.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_162">[162]</span></p> + +<h2>CHAPTER XIX.<br> +<span class="subhed"><b>CHOICE OF ANÆSTHETIC.</b></span></h2></div> + +<p>In considering this matter, some repetition of points to which +reference has already been made, is inevitable. Indeed, this chapter +may be regarded as a revision of the whole subject.</p> + +<p>Before deciding upon drug and method suitable for the individual case, +we must consider the age and sex, the physical type and temperament, +the possible presence of some definite pathological condition, and the +nature and duration of the operation.</p> + +<p>In relation to this last point, we must remember that an anæsthesia +must be adequate to the purpose of the surgeon, but that it is improper +to incur more risk to life than is necessary. For instance, an +abdominal section case must be fully relaxed, and if in an individual +case, chloroform is the only drug which will give that effect, there +need be no hesitation in using it. On the other hand, many other +methods with a far smaller mortality rate are available if all that is +required is the extraction of a tooth or the incision of an abscess, +and in that group of cases, unfamiliarity with such anæsthetics as +nitrous oxide or “ethyl chloride and ether” will not be held as a +sufficient defence if chloroform has been given with a fatal effect.</p> + + +<h3><b>Normal Subjects.</b></h3> + +<p>Let us take first the case of the healthy adult about to undergo a +<i>major</i> operation. For this, we unhesitatingly choose what we may +term the “stock” method—open-ether preceded by morphia and atropine.</p> + +<p><span class="pagenum" id="Page_163">[163]</span></p> + +<p>If the operation be <i>brief</i>, we have a choice of methods. For +the extraction of teeth, where access to the mouth is essential, the +following table will help:—</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="ctrtrbl smcap">Anæsthetic Drug and Method.</td> + <td class="ctrtrb">Duration of Available Anæsthesia, when given as “Single<br>Dose.”</td> + <td class="ctrtrb smcap">Remarks.</td> + </tr> + + <tr> + <td class="chtrl">Nitrous oxide</td> + <td class="chtr">30 to 40 seconds</td> + <td class="chtr"></td> + </tr> + + <tr> + <td class="chtrl">Nitrous oxide and<br>oxygen</td> + <td class="chtr">40 to 50 seconds</td> + <td class="chtr"></td> + </tr> + + <tr> + <td class="chtrl">Ethyl chloride</td> + <td class="chtr">70 to 90 seconds</td> + <td class="chtr">Only to be recommended in special cases (<i>see</i> page <a href="#Page_127">127</a>).</td> + </tr> + + <tr> + <td class="chtrl">Gas and ethyl chloride</td> + <td class="chtr">70 to 90 seconds</td> + <td class="chtr"></td> + </tr> + + <tr> + <td class="chtrl">Gas-oxygen and ethyl<br>chloride</td> + <td class="chtr">70 to 90 seconds</td> + <td class="chtr"></td> + </tr> + + <tr> + <td class="chtrl">Gas and ether</td> + <td class="chtr">Anything up to 2 to 5 minutes according to duration of inhalation</td> + <td class="chtr">May cause after vomiting.</td> + </tr> + + <tr> + <td class="chtrl">Ethyl chloride and ether</td> + <td class="chtr">Anything up to 2 to 5 minutes according to duration of inhalation</td> + <td class="chtr">May cause after vomiting. More portable.</td> + </tr> + + <tr> + <td class="chtrl">Nasal gas</td> + <td class="chtr">5 to 10 minutes (not a “single dose” anæsthetic)</td> + <td class="chtr">Requires considerable practice to give well.</td> + </tr> + + <tr> + <td class="chtrbl">Nasal gas and oxygen</td> + <td class="chtrb">No limit</td> + <td class="chtrb">Easier to give than above but apparatus rather importable.</td> + </tr> +</table> + +<p>In cases where access to the mouth is not required, and where it is +therefore unnecessary to “charge up” the patient with anæsthetic, we +have also a choice which may be expressed tabularly:—</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="ctrtrbl smcap">Anæsthetic.</td> + <td class="ctrtrb smcap">Remarks.</td> + </tr> + + <tr> + <td class="chtrl">Nitrous oxide</td> + <td class="chtr">Apparatus simple: short administration can be +mastered easily. A little more practice required +for cases prolonged by admitting air. Muscles +not relaxed, and patient may move when cut.<span class="pagenum" id="Page_164">[164]</span></td> + </tr> + + <tr> + <td class="chtrl">Nitrous oxide and oxygen</td> + <td class="chtr">Apparatus more complicated, but short administrations + present no great difficulty to the beginner. | + Muscles not completely relaxed unless a little | + ether added.</td> + </tr> + + <tr> + <td class="chtrl">Gas and ether</td> + <td class="chtr">Quick and safe anæsthetic. Deep anæsthesia + may be obtained if ether is “pushed.”</td> + </tr> + + <tr> + <td class="chtrbl">Ethyl chloride and ether</td> + <td class="chtrb">The same. More portable than above.</td> + </tr> +</table> + +<p>In this group of short operations, special reference must be made to +the <i>reduction of dislocations</i>. Here two important features +require notice. The whole object of the proceeding is to relax muscles, +and therefore nitrous oxide or gas-oxygen are unsuitable. Secondly, +the tendency to reflex syncope just at the moment of reduction is very +great. For this reason, chloroform has here a painfully high mortality +rate; closed-ether, preceded by gas or ethyl chloride, is undoubtedly +the method of choice.</p> + + +<h3><b>The Extremes of Age.</b></h3> + +<p>Children up to the age of ten years take ether badly, salivation +and bronchial secretion being sometimes very troublesome. Atropine +mitigates this nuisance to a limited degree only. Chloroform is the +best drug up to five or six years; from five to ten, mixture; after +that, open ether.</p> + +<p>In children of any age, suffering from acute sepsis, the immediate +annoyances and possible respiratory sequelæ of ether must be faced +(<i>see</i> page <a href="#Page_156">156</a>), owing to the probability of acidosis.</p> + +<p>As regards short anæsthetics in children, nitrous oxide, if given at +all, should be freely diluted with oxygen, otherwise most undesirable +cyanosis will occur. To children under three or four, even gas-oxygen +is of doubtful safety. Short anæsthesias in such cases may be induced +by open ethyl chloride, with a few drops of ether added.</p> + +<p><span class="pagenum" id="Page_165">[165]</span></p> + +<p>Old people are, unless very feeble, best anæsthetised by a mixture of +chloroform and ether. Whatever anæsthetic be chosen, the utmost care +must be taken to avoid cyanosis. A cylinder of oxygen should be at hand +from which to enrich the atmosphere breathed, by trickling the gas into +the mouth through a rubber tube, and is a great safeguard in dealing +with the old.</p> + + +<h3><b>Sex.</b></h3> + +<p>On the average, women take anæsthetics much better than men, being far +less liable to jaw clenching and other forms of mechanical asphyxia, +and showing less excitement during the induction stage. In the female +subject induction by open-ether requires very little assistance from +C.E. mixture.</p> + + +<h3><b>Physical Type and Temperament, and Habits of Life.</b></h3> + +<p>Heavily built muscular men are troublesome subjects. Induction requires +a rather strong vapour of ether: if the open method is used, there may +be to the beginner much temptation to make use during the induction +stage of C.E. mixture to an extent not contemplated in the description +given of that method in chapter <span class="allsmcap">IX.</span>: it is therefore wise to +induce either with closed-ether or with C.E. mixture as described in +chapter <span class="allsmcap">XV.</span>, and to change to the perhalation method only when +full anæsthesia is attained.</p> + +<p>As regards alcoholics and excessive smokers, these are well dealt with +by the C.E. open-ether sequence. Recourse may be made to the Ormsby +inhaler as already explained on page 137. The reader is warned not to +be deceived by the stout, rosy face of the typical alcoholic. He often +looks a great deal stronger than he really is. Many such are really +feeble subjects: although they shout and struggle no great addition +to the usual vapour strength of anæsthetic is safe or required: what +<i>is</i> required, is a little extra time. Once fully under, the +robust appearance of the<span class="pagenum" id="Page_166">[166]</span> patient disappears, and the fact that one is +dealing with a rather broken constitution and a poor circulation is +obvious.</p> + +<p>Reference has already been made to the fact that persons with defective +nervous systems, neurotics, and especially epileptics, show persistence +of some muscular movements for some time, and therefore require very +careful watching.</p> + + +<h3><b>Special Operations and Pathological Conditions in the Patient.</b></h3> + +<p>These are of the utmost importance, but to consider each fully from +the anæsthetic point of view, would lead us into great detail. The +anæsthetist must acquaint himself with any abnormality present, and +consider it carefully in the light of the general principles already +explained. The following very brief hints for selected cases and +operations may, however, be found useful.</p> + + +<h4 class="smcap">Upper Air Passages.</h4> + +<p><i>Artificial teeth.</i> Must be removed before inducing.</p> + +<p><i>Tongue and jaw cases.</i>—Intratracheal ether the best—failing +that, rectal oil ether, or Junker’s inhaler.</p> + +<p><i>Nasal operations.</i>—If adrenalin is to be used, it must precede, +not follow, chloroform—many fatalities have occurred from injecting +or even packing with adrenalin in light chloroform narcosis. Some +surgeons object to ether because of the bleeding, but this can be +largely remedied by raising the head and shoulders, and by packing with +adrenalin. Many surgeons prefer local to general anæsthesia.</p> + +<p><i>Nasal insufficiency.</i>—Don’t allow a patient to continue to make +ineffectual attempts to breathe through a narrow nose. Establish mouth +breathing, or use Silk’s tubes (<i>see</i> Fig. <a href="#i_p023c">9</a>).</p> + +<p><i>Tonsils and adenoids.</i>—Give ethyl chloride by the vapour method.</p> + +<p><i>Tumours and inflammatory swellings obstructing respiration.</i>—<span class="pagenum" id="Page_167">[167]</span> +Don’t use closed methods. Have tracheotomy instruments at hand, and a +cylinder of oxygen.</p> + +<p><i>Gôitres, especially exophthalmic gôitre.</i>—Don’t use chloroform: +it has caused many fatalities; morph-atropine, followed by open-ether +is the safest. In bad cases, use rectal oil ether if intratracheal is +not available. The “sitting up posture” is a great help (<i>see</i> +page <a href="#Page_168">168</a>). Use anoci-association if surgeon is willing.</p> + + +<h4 class="smcap">Chest.</h4> + +<p><i>Bronchitis and pneumonia</i> (<i>see</i> remarks in chapter +<span class="allsmcap">XVII</span>).</p> + +<p><i>Emphysema and rigid chest wall.</i>—Patients take anæsthetics +badly; they cyanose quickly, the abdominal wall cannot be made either +lax or quiet, since the patient’s natural method of respiration is +abdominal rather than thoracic. Lastly, there is frequently a dilated +heart with degenerate cardiac muscle, giving an abnormal tendency to +secondary syncope. Give a trickle of oxygen through a tube from a +cylinder: don’t be tempted to overdose with anæsthetic in the vain hope +of securing ideal relaxation of the abdominal wall.</p> + +<p><i>Empyæma.</i>—Be careful: a good many accidents have happened. Use +chloroform with added oxygen: aim at an anæsthesia just deep enough +to prevent straining which might rupture the empyæma into the lung +and drown him in his own pus. Withdraw the anæsthetic as soon as the +abscess is opened.</p> + +<p><i>Phthisis.</i>—Don’t use closed-ether: it may start +hæmorrhage—open-ether rarely does any harm unless the condition is +very acute.</p> + + +<h4 class="smcap">Circulatory System.</h4> + +<p><i>High tension, arterio-sclerosis, and aneurysm.</i>—Avoid pure +nitrous oxide: in severe cases, C.E. mixture and oxygen is the safest.</p> + +<p><i>Heart.</i>—Well compensated cases of <i>valvular disease</i> +take chloroform or open-ether well, provided a free air-way is +maintained.<span class="pagenum" id="Page_168">[168]</span> Closed methods should be avoided. Cases of <i>myocardial +disease</i> with dilated cavities present special dangers. Open-ether +with added oxygen meets the case better than any other anæsthetic. +<i>Pericarditis</i>, both acute and chronic, has been found as the +determining factor in many anæsthetic fatalities.</p> + + +<h4 class="smcap">Acute Infectious Disease.</h4> + +<p><i>Febrile patients</i> absorb anæsthetics very rapidly and therefore +go under very quickly. Acute septic cases must not have chloroform +or ethyl chloride (<i>see</i> page <a href="#Page_155">155</a>): nitrous oxide and oxygen is +ideal, ether the next best. Patients who have suffered from acute +infectious disease, especially diphtheria and influenza, may present +some weakness of heart muscle for many months after the attack.</p> + + +<h4 class="smcap">Exhausted and Shocked Cases.</h4> + +<p>Give nitrous oxide and oxygen if possible—failing that, ether. +Closed-ether sometimes does very well for the induction stage.</p> + + +<h4 class="smcap">Diabetes.</h4> + +<p>Chloroform is wholly inadmissible.</p> + + +<h4 class="smcap">Genito-urinary System.</h4> + +<p><i>Kidneys.</i>—Avoid ether in acute or sub-acute nephritis: give it, +however, for nephrectomy when the other kidney is sound.</p> + +<p><i>Bladder.</i>—Distending the bladder with lotion often causes reflex +inhibition of respiration: if that happens, stop the anæsthetic, give +artificial respiration, and ask the surgeon to get on with opening +the bladder. <i>Morphia</i> usually arrests temporarily the secretion +of urine: it should therefore not be given if chromocystoscopy or +catheterisation of the ureters is contemplated.</p> + +<p><i>Prostatectomy cases</i> are often rather broken subjects: give +a fairly deep anæsthesia until the shelling out of the prostate is +begun: then be careful—the patient is breathing deeply as a rule,<span class="pagenum" id="Page_169">[169]</span> +and can readily get an overdose. He will inevitably suffer a fair +amount of shock: be ready to lower the table at the head end if any +serious collapse occurs. Don’t be shy of starting a little artificial +respiration even though the natural function is not entirely abolished.</p> + +<p><i>Circumcision</i> usually causes a good deal of laryngeal spasm, +especially in children. Don’t try to abolish this by deepening the +anæsthesia. You won’t succeed unless you nearly kill the patient. Rub +the lips, and if very severe ask the surgeon to stop a minute until the +crowing becomes less.</p> + +<p><i>Castration.</i>—Always give ether, or gas-oxygen. Castration and +reduction of dislocation are the two commonest causes of reflex syncope +under chloroform.</p> + + +<h4 class="smcap">Menstruation, Pregnancy, and Labour.</h4> + +<p>It is usual to avoid anæsthetics during the menstrual period if +possible, the nervous system being unlikely to be at its best at that +time.</p> + +<p>Pregnant patients take no harm from an anæsthetic properly given, +but undue cyanosis must be avoided or abortion may occur. The pains +of labour may be alleviated by chloroform given to an early second +stage only, or by “twilight sleep” (<i>see</i> page <a href="#Page_44">44</a>). For the major +operations of obstetrics, however, ether has its usual advantages, +provided no bronchitis be present. The shock of such operations as a +difficult version is considerable, and quite sufficient to call for +ether rather than chloroform.</p> + +<div class="blockquot"> + +<p><i>Indication for Local and Spinal Anæsthesia.</i>—The +foregoing has been written in reference to inhalational +anæsthesia solely. Mr Wood has indicated in chapters +<span class="allsmcap">XX.</span> and <span class="allsmcap">XXI.</span> the class of case in which the +methods he describes are to be preferred.</p> +</div> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_170">[170]</span></p> + +<h2>CHAPTER XX.<br> +<span class="subhed"><b>LOCAL ANÆSTHESIA.</b></span></h2></div> + +<p>By the term local anæsthesia, or more correctly <i>local analgesia</i>, +is meant the loss of sensibility to painful stimuli without loss of +general consciousness. It may be induced in a considerable number +of ways, but for practical purposes there are only four methods of +value:—(1) by infiltration of the tissues to be operated upon by a +solution of the drug, (2) by injecting the solution into or around +the nerve trunks supplying the part, (3) by painting the solution on +a mucous surface, and (4) by the application of intense cold. The +last method has only a limited application. The method of injecting +the anæsthetic into the blood vessels of the part is still in the +experimental stage and is not to be recommended for general use.</p> + +<p>It is advisable first to consider the behaviour of the principal drugs +which are employed.</p> + + +<h3><b>Cocaine.</b></h3> + +<p>This was the first drug to be widely used for the production of +local anæsthesia. It is an alkaloid occurring in the leaves of +<i>Erythroxylon Coca</i>. It is only slightly soluble in water—about +1 in 1300, but the hydrochloride of cocaine is freely soluble, and it +is this salt that is commonly used for aqueous solutions. The solutions +do not keep well, and should be made up shortly before being used. The +drug is decomposed by boiling.</p> + +<p><span class="smcap">Action.</span>—When a solution of cocaine is injected into the +tissues, the sensory nerve endings become anæsthetic over the area into +which the drug penetrates, direct paralysis of the nerve<span class="pagenum" id="Page_171">[171]</span> terminals +being produced. When it is injected into or around a nerve trunk it +blocks the transmission of nerve impulses. When it is applied locally +to a mucous membrane, it produces, besides a loss of sensation, a +feeling of constriction and a distinct pallor and contraction of the +vessels, which point to a local action on the vessel walls. The drug is +very frequently applied to the eye. There it produces not only local +anæsthesia, but also contraction of the conjunctival vessels, and this +is followed by dilatation of the pupil and often by partial loss of the +power of accommodation.</p> + +<p><span class="smcap">Cocaine Poisoning.</span>—Certain patients show an idiosyncrasy +to the action of cocaine, and the greatest care must be exercised +in its use. Absorption of small quantities usually causes mental +excitement. The patient becomes restless and garrulous, and a feeling +of happiness may be produced, but in other cases the patient becomes +anxious and confused. In some patients a small dose is followed by a +calm languorous state, resembling that produced by morphia, but with +less tendency to sleep. The pulse is accelerated, the respiration is +quick and deep, and the pupils are dilated. When poisonous doses have +been administered, the heart becomes extremely accelerated, powerful +tonic or clonic convulsions supervene, the breathing becomes rapid +and shallow, and may be finally arrested during a convulsion. In some +cases a different set of symptoms are observed, fainting and collapse +occur, and convulsive seizures are almost entirely absent. The heart +is slow and and weak, the respirations are slow and shallow, the skin +is cyanotic and cold, and death takes place from gradual arrest of +respiration.</p> + +<p><span class="smcap">Treatment.</span>—The treatment consists in endeavouring to +encourage the action of the heart by every possible means. The patient +is placed flat on his back, if he is not already in this position, +hypodermic injections of ether and strychnine are administered, and hot +coffee given by the mouth; warmth is of<span class="pagenum" id="Page_172">[172]</span> great importance. Artificial +respiration is commenced if respiration begins to fail. There is no +specific antidote to cocaine.</p> + +<p><span class="smcap">Dosage.</span>—The maximum dose of cocaine that can be given with +safety is 3/4 of a grain. The amount of solution that may be employed +depends upon the strength. To make a 1 per cent solution, 1 gr. of +cocaine hydrochloride is dissolved in 110 minims of distilled water +or half strength normal saline; from these proportions the amount of +cocaine in a given solution can be calculated. It will be seen that +the amount of cocaine solution, even with strengths as weak as ½ or ¼ +per cent, that can be used with safety is small and insufficient to +anæsthetise an area of any great extent. Owing to its toxicity cocaine +has largely fallen out of use for the production of infiltration or +regional anæsthesia, though it is still widely used in ophthalmic +surgery and in the surgery of the ear, nose and throat.</p> + + +<h3><b>Novocaine.</b></h3> + +<p>This drug is immensely superior to cocaine for ordinary surgical +purposes. It is the hydrochloride of a synthetic base, its chemical +formula being C<sub>13</sub>H<sub>20</sub>N<sub>2</sub>O<sub>2</sub>, HCl. It is soluble in water 1 +in 1, and can be heated to 120°C without decomposition. Its solutions +possess slight antiseptic properties, and are capable of repeated +boiling without affecting their strength. They may be kept for several +months without suffering any change in their action, a quality not +possessed by any other anæsthetic agent.</p> + +<p>The <i>toxicity</i> of novocaine is one-fifth or one-seventh of that +of cocaine. When used in conjunction with adrenalin, its anæsthetic +activity is equal to that of cocaine. When injected into the tissues +it produces no irritant effects like certain other local anæsthetics, +notably stovaine. For the production of local anæsthesia it is used in +½ per cent. solution with the addition of three or four minims of 1 in +1000 solution of adrenalin chloride to each ounce.<span class="pagenum" id="Page_173">[173]</span> Several ounces of +this preparation may be used with the greatest safety.</p> + +<p>Allen makes the following statement regarding this drug:—“After a +rather extended experience, including a large number of cases embracing +the entire field of surgery, in which this agent has been almost +exclusively used, we have failed to note a single case in which there +has been any unpleasant local or constitutional action. We, therefore, +feel thoroughly justified in unqualifiedly recommending it as the +safest, most reliable, and satisfactory of any local anæsthetic agent +yet introduced.”</p> + + +<h3><b>Tropacocaine.</b></h3> + +<p>This drug was first isolated from the leaves of the coca plant of Java, +but is now prepared synthetically. Its formula is C<sub>15</sub>H<sub>19</sub>NO<sub>2</sub>. +Its action is exactly the same as that of cocaine, except that it +is one-half as toxic and the duration of anæsthesia is shorter. The +hydrochloride is freely soluble in water, and can be boiled without +fear of decomposition. It is the agent which is most suitable for +spinal anæsthesia, as fewer unpleasant effects have followed its use +than that of any other drug.</p> + + +<h3><b>Stovaine.</b></h3> + +<p>Stovaine is the hydrochloride of a synthetic compound of the benzoyl +group. It occurs as a white crystalline powder, soluble in water, 1 in +14. Its solutions withstand boiling, but are decomposed when heated +to 120°C. Its action is the same as that of cocaine, except that it +is slightly less toxic and less powerful. It has a distinct irritant +effect locally. When injected in dilute solution, it produces a slight +burning pain before anæsthesia appears, and very often a distinct +inflammatory reaction persists for some time after the operation. It is +therefore unsuited for local anæsthesia. It has been widely used for +the production of spinal anæsthesia, especially by the French school, +but since its injurious effects on<span class="pagenum" id="Page_174">[174]</span> nerve tissues have become more +apparent, it has been less used than formerly.</p> + + +<h3><b>Eucaine.</b></h3> + +<p>Eucaine was introduced as a substitute for cocaine, and, before the +introduction of novocaine, was extensively used. It has a similar +action to cocaine, and although it is less toxic, it is by no means +free from danger unless it is used in very dilute solutions. It is a +vaso-dilator, and must therefore be used in combination with adrenalin. +It can be boiled without undergoing decomposition, and is practically +non-irritant. It has been largely superseded by novocaine.</p> + + +<h3><b>Quinine and Urea Hydrochloride.</b></h3> + +<p>The use of this drug for purposes of local anæsthesia is still in the +experimental stage. It is made by adding urea to a solution of quinine +in hydrochloric acid. The crystals are soluble in their own weight of +water. For the production of local anæsthesia it is used in strengths +of ·25 to 1 per cent. It is free from toxic effects, and its solutions +can be sterilised by boiling.</p> + +<p>The striking feature about this drug is the extraordinary duration of +the anæsthesia, this being from one to six days. It has therefore been +used by Crile and other American surgeons to prevent pain during the +first few days after operation. The great drawback to its use, however, +is that it causes a persistent indurated condition of the tissues which +interferes with primary union, and which is sometimes followed by +actual sloughing. In addition, it is now established that its use has +been followed by tetanus in several cases, and it is recommended that a +dose of antitetanic serum should be given immediately before or after +the injection of quinine.</p> + +<p>Although the action of this drug is of great interest, it cannot be +recommended at present for ordinary purposes.</p> + +<p><span class="pagenum" id="Page_175">[175]</span></p> + + +<h3><b>Adrenalin.</b></h3> + +<p>Adrenalin is obtained as an extract from the suprarenal glands of +animals. It is a greyish white powder, slightly soluble in water, and +readily so in weak acids. The usual preparation is a 1 in 1000 solution +of adrenalin chloride in normal saline. It contains ·5 per cent. of +chloroform as a preservative. The drawback to the animal extract is +that the solution does not keep well, decomposition being indicated by +a brownish colour. Of late a synthetic preparation has been introduced, +which appears to have the same action, and which can be sterilised by +boiling.</p> + +<p>The action of the drug is to cause marked vaso-constriction by direct +action on the vessel walls. It has no analgesic action, and is used as +an addition to solutions of anæsthetic drugs. The advantages of its use +are that the action of the anæsthetic is concentrated and prolonged, +owing to the delay in absorption, and that the field of operation is +rendered practically bloodless. In large doses it may produce toxic +symptoms in the form of palpitations and breathlessness, or even actual +syncope, so that care is necessary in its use. For purposes of local +anæsthesia, it is added to the solution of the anæsthetic drug in the +strength of 3 drops to the ounce, and large injections of this dilute +solution may be made without risk. At least twenty drops may be safely +given.</p> + + +<h3><b>Induction of Local Anæsthesia</b></h3> + +<p>Local anæsthesia may be induced by the use of anæsthetic drugs in three +ways—(1) infiltration anæsthesia, (2) regional anæsthesia, and (3) by +application to a mucous surface or to the surface of the eye.</p> + +<p><span class="smcap">Infiltration Anæsthesia.</span>—In this method anæsthesia is induced +by injection of the drug directly into the tissues to be operated upon. +This method acts by paralysing the sensory nerve-endings. Although +the term anæsthesia is constantly used, it is, strictly speaking, +an operative analgesia that is aimed at; it is a<span class="pagenum" id="Page_176">[176]</span> paralysis of the +pain-conducting fibres, and not of those which conduct purely tactile +sensations, the patient being often able to feel the contact of the +fingers and instruments during the operation. True anæsthesia can be +secured, but it is necessary to use considerably stronger solutions +than those that are required for the production of analgesia.</p> + +<p><span class="smcap">Solution of the Drug.</span>—Novocaine is far superior to any other +drug for infiltration anæsthesia. The strength for most purposes is ½ +per cent., though some operators find ¼ per cent. quite satisfactory. +In specially sensitive parts, such as the nose, throat, or mouth, 1 +or even 2 per cent. solutions may be preferable. Sufficient sodium +chloride should be added to prevent osmosis of the solution into the +tissue cells. The most satisfactory preparation is:—</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="cht">Novocaine</td> + <td class="right">0·25, 0·5, 1 or 2 (¼ to 2 percent.)</td> + </tr> + + <tr> + <td class="cht">Normal salt solution (half strength)</td> + <td class="right">100·0 (·45 per cent. NaCl)</td> + </tr> +</table> + + <div class="figcenter" id="i_p176" style="max-width: 600px"> + <img + class="p1" + src="images/i_p176.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig</span>. 51. All-Metal Syringe for Infiltration Anæsthesia.</p> + </div> + +<p>Adrenalin is added to the solution in the proportion of 3 drops of 1 in +1000 adrenalin chloride to the ounce, and as much as 6 ounces of this +preparation may be safely given. The novocaine solution can be boiled +before use, but the adrenalin must not be added until after boiling.</p> + +<p>For private practice it is sometimes convenient to procure the<span class="pagenum" id="Page_177">[177]</span> +novocaine in tabloid form of definite strength combined with sodium +chloride. These tabloids are added to the necessary amount of water, +and the whole boiled. The adrenalin can then be added.</p> + +<p><span class="smcap">Choice of Syringe.</span>—The best form of syringe for infiltration +anæsthesia is the all-metal syringe illustrated in Fig. 51. It ought +to have a capacity of at least 10 c.c. The advantage of the all-metal +syringe over glass syringes is that it can be safely sterilised by +boiling, and does not get broken. Between the syringe and the needle is +a metal segment which is curved so that the needle is set at an obtuse +angle to the syringe. This renders the infiltration of the tissues at +the proper depth much easier. The needles employed are the ordinary +hypodermic needles which are sold in small tubes. The sizes which +should be selected are 1 inch, and 3 or 3½ inches. The needle fits into +a hole in a small metal mount, which screws on to the intermediate +metal portion. This section also is attached to the syringe by a screw, +and these screw attachments have the advantage of rendering leakage +impossible.</p> + +<p>Failing the syringe described, a 10 c.c. Record syringe will be found +to be quite efficient, if suitable needles can be obtained. The +syringe, needles, and glass measure for the solution should be boiled +in plain water or normal saline, as soda interferes with the action of +the drug.</p> + +<p><span class="smcap">Technique of Injection.</span>—The needle is introduced into the +subcutaneous tissue, and pushed on slowly to its full length, the +fluid being injected as the needle advances. The needle is then partly +withdrawn, and pushed in in a different direction so as to infiltrate a +fresh area. This procedure is repeated, and as wide an area as possible +infiltrated from the one puncture. The needle can then be completely +withdrawn and introduced at a fresh point which has already been +rendered analgesic. The deeper tissues can nearly always be infiltrated +from the surface, but if large blood-vessels traverse the region to be +infiltrated, it may be necessary to<span class="pagenum" id="Page_178">[178]</span> defer the deeper injection until +these have been exposed. It is wise to infiltrate wide of the intended +line of the incision, since it is not possible to anticipate with +certainty the extent of an operation until it has been commenced. The +secret of successful anæsthesia is to employ plenty of the solution, +and make the injection thorough.</p> + +<p>The skin over the area becomes blanched within a few minutes of the +injection owing to the action of the adrenalin. Anæsthesia is not +usually complete until ten minutes have elapsed, and the operation +should not be commenced until it has been made certain by suitable +tests that the anæsthesia is complete. The duration of the anæsthesia +is usually at least an hour and a half.</p> + +<p>It will be seen that the injection in the manner described above is +entirely subcutaneous, the pain-conducting nerves from the skin being +caught up by the drug as they traverse the superficial fascia in the +area infiltrated. This method usually gives complete satisfaction, +but some surgeons advise that the infiltration should be commenced +with an <i>intra-dermal</i> injection so as to reduce the pain of the +needle punctures to a minimum. A fine needle is employed, the prick +of which is practically painless. If the skin at the selected point +is pinched up between the finger and thumb, and held firmly, this +lessens its sensibility. The needle is advanced beneath the epidermis +with a quick but light thrust. The injection into the substance of the +skin causes a distinct wheal, which stands out from its surroundings +like an urticarial wheal. From this starting-point a long needle can +be introduced into the deeper tissues without pain. The intra-dermal +injection may be carried along the whole length of the area to be +infiltrated, each fresh puncture being made in the margin of the +wheal-like area already anæsthetised.</p> + +<p><span class="smcap">Precautions.</span>—The most careful asepsis is essential +throughout. Infiltration with novocaine causes no interference with the +healing<span class="pagenum" id="Page_179">[179]</span> of the wound, and although cases of sloughing of the tissues +have been reported after its use, these are almost certainly due to +infection of the wound. Care must be exercised also to avoid injecting +the drug into a vein. When this accident takes place, the drug is +carried at once into the general circulation, and may reach the higher +nerve centres in such quantity as to produce serious toxic results. The +use of adrenalin calls for special care and thoroughness in securing +all bleeding-points, as, after the effect of the adrenalin passes off, +even a slight ooze may increase and give rise to a hæmatoma which may +jeopardise the healing of the wound.</p> + + +<h3><b>Regional Anæsthesia.</b></h3> + +<p>In this method of producing anæsthesia, the sensory nerve paths are +blocked by injecting the anæsthetic drug into, or around, a nerve +trunk. By this procedure complete anæsthesia is produced in the area of +distribution of the nerve, and the effect corresponds to a temporary +physiological section of the nerve trunk. A temporary motor paralysis +is also produced in a mixed nerve.</p> + +<p><span class="smcap">Technique.</span>—The solution of the drug must be stronger than +that employed for infiltration anæsthesia. A 2 per cent. solution of +novocaine in half-strength normal saline with the addition of adrenalin +is employed. The injection may be paraneural or intraneural.</p> + +<p>A <i>paraneural</i> injection is made by passing a needle through +the tissues to the known position of a nerve trunk and injecting the +anæsthetic around it. The solution gradually diffuses into the nerve +tissue, and anæsthesia of the nerve is produced. This method is open +to the objection that unless the anæsthetic is accurately placed, no +anæsthesia will result, and that in the case of certain nerves there is +considerable risk of making the injection into a vein. The latter risk +can be avoided by using a glassbarrelled<span class="pagenum" id="Page_180">[180]</span> syringe and applying a little +suction before the injection is made; if a vein has been pierced, blood +will enter the syringe.</p> + +<p>The <i>intraneural</i> method is more accurate but requires the +expenditure of considerable additional time and trouble, and is only +employed where other methods of anæsthesia are not feasible. The tissue +over the nerve having been infiltrated, the nerve is exposed by open +dissection. It must not be pinched by forceps or other instruments, +as such manipulations cause severe pain referred to its peripheral +distribution. The injection should be made with the nerve lying in its +bed by inserting a fine needle in the long axis of the nerve, first +into the sheath, which is infiltrated, and then into the nerve itself. +The infiltration of the nerve is continued until it presents a fusiform +swelling and this may require from 5 to 15 minims of the solution. +Complete anæsthesia of its entire distribution usually results in from +five to ten minutes.</p> + +<p>A third method of inducing regional anæsthesia—first recommended by +Hackenbruch—which is worth mention, is by the production of a ring +of infiltration around a peripheral part, such as a finger, or around +and underneath a tumour. By this means the nerve fibres are caught up +by the anæsthetic and their conductivity interrupted as they enter the +area to be operated upon. In dealing with such conditions as a large +lipoma, or an umbilical hernia, it may be possible to avoid the use of +an excessive amount of anæsthetic solution by employing this method.</p> + + +<h3><b>Methods of Application of Infiltration and Regional Anæsthesia.</b></h3> + +<p>It is sometimes stated that local anæsthesia should be limited to +small and superficial operations, but with a knowledge of anatomy and +of the correct technique, there are few operations which the surgeon +cannot undertake with this form of anæsthesia. If we remember that the +mortality from the anæsthetic is practically nil, it is obvious that it +is often the duty of the operator to<span class="pagenum" id="Page_181">[181]</span> give the patient the choice of +local anæsthesia. In urgent conditions in which the administration of a +general anæsthetic would be attended with great danger, it is often a +life-saving measure. Either infiltration or regional anæsthesia may be +used alone; in some cases it is convenient to combine the two methods.</p> + + +<h3><b>Operations on the Upper Extremity.</b></h3> + +<p>Regional anæsthesia is sometimes employed in operations on the upper +extremity in conditions, such as diabetic gangrene or advanced cardiac +disease, where a general anæsthetic is contra-indicated. In similar +conditions in the lower extremity, spinal anæsthesia is usually +preferred, though it is quite possible to anæsthetise the lower limb +by blocking the sciatic, femoral, and lateral cutaneous nerves with a +local anæsthetic. Crile lays great stress on the blocking of nerves +with a local anæsthetic during operations on the limbs as a means of +preventing shock, even where a general anæsthetic is being employed. +The effect of the local anæsthetic is to prevent the impulses which +produce shock from passing up to the higher centres. Only those methods +which are applied to the upper extremity need special description.</p> + +<p><span class="smcap">Anæsthesia of the Whole Arm.</span>—The nerves of the upper +extremity are all derived from the brachial plexus except the +intercosto-brachial. This nerve, which is the lateral cutaneous +branch of the second intercostal, crosses the axilla and pierces the +deep fascia on the medial side of the arm. It supplies the skin on +the dorsal part of the medial aspect of the upper arm. The lateral +cutaneous branch of the third intercostal nerve sometimes crosses +the axilla also, and reaches the medial side of the arm. Injection +of the brachial plexus produces complete analgesia of the shoulder +and entire arm, and is particularly suited to high amputations +and disarticulations at the shoulder. If the area supplied by the +intercosto-brachial is encroached upon, this can be anæsthetised<span class="pagenum" id="Page_182">[182]</span> by +infiltration with a few drams of solution injected subcutaneously along +the floor of the axilla from its lateral and posterior borders.</p> + +<p><span class="smcap">Method.</span>—The injection may be intraneural or paraneural. The +intraneural is made after exposing the plexus by an incision under +infiltration anæsthesia from the junction of the middle and lower +thirds of the sterno-mastoid to the union of the middle and lateral +thirds of the clavicle. It is found lying on the scalenus medius and +each of its branches is separately injected with a few drops of 5 per +cent. solution of novocaine containing a few drops of adrenalin to the +ounce.</p> + +<p>The paraneural injection is less satisfactory, since the nerves +are too large to be readily penetrated in effective quantities by +the anæsthetic solution, and since there are numerous veins in the +neighbourhood into which the solution may be accidentally injected with +dangerous results.</p> + +<p>The injection is usually made above the clavicle. In this region the +plexus lies mainly above and to the lateral side of the third part +of the subclavian artery, the lowest trunk lying directly behind the +vessel as it rests on the first rib. The position of the artery is +first localised with the finger by its pulsations, and the skin and +subcutaneous tissue infiltrated immediately above the mid-point of +the clavicle. From this point a long fine needle, unattached to the +syringe, is passed downwards, backwards, and medially in the direction +of the second or third thoracic spine. The distance to which the +needle penetrates varies from 2 to 4 c.m. When the plexus is reached a +slight radiating pain is felt down the distribution of the radial or +median nerve. At this point the needle is held stationary, the syringe +attached, and the injection made. The reason for not attaching the +syringe earlier is that should the artery be entered, blood will flow. +This accident is of little consequence, the needle being withdrawn +slightly and introduced a little more laterally. About 10 c.c. of a +2 per cent.<span class="pagenum" id="Page_183">[183]</span> solution of novocaine and adrenalin is injected; the +needle is then slightly withdrawn and a further 10 c.c. injected in the +neighbourhood. Anæsthesia occurs in from three to fifteen minutes.</p> + + <div class="figcenter" id="i_p183" style="max-width: 350px"> + <img + class="p1" + src="images/i_p183.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig. 52.</span>—Point at which the needle is +introduced in paraneural injection of brachial plexus.</p> + </div> + +<p>The individual nerves of the upper limb can be readily injected. +The <i>median</i> can be exposed at the bend of the elbow for an +intraneural injection, or a needle may be passed under the tendon +of the palmaris longus at the wrist for a paraneural injection. +The <i>ulnar</i> can be easily reached as it lies on the posterior +aspect of the medial epicondyle of the humerus for a paraneural or +intraneural injection. The <i>superficial radial</i> can be reached for +a paraneural<span class="pagenum" id="Page_184">[184]</span> injection about two inches above the wrist to the lateral +side of the tendon of the brachio-radialis (supinator longus). The +injection is made into the deep fascia, and carried across the lateral +border of the forearm for about an inch, to ensure reaching all the +branches of the nerve.</p> + +<p>The <i>medial antibrachial</i> (internal) <i>cutaneous</i> can be +blocked on the front of elbow by a paraneural injection about half +an inch medial to the biceps tendon, and the <i>lateral antibrachial +cutaneous</i> (musculo-cutaneous) at a corresponding point on the other +side of the tendon.</p> + +<p><span class="smcap">Anæsthesia of the Arm below the Elbow.</span>—In operations +below the elbow, in conditions in which a general anæsthetic is not +permissible, as in diabetes, nephritis or advanced cardiac disease, a +full anæsthesia can be obtained by intraneural injection of the median, +ulnar, and radial (musculo-spiral) nerves, combined with paraneural +injection of the medial and lateral antibrachial cutaneous. The +median and radial are each exposed by an incision under infiltration +anæsthesia, the radial being exposed in the groove between the +brachialis and brachio-radialis. The infiltration to expose the median +nerve usually blocks the anterior branch of the medial antibrachial +cutaneous. To make certain that the posterior branch is also +anæsthetised, it is advisable to inject a little anæsthetic solution +over the front of the medial epicondyle. The intraneural injection into +the ulnar nerve can often be made without exposing it.</p> + +<p><span class="smcap">Anæsthesia of Finger.</span>—The paraneural method applied to the +digital nerves at the root of the finger gives perfect results. A +circle of anæsthetic solution is first injected round the root of the +finger. The needle is then passed through the infiltrated skin on each +side of the finger, and a few drops of ½ per cent. novocaine solution +injected around the nerves. Complete anæsthesia of the finger results +in a few minutes.</p> + +<p><span class="pagenum" id="Page_185">[185]</span></p> + +<p><span class="smcap">In the Lower Limb</span> injection of individual nerves is rarely +employed, as anæsthesia is easily obtained by the method of spinal +analgesia. The <i>lateral cutaneous</i> can be injected as it lies +immediately medial to the anterior superior iliac spine emerging from +under cover of the inguinal ligament. This procedure may be useful in +obtaining skin grafts, the grafts being taken from the antero-lateral +aspect of the thigh. Amputations in the middle third of the thigh have +been performed by injecting the sciatic, the posterior cutaneous (small +sciatic), the femoral (anterior crural), and the lateral cutaneous at +the root of the limb. The obturator nerve is difficult to find and +anæsthetise in such cases. Operations below the knee can be painlessly +performed by this method of anæsthesia.</p> + + +<h3><b>Operations on the Neck.</b></h3> + +<p><span class="smcap">Tracheotomy.</span>—This operation is conveniently and safely +performed under infiltration anæsthesia. The anæsthetic solution is +injected in the usual way in the line of the incision down to the +trachea but not into it, as the trachea itself is insensitive to pain.</p> + +<p><span class="smcap">Goitre.</span>—A parenchymatous or adenomatous goitre can be readily +removed under local anæsthesia, though the administration of ether by +intra-tracheal insufflation is usually to be preferred. The principal +nerve supply to the field of operation is derived from the cervical +plexus, whose branches become superficial about the middle of the +posterior border of the sterno-mastoid. An intradermal injection may +be made first at this point, and a longer needle then passed down +to the posterior border of the muscle, and an area of infiltration +produced. From this point the needle is directed first upwards and +then downwards round the margin of the goitre so as to produce a zone +of infiltration. The same procedure may be repeated on the opposite +side, so that the whole gland is surrounded with a zone of infiltration +with a special depot of solution around the branches of the cervical +plexus. Where only one lobe is involved, it is sufficient to carry the +injection down<span class="pagenum" id="Page_186">[186]</span> in the middle line after one side has been encircled. +When the sheath has been incised and the surface of the gland exposed, +the isthmus is infiltrated and divided. The affected half of the gland +is then rolled outwards, and the attachments between the posterior +aspect of the gland and the larynx and trachea are infiltrated, special +attention being paid to the upper pole. The rest of the operation can +then be carried out painlessly.</p> + +<p><span class="smcap">Exophthalmic Goitre</span> may also be operated upon under local +anæsthesia after a preliminary hypodermic injection of morphia and +scopolamin, though many operators prefer a general anæsthetic on +account of the nervous state of the patient. In bad cases a procedure +which is often of great value is ligature of the superior thyroid +artery on both sides under local anæsthesia. After ligature of the +vessels a colloid degeneration takes place in the gland, and the +symptoms of hyperthyroidism subside. After a delay of two or three +months it may be possible to carry out the radical operation with +little or no danger. The incision is two and a half inches in length, +and crosses transversely the central part of the thyroid cartilage. +The line of the incision is infiltrated with novocain solution in the +ordinary way, and both superior thyroid arteries exposed and ligatured.</p> + + +<h3><b>Operations on the Thorax.</b></h3> + +<p>The greater part of the wall of the thorax is supplied by the +intercostal nerves. In front the supraclavicular nerves come down +as far as the second intercostal space or sometimes as far as the +nipple, and the lateral and medial anterior thoracic nerves supply +the pectoral muscles, sending a few twigs to the overlying skin. The +long thoracic nerve extends down the side of the chest, supplying the +serratus anterior. The intercostal nerves can be blocked in the region +of the angles of the ribs and the supraclavicular by carrying a line of +infiltration along the clavicle. The anterior thoracic can be blocked +by deeper injections. In<span class="pagenum" id="Page_187">[187]</span> this way the greater part of the chest wall +and the pleura can be anæsthetised.</p> + +<p><span class="smcap">Acute Empyema.</span>—This operation should always be performed +under local anæsthesia. Exhaustion from septic absorption and from +the antecedent pneumonia or other disease, with the dyspnœa from +the pressure of the pus on the lung may render a general anæsthetic +highly dangerous. The method of producing local anæsthesia is simple +and easily carried out. A point is selected on the rib which is to +be resected a short distance behind the line of the incision and an +intra-dermal injection made with a fine needle. A long needle is then +substituted and passed down to the upper border of the rib until it +reaches the plane between the external and internal intercostal muscle, +the injection being continued lightly as it advances. When the desired +point is reached one or two drams of the solution are injected. The +needle is then slightly withdrawn and passed to the lower border of +the rib to reach the same plane and the same procedure carried out. +The infiltration is then carried along the line of the incision or it +may be made to pass obliquely upwards to the rib above and obliquely +downwards to the rib below so as to catch up the nerves coming from +behind into the area of operation. The anæsthesia of soft parts, bone, +and pleura is perfect after the above injection.</p> + + +<h3><b>Operations on the Abdomen.</b></h3> + +<p>The anterior abdominal wall, including the anterior parietal +peritoneum, is supplied by the lower six intercostal nerves, the last +thoracic nerve, and the ilio-hypogastric and ilio-inguinal nerves +from the first lumbar. It is a very interesting and important fact +that, although the parietal peritoneum is exceedingly sensitive to +touch and pain, the visceral peritoneum and the viscera themselves +are insensitive. When operations are performed under local anæsthesia +of the abdominal wall, the<span class="pagenum" id="Page_188">[188]</span> viscera can be freely handled or incised +without the patient experiencing the slightest discomfort, provided +that the parietal peritoneum is not put upon the stretch by traction +on the mesentery or other peritoneal attachment. Thus the colon +can be opened twenty-four or forty-eight hours after being brought +outside the abdominal wall without any anæsthetic in the operation of +colostomy. Local anæsthesia is therefore well adapted to cases in which +a small amount of manipulation of the viscera is required, and where a +general anæsthetic would be dangerous, as in grave cases of intestinal +obstruction and in cases of carcinoma of the œsophagus with weakness +and loss of flesh from starvation.</p> + +<p><span class="smcap">Gastrostomy.</span>—This operation is commonly performed under +local anæsthesia and may be taken as an illustration of the procedure +employed. The incision is made through the middle of the left rectus +and is about two and a half or three inches long, beginning about an +inch below the costal margin. An intradermal wheal is established at +the middle of the proposed incision. A long needle is entered at this +point and passed first upwards and then downwards in the line of the +incision, infiltrating the subcutaneous fat as it goes. The needle is +then passed in through the anterior wall of the rectus sheath, this +being easily recognised as a plane of decided resistance. The needle +is advanced a little inside the sheath, the injection being continued +as it advances. The same procedure is repeated at various points along +the line of the incision. The extra-peritoneal fat may be infiltrated +in the same way, the posterior wall of the sheath being identified +as a deeper plane of resistance and gently pierced. This step may be +deferred until the posterior wall of the sheath has been exposed. +The infiltration may be completed by forming a line of intradermal +infiltration along the line of incision, though this last step can +often be omitted.</p> + +<p>The abdomen can then be opened painlessly. The only step in<span class="pagenum" id="Page_189">[189]</span> the +operation which may cause a little discomfort is the traction which may +be necessary to bring the shrunken stomach down from under cover of the +ribs. The incision into the stomach is quite painless.</p> + +<p><span class="smcap">Gastro-enterostomy</span> can be performed under local anæsthesia, +the only special step required being infiltration of the meso-colon +before it is perforated.</p> + +<p><span class="smcap">Appendicectomy</span> is not suitable, as a rule, for local +anæsthesia. If the cæcum is fixed or the appendix bound down by +adhesions, the traction necessary to bring the appendix to the surface +causes considerable pain.</p> + +<p>In <span class="smcap">Acute Obstruction</span>, when the procedure of enterostomy has +been decided upon owing to the gravity of the patient’s condition, +local anæsthesia is often of great value. The abdominal wall is +infiltrated in the manner described, and a distended loop of bowel +brought to the surface and sutured to the parietal peritoneum. A Paul’s +tube can then be introduced.</p> + +<p><span class="smcap">Inguinal Hernia.</span> Local anæsthesia is specially suited to cases +of strangulated hernia, but it may be employed in the ordinary case. It +should be pointed out that spinal anæsthesia gives equally good results +and is less troublesome to carry out.</p> + +<p>The injection is commenced with a fine needle a little beyond the +lateral end of the proposed incision. An intradermal wheal is produced +at this point, a long needle introduced into the subcutaneous tissue, +and about half-an-ounce of anæsthetic solution injected in this +position. The needle is then passed downwards and medially, and the +subcutaneous fat infiltrated in the line of the incision. The needle +is then partly withdrawn and again advanced until it reaches the +resistance of the aponeurosis of the external oblique. This is gently +pierced and about half-an-ounce of solution injected underneath so as +to block the ilio-hypogastric and ilio-inguinal nerves. In most cases +this is all that is necessary.<span class="pagenum" id="Page_190">[190]</span> As additional precautions the line of +incision may be infiltrated intradermally, and an injection may be made +around the neck of the sac after it is exposed.</p> + +<p><span class="smcap">Femoral Hernia.</span>—A femoral hernia may be anæsthetised by +infiltration along the line of the incision, or by injecting around +the circumference of the hernia after the method of Hackenbruch. After +the sac has been exposed and defined, it is necessary to inject some +novocaine solution around the neck, care being taken to avoid the +femoral vein which lies on the lateral side.</p> + +<p><span class="smcap">Umbilical Hernia.</span>—Local anæsthesia is sometimes of +great value in dealing with umbilical hernia, especially if it is +strangulated, in stout patients who are bad subjects for a general +anæsthetic. The injection is best made around the circumference of the +hernia. Several intradermal injections are made at points around the +swelling, and through these the long needle can be introduced and the +deeper tissues infiltrated. If the muscles are fairly well defined +and can be felt, they may be infiltrated at the commencement, but +it may be advisable in fat subjects to inject only the subcutaneous +tissues to begin with, and to delay the injection of the muscles and +extra-peritoneal fat until the sac has been opened and a protecting +finger can be introduced to guard the intestines. Omental adhesions +can be divided without causing pain. If the intestines are extensively +adherent to the sac it is better to infiltrate the points of adhesion, +as extensive manipulation may cause cramp-like pains.</p> + +<p>After the circumferential injection has been made in these cases, it is +best to wait for ten or fifteen minutes before making the incision in +order to allow the anæsthetic solution to diffuse.</p> + +<p><span class="smcap">Suprapubic Cystotomy.</span>—In operations for drainage of +the bladder local anæsthesia is highly successful. The skin and +subcutaneous tissues are infiltrated in the line of the incision. +The needle is then carried between or through the recti muscles and<span class="pagenum" id="Page_191">[191]</span> +several drams injected into the layer of fat in front of the bladder. +It is unnecessary to inject the wall of the bladder itself.</p> + +<p><span class="smcap">Hæmorrhoids.</span>—In patients in whom there is some +contra-indication to the use of a general anæsthetic the removal of +hæmorrhoids can be carried out quite safely and painlessly under local +anæsthesia. A circumferential injection is first carried out round the +muco-cutaneous junction. It is best to start the infiltration about an +inch out from the anus as the skin immediately around the anal orifice +is extremely sensitive. The infiltration is made subcutaneously, +and each re-insertion of the needle is made just short of where the +previous injection stopped. When the circumferential injection has been +completed, a finger is passed into the rectum, and the long needle +introduced through the anæsthetised area, injecting as it advances, to +a depth of about 2½ inches, keeping just outside the sphincters. Four +such injections are made, one on each side of the bowel, one in front +and one behind, from 5 to 10 c.c. being injected in each position.</p> + +<p>Anæsthesia results almost immediately and the anal canal can be readily +dilated.</p> + +<p><span class="smcap">The Tongue.</span>—For the Whitehead operation of removal of +one half of the tongue, complete anæsthesia can be obtained by the +infiltration method. A long needle is introduced at the tip of the +tongue, and the injection carried in the middle line to a point behind +the tumour. The mucous membrane of the floor of the mouth and the +glosso-palatine fold are infiltrated, and a last injection made across +the affected half of the tongue well behind the tumour.</p> + +<p>The tongue can be anæsthetised also by blocking the lingual nerve +with a paraneural injection. The nerve lies under the mucous membrane +of the mouth opposite the last molar tooth. If the tongue is drawn +well over to the opposite side, the nerve can be felt and the +injection made around it. The only drawback<span class="pagenum" id="Page_192">[192]</span> to this method is that +it does not anæsthetise the posterior third, which is supplied by the +glosso-pharyngeal nerve.</p> + +<p><span class="smcap">Operations on the Skull and Brain</span> can be readily performed +by infiltration of the scalp. In the later stages of the recent +war, a large proportion of operations on the skull and brain were +performed under local anæsthesia. The brain itself is insensitive to +touch and painful stimuli, and infiltration of the scalp is all that +is necessary. A 1 per cent. solution of novocaine with adrenalin has +been commonly employed, and is injected into the subaponeurotic space +so as to surround the field of operation with a wall of anæsthetic +solution—the method of Hackenbruch. The advantages are that hæmorrhage +is reduced to a minimum, and the head can be conveniently and safely +elevated and the intra-cranial tension thus reduced.</p> + + +<h3><b>Analgesia from the Application of Cocaine to the Eye or to a Mucous +Surface.</b></h3> + +<p><span class="smcap">For Operations on the Eye.</span>—Analgesia is obtained by the +instillation of a few drops of a 4 per cent. solution into the +conjunctival sac. This is repeated two or three times, and analgesia +is obtained in five or ten minutes. It may be necessary to repeat the +instillation during the course of the operation.</p> + +<p><span class="smcap">For Operations on the Nose, Pharynx, or Larynx</span> cocaine is +commonly used. A 5 or 10 per cent. solution is employed and is merely +painted on the surface. Care must be taken that such strong solutions +are not swallowed.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_193">[193]</span></p> + +<h2>CHAPTER XXI.<br> +<span class="subhed"><b>SPINAL ANÆSTHESIA.</b></span></h2></div> + +<p>Spinal Anæsthesia or <i>Analgesia</i>, consists in the production of +analgesia in the lower extremities and in the lower part of the trunk +by the injection into the subarachnoid space of an anæsthetic drug +which blocks the spinal nerves as they enter and leave the spinal +cord. The cord ends at the lower border of the first lumbar vertebra +and the subarachnoid space at the second sacral vertebra so that there +is a considerable area into which the injection may be made without +risk of injury to the cord. It is, in reality, a special variety of +regional analgesia, the anæsthetic being injected into that part of +the subarachnoid space which is occupied by the cauda equina. The +subarachnoid space of the medulla spinalis contains the cerebro-spinal +fluid and communicates above with the subarachnoid space inside the +skull and through the foramen of Magendie, with the ventricular system +of the brain. The subdural space of the medulla spinalis is merely a +capillary interval. At the upper end of the cauda equina the nerve +trunks of the two sides are separated by a median interval—containing +only the filum terminale—which has been termed the cysterna +terminalis. It is into this median space that the injection is made, in +order to avoid wounding the nerve trunks and to procure equal diffusion +of the anæsthetic to both sides of the middle line. If the injection is +made among the nerve trunks on one side, a unilateral anæsthesia may +result, the drug being prevented from diffusing freely to the other +side by the presence of the numerous nerves.</p> + +<p><span class="pagenum" id="Page_194">[194]</span></p> + +<p>The ligamentum denticulatum forms an imperfect scalloped septum between +the posterior and the anterior nerve roots, passing from the surface +of the cord to the dura mater. The presence of this septum probably +explains the fact that the motor nerves are not affected with the same +constancy and to the same extent as the sensory roots.</p> + + +<h3><b>Technique.</b></h3> + +<p>The drug which is most commonly employed in the Edinburgh school is +Tropacocaine, and the results of its use with proper technique are +eminently satisfactory. The dose of the drug for most purposes is ·07 +gramme. Smaller doses are sometimes used but the larger dose gives +more constant anæsthesia and appears to be well within the limits +of safety. The dose is dissolved in 1 c.cm. of distilled water and +sufficient sodium chloride added to make a solution isotonic with the +cerebro-spinal fluid. A convenient method of obtaining the drug is +in glass ampoules, each ampoule containing one dose, which has been +carefully sterilised.</p> + + <div class="figcenter" id="i_p194" style="max-width: 590px"> + <img + class="p1" + src="images/i_p194.jpg" + alt=""> + <p class="p0 center smaller"><span class="smcap">Fig</span>. 53.—Needle and syringe for spinal +analgesia. Note the short oblique character of the point of the needle.</p> + </div> + +<p>The syringe and needle employed are illustrated in Fig. 53.</p> + +<p>The point of the needle must be sharp but short. If a needle with a +long slender point is employed, only part of the point may enter the +membranes; a free flow of cerebro-spinal fluid may then take place, +but when the injection is made part of the anæsthetic solution escapes +outside the membranes. The needle<span class="pagenum" id="Page_195">[195]</span> should he 3½ to 4 inches long and 1 +m.m. in diameter. A stylet fits inside the needle and prevents it from +becoming blocked during the introduction. To prevent the possibility +of rusting, both needle and stylet should consist of hard nickel. The +barrel of the syringe must consist of glass so that the appearance +of the cerebro-spinal fluid can be seen. The Record type is very +satisfactory. The syringe usually supplied for spinal analgesia has +a capacity of 2 or 3 c.cm., but one holding 10 c.cm. is more useful. +Syringe and needle must be carefully sterilised by boiling in plain +water; any trace of soda causes decomposition of the drug. The ampoule +containing the tropococaine is sterilised in a strong antiseptic +solution so as to avoid the possibility of contamination of the hands +when the drug is being transferred to the syringe.</p> + +<p><i>Method of Injection.</i>—The patient should be given a hypodermic +injection of ⅛ gr. of morphine and ¹⁄₁₅₀ gr. of scopolamine an hour +before the operation. There are a number of minor variations in the +method of making the spinal injection, but limitations of space forbid +a discussion of theoretical questions and of the relative merits of +the different procedures. Only one method, which has been found safe +and reliable, will be considered here. The injection is made in the +space between the third and fourth lumbar spines, the objective being +the mid-line of the subarachnoid space between the two divisions of +the cauda equina. The position of the patient is such that the spaces +between the lumbar spines are opened up as widely as possible. The +most convenient plan is to have the patient sitting on the table with +the head and shoulders bent well forward (<i>see</i> Fig. <a href="#i_p196">54</a>.) If the +patient is unable to sit up, the injection may be made with him lying +on his side, with the knees drawn up and the shoulders bent forward.</p> + + <div class="figcenter" id="i_p196" style="max-width: 420px"> + <img + class="p1" + src="images/i_p196.jpg" + alt=""> + <p class="p0 hangingindent smaller"><span class="smcap">Fig</span>. 54. Position for the injection. The cross +indicates the point at which the lumbar puncture is made—about +half an inch from the median plane and in the space between the +third and fourth lumbar spines.</p> + </div> + +<p>The skin of the back is carefully sterilised; painting with tincture of +iodine serves admirably. The ampoule containing the<span class="pagenum" id="Page_196">[196]</span> tropacocaine is +opened, and the drug sucked into the syringe through a spare cannula. +The loaded syringe is then placed on a sterile towel at the back of the +patient. With a little practice there is no difficulty in making the +lumbar puncture. The fourth lumbar spine is located by noting the level +of the highest point on the iliac crest—this may be indicated by an +assistant. A line joining the highest points on the two iliac crests +will pass through the tip of the fourth lumbar spine. When this process +has been carefully identified, the needle is introduced half-an-inch to +one side of the median plane and midway between the third and fourth +spine. Some surgeons prefer to go in exactly in the middle line to make +sure of entering the middle of the subarachnoid space, but in<span class="pagenum" id="Page_197">[197]</span> this +position the tough supra-spinous and interspinous ligaments are met +with, and to avoid the resistance of these it is best to keep a short +distance out from the median plane. By carefully noting the direction +of the needle, the cysterna terminalis can always be entered. The +needle is passed forwards, very slightly upwards, and slightly medially +so as to hit off the centre of the subarachnoid space. As the needle +passes through the ligamentum flavum, there is a sudden diminution of +resistance and immediately afterwards the point of the needle lies in +the subarachnoid space. The passage of the needle through the membranes +is sometimes accompanied by a slight pricking pain.</p> + +<p>The stylet is withdrawn at this stage and the cerebro-spinal fluid +usually trickles out drop by drop. The syringe is picked up, carefully +emptied of air bubbles, and fitted on to the needle. The piston is +withdrawn until the syringe is filled with cerebro-spinal fluid, which +mixes freely with the anæsthetic solution, and the contents then +slowly injected. The 10 c.cm. syringe is to be preferred for this +purpose as it is essential to mix the tropacocaine thoroughly with the +cerebro-spinal fluid. If the smaller syringe is used, it should be +refilled with cerebro-spinal fluid and emptied a second time so as to +ensure thorough diffusion of the drug. The needle is then withdrawn and +the puncture sealed with collodion.</p> + +<p>The injection should never be made until a free flow of cerebro-spinal +fluid is obtained, since this is the only certain indication that the +needle has entered the subarachnoid space. If failure is met with in +the space between the third and fourth spines, the interspinous space +above or below should be tried.</p> + +<p>After the injection has been completed the patient is placed flat on +his back and then lowered into the Trendelenburg position. Analgesia +appears first in the scrotum and perineum, extends down the medial +side of the leg to the foot, then appears on the front of the leg, and +travels up to the groin and the lower part of the abdomen. The progress +of the analgesia is tested from<span class="pagenum" id="Page_198">[198]</span> time to time by lightly pinching +or pricking the skin, the patient’s eyes being screened. When the +analgesia reaches the level of the nipples, the patient is raised into +the horizontal position and the the operation may be commenced. Some +surgeons object to the lowering of the head as rendering paralysis of +the respiratory centre from upward diffusion of the drug more likely. +If tropacocaine is used in the dosage indicated and the table elevated +when the anæsthesia reaches the nipple line, there seems to be little +risk of this complication. If analgesia is only desired in the lower +extremity, the lowering of the table may be omitted; but if a good +anæsthesia is desired above the level of the groin, it should always be +carried out.</p> + +<p>Analgesia is complete in five or ten minutes as a rule. The duration +varies from three-quarters of an hour to an hour and a half. If a +preliminary hypodermic injection of morphine and scopolamine has been +given, the patient lies quietly and patiently until the operation is +completed. In some cases the patient actually drops off to sleep from +the effects of the morphine. It is not uncommon to observe a temporary +nausea and faintness about fifteen or twenty minutes after the +injection has been made, and it is good practice to give the patient a +little brandy and water at this stage.</p> + + +<h3><b>Complications and After-Effects.</b></h3> + +<p>A great deal has been written in the past with regard to unpleasant +results of spinal analgesia, but most of these would appear to have +been the result of faulty technique or of the use of an impure or +irritating drug. When tropacocaine is used in the manner described, the +usual result is that, except for occasional nausea and faintness at +the commencement, the patient has a comfortable, painless operation, +and a recovery which is unmarred by the sickness and other distressing +symptoms which are so common after general anæsthesia.</p> + +<p><i>Deaths</i> have been recorded, and these have been ascribed to<span class="pagenum" id="Page_199">[199]</span> +the drug having travelled too high and brought about paralysis of +the respiratory centre in the medulla oblongata. Too much importance +has probably been ascribed to these fatal cases. They have been most +common in patients greatly enfeebled by shock, old age, or debilitating +illness, who are liable to die during the operation whatever anæsthetic +is used. Thousands of cases have been recorded without a death, and +in the hands of surgeons of skill and judgment fatal cases are almost +unknown.</p> + +<p>An occasional complication is severe <i>headache</i> which may +persist for a week or longer. Other complications are all exceedingly +rare; paralysis of the lateral rectus muscle of the eyeball or of +other ocular muscles has been recorded, and is probably due to toxic +bye-products which are the result of impurity of the drug. Persistent +nausea and paralysis of the bladder and rectum and even of the lower +extremities have also been recorded, but are to be regarded as the +greatest rareties, and probably due to impurity of the anæsthetic.</p> + + +<h3><b>Indications.</b></h3> + +<p>Spinal analgesia may be used for any operation at or below the level of +the umbilicus. Excellent anæsthesia is obtained for the operation for +radical cure of umbilical hernia, but anæsthesia above this level is +not so constant, and is regarded by many authorities as unsafe.</p> + +<p>The procedure is of special value in cases in which a general +anæsthetic is unsafe:—(1) In old enfeebled patients suffering from +strangulated hernia, enlarged prostate, disease of the female pelvic +organs, and other conditions where anæsthesia is necessary below the +umbilicus. (2) In patients who are already suffering, or who are likely +to suffer, from severe shock. The drug has the same effect on the nerve +trunks of the cauda equina as on the peripheral nerves—it causes +blocking of the centripetal sensory impulses which are such a potent +factor in the causation of shock.</p> + +<p><span class="pagenum" id="Page_200">[200]</span></p> + +<p>(3) In diabetic gangrene spinal analgesia is the safest form of +anæsthesia to employ.</p> + + +<h3><b>Contra-Indications</b></h3> + +<p>Children up to the age of fourteen or so are apt to be frightened, +and spinal analgesia is better avoided except in special cases. It +is contra-indicated also in septic conditions on account of the +possibility of septic meningitis resulting from metastasis of the +infection, the drug having possibly the action of lowering the vitality +of the cord and meninges. In tuberculosis and syphilis it is better +avoided for the same reason. It should not be used where organic +disease of the spinal cord or brain is already present.</p> + + +<h3><b>Analgesia Produced by Freezing.</b></h3> + +<p>A transient analgesia can be produced by freezing the skin. An ether +spray was formerly employed, but was found to be troublesome and +inconvenient. The most convenient procedure consists in freezing the +part by means of a spray of ethyl chloride. This drug is supplied in a +glass cylinder with a very fine outlet so that it breaks up into a fine +spray as it escapes. The cylinder is held about 8 or 10 inches from the +patient’s skin, and pressure applied with the thumb to a stopcock on +the neck of the cylinder. Under the influence of the heat of the hand +the liquid escapes in a fine jet which impinges on the patient’s skin. +Freezing takes place in a few seconds, the frozen patch becoming hard +and white. The freezing can be hastened by blowing on the skin.</p> + +<p>This method is only suitable for the opening of small abscesses and +other procedures requiring a very short anæsthesia. The anæsthesia is +very imperfect, and only lasts for a few seconds. Many patients appear +to have as much pain with this form of anæsthesia as without it.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_201">[201]</span></p> + +<h2 class="gesperrt">APPENDIX I.<br> +<span class="subhed"><b>SOME EXPERIMENTAL OBSERVATIONS BY THE AUTHOR UPON THE PHYSICAL FACTS OF +ETHER EVAPORATION.</b></span></h2></div> + + +<p>The apparatus was very simple. It consisted of a pump which would +propel air towards the ether bottle; a glass bottle containing ether, +the roof of which was pierced by two tubes, one of which carried the +air from pump to bottle, and the other from bottle to a Waller’s tube, +where it was collected. The percentage of ether in the air was then +estimated by Waller’s gravimetric method. The ether jar stood in a +water bath which could be either left otherwise empty or filled up +with water of known temperature. The following tables show some of the +results. In each case, the air was propelled for five minutes, by which +time the cooling effect upon the ether was very marked; the figures +given are averages taken from several observations.</p> + + +<p class="center p1">TABLE A.</p> + +<p class="smcap center sm">Air Blowing over Surface of Ether.</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="ctrtrbl">Temperature of Bath (Fahr.) before experiment.</td> + <td class="ctrtrb">Quantity of ether before experiment.</td> + <td class="ctrtrb">Rate of pump.</td> + <td class="ctrtrb">Temperature of ether (Fahr.) at end of experiment.</td> + <td class="ctrtrb">Percentage obtained.</td> + </tr> + + <tr> + <td class="ctrrl">75</td> + <td class="ctrr">100 c.c.</td> + <td class="ctrr">30</td> + <td class="ctrr">50 F.</td> + <td class="ctrr">12·7</td> + </tr> + + <tr> + <td class="ctrrl">85</td> + <td class="ctrr">100 c.c.</td> + <td class="ctrr">30</td> + <td class="ctrr">52 F.</td> + <td class="ctrr">12·8</td> + </tr> + + <tr> + <td class="ctrrl">75</td> + <td class="ctrr">100 c.c.</td> + <td class="ctrr">90</td> + <td class="ctrr">45 F.</td> + <td class="ctrr">8·7</td> + </tr> + + <tr> + <td class="ctrrl">85</td> + <td class="ctrr">100 c.c.</td> + <td class="ctrr">90</td> + <td class="ctrr">45 F.</td> + <td class="ctrr">8·8</td> + </tr> + + <tr> + <td class="ctrrl">No water in bath</td> + <td class="ctrr">100 c.c.</td> + <td class="ctrr">30</td> + <td class="ctrr">32 F.</td> + <td class="ctrr">8·2</td> + </tr> + + <tr> + <td class="ctrrl">No water in bath</td> + <td class="ctrr">100 c.c.</td> + <td class="ctrr">90</td> + <td class="ctrr">23 F.</td> + <td class="ctrr">5·4</td> + </tr> + + <tr> + <td class="ctrrl">No water in bath</td> + <td class="ctrr">200 c.c.</td> + <td class="ctrr">30</td> + <td class="ctrr">38 F.</td> + <td class="ctrr">9·6</td> + </tr> + + <tr> + <td class="ctrrbl">No water in bath</td> + <td class="ctrrb">200 c.c.</td> + <td class="ctrrb">90</td> + <td class="ctrrb">29 F.</td> + <td class="ctrrb">6·6</td> + </tr> +</table> + +<p><span class="pagenum" id="Page_202">[202]</span></p> + + +<p class="center p1">TABLE B.</p> + +<p>Showing increased percentage obtained by “bubbling through” instead of +“blowing over” ether—</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="ctr smcap" colspan="2">Water Bath at 75° Fahr.</td> + </tr> + + <tr> + <td class="ctr">Quantity of ether.</td> + <td class="ctr">Rate of pump.</td> + </tr> + + <tr> + <td class="ctr">100 c.c.</td> + <td class="ctr">30</td> + </tr> +</table> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="cht">Air blown over surface of ether gave percentage of ether</td> + <td class="cht">12·8</td> + </tr> + + <tr> + <td class="cht">Air bubbled <i>through</i> ether</td> + <td class="cht">23·8</td> + </tr> +</table> + + +<p class="center">TABLE C.</p> + +<p>Showing amounts of ether vaporised at varying pump rates. In each case, +the temperature of the water bath was 75, and the initial amount of +ether was 100 cc.—</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="ctr">Pump Rate.</td> + <td class="ctr">Amount of Ether<br>Vaporised.</td> + </tr> + + <tr> + <td class="ctr">30</td> + <td class="ctr">30 c.c.</td> + </tr> + + <tr> + <td class="ctr">90</td> + <td class="ctr">38 c.c.</td> + </tr> +</table> + +<p>These experiments justify one in drawing the following conclusions:—</p> + +<div class="blockquot"> + +<p>1. The effect of a water bath has a marked effect in increasing +the strength of the vapour yielded, but small variations in the +temperature of the bath (as between 75 and 85 Fahr.) have but +little effect.</p> + +<p>2. If ether is vaporising quickly, it cannot pick up heat from +the water bath as quickly as it is losing its own heat. Though +not shown in the tables, the actual loss of temperature on the +water bath was small—about 2 degrees Fahr. during the five +minutes experiment.</p> + +<p>3. The more forcible the blast of air blown over or through +the ether, the less the percentage of ether yielded. Table C +shows that this loss of percentage is not compensated for by an +increase in the total amount vaporised.</p> +</div> + +<p><span class="pagenum" id="Page_203">[203]</span></p> + +<p>Of course, these results only apply to the case of a strong current +of air. If the current of air were <i>very</i> small, the ether could +pick up heat as fast as it parted with it, and within moderate degrees +a little increase of the air stream would increase the total amount of +ether vaporised without reducing the percentage strength.</p> + +<p>These results are of some practical importance in connection with +so-called “vapour anæsthesia” as given for instance by Shipway’s +instrument (page 90), and in devising and using the ether chambers of +intratracheal apparatus.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_204">[204]</span></p> + +<h2><span class="gesperrt">APPENDIX II.</span><br> +<span class="subhed"><b>THE PERCENTAGE STRENGTH IN OPEN ETHER.</b></span></h2></div> + +<p>Hewitt and Syme (<i>Lancet</i>, 27th Jan. 1912) estimated the +percentage of ether obtainable from an open mask with varying materials +and quantities of the drug. The results are tabulated below:—</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="ctr smcap" colspan="3">A.—A Whole Mask just Moist.</td> + </tr> + + <tr> + <td class="ctr">Material stretched<br>on mask.</td> + <td class="ctr">Number of<br>layers.</td> + <td class="ctr">Percentage<br>obtained.</td> + </tr> + + <tr> + <td class="cht1">Gauze</td> + <td class="right1">4</td> + <td class="right1">11</td> + </tr> + + <tr> + <td class="cht1"></td> + <td class="right1">8</td> + <td class="right2">11·4</td> + </tr> + + <tr> + <td class="cht1"></td> + <td class="right1">12</td> + <td class="right1">11</td> + </tr> + + <tr> + <td class="cht1">Flannel</td> + <td class="right1">1</td> + <td class="right2">8·0</td> + </tr> + + <tr> + <td class="cht1"></td> + <td class="right1">2</td> + <td class="right2">8·0</td> + </tr> + + <tr> + <td class="cht1">Lint</td> + <td class="right1">1</td> + <td class="right2">10·0</td> + </tr> + + <tr> + <td class="ctr smcap" colspan="3">B.—Whole Mask Wet.</td> + </tr> + + <tr> + <td class="cht1">Gauze</td> + <td class="right1">4</td> + <td class="right1">12</td> + </tr> + + <tr> + <td class="cht1"></td> + <td class="right1">8</td> + <td class="right2">13·4</td> + </tr> + + <tr> + <td class="cht1"></td> + <td class="right1">12</td> + <td class="right2">14·0</td> + </tr> + + <tr> + <td class="cht1">Flannel</td> + <td class="right1">1</td> + <td class="right2">8·0</td> + </tr> + + <tr> + <td class="cht1"></td> + <td class="right1">2</td> + <td class="right2">8·0</td> + </tr> + + <tr> + <td class="cht1">Lint</td> + <td class="right1">1</td> + <td class="right2">8·0</td> + </tr> +</table> + +<p>By excessive douching the observers were able to obtain 17 per cent.</p> + +<p>In these results, air and ether vapour were drawn by a pump through +the material to imitate the inspiration, but no attempt seems to have +been made to imitate expiration. The effect upon the material used of +moisture condensed from the expired air is<span class="pagenum" id="Page_205">[205]</span> not taken into account +in these experiments. This is a serious hiatus in the argument, +particularly as regards lint. This material in actual use rapidly +becomes quite sodden, and ether will not vaporise from it properly.</p> + +<p>In spite of this fault, these observations may probably be taken as +being reasonably accurate.</p> + +<p>With them may be compared the figures of Karl Connell, who, working +with quite accurate methods, estimated the percentages of ether +necessary to induce and maintain anæsthesia:—</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="ctr">Period of Anæsthesia.</td> + <td class="ctr">Percentage.</td> + </tr> + + <tr> + <td class="cht">First 5 minutes (<i>i.e.</i> induction)</td> + <td class="right1">18</td> + </tr> + + <tr> + <td class="cht">Next 25 „</td> + <td class="right1">14</td> + </tr> + + <tr> + <td class="cht">Next 30 „</td> + <td class="right1">12</td> + </tr> + + <tr> + <td class="cht">Next 60 „</td> + <td class="right2">12·8</td> + </tr> +</table> + +<p>“Bad” subjects on the average required an extra 4 per cent. during +first half hour, feeble patients required 2 per cent. less. +(<i>Journal</i> of the American Medical Association, 22nd March 1913).</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_206">[206]</span></p> + +<h2><span class="gesperrt">APPENDIX III.</span><br> +<span class="subhed"><b>THE ACTION OF ANÆSTHETICS UPON THE BLOOD.</b></span></h2></div> + + +<h3><i>The Blood Gases in Anæsthesia.</i></h3> + +<p>Buckmaster and Gardner (<i>Journal of Physiology</i>, vol. xli., +p. 246), analysed the blood gases in various stages of chloroform +anæsthesia, and some of their results are shown below in tabular form. +They show a very definite reduction in the oxygen content of the blood. +So far as one gathers from the text of the paper, the animals were +not subjected to any considerable trauma during the progress of the +anæsthesia, so that the figures arrived at with regard to the CO<sub>2</sub> +content do not bear upon the Acapnia question. If there was no trauma, +there would be no deep breathing, and a reduction of CO<sub>2</sub> could not +be expected.</p> + +<table class="smaller" style="max-width: 50em"> + <tr> + <td class="ctrtrbl" rowspan="2"></td> + <td class="ctrtrb" colspan="3">Average volume in<br>c.c. per 100 c.c.<br>of blood</td> + <td class="ctrtrb" colspan="3">Average composition<br>per cent. of gas</td> + <td class="ctr1trb" rowspan="2">Relation<br>of<br>O<sub>2</sub> to CO<sub>2</sub></td> + </tr> + + <tr> + <td class="ctrrb">CO<sub>2</sub></td> + <td class="ctrrb">O<sub>2</sub></td> + <td class="ctrrb">Nitr.</td> + <td class="ctrrb">CO<sub>2</sub></td> + <td class="ctrrb">O<sub>2</sub></td> + <td class="ctrrb">Nitr.</td> + </tr> + + <tr> + <td class="chtrl">Normal cats.</td> + <td class="rightr">25·07</td> + <td class="rightr">13·60</td> + <td class="rightr">1·00</td> + <td class="rightr">63·2 </td> + <td class="rightr">34·28</td> + <td class="rightr">2·52</td> + <td class="rightr">1 to 1·84</td> + </tr> + + <tr> + <td class="chtrl">Reflexes just re-appearing</td> + <td class="rightr">29·02</td> + <td class="rightr">11·49</td> + <td class="rightr">1·33</td> + <td class="rightr">65·06</td> + <td class="rightr">25·44</td> + <td class="rightr">2·87</td> + <td class="rightr">1 to 2·55</td> + </tr> + + <tr> + <td class="chtrl">Reflexes just disappearing</td> + <td class="rightr">29·57</td> + <td class="rightr">7·78</td> + <td class="rightr">2·15</td> + <td class="rightr">69·14</td> + <td class="rightr">18·17</td> + <td class="rightr">5·09</td> + <td class="rightr">1 to 3·8 </td> + </tr> + + <tr> + <td class="chtrbl">2nd Stage Anæsthesia</td> + <td class="rightrb">36·00</td> + <td class="rightrb">8·14</td> + <td class="rightrb">1·49</td> + <td class="rightrb">71·27</td> + <td class="rightrb">16·12</td> + <td class="rightrb">2·95</td> + <td class="rightrb">1 to 4·32</td> + </tr> +</table> + +<p><span class="pagenum" id="Page_207">[207]</span></p> + + +<h3><i>Other Blood changes in Anæsthesia.</i></h3> + +<p>Hamburger and Ewing (<i>Journal</i> of the American Medical Assoc. +1908) examined the blood changes incidental to surgical anæsthesia. +Their results may be condensed as follows:—</p> + +<p><i>Nitrous Oxide.</i>—Hæmoglobin is not permanently decreased and +no anæmia follows the administration. Hæmolysis is not increased. +The coagulation time of the blood is not always affected in the same +direction. Usually it is slightly increased.</p> + +<p><i>Ether.</i>—The hæmoglobin is slightly reduced and anæmia persists +for seven to ten days. Hæmolysis is not however materially increased. +There is some evidence of blood inspissation. The coagulation time is +markedly increased.</p> + +<p><i>Chloroform.</i>—The hæmoglobin is reduced and a distinct anæmia +produced. Hæmolysis is definitely increased. There is a slight increase +in the coagulation time.</p> +<hr class="chap x-ebookmaker-drop"> + +<div class="chapter"> +<p><span class="pagenum" id="Page_209">[209]</span></p> + +<h2>INDEX.</h2> +</div> + +<p class="p-index">A</p> + +<ul> + <li class="i1">Abdominal operations, + <a href="#Page_ix">ix</a>, + <a href="#Page_7">7</a></li> + <li class="i2">local anæsthesia in, + <a href="#Page_187">187</a></li> + + <li class="i1">Abdominal muscles, rigidity of, + <a href="#Page_19">19</a></li> + + <li class="i1">Abnormalities of anæsthesia, minor, + <a href="#Page_38">38</a></li> + <li class="i2">major, + <a href="#Page_140">140</a></li> + + <li class="i1" id="Acapnia">Acapnia, + <a href="#Page_10">10</a>, + <a href="#Page_29">29</a>, + <a href="#Page_39">39</a></li> + + <li class="i1">Accidents of anæsthesia, + <a href="#Page_140">140</a></li> + + <li class="i1">Acetonuria, + <a href="#Page_153">153</a></li> + + <li class="i1">Acidosis, + <a href="#Page_153">153</a></li> + + <li class="i1">Adenoids, + <a href="#Page_127">127</a>, + <a href="#Page_166">166</a></li> + <li class="i2">in status lymphaticus, + <a href="#Page_148">148</a></li> + + <li class="i1">Adrenalin, + <a href="#Page_175">175</a></li> + <li class="i2">danger of, with chloroform, + <a href="#Page_113">113</a>, + <a href="#Page_166">166</a></li> + + <li class="i1">Aedentulous patients, + <a href="#Page_23">23</a></li> + + <li class="i1">After-effects of anæsthetics, <i>see</i> Sequelae</li> + + <li class="i1">Ages, dosage of morphia at various, + <a href="#Page_45">45</a></li> + <li class="i2">selection of anæsthetic at various, + <a href="#Page_164">164</a></li> + + <li class="i1">Airshaft, natural, + <a href="#Page_96">96</a></li> + + <li class="i1">Airway, natural, + <a href="#Page_15">15</a>, + <a href="#Page_31">31</a>, + <a href="#Page_114">114</a>, + <a href="#Page_145">145</a></li> + <li class="i2">artificial, + <a href="#Page_23">23</a></li> + + <li class="i1">Alcoholics, anæsthesia in, + <a href="#Page_2">2</a>, + <a href="#Page_87">87</a>, + <a href="#Page_103">103</a>, + <a href="#Page_137">137</a>, + <a href="#Page_165">165</a></li> + + <li class="i1">Alkaloids, + <a href="#Page_12">12</a>, + <a href="#Page_43">43</a>, + <a href="#Page_88">88</a>, + <a href="#Page_103">103</a></li> + + <li class="i1">Aneurysm, + <a href="#Page_56">56</a></li> + + <li class="i1">Anoci-association, + <a href="#Page_11">11</a></li> + + <li class="i1">Anoxæmia, + <a href="#Page_15">15</a></li> + + <li class="i1">Arm, management of in anæsthesia, + <a href="#Page_157">157</a></li> + <li class="i2">regional anæsthesia of, + <a href="#Page_181">181</a></li> + + <li class="i1">Arteries, spouting of, + <a href="#Page_x">x</a>, + <a href="#Page_37">37</a></li> + + <li class="i1">Arterio-sclerosis, + <a href="#Page_56">56</a>, + <a href="#Page_167">167</a></li> + + <li class="i1">Artificial respiration, + <a href="#Page_146">146</a></li> + + <li class="i1">Asphyxia, + <a href="#Page_15">15</a></li> + + <li class="i1">Athetosis, + <a href="#Page_38">38</a></li> + + <li class="i1">Atropine, + <a href="#Page_43">43</a>, + <a href="#Page_45">45</a>, + <a href="#Page_112">112</a>, + <a href="#Page_147">147</a></li> + + <li class="i1">Auer and Meltzer, + <a href="#Page_96">96</a></li> +</ul> + +<p class="p-index">B</p> + +<ul> + <li class="i1">Barth 3-way tap, + <a href="#Page_50">50</a></li> + + <li class="i1">Bicarbonate of soda in acidosis, + <a href="#Page_156">156</a></li> + + <li class="i1">Bladder, reflexes from, + <a href="#Page_39">39</a>, + <a href="#Page_168">168</a></li> + <li class="i2">local anæsthesia in operations upon, + <a href="#Page_190">190</a></li> + + <li class="i1">Blistering, by chloroform, + <a href="#Page_109">109</a></li> + + <li class="i1">Blood, changes in, during anæsthesia, + <a href="#Page_207">207</a></li> + <li class="i2">spouting of, from cut arteries, + <a href="#Page_x">x</a>, + <a href="#Page_37">37</a></li> + + <li class="i1">Blood-pressure, in natural sleep, + <a href="#Page_1">1</a></li> + <li class="i2">in shock, + <a href="#Page_6">6</a></li> + <li class="i2">in asphyxia, + <a href="#Page_17">17</a></li> + <li class="i2">in nitrous oxide, + <a href="#Page_46">46</a></li> + <li class="i2">in ether, + <a href="#Page_75">75</a></li> + <li class="i2">in chloroform, + <a href="#Page_110">110</a></li> + <li class="i2">in ethyl chloride, + <a href="#Page_122">122</a></li> + <li class="i2">clinical observation of, + <a href="#Page_37">37</a></li> + + <li class="i1">Blowing respiration, + <a href="#Page_34">34</a>, + <a href="#Page_89">89</a></li> + + <li class="i1">Boothby, on ether percentages, + <a href="#Page_99">99</a></li> + + <li class="i1">Boyle, Mr Leonard, + <a href="#Page_70">70</a></li> + + <li class="i1">Brachial plexus, nerve blocking in, + <a href="#Page_181">181</a></li> + + <li class="i1">Brain, <i>see</i> <a href="#Nervous">Nervous System</a></li> + <li class="i2">local anæsthesia for operation upon, + <a href="#Page_191">191</a></li> + + <li class="i1">Breath-holding, + <a href="#Page_34">34</a>, + <a href="#Page_112">112</a>, + <a href="#Page_114">114</a></li> + + <li class="i1">Breathing, deep (<i>see</i> <a href="#Acapnia">Acapnia</a>)</li> + + <li class="i1">Bronchitis, + <a href="#Page_150">150</a></li> +</ul> + +<p class="p-index">C</p> + +<ul> + <li class="i1">Carbon-dioxide, + <a href="#Page_10">10</a>, + <a href="#Page_18">18</a>, + <a href="#Page_206">206</a></li> + + <li class="i1">Cardiac cyanosis, + <a href="#Page_37">37</a></li> + + <li class="i1">Cardiac disease, + <a href="#Page_107">107</a></li> + + <li class="i1">Cardiac failure (<i>see</i> <a href="#Syncope">Syncope</a>)</li> + + <li class="i1">Castration, anæsthesia in, + <a href="#Page_169">169</a></li> + + <li class="i1">C.E. mixture, + <a href="#Page_83">83</a>, + <a href="#Page_134">134</a>, + <a href="#Page_137">137</a></li> + + <li class="i1">Cells, nerve, changes in, + <a href="#Page_5">5</a></li> + + <li class="i1">Centripetal impulses, + <a href="#Page_6">6</a></li> + + <li class="i1">Children, + <a href="#Page_45">45</a>, + <a href="#Page_94">94</a>, + <a href="#Page_125">125</a>, + <a href="#Page_164">164</a></li> + + <li class="i1">Chloretone, + <a href="#Page_93">93</a></li> + + <li class="i1">Chloride of ethyl (<i>see</i> <a href="#Ethyl">Ethyl Chloride</a>)</li> + + <li class="i1">Chloroform, administration of, + <a href="#Page_113">113</a></li> + <li class="i2">decomposition of, + <a href="#Page_109">109</a></li> + <li class="i2">delayed poisoning by, + <a href="#Page_153">153</a></li> + <li class="i2">physiology of, + <a href="#Page_109">109</a></li> + + <li class="i1">Choice of anæsthetics, + <a href="#Page_162">162</a></li> + + <li class="i1">Circulation, observation of, + <a href="#Page_x">x</a>, + <a href="#Page_37">37</a></li> + <li class="i2">in shock, + <a href="#Page_10">10</a></li> + <li class="i2">in asphyxia, + <a href="#Page_17">17</a></li> + <li class="i2">in valved breathing, + <a href="#Page_29">29</a></li> + <li class="i2">in nitrous oxide, + <a href="#Page_46">46</a></li> + <li class="i2">in ether, + <a href="#Page_75">75</a></li> + <li class="i2">in chloroform, + <a href="#Page_110">110</a></li> + <li class="i2">in ethyl chloride, + <a href="#Page_122">122</a></li> + <li class="i2">in C.E. mixture, + <a href="#Page_131">131</a></li> + <li class="i2">failure of (<i>see</i> <a href="#Syncope">Syncope</a>)</li> + + <li class="i1">Circumcision, anæsthesia in, + <a href="#Page_169">169</a></li> + + <li class="i1">Clarke’s apparatus, + <a href="#Page_69">69</a></li> + + <li class="i1">Clenching of Jaws, + <a href="#Page_15">15</a>, + <a href="#Page_24">24</a></li> + + <li class="i1">Clinical phenomena of asphyxia, + <a href="#Page_18">18</a></li> + <li class="i2">of normal anæsthesia, + <a href="#Page_33">33</a></li> + + <li class="i1">Closed ether, + <a href="#Page_78">78</a></li> + + <li class="i1">Closed method, features of, + <a href="#Page_29">29</a></li> + + <li class="i1">Clover’s inhaler, + <a href="#Page_78">78</a>, + <a href="#Page_138">138</a></li> + + <li class="i1">Cocaine, + <a href="#Page_170">170</a></li> + + <li class="i1">Collapse (<i>see</i> <a href="#Syncope">Syncope</a>)</li> + + <li class="i1">Conduction of nerve impulses, + <a href="#Page_3">3</a></li> + + <li class="i1">Connell, Karl, + <a href="#Page_90">90</a>, + <a href="#Page_205">205</a></li> + + <li class="i1">Conjunctival reflex, + <a href="#Page_31">31</a>, + <a href="#Page_35">35</a></li> + + <li class="i1">Convulsions, + <a href="#Page_17">17</a></li> + + <li class="i1">Corneal reflex, + <a href="#Page_32">32</a>, + <a href="#Page_35">35</a></li> + + <li class="i1">Crile, Prof., + <a href="#Page_5">5</a>, + <a href="#Page_9">9</a></li> + + <li class="i1">Crowing respiration, + <a href="#Page_16">16</a>, + <a href="#Page_169">169</a></li> + <li class="i2">night crowing, + <a href="#Page_148">148</a></li> + + <li class="i1">Cyanosis, + <a href="#Page_18">18</a>, + <a href="#Page_37">37</a>, + <a href="#Page_53">53</a></li> + + <li class="i1">Cylinders for nitrous oxide, + <a href="#Page_43">43</a></li> + <li class="i2">for oxygen, + <a href="#Page_64">64</a></li> +</ul> + +<p class="p-index">D</p> + +<ul> + <li class="i1">Dangers of chloroform, Prof. L. Hill upon, + <a href="#Page_120">120</a></li> + + <li class="i1">Death, causes of, + <a href="#Page_17">17</a>, + <a href="#Page_110">110</a>, + <a href="#Page_140">140</a>, + <a href="#Page_144">144</a>, + <a href="#Page_148">148</a></li> + + <li class="i1">Decomposition of chloroform, + <a href="#Page_109">109</a></li> + <li class="i2">of ether, + <a href="#Page_74">74</a></li> + + <li class="i1">Deep breathing, + <a href="#Page_10">10</a></li> + + <li class="i1">Degrees of anæsthesia, + <a href="#Page_31">31</a></li> + + <li class="i1" id="Dental">Dental anæsthesia, + <a href="#Page_54">54</a>, + <a href="#Page_57">57</a>, + <a href="#Page_128">128</a>, + <a href="#Page_131">131</a>, + <a href="#Page_163">163</a></li> + + <li class="i1">Depth of anæsthesia, + <a href="#Page_36">36</a></li> + + <li class="i1">Dextrose in acidosis, + <a href="#Page_156">156</a></li> + + <li class="i1">Difficulties of anæsthesia, major, + <a href="#Page_140">140</a></li> + <li class="i2">minor, + <a href="#Page_38">38</a></li> + + <li class="i1">Dilatation of pupils, + <a href="#Page_5">5</a>, + <a href="#Page_17">17</a>, + <a href="#Page_35">35</a>, + <a href="#Page_53">53</a>, + <a href="#Page_66">66</a>, + <a href="#Page_125">125</a>, + <a href="#Page_136">136</a>, + <a href="#Page_141">141</a>, + <a href="#Page_143">143</a></li> + + <li class="i1">Disease, relation of anæsthesia to, + <a href="#Page_166">166</a></li> + <li class="i2">acute infectious, + <a href="#Page_168">168</a></li> + + <li class="i1">Dislocations, anæsthesia in reduction of, + <a href="#Page_164">164</a></li> + + <li class="i1">Dorsal position, + <a href="#Page_157">157</a></li> + + <li class="i1">Dosimetric method for chloroform, + <a href="#Page_114">114</a></li> + <li class="i2">for ether, + <a href="#Page_90">90</a></li> + + <li class="i1">Dott, Mr N., direct laryngoscope, + <a href="#Page_104">104</a></li> + + <li class="i1">Douche method, + <a href="#Page_20">20</a></li> + + <li class="i1">Dread (<i>see</i> <a href="#Fear">Fear</a>)</li> + + <li class="i1">Drop bottles; chloroform, + <a href="#Page_117">117</a></li> + <li class="i2">ether, + <a href="#Page_83">83</a></li> + + <li class="i1">Drop method, + <a href="#Page_30">30</a>, + <a href="#Page_83">83</a></li> + + <li class="i1">Drugs for local and spinal anæsthesia, + <a href="#Page_170">170 to 174</a></li> +</ul> + +<p class="p-index">E</p> + +<ul> + <li class="i1">Emphysema, + <a href="#Page_167">167</a></li> + + <li class="i1">Empyæma, + <a href="#Page_167">167</a>, + <a href="#Page_187">187</a></li> + + <li class="i1">Enema, before operation, + <a href="#Page_42">42</a></li> + + <li class="i1">Ether, + <a href="#Page_74">74</a>, <i>et seq.</i></li> + <li class="i2">closed, + <a href="#Page_78">78</a></li> + <li class="i2">intratracheal, + <a href="#Page_96">96</a></li> + <li class="i2" id="Ether">open, + <a href="#Page_83">83</a></li> + <li class="i2">physiology of, + <a href="#Page_75">75</a></li> + <li class="i2">rectal, + <a href="#Page_93">93</a></li> + <li class="i2">warmed vapour, + <a href="#Page_90">90</a></li> + + <li class="i1">Ether, respiratory sequelæ of, + <a href="#Page_150">150</a></li> + + <li class="i1">Ether tremor, + <a href="#Page_38">38</a></li> + + <li class="i1" id="Ethyl">Ethyl chloride, + <a href="#Page_122">122</a>, <i>et seq.</i></li> + <li class="i2">combined with nitrous oxide, + <a href="#Page_128">128</a></li> + <li class="i2">freezing anæsthesia by, + <a href="#Page_200">200</a></li> + + <li class="i1">Eucain, + <a href="#Page_174">174</a></li> + + <li class="i1">Excitement (<i>see</i> <a href="#Struggling">Struggling</a>)</li> + + <li class="i1">Extraction of teeth (<i>see</i> <a href="#Dental">Dental Anæsthesia</a>)</li> + + <li class="i1">Eye reflexes, definition of, + <a href="#Page_31">31</a></li> +</ul> + +<p class="p-index">F</p> + +<ul> + <li class="i1">Face-down posture, + <a href="#Page_157">157</a></li> + + <li class="i1">Face, adaptation of masks to, + <a href="#Page_21">21</a>, + <a href="#Page_52">52</a>, + <a href="#Page_83">83</a></li> + + <li class="i1">Face-pieces for nitrous oxide, + <a href="#Page_51">51</a></li> + + <li class="i1">False anæsthesia, + <a href="#Page_41">41</a></li> + + <li class="i1">Faradism of motor nerves in anæsthesia, + <a href="#Page_3">3</a></li> + + <li class="i1">Fat patients, + <a href="#Page_158">158</a>, + <a href="#Page_165">165</a></li> + + <li class="i1">Fatty changes after anæsthesia, + <a href="#Page_153">153</a></li> + + <li class="i1" id="Fear">, effects of, + <a href="#Page_9">9</a></li> + <li class="i2">prevention of, + <a href="#Page_11">11</a>, + <a href="#Page_43">43</a>, + <a href="#Page_88">88</a></li> + + <li class="i1">Feeble patients, + <a href="#Page_168">168</a></li> + + <li class="i1">Ferguson, Dr., W. J., + <a href="#Page_87">87</a></li> + + <li class="i1">Fingers, regional anæsthesia for, + <a href="#Page_184">184</a></li> + + <li class="i1">Flame, open, dangers of, + <a href="#Page_74">74</a>, + <a href="#Page_104">104</a></li> + + <li class="i1">Forceps, tongue, + <a href="#Page_24">24</a></li> + + <li class="i1">Food before anæsthesia, + <a href="#Page_42">42</a></li> + + <li class="i1">Foreign bodies in the larynx, + <a href="#Page_16">16</a></li> + + <li class="i1">Freezing analgesia, + <a href="#Page_201">201</a></li> + + <li class="i1">Fright (<i>see</i> <a href="#Fear">Fear</a>)</li> +</ul> + +<p class="p-index">G</p> + +<ul> + <li class="i1">Gags, + <a href="#Page_25">25</a></li> + + <li class="i1">Gardner, Mr Bellamy, + <a href="#Page_23">23</a>, + <a href="#Page_24">24</a>, + <a href="#Page_83">83</a></li> + + <li class="i1">Gas and air, + <a href="#Page_54">54</a></li> + + <li class="i1">Gas and ether, + <a href="#Page_138">138</a></li> + + <li class="i1">Gas and ethyl chloride, + <a href="#Page_128">128</a></li> + + <li class="i1">Gas-oxygen, + <a href="#Page_60">60</a></li> + + <li class="i1">Gasping, + <a href="#Page_40">40</a></li> + + <li class="i1">Genito-urinary operations, + <a href="#Page_168">168</a></li> + + <li class="i1">Glossotilt, + <a href="#Page_24">24</a></li> + + <li class="i1">Glottis, spasm of, + <a href="#Page_16">16</a>, + <a href="#Page_20">20</a>, + <a href="#Page_26">26</a>, + <a href="#Page_105">105</a></li> + + <li class="i1" id="Goitre">Goitre, anæsthesia for, + <a href="#Page_160">160</a>, + <a href="#Page_185">185</a></li> + + <li class="i1">Goitre, exopthalmic, + <a href="#Page_9">9</a>, + <a href="#Page_167">167</a></li> + + <li class="i1">Grey and Parsons on shock, + <a href="#Page_6">6</a></li> + + <li class="i1">Guy, Dr Wm., + <a href="#Page_128">128</a></li> + + <li class="i1">Guy-Ross, gas oxygen method, + <a href="#Page_131">131</a></li> + + <li class="i1">Gwathmey, warmed ether vapour, + <a href="#Page_90">90</a></li> + <li class="i2">oil-ether, + <a href="#Page_93">93</a></li> +</ul> + +<p class="p-index">H</p> + +<ul> + <li class="i1">Hæmorrhage, as a factor in shock production, + <a href="#Page_9">9</a></li> + <li class="i2">observation of, by anæsthetist, + <a href="#Page_x">x</a>, + <a href="#Page_37">37</a></li> + + <li class="i1">Hæmorrhoids, local anæsthesia for, + <a href="#Page_191">191</a></li> + + <li class="i1">Harcourt, Vernon, + <a href="#Page_114">114</a></li> + + <li class="i1">Head and neck operations, position for, + <a href="#Page_158">158</a></li> + + <li class="i1">Head and neck, raising, + <a href="#Page_152">152</a></li> + <li class="i2">lowering, + <a href="#Page_110">110</a>, + <a href="#Page_145">145</a></li> + <li class="i2">extra pillow in deep chested patients, + <a href="#Page_157">157</a></li> + + <li class="i1">Heart, failure in asphyxia, + <a href="#Page_17">17</a></li> + <li class="i2">observation of, + <a href="#Page_37">37</a></li> + <li class="i2">action of ether upon, + <a href="#Page_75">75</a></li> + <li class="i2">of chloroform upon, + <a href="#Page_110">110</a></li> + <li class="i2">of ethyl chloride upon, + <a href="#Page_122">122</a></li> + <li class="i2">failure of, in secondary syncope, + <a href="#Page_144">144</a></li> + + <li class="i1">Heart disease, anæsthetics in, + <a href="#Page_167">167</a></li> + + <li class="i1">Henderson, Yandell, + <a href="#Page_10">10</a>, + <a href="#Page_29">29</a></li> + + <li class="i1">Hernia, local anæsthesia in, + <a href="#Page_189">189</a></li> + + <li class="i1">Heroin, + <a href="#Page_44">44</a></li> + + <li class="i1">Hewitt, Sir Frederick, + <a href="#Page_22">22</a>, + <a href="#Page_50">50</a>, + <a href="#Page_62">62</a>, + <a href="#Page_81">81</a>, + <a href="#Page_137">137</a></li> + + <li class="i1">Hill’s direct laryngoscope, + <a href="#Page_104">104</a></li> + + <li class="i1">Hill, Prof. Leonard, + <a href="#Page_111">111</a>, + <a href="#Page_120">120</a></li> + + <li class="i1">Hornabrook, + <a href="#Page_87">87</a>, + <a href="#Page_123">123</a></li> + + <li class="i1">Hydrochloric acid, as an impurity in chloroform, + <a href="#Page_109">109</a></li> + + <li class="i1">Hypnotics, + <a href="#Page_12">12</a>, + <a href="#Page_42">42</a></li> + + <li class="i1">Hypodermic medication, + <a href="#Page_12">12</a>, + <a href="#Page_42">42</a></li> +</ul> + +<p class="p-index">I</p> + +<ul> + <li class="i1">Impurities of anæsthetics, + <a href="#Page_74">74</a>, + <a href="#Page_109">109</a>, + <a href="#Page_122">122</a></li> + + <li class="i1">Infiltration analgesia, + <a href="#Page_175">175</a></li> + + <li class="i1">Inhalers, Clover, + <a href="#Page_78">78</a></li> + <li class="i2">Clarke, + <a href="#Page_68">68</a></li> + <li class="i2">Guy, + <a href="#Page_128">128</a></li> + <li class="i2">Guy-Ross, + <a href="#Page_130">130</a></li> + <li class="i2">Hewitt, + <a href="#Page_50">50</a>, + <a href="#Page_62">62</a>, + <a href="#Page_81">81</a></li> + <li class="i2">Junker’s, + <a href="#Page_115">115</a></li> + <li class="i2">Ormsby, + <a href="#Page_81">81</a></li> + <li class="i2">Paterson, + <a href="#Page_58">58</a></li> + <li class="i2">Rendle, + <a href="#Page_135">135</a></li> + + <li class="i1">Inhibition, vagal, + <a href="#Page_111">111</a>, + <a href="#Page_143">143</a></li> + + <li class="i1">Intestinal obstruction, + <a href="#Page_141">141</a>, + <a href="#Page_189">189</a></li> + + <li class="i1">Intranasal surgery, + <a href="#Page_160">160</a>, + <a href="#Page_166">166</a>, + <a href="#Page_192">192</a></li> + + <li class="i1">Intratracheal method, + <a href="#Page_96">96</a></li> + <li class="i2">Kelly’s instrument for, + <a href="#Page_100">100</a></li> + <li class="i2">Shipway’s, + <a href="#Page_101">101</a></li> + + <li class="i1">Inversion, Leonard Hill’s experiments upon, + <a href="#Page_110">110</a>, + <a href="#Page_111">111</a></li> +</ul> + +<p class="p-index">J</p> + +<ul> + <li class="i1">Jactitations, + <a href="#Page_53">53</a></li> + + <li class="i1">Jaundice, + <a href="#Page_154">154</a></li> + + <li class="i1">Jaws, clenching of, + <a href="#Page_15">15</a>, + <a href="#Page_26">26</a></li> + <li class="i2">falling back of, + <a href="#Page_16">16</a></li> + <li class="i2">operations upon, + <a href="#Page_166">166</a></li> + <li class="i2">management of, in anæsthesia, + <a href="#Page_23">23</a>, + <a href="#Page_83">83</a></li> + + <li class="i1">Joints, anæsthesia in dislocation of, + <a href="#Page_164">164</a></li> + + <li class="i1">Junker’s inhaler, + <a href="#Page_115">115</a></li> +</ul> + +<p class="p-index">K</p> + +<ul> + <li class="i1">Kidney, position for operations upon, + <a href="#Page_168">168</a></li> + + <li class="i1">Kelly’s intratracheal instrument, + <a href="#Page_100">100</a></li> +</ul> + +<p class="p-index">L</p> + +<ul> + <li class="i1">Labour, anæsthesia in, + <a href="#Page_44">44</a>, + <a href="#Page_169">169</a></li> + + <li class="i1">Lane, Sir Arbuthnott, + <a href="#Page_14">14</a></li> + + <li class="i1">Laryngeal stridor, + <a href="#Page_16">16</a>, + <a href="#Page_20">20</a>, + <a href="#Page_26">26</a>, + <a href="#Page_40">40</a>, + <a href="#Page_169">169</a></li> + + <li class="i1">Levy, Goodman, + <a href="#Page_112">112</a>, + <a href="#Page_145">145</a></li> + + <li class="i1">Light anæsthesia, dangers of, in chloroform, + <a href="#Page_9">9</a>, + <a href="#Page_112">112</a></li> + <li class="i2">Levy’s views, + <a href="#Page_113">113</a></li> + + <li class="i1">Light reflex, + <a href="#Page_32">32</a></li> + + <li class="i1">Local anæsthesia, + <a href="#Page_170">170</a> <i>et seq.</i></li> + + <li class="i1">Lowering of head and shoulders, + <a href="#Page_110">110</a>, + <a href="#Page_145">145</a></li> + + <li class="i1">Lumbar puncture, site for, + <a href="#Page_196">196</a></li> + + <li class="i1">Lungs, ventilation of, by normal breathing, + <a href="#Page_96">96</a></li> + <li class="i2">by intratracheal method, + <a href="#Page_97">97</a></li> + + <li class="i1">Lymphatism, + <a href="#Page_148">148</a></li> +</ul> + +<p class="p-index">M</p> + +<ul> + <li class="i1">Malcolm, J. D., + <a href="#Page_9">9</a></li> + + <li class="i1">Marshall, Dr Geoffrey, + <a href="#Page_70">70</a></li> + + <li class="i1">Masks for chloroform, + <a href="#Page_110">110</a></li> + <li class="i2">for ether, + <a href="#Page_82">82</a></li> + <li class="i2">for perhalation method, + <a href="#Page_28">28</a></li> + + <li class="i1">Massage of heart, + <a href="#Page_148">148</a></li> + + <li class="i1">Mechanical asphyxia, + <a href="#Page_15">15</a></li> + + <li class="i1">Meltzer and Auer, on intratracheal method, + <a href="#Page_96">96</a></li> + + <li class="i1">Menstruation, + <a href="#Page_169">169</a></li> + + <li class="i1">Micturition before nitrous oxide, + <a href="#Page_51">51</a></li> + + <li class="i1">Mixtures, C. E., + <a href="#Page_83">83</a>, + <a href="#Page_134">134</a>, + <a href="#Page_137">137</a></li> + <li class="i2">of nitrous oxide and oxygen, + <a href="#Page_60">60</a></li> + <li class="i2">of nitrous oxide and ethyl chloride, + <a href="#Page_128">128</a></li> + + <li class="i1">Morphine, + <a href="#Page_12">12</a>, + <a href="#Page_43">43</a>, + <a href="#Page_152">152</a></li> + + <li class="i1">Mouth, breathing through, + <a href="#Page_22">22</a></li> + + <li class="i1">Mouth, operations upon, + <a href="#Page_165">165</a></li> + + <li class="i1">Mouth props, + <a href="#Page_22">22</a></li> + + <li class="i1">Mucus in air passages, + <a href="#Page_40">40</a></li> + + <li class="i1">Musculo-spiral paralysis, + <a href="#Page_157">157</a></li> + + <li class="i1">Muscles in anæsthesia, + <a href="#Page_ix">ix</a>, + <a href="#Page_3">3</a>, + <a href="#Page_19">19</a>, + <a href="#Page_34">34</a></li> + + <li class="i1">Muscle tone, + <a href="#Page_3">3</a>, + <a href="#Page_19">19</a>, + <a href="#Page_53">53</a></li> +</ul> + +<p class="p-index">N</p> + +<ul> + <li class="i1">Nasal breathing, + <a href="#Page_23">23</a>, + <a href="#Page_166">166</a></li> + + <li class="i1">Naso-pharyngeal catarrh, + <a href="#Page_151">151</a></li> + + <li class="i1">Nasal methods of giving nitrous oxide, + <a href="#Page_57">57</a></li> + + <li class="i1">Nasal tube for Junker’s bottle, + <a href="#Page_119">119</a></li> + + <li class="i1">Neck, position of, + <a href="#Page_20">20</a></li> + <li class="i2">relaxation of muscles of, + <a href="#Page_21">21</a></li> + <li class="i2">posture for operation upon, + <a href="#Page_159">159</a></li> + <li class="i2">tumours and inflammatory swellings in, + <a href="#Page_7">7</a>, + <a href="#Page_166">166</a></li> + + <li class="i1">Nephritis, influence of, upon choice of anæsthetics, + <a href="#Page_77">77</a>, + <a href="#Page_168">168</a></li> + + <li class="i1" id="Nervous">Nervous system, effects of anæsthetics upon, + <a href="#Page_2">2</a>, + <a href="#Page_75">75</a></li> + + <li class="i1">Nerves, peripheral, unaffected by anæsthetics, + <a href="#Page_3">3</a></li> + + <li class="i1">Nerve blocking, + <a href="#Page_12">12</a>, + <a href="#Page_179">179</a></li> + + <li class="i1">Night-crowing, + <a href="#Page_148">148</a></li> + + <li class="i1">Nitrous oxide, + <a href="#Page_46">46</a></li> + <li class="i2">with air, + <a href="#Page_54">54</a></li> + <li class="i2">with ether, + <a href="#Page_138">138</a></li> + <li class="i2">with ethyl chloride, + <a href="#Page_128">128</a></li> + <li class="i2">nasal, + <a href="#Page_57">57</a></li> + <li class="i2">physiology of, + <a href="#Page_46">46</a></li> + <li class="i2">contra-indications to, + <a href="#Page_56">56</a></li> + + <li class="i1" id="Nitrous">Nitrous oxide and oxygen, + <a href="#Page_8">8</a>, + <a href="#Page_12">12</a>, + <a href="#Page_60">60</a></li> + <li class="i2">various systems for, + <a href="#Page_66">66</a>, + <a href="#Page_70">70</a>, + <a href="#Page_130">130</a></li> + <li class="i2">for use in major surgery, + <a href="#Page_72">72</a></li> + <li class="i2">with ethyl chloride, + <a href="#Page_131">131</a></li> +</ul> + +<p class="p-index">O</p> + +<ul> + <li class="i1">Obesity, + <a href="#Page_158">158</a>, + <a href="#Page_165">165</a></li> + + <li class="i1">Obstruction, intestinal, + <a href="#Page_141">141</a></li> + <li class="i2">respiratory, + <a href="#Page_15">15</a>, + <a href="#Page_141">141</a></li> + + <li class="i1">Oil ether, Gwathmey’s method of, + <a href="#Page_93">93</a></li> + + <li class="i1">Oligæmia in shock, + <a href="#Page_10">10</a></li> + + <li class="i1">Omnopon, + <a href="#Page_44">44</a></li> + + <li class="i1">Open method, definition of, + <a href="#Page_28">28</a></li> + <li class="i2">chloroform, + <a href="#Page_117">117</a></li> + <li class="i2">ether, + <a href="#Page_83">83</a></li> + <li class="i2">ethyl chloride, + <a href="#Page_123">123</a></li> + + <li class="i1">O’Malley’s technique for intra-nasal surgery, + <a href="#Page_160">160</a></li> + + <li class="i1">Ormsby’s inhaler, + <a href="#Page_81">81</a>, + <a href="#Page_137">137</a></li> + + <li class="i1">Over-dosage, + <a href="#Page_36">36</a>, + <a href="#Page_110">110</a>, + <a href="#Page_144">144</a></li> + <li class="i2">with nitrous oxide, + <a href="#Page_54">54</a></li> + + <li class="i1">Oxygen, reduction in blood in anæsthesia, + <a href="#Page_206">206</a></li> + <li class="i2">as a relief in asphyxia, + <a href="#Page_27">27</a></li> + <li class="i2">to old patients, + <a href="#Page_165">165</a></li> + <li class="i2">with nitrous oxide (<i>see</i> <a href="#Nitrous">Nitrous Oxide and Oxygen</a>)</li> + <li class="i2">with nitrous oxide and ethyl chloride, + <a href="#Page_130">130</a></li> +</ul> + +<p class="p-index">P</p> + +<ul> + <li class="i1">Paralysis, musculo-spiral, + <a href="#Page_157">157</a></li> + + <li class="i1">Patella reflex in anæsthesia, + <a href="#Page_3">3</a></li> + + <li class="i1">Percentages of chloroform and ether required in anæsthesia, + <a href="#Page_6">6</a></li> + <li class="i2">of chloroform, + <a href="#Page_111">111</a></li> + <li class="i2">of ether, + <a href="#Page_86">86</a>, + <a href="#Page_99">99</a>, + <a href="#Page_201">201</a>, + <a href="#Page_204">204</a></li> + + <li class="i1">Perhalation method, definition of, + <a href="#Page_28">28</a></li> + <li class="i2">ether (<i>see</i> <a href="#Ether">open Ether</a>)</li> + + <li class="i1">Phenomena of anæsthesia</li> + <li class="i2">normal, + <a href="#Page_33">33</a></li> + <li class="i2">abnormal, + <a href="#Page_38">38</a></li> + <li class="i2">of nitrous oxide, + <a href="#Page_52">52</a></li> + <li class="i2">of ethyl chloride, + <a href="#Page_125">125</a></li> + + <li class="i1">Pericarditis as a cause of death in anæsthesia, + <a href="#Page_168">168</a></li> + + <li class="i1">Phillip’s artificial airway, + <a href="#Page_23">23</a>, + <a href="#Page_160">160</a></li> + + <li class="i1">Physics of natural respiration, + <a href="#Page_96">96</a></li> + + <li class="i1" id="Physiology">Physiology of anæsthetic drugs, + <a href="#Page_1">1</a></li> + <li class="i2">of asphyxia, + <a href="#Page_17">17</a></li> + <li class="i2">of chloroform, + <a href="#Page_109">109</a></li> + <li class="i2">of ether, + <a href="#Page_75">75</a></li> + <li class="i2">of ethyl chloride, + <a href="#Page_122">122</a></li> + <li class="i2">of nitrous oxide, + <a href="#Page_46">46</a></li> + + <li class="i1">Phthisis, + <a href="#Page_167">167</a></li> + + <li class="i1">Pneumonia, post anæsthetic, + <a href="#Page_157">157</a></li> + + <li class="i1">Position in anæsthesia, + <a href="#Page_157">157</a></li> + + <li class="i1">Positive pressure in nitrous oxide, + <a href="#Page_52">52</a></li> + <li class="i2">in nitrous oxide and oxygen, + <a href="#Page_66">66</a></li> + + <li class="i1">Post-chloroform poisoning, + <a href="#Page_153">153</a></li> + + <li class="i1">Post anæsthetic complications, + <a href="#Page_150">150</a></li> + + <li class="i1">Pregnancy, anæsthesia in, + <a href="#Page_169">169</a></li> + + <li class="i1">Preliminary hypodermic medication, + <a href="#Page_11">11</a>, + <a href="#Page_43">43</a>, + <a href="#Page_152">152</a></li> + + <li class="i1">Preparation of patient, + <a href="#Page_42">42</a></li> + + <li class="i1">Primary syncope, + <a href="#Page_110">110</a>, + <a href="#Page_143">143</a></li> + + <li class="i1">Protection from shock by general anæsthetics, + <a href="#Page_8">8</a></li> + + <li class="i1">Pulse, rate in shock, + <a href="#Page_6">6</a></li> + <li class="i2">clinical observation of, + <a href="#Page_37">37</a></li> + + <li class="i1">Pupil, light reflex of, + <a href="#Page_32">32</a></li> + <li class="i2">size of, + <a href="#Page_35">35</a></li> + <li class="i2">in asphyxia, + <a href="#Page_17">17</a></li> + + <li class="i1">Purging before anæsthetics, + <a href="#Page_40">40</a></li> +</ul> + +<p class="p-index">Q</p> + +<ul> + <li class="i1">Quinine and urea hydrochloride, + <a href="#Page_174">174</a></li> +</ul> + +<p class="p-index">R</p> + +<ul> + <li class="i1">Rebreathing method, + <a href="#Page_18">18</a></li> + <li class="i2">in nitrous oxide, + <a href="#Page_68">68</a></li> + + <li class="i1">Rectal administration of ether, + <a href="#Page_93">93</a></li> + + <li class="i1">Rectal saline, + <a href="#Page_42">42</a></li> + + <li class="i1">Reflexes as a cause of shock, + <a href="#Page_4">4</a>, + <a href="#Page_6">6</a></li> + <li class="i2">order of disappearance of, + <a href="#Page_3">3</a></li> + + <li class="i1">Reflex, conjunctival, + <a href="#Page_31">31</a>, + <a href="#Page_35">35</a></li> + <li class="i2">corneal, + <a href="#Page_32">32</a>, + <a href="#Page_35">35</a></li> + <li class="i2">light, + <a href="#Page_32">32</a>, + <a href="#Page_35">35</a></li> + <li class="i2">patella, + <a href="#Page_3">3</a></li> + <li class="i2">skin, + <a href="#Page_37">37</a></li> + + <li class="i1">Reflex syncope, + <a href="#Page_8">8</a>, + <a href="#Page_112">112</a>, + <a href="#Page_145">145</a></li> + + <li class="i1">Regional anæsthesia, + <a href="#Page_179">179</a></li> + + <li class="i1">Renal disease, + <a href="#Page_163">163</a></li> + + <li class="i1">Rendle’s cone, + <a href="#Page_135">135</a></li> + + <li class="i1">Repeated administrations, + <a href="#Page_60">60</a>, + <a href="#Page_156">156</a></li> + + <li class="i1">Respiration, arrest of, + <a href="#Page_142">142</a></li> + <li class="i2">artificial, + <a href="#Page_146">146</a></li> + <li class="i2">blowing, + <a href="#Page_34">34</a>, + <a href="#Page_89">89</a></li> + <li class="i2">crowing, + <a href="#Page_16">16</a></li> + <li class="i2">depressed, + <a href="#Page_39">39</a>, + <a href="#Page_43">43</a></li> + <li class="i2">effect of morphia and chloroform upon, + <a href="#Page_43">43</a>, + <a href="#Page_86">86</a></li> + <li class="i2">normal, + <a href="#Page_34">34</a></li> + <li class="i2">obstructed, + <a href="#Page_15">15</a>, + <a href="#Page_141">141</a>, + <a href="#Page_166">166</a></li> + + <li class="i1">Respiration, physics of natural, + <a href="#Page_96">96</a></li> + <li class="i2">reflex arrest of, + <a href="#Page_39">39</a></li> + + <li class="i1">Respiratory abnormalities, minor, + <a href="#Page_39">39</a></li> + <li class="i2">major, + <a href="#Page_141">141</a></li> + + <li class="i1">Respiratory system, effects of ether upon, + <a href="#Page_76">76</a></li> + <li class="i2">after-effects of anæsthetics upon, + <a href="#Page_150">150</a></li> + + <li class="i1">Rigidity of muscles in asphyxia, + <a href="#Page_19">19</a>, + <a href="#Page_38">38</a>, + <a href="#Page_39">39</a></li> + <li class="i2">in second stage, + <a href="#Page_33">33</a></li> +</ul> + +<p class="p-index">S</p> + +<ul> + <li class="i1">Saline injections, per rectus, + <a href="#Page_42">42</a></li> + <li class="i2">subcutaneous, + <a href="#Page_14">14</a></li> + + <li class="i1">Schimmelbusch’s mask, + <a href="#Page_28">28</a>, + <a href="#Page_116">116</a></li> + + <li class="i1">Scopolamine, + <a href="#Page_44">44</a>, + <a href="#Page_103">103</a></li> + + <li class="i1">Secondary syncope, + <a href="#Page_17">17</a>, + <a href="#Page_138">138</a>, + <a href="#Page_143">143</a></li> + + <li class="i1">Secretion of mucus, + <a href="#Page_40">40</a>, + <a href="#Page_76">76</a></li> + <li class="i2">of urine, + <a href="#Page_168">168</a></li> + + <li class="i1">Sedatives, + <a href="#Page_12">12</a>, + <a href="#Page_42">42</a></li> + + <li class="i1">Selection of anæsthetic, + <a href="#Page_162">162</a></li> + + <li class="i1">Semi-open method, + <a href="#Page_28">28</a></li> + + <li class="i1">Septic cases, + <a href="#Page_9">9</a>, + <a href="#Page_60">60</a>, + <a href="#Page_156">156</a>, + <a href="#Page_168">168</a></li> + + <li class="i1">Sequelæ of anæsthesia, + <a href="#Page_100">100</a></li> + + <li class="i1">Sex, relation to anæsthesia, + <a href="#Page_165">165</a></li> + + <li class="i1">Shipway, Dr, + <a href="#Page_91">91</a>, + <a href="#Page_101">101</a></li> + + <li class="i1">Shock, + <a href="#Page_5">5</a></li> + <li class="i2">difference between syncope and, + <a href="#Page_142">142</a></li> + + <li class="i1">Short, Mr Rendle, + <a href="#Page_154">154</a></li> + + <li class="i1">Sickness (<i>see</i> <a href="#Vomiting">Vomiting</a>)</li> + + <li class="i1">Sighing, + <a href="#Page_40">40</a></li> + + <li class="i1">Sight-feed machines for gas-oxygen, + <a href="#Page_70">70</a></li> + + <li class="i1">Signs of anæsthesia, + <a href="#Page_36">36</a>, + <a href="#Page_53">53</a>, + <a href="#Page_65">65</a></li> + + <li class="i1">Silk, Dr J. W., + <a href="#Page_23">23</a>, + <a href="#Page_87">87</a></li> + + <li class="i1">Single dose anæsthetics, + <a href="#Page_30">30</a>, + <a href="#Page_163">163</a></li> + + <li class="i1">Sitting posture, + <a href="#Page_21">21</a>, + <a href="#Page_158">158</a></li> + + <li class="i1">Slow respiration, + <a href="#Page_39">39</a></li> + + <li class="i1">Spasm, muscular, + <a href="#Page_19">19</a></li> + <li class="i2">of jaw muscles, + <a href="#Page_15">15</a></li> + <li class="i2">of larynx, + <a href="#Page_16">16</a>, + <a href="#Page_26">26</a>, + <a href="#Page_169">169</a></li> + + <li class="i1">Specific gravity of chloroform, + <a href="#Page_109">109</a></li> + <li class="i2">of ether, + <a href="#Page_74">74</a></li> + + <li class="i1">Spinal anæsthesia, + <a href="#Page_193">193</a></li> + + <li class="i1">Stages of anæsthesia, + <a href="#Page_31">31</a></li> + + <li class="i1">Starvation, a cause of shock, + <a href="#Page_9">9</a></li> + <li class="i2">of acidosis, + <a href="#Page_155">155</a></li> + + <li class="i1">Status lymphaticus, + <a href="#Page_148">148</a></li> + + <li class="i1">Stertor, + <a href="#Page_40">40</a>, + <a href="#Page_53">53</a></li> + + <li class="i1">Stimuli from field of operations, + <a href="#Page_6">6</a></li> + + <li class="i1">Stomach tube, before operation, + <a href="#Page_141">141</a></li> + + <li class="i1">Stovaine, + <a href="#Page_173">173</a></li> + + <li class="i1">Stridor, + <a href="#Page_16">16</a>, + <a href="#Page_26">26</a>, + <a href="#Page_40">40</a></li> + + <li class="i1" id="Struggling">Struggling, + <a href="#Page_34">34</a></li> + + <li class="i1">Strychnine, + <a href="#Page_147">147</a></li> + + <li class="i1">Subcutaneous saline, + <a href="#Page_14">14</a></li> + + <li class="i1">Swallowing, movements of, + <a href="#Page_33">33</a></li> + + <li class="i1">Sylvester’s method of artificial respiration, + <a href="#Page_146">146</a></li> + + <li class="i1" id="Syncope">Syncope, + <a href="#Page_142">142</a></li> + + <li class="i1">Syringe for local anæsthesia, + <a href="#Page_176">176</a></li> + <li class="i2">for spinal anæsthesia, + <a href="#Page_176">176</a></li> +</ul> + +<p class="p-index">T</p> + +<ul> + <li class="i1">Teeth, danger of dropping of into larynx, + <a href="#Page_16">16</a></li> + <li class="i2">extraction of, + <a href="#Page_54">54</a>, + <a href="#Page_57">57</a>, + <a href="#Page_128">128</a>, + <a href="#Page_131">131</a>, + <a href="#Page_163">163</a></li> + + <li class="i1">Teter, Dr., on nitrous oxide and oxygen, + <a href="#Page_68">68</a></li> + + <li class="i1">Thomson, Prof. Alexis, + <a href="#Page_12">12</a>, + <a href="#Page_158">158</a></li> + + <li class="i1">Thomson, Torrance, on intratracheal anæsthesia, + <a href="#Page_96">96</a></li> + + <li class="i1">Thoracic operations, local anæsthesia in, + <a href="#Page_186">186</a></li> + + <li class="i1">Three-way tap for nitrous oxide, + <a href="#Page_50">50</a>, + <a href="#Page_128">128</a></li> + + <li class="i1">Thyroid gland, <i>see</i> <a href="#Goitre">Goitre</a></li> + + <li class="i1">Time for operations, + <a href="#Page_42">42</a></li> + + <li class="i1">Time afforded by single dose anæsthetics, + <a href="#Page_163">163</a></li> + + <li class="i1">Tongue falling back of, + <a href="#Page_16">16</a></li> + <li class="i2">forceps for, + <a href="#Page_24">24</a></li> + <li class="i2">operations upon, + <a href="#Page_97">97</a>, + <a href="#Page_118">118</a>, + <a href="#Page_166">166</a></li> + <li class="i2">local anæsthesia for, + <a href="#Page_191">191</a></li> + + <li class="i1">Tonsils and adenoids, + <a href="#Page_127">127</a>, + <a href="#Page_166">166</a></li> + + <li class="i1">Trachea, mucus in, + <a href="#Page_40">40</a></li> + <li class="i2">pressure upon, + <a href="#Page_17">17</a></li> + + <li class="i1">Trachetomy, + <a href="#Page_142">142</a>, + <a href="#Page_185">185</a></li> + + <li class="i1">Tremor, ether, + <a href="#Page_38">38</a></li> + + <li class="i1">Trendelenberg posture, + <a href="#Page_158">158</a></li> + + <li class="i1">Tropacocaine, + <a href="#Page_173">173</a></li> + + <li class="i1">Turner, Dr Logan, + <a href="#Page_125">125</a></li> +</ul> + +<p class="p-index">U</p> + +<ul> + <li class="i1">Urine, secretion of prevented by morphia, + <a href="#Page_168">168</a></li> +</ul> + +<p class="p-index">V</p> + +<ul> + <li class="i1">Vagus nerve, + <a href="#Page_110">110</a>, + <a href="#Page_145">145</a></li> + + <li class="i1">Valved method, features of, + <a href="#Page_29">29</a></li> + + <li class="i1">Vapour method, ether, + <a href="#Page_90">90</a></li> + <li class="i2">ethyl chloride, + <a href="#Page_125">125</a></li> + + <li class="i1">Vaso-motor system, in shock, + <a href="#Page_9">9</a></li> + <li class="i2">in asphyxia, + <a href="#Page_17">17</a></li> + <li class="i2">in nitrous oxide, + <a href="#Page_46">46</a> (and <i>see</i> <a href="#Physiology">Physiology</a>)</li> + + <li class="i1">Veins, large, emptying into heart, + <a href="#Page_10">10</a></li> + <li class="i2">engorgement of, + <a href="#Page_20">20</a>, + <a href="#Page_151">151</a></li> + + <li class="i1">Venesection in syncope, + <a href="#Page_147">147</a></li> + + <li class="i1">Veronal, + <a href="#Page_12">12</a></li> + + <li class="i1">Vicious circle of asphyxia, + <a href="#Page_20">20</a></li> + + <li class="i1">Vital medullary centres, + <a href="#Page_3">3</a></li> + + <li class="i1" id="Vomiting">Vomiting, + <a href="#Page_140">140</a>, + <a href="#Page_152">152</a></li> + <li class="i2">impending, + <a href="#Page_39">39</a>, + <a href="#Page_141">141</a></li> +</ul> + +<p class="p-index">W</p> + +<ul> + <li class="i1">War, anti-shock, measures in, + <a href="#Page_11">11</a></li> + <li class="i2">lessons of, + <a href="#Page_61">61</a>, + <a href="#Page_151">151</a></li> + + <li class="i1">Warming anæsthetic vapours, + <a href="#Page_62">62</a>, + <a href="#Page_90">90</a>, + <a href="#Page_101">101</a></li> + + <li class="i1">Wedge for opening clenched jaws, + <a href="#Page_25">25</a></li> + + <li class="i1">Withdrawal of anæsthetic, for stridor, + <a href="#Page_26">26</a></li> + <li class="i2">for breath holding and struggling, + <a href="#Page_34">34</a></li> + <li class="i2">for syncope, + <a href="#Page_145">145</a></li> +</ul> + + +<div class="footnotes"><h2>FOOTNOTES:</h2> + +<div class="footnote"> + +<p><a id="Footnote_1" href="#FNanchor_1" class="label">[1]</a> This can be done to a very limited extent indeed if the +ordinary valves here described are used. <i>See</i> page <a href="#Page_68">68</a>.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_2" href="#FNanchor_2" class="label">[2]</a> A safeguard provided on some machines is a side lead from +the oxygen supply direct to the facepiece whereby pure oxygen can be +given if required.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_3" href="#FNanchor_3" class="label">[3]</a> The amount of oxygen in a cylinder is designated in terms +of cubic feet. A cylinder which would hold 100 gallons of N<sub>2</sub>O, will +contain 30 cubic feet of oxygen.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_4" href="#FNanchor_4" class="label">[4]</a> In the figure the Clover is shown with gas valves and +2-gallon bag, arranged for “gas and ether.”</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_5" href="#FNanchor_5" class="label">[5]</a> Trans. xvii. Internat. Med. Cong. Sub-sect. (vii.) Part i.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_6" href="#FNanchor_6" class="label">[6]</a> <i>Journal</i> Amer. Med. Assoc., Sept. 1913.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_7" href="#FNanchor_7" class="label">[7]</a> Trans. xvii., Internat. Med. Cong. Sub-sec. (vii.), Part +i.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_8" href="#FNanchor_8" class="label">[8]</a> Trans. xvii., Internat. Med. Cong., Sub-sec. (vii.), Part +ii.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_9" href="#FNanchor_9" class="label">[9]</a> Trans. xvii., Internat. Med. Cong., Sub-sec. (vii.), Part +I.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_10" href="#FNanchor_10" class="label">[10]</a> The student should be careful to be sure that the bulb is +attached to the <i>inlet pipe</i>: if by accident it be slipped on to +the outlet pipe, the first compression of the bulb will eject a stream +of liquid chloroform from the instrument.</p> + +</div> + +<div class="footnote"> + +<p><a id="Footnote_11" href="#FNanchor_11" class="label">[11]</a> The author described this method in a paper read before +the Scottish Branch of the British Dental Association, and afterwards +published in the <i>Journal</i> of the Association under the title “The +Edinburgh System of Dental Anæsthesia.” To the use of this term Dr J. +H. Gibbs, of Edinburgh, took strong exception in a letter to the Editor +of the <i>Journal</i>. The author has and had no desire to convey the +impression that this system was universally used in Edinburgh, but +simply that it is the method taught by Dr Guy, Dean of the School, to +the students in the Extraction Room.</p> + +</div> +</div> + + +<p class="transnote">Transcriber’s Notes:<br> +<br> +1. Obvious printers’, punctuation and spelling errors have been +corrected silently.<br> +<br> +2. Where hyphenation is in doubt, it has been retained as in the +original.<br> +<br> +3. Some hyphenated and non-hyphenated versions of the same words have +been retained as in the original.</p> + + +<div style='text-align:center'>*** END OF THE PROJECT GUTENBERG EBOOK 75985 ***</div> +</body> +</html> + diff --git a/75985-h/images/cover.jpg b/75985-h/images/cover.jpg Binary files differnew file mode 100644 index 0000000..a254c3e --- /dev/null +++ b/75985-h/images/cover.jpg diff --git a/75985-h/images/i_p006.jpg b/75985-h/images/i_p006.jpg Binary files differnew file mode 100644 index 0000000..83e8f6a --- /dev/null +++ b/75985-h/images/i_p006.jpg diff --git a/75985-h/images/i_p008.jpg b/75985-h/images/i_p008.jpg Binary files differnew file mode 100644 index 0000000..af719d7 --- /dev/null +++ b/75985-h/images/i_p008.jpg diff --git a/75985-h/images/i_p011.jpg b/75985-h/images/i_p011.jpg Binary files differnew file mode 100644 index 0000000..355ac26 --- /dev/null +++ b/75985-h/images/i_p011.jpg diff --git a/75985-h/images/i_p013.jpg b/75985-h/images/i_p013.jpg Binary files differnew file mode 100644 index 0000000..d2897f2 --- /dev/null +++ b/75985-h/images/i_p013.jpg diff --git a/75985-h/images/i_p020.jpg b/75985-h/images/i_p020.jpg Binary files differnew file mode 100644 index 0000000..cdc5c2b --- /dev/null +++ b/75985-h/images/i_p020.jpg diff --git a/75985-h/images/i_p022.jpg b/75985-h/images/i_p022.jpg Binary files differnew file mode 100644 index 0000000..bc7637f --- /dev/null +++ b/75985-h/images/i_p022.jpg diff --git a/75985-h/images/i_p023a.jpg b/75985-h/images/i_p023a.jpg Binary files differnew file mode 100644 index 0000000..fd8dc1f --- /dev/null +++ b/75985-h/images/i_p023a.jpg diff --git a/75985-h/images/i_p023b.jpg b/75985-h/images/i_p023b.jpg Binary files differnew file mode 100644 index 0000000..01725a0 --- /dev/null +++ b/75985-h/images/i_p023b.jpg diff --git a/75985-h/images/i_p023c.jpg b/75985-h/images/i_p023c.jpg Binary files differnew file mode 100644 index 0000000..e4eb695 --- /dev/null +++ b/75985-h/images/i_p023c.jpg diff --git a/75985-h/images/i_p024a.jpg b/75985-h/images/i_p024a.jpg Binary files differnew file mode 100644 index 0000000..602a1dc --- /dev/null +++ b/75985-h/images/i_p024a.jpg diff --git a/75985-h/images/i_p024b.jpg b/75985-h/images/i_p024b.jpg Binary files differnew file mode 100644 index 0000000..48daebc --- /dev/null +++ b/75985-h/images/i_p024b.jpg diff --git a/75985-h/images/i_p024c.jpg b/75985-h/images/i_p024c.jpg Binary files differnew file mode 100644 index 0000000..4f0fff8 --- /dev/null +++ b/75985-h/images/i_p024c.jpg diff --git a/75985-h/images/i_p025a.jpg b/75985-h/images/i_p025a.jpg Binary files differnew file mode 100644 index 0000000..0c53bdc --- /dev/null +++ b/75985-h/images/i_p025a.jpg diff --git a/75985-h/images/i_p025b.jpg b/75985-h/images/i_p025b.jpg Binary files differnew file mode 100644 index 0000000..99931bb --- /dev/null +++ b/75985-h/images/i_p025b.jpg diff --git a/75985-h/images/i_p025c.jpg b/75985-h/images/i_p025c.jpg Binary files differnew file mode 100644 index 0000000..3c425da --- /dev/null +++ b/75985-h/images/i_p025c.jpg diff --git a/75985-h/images/i_p047.jpg b/75985-h/images/i_p047.jpg Binary files differnew file mode 100644 index 0000000..41f9a22 --- /dev/null +++ b/75985-h/images/i_p047.jpg diff --git a/75985-h/images/i_p048.jpg b/75985-h/images/i_p048.jpg Binary files differnew file mode 100644 index 0000000..c253b11 --- /dev/null +++ b/75985-h/images/i_p048.jpg diff --git a/75985-h/images/i_p049.jpg b/75985-h/images/i_p049.jpg Binary files differnew file mode 100644 index 0000000..b6dd330 --- /dev/null +++ b/75985-h/images/i_p049.jpg diff --git a/75985-h/images/i_p050a.jpg b/75985-h/images/i_p050a.jpg Binary files differnew file mode 100644 index 0000000..ad3394b --- /dev/null +++ b/75985-h/images/i_p050a.jpg diff --git a/75985-h/images/i_p050b.jpg b/75985-h/images/i_p050b.jpg Binary files differnew file mode 100644 index 0000000..b7dad97 --- /dev/null +++ b/75985-h/images/i_p050b.jpg diff --git a/75985-h/images/i_p058.jpg b/75985-h/images/i_p058.jpg Binary files differnew file mode 100644 index 0000000..18cd744 --- /dev/null +++ b/75985-h/images/i_p058.jpg diff --git a/75985-h/images/i_p063.jpg b/75985-h/images/i_p063.jpg Binary files differnew file mode 100644 index 0000000..a84bae8 --- /dev/null +++ b/75985-h/images/i_p063.jpg diff --git a/75985-h/images/i_p067.jpg b/75985-h/images/i_p067.jpg Binary files differnew file mode 100644 index 0000000..16647f9 --- /dev/null +++ b/75985-h/images/i_p067.jpg diff --git a/75985-h/images/i_p068.jpg b/75985-h/images/i_p068.jpg Binary files differnew file mode 100644 index 0000000..502cd33 --- /dev/null +++ b/75985-h/images/i_p068.jpg diff --git a/75985-h/images/i_p069.jpg b/75985-h/images/i_p069.jpg Binary files differnew file mode 100644 index 0000000..08074c9 --- /dev/null +++ b/75985-h/images/i_p069.jpg diff --git a/75985-h/images/i_p070.jpg b/75985-h/images/i_p070.jpg Binary files differnew file mode 100644 index 0000000..9faa364 --- /dev/null +++ b/75985-h/images/i_p070.jpg diff --git a/75985-h/images/i_p077.jpg b/75985-h/images/i_p077.jpg Binary files differnew file mode 100644 index 0000000..bafeb6b --- /dev/null +++ b/75985-h/images/i_p077.jpg diff --git a/75985-h/images/i_p078.jpg b/75985-h/images/i_p078.jpg Binary files differnew file mode 100644 index 0000000..b2a5560 --- /dev/null +++ b/75985-h/images/i_p078.jpg diff --git a/75985-h/images/i_p080.jpg b/75985-h/images/i_p080.jpg Binary files differnew file mode 100644 index 0000000..6f3bdad --- /dev/null +++ b/75985-h/images/i_p080.jpg diff --git a/75985-h/images/i_p081.jpg b/75985-h/images/i_p081.jpg Binary files differnew file mode 100644 index 0000000..a7a953d --- /dev/null +++ b/75985-h/images/i_p081.jpg diff --git a/75985-h/images/i_p083.jpg b/75985-h/images/i_p083.jpg Binary files differnew file mode 100644 index 0000000..256f8aa --- /dev/null +++ b/75985-h/images/i_p083.jpg diff --git a/75985-h/images/i_p084a.jpg b/75985-h/images/i_p084a.jpg Binary files differnew file mode 100644 index 0000000..7f438d6 --- /dev/null +++ b/75985-h/images/i_p084a.jpg diff --git a/75985-h/images/i_p084b.jpg b/75985-h/images/i_p084b.jpg Binary files differnew file mode 100644 index 0000000..007dcf9 --- /dev/null +++ b/75985-h/images/i_p084b.jpg diff --git a/75985-h/images/i_p085a.jpg b/75985-h/images/i_p085a.jpg Binary files differnew file mode 100644 index 0000000..0114d15 --- /dev/null +++ b/75985-h/images/i_p085a.jpg diff --git a/75985-h/images/i_p085b.jpg b/75985-h/images/i_p085b.jpg Binary files differnew file mode 100644 index 0000000..8ecf96f --- /dev/null +++ b/75985-h/images/i_p085b.jpg diff --git a/75985-h/images/i_p091.jpg b/75985-h/images/i_p091.jpg Binary files differnew file mode 100644 index 0000000..4a67072 --- /dev/null +++ b/75985-h/images/i_p091.jpg diff --git a/75985-h/images/i_p098.jpg b/75985-h/images/i_p098.jpg Binary files differnew file mode 100644 index 0000000..fe34713 --- /dev/null +++ b/75985-h/images/i_p098.jpg diff --git a/75985-h/images/i_p099.jpg b/75985-h/images/i_p099.jpg Binary files differnew file mode 100644 index 0000000..8163709 --- /dev/null +++ b/75985-h/images/i_p099.jpg diff --git a/75985-h/images/i_p100.jpg b/75985-h/images/i_p100.jpg Binary files differnew file mode 100644 index 0000000..af62c45 --- /dev/null +++ b/75985-h/images/i_p100.jpg diff --git a/75985-h/images/i_p102.jpg b/75985-h/images/i_p102.jpg Binary files differnew file mode 100644 index 0000000..b0a19ca --- /dev/null +++ b/75985-h/images/i_p102.jpg diff --git a/75985-h/images/i_p104.jpg b/75985-h/images/i_p104.jpg Binary files differnew file mode 100644 index 0000000..8a81471 --- /dev/null +++ b/75985-h/images/i_p104.jpg diff --git a/75985-h/images/i_p110.jpg b/75985-h/images/i_p110.jpg Binary files differnew file mode 100644 index 0000000..87e06dd --- /dev/null +++ b/75985-h/images/i_p110.jpg diff --git a/75985-h/images/i_p115.jpg b/75985-h/images/i_p115.jpg Binary files differnew file mode 100644 index 0000000..63a536d --- /dev/null +++ b/75985-h/images/i_p115.jpg diff --git a/75985-h/images/i_p116.jpg b/75985-h/images/i_p116.jpg Binary files differnew file mode 100644 index 0000000..9af49be --- /dev/null +++ b/75985-h/images/i_p116.jpg diff --git a/75985-h/images/i_p117.jpg b/75985-h/images/i_p117.jpg Binary files differnew file mode 100644 index 0000000..b50d28d --- /dev/null +++ b/75985-h/images/i_p117.jpg diff --git a/75985-h/images/i_p119.jpg b/75985-h/images/i_p119.jpg Binary files differnew file mode 100644 index 0000000..e74a88d --- /dev/null +++ b/75985-h/images/i_p119.jpg diff --git a/75985-h/images/i_p122.jpg b/75985-h/images/i_p122.jpg Binary files differnew file mode 100644 index 0000000..176f344 --- /dev/null +++ b/75985-h/images/i_p122.jpg diff --git a/75985-h/images/i_p124.jpg b/75985-h/images/i_p124.jpg Binary files differnew file mode 100644 index 0000000..e2af13a --- /dev/null +++ b/75985-h/images/i_p124.jpg diff --git a/75985-h/images/i_p128.jpg b/75985-h/images/i_p128.jpg Binary files differnew file mode 100644 index 0000000..bd4b883 --- /dev/null +++ b/75985-h/images/i_p128.jpg diff --git a/75985-h/images/i_p129.jpg b/75985-h/images/i_p129.jpg Binary files differnew file mode 100644 index 0000000..3b15db2 --- /dev/null +++ b/75985-h/images/i_p129.jpg diff --git a/75985-h/images/i_p130.jpg b/75985-h/images/i_p130.jpg Binary files differnew file mode 100644 index 0000000..0c2c90e --- /dev/null +++ b/75985-h/images/i_p130.jpg diff --git a/75985-h/images/i_p131.jpg b/75985-h/images/i_p131.jpg Binary files differnew file mode 100644 index 0000000..ba70a56 --- /dev/null +++ b/75985-h/images/i_p131.jpg diff --git a/75985-h/images/i_p135.jpg b/75985-h/images/i_p135.jpg Binary files differnew file mode 100644 index 0000000..482c90b --- /dev/null +++ b/75985-h/images/i_p135.jpg diff --git a/75985-h/images/i_p139.jpg b/75985-h/images/i_p139.jpg Binary files differnew file mode 100644 index 0000000..ddb54ea --- /dev/null +++ b/75985-h/images/i_p139.jpg diff --git a/75985-h/images/i_p146.jpg b/75985-h/images/i_p146.jpg Binary files differnew file mode 100644 index 0000000..0f83230 --- /dev/null +++ b/75985-h/images/i_p146.jpg diff --git a/75985-h/images/i_p147.jpg b/75985-h/images/i_p147.jpg Binary files differnew file mode 100644 index 0000000..c67a633 --- /dev/null +++ b/75985-h/images/i_p147.jpg diff --git a/75985-h/images/i_p159.jpg b/75985-h/images/i_p159.jpg Binary files differnew file mode 100644 index 0000000..a3131b9 --- /dev/null +++ b/75985-h/images/i_p159.jpg diff --git a/75985-h/images/i_p160.jpg b/75985-h/images/i_p160.jpg Binary files differnew file mode 100644 index 0000000..ceaffaf --- /dev/null +++ b/75985-h/images/i_p160.jpg diff --git a/75985-h/images/i_p176.jpg b/75985-h/images/i_p176.jpg Binary files differnew file mode 100644 index 0000000..1e102a6 --- /dev/null +++ b/75985-h/images/i_p176.jpg diff --git a/75985-h/images/i_p183.jpg b/75985-h/images/i_p183.jpg Binary files differnew file mode 100644 index 0000000..a26d82c --- /dev/null +++ b/75985-h/images/i_p183.jpg diff --git a/75985-h/images/i_p194.jpg b/75985-h/images/i_p194.jpg Binary files differnew file mode 100644 index 0000000..c662a54 --- /dev/null +++ b/75985-h/images/i_p194.jpg diff --git a/75985-h/images/i_p196.jpg b/75985-h/images/i_p196.jpg Binary files differnew file mode 100644 index 0000000..46390fa --- /dev/null +++ b/75985-h/images/i_p196.jpg |
