OPEN ETHER

Being the Official Report at the Seventeenlh International

Congress of Medicine, London, August, 1913

BY

ROBERT H. FERGUSON, A.M., M.D., Sc.D.

Fellow American Association of Anaesthetists; Member New YorkSociety of Anaesthetists; Fellow Massachusetts Medical Society;Member American Medical Association, The Mississippi ValleyMedical Association; Fellow New York Academy of Medicine;Member American Association for the Advancement of Sci-ence; Fellow Royal Society of Medicine, London, Eng.

Corrected and revised by the author, Fcbruary, 1915

PUBLISHED BYDEPARTMENT OF ANESTHETICS, E. R. SQUIBB & SONS

80 Beekman Street, New York City

WOOD LIBRARY-MUSaEUM

Accession no. ... w .......

OPEN ETHER*

By ROBERT H. FERGUSON, A.M., M.D., Sc.D.

East Orange, N. J.BY "Open Ether" is meant the administrationof ether for surgical amsthesia by means ofany apparatus which permits to the respira-

tory gases an unrestricted interchange between thepatient's lungs and the external air, at the sametime that ether vapour is inhaled in sufficient amountto produce and maintain the anasthesia. An openether anmesthesia, then, is conducted by means ofthe simplest apparatus possible, the purpose ofwhich must not extend beyond the holding of theliquid ether while it evaporates and the conservingof the vapour for the patient's use. Neither theether vapour nor the exhaled air must be confinedin such quantities or for so long a time that the con-finement itself can exercise any appreciable influ-ence on the anaesthesia.

Open ether is to be distinguished from the semi-open method, or the administration of ether bymeans of a cone or similar apparatus such as theAllis inhaler, and also from the closed method, theinhaler for which requires a reservoir for to-and-frobreathing, whether or not the apparatus be providedwith valves to allow an escape of expired air. Itis to be differentiated further from the so-called"Vapour" methods by which the ether vapour,either alone or in conjunction with another anmes-thetic vapour, is supplied to the patient forcibly bymeans of some sort of pump.

*The official report at the Seventeenth International CongressMedicine, London. August, 1913.

Thus an anaesthesia by the method called openether is produced by depositing liquid ether uponsome absorbent substance through which air canpass easily, and which is so placed on the patient'sface that from it he can readily inhale the ethervapour which has not been prepared previously, butas it evaporates spontaneously from the permeablesubstance. Also all exhalations from the lungs ofthe patient pass without hindrance through the sub-stance which holds the liquid ether, into the externalair.

There are various ways of exhibiting open ether,the differential points of which consist in variousapparently small but nevertheless important partic-ulars, as for instance:

(a) In the material used to hold the liquid etherwhile it evaporates, such as plain surgical gauze,stockinet, and the like.

(b) In the mode of adjusting this material to theface, that is, by simply laying it loosely on the face;or by means of some support such as can be had inthe frame of an Esmarch, Schimmelbusch, Ochsner,Yankauer, Skinner, or a Ferguson mask.

(c) In the way the frame is made, whether rigidas an Esmarch or an Ochsner, or flexible as aFerguson mask.

(d) In the size of the frame, that is, whether itis so large that it will cover the greater part of theface and fall below the chin as does the Schimmel-busch mask, or of such a size that it encircles onlythe nose and mouth as the Ferguson mask does.

(e) Another very special and important distin-guishing feature is the method that is used to preventthe undesirable dispersion of the vapour, a phenom-enon due to the specific gravity of ether vapour,and one which is inevitable if a mask with an un-protected surface is employed. This conservationof vapour is sought sometimes by encircling themask with gauze even to the extent of its wrappingthe face as with a turban, or by covering the framewith towels dry or wet, by rubber dam laid over the

frame, or by means of a suitable chamber above theconvex diaphragm.

(f) Yet again there are different methods ofapplying the liquid ether, as, for instance, by pour-ing it on at intervals, sprinkling it over the absor-bent covering from time to time, or by dropping iton intermittently or continuously.

Inasmuch as the dropping of the ether steadilyon to the mask is by far the most convenient andmost efficient method of delivering ether for theopen method, this report will consider open etherchiefly from the point of view of the open-dropmethod, and therefore whatever advantages or dis-advantages there may be in the other ways of deliv-ering ether will be considered in the setting forthof the subject from this standpoint.

The question naturally arises-Is the open-dropmethod of ether anaesthesia trustworthy and other-wise satisfactory for all cases? The answer is posi-tively Yes. It may be that for certain patients, towhom attention will be given farther on, a prelimi-nary dose of morphine may be desirable, but nooftener and for no other reason than holds goodfor ether by either the semi-open or by the closedmethods.

That open ether, especially by the drop method, isall that can be desired, can be determined by anyanaesthetist who will try the method long enough tobecome familiar with its proper technique. A goodether is necessary for the best results, inasmuch aswith the open-drop method, properly conducted,there is no accumulation of carbon dioxide or othergases to help out the anesthesia. The work is doneby ether alone, and there are some ethers fromwhich good results cannot be obtained. Further, apractical illustration of the efficiency of the open-drop method is to be found in the fact that, accord-ing to conservative estimates, over 90 per cent. ofthe anaesthesias of the United States are by openether.

Before taking up in detail an anaesthesia by open

ether it is necessary to consider certain essentialsfor obtaining the best results with it. I do not nowhave in mind conditions which must be presupposedfor an anaesthesia by any inhalational method. 1,Iorder to obtain a good anaesthesia by any methodwhatever, there must be a thorough physical prepara-tion of the patient; a proper position of the patienton the table; tranquil surroundings; and prelimi-nary medication if absolutely necessary. I refer hereonly to certain facts which are more or less peculiarto open ether or the open-drop method. Theseshould be constantly kept in mind. I will mentionsix. They are:

A. No AIR SHOULD BE ALLOWED TO PASS BE-

TWEEN THE INHALER AND THE FACE, BUT ALL RES-PIRATORY AIR SHOULD GO THROUGH THE GAUZE ON

WHICH THE ETHER IS.

The simplest exhibition of the open-drop methodis by the use of plain gauze only. When I laidaside the closed inhaler and the cone I placed sev-eral thicknesses of absorbent surgical gauze upon theface and dropped the ether on it, each side of thenose and between the nostrils and the upper lip. Assuch gauze rests on the face, it forms a sort ofbridge from the nose to the cheek, and the spacebetween these is a chamber which conserves theetherized air. A very good anaesthesia may be hadin this way. At Professor John Deaver's clinic atthe German Hospital in Philadelphia in the UnitedStates, all -the patients for operation are anaesthe-tized and kept under ether by this method. If thisform of the open-drop method is used, the faceshould be first smeared with some unguent to pre-vent any liquid ether that may come in contact withthe skin producing an erythema. The gauze shouldbe large enough to go from external of the malarbone of one cheek to external of the malar bone ofthe other cheek, and from the nasal bone to belowthe mental process, and great care should be takenthat all around the edges it is flat on the face, sothat there are no avenues from wrinkling through

6

which unetherized air can gain access to the noseand mouth between the gauze and the cheek. Ofgauze with twenty threads to the inch about twelvelayers loosely separated where they rest over thenose and mouth may be used. A piece of linen orrubber dam, somewhat larger than the gauze andwith a hole three or four inches in diameter cut init, laid on the gauze may aid in more effectually ex-cluding peripheral air than any manipulation of theplain gauze can do.

If an Esmarch, Schimmelbusch, Yankauer, Ochs-ner, Skinner, or any similar frame over which thegauze is stretched be used, some special means ofexcluding air from entrance between the inhalerframe and the face must be employed, inasmuch asthese frames are made of unbendable wire, andwhen they rest on the face they easily permit anabundance of unetherized air to enter beneath themask. There are in actual use four particular waysof excluding such air. The first is by encircling theframe with an indefinite number of yards of sur-gical gauze bandage, even to the wrapping up ofthe head so that it looks as if it were beneath aturban, but leaving an opening over the centre ofthe inhaler. Secondly, by surrounding the framewith dry towels in a way similar to the using ofgauze. Thirdly, by the use of the wet bandages ortowels in the same way that dry ones are employed.Fourthly, by covering the mask with a piece ofheavy cloth or of rubber dam large enough to hangdown all around the mask, and in which, over thecentre of the mask, a hole is cut an inch or more indiameter.

The first three adaptations are particularly bad,as they are inconvenient to manage and cover upvery much, if not all, of the patient's face. I haveknown of patients dying and remaining dead onthe table for an unknown length of time simply be-cause the amount of gauze or towels that werearound the inhaler and over the face prevented theeyes or countenance being seen by the anaesthetist.

Further, wet bandages and towels are worse thandry ones, for the additional reason that the moistureinterferes with the efficacy of the ether.

The best way to exclude the air from entrancebetween the inhaler and the face, if one of the rigidmasks is to be used, is by means of an oval cushionor pad of gauze or of absorbent cotton, Thisshould be made of some thickness, half an inch ormore being usually necessary, and of such a sizethat the inside of the ring does not in any way en-croach on the mouth and with a periphery largerthan that of the mask. First, this pad is laid in theproper position on the face, and then the mask islaid and pressed down on it. I have never seen thisused except in England, but it is so efficient with amask with a rigid face wire that it is to be highlycommended. If the anaesthetist wishes the passageof respiratory air restricted to the centre of themask, he can do it by placing a gauze collar of anydesired width over the mask in the way so clearlydescribed in the fourth edition of Sir FrederickHewitt's book,Ana sthetics and their Administration,

pp. 339 and 340, or by laying over the mask a pieceof sheet rubber with a hole cut in it as described intheJournal of the American Medical Association for1912, November 23, p. 1853. What I consider to bean altogether better way to exclude air from aroundthe periphery of the inhaler is to use a mask whichwill have the part on the face fit the features ex-actly. As no rigid instrument can be constructedto do this I use the Ferguson mask, which was de-scribed in the Journal of the American MedicalAssociation, 1905, December 30, pp. 2014, 2015.1This instrument is in general the shape and size ofan ordinary Esmarch chloroform mask, but it hasseveral peculiarities which make it a new instru-ment. The characteristic I mention here is thegreat flexibility of the wire that comes into contactwith the face. It and certain adjacent parts of the

(t) See also Guide to Ansthketics, 4 th ed., by Thos. D. Luke, M.D.. Edin-burgh, pp. 31-5. Anasthetics by Dudley M. Buxton, M.D , 5 th ed. London.Anesthetics by James T. Gwathmey, M.D., New York, 191 4 .

8

frame are made of annealed copper wire so that itcan be easily bent, and therefore the mask mouldedto make it conform exactly with the contour of thepatient's face. If the instrument has been properlyfitted to the face of the patient then no air can enterbetween the face wire and the face. All the airmust pass through the gauze on which the liquidether is, and all this is accomplished without the useof an extra piece of apparatus or without encroach-ing upon any part of the patient's face. When themask is in use the eyes and whole countenance arein full view, a condition of affairs that I like andconsider to be very useful.

Since I have called attention to the size of thismask, which is especially adapted to open ether, Imay be permitted to add that for the size there were

CIZ

FIG. I.

other determinants than those just mentioned. Iwish in this connexion to emphasize two of them.

The first is that which determined its being madeso as not in any way to cover the eyes. During ex-periments in the psychological laboratory, I noticedthat if a student had any fear of the experiment,when I blindfolded him so that he could not seewhat instrument I was to use, he complained of asense of impending suffocation. Reasoning fromthis I raised the question whether the sense of im-

9

pending suffocation, of which certain patients com-plain when they are about to be anaesthetized, mightnot be due to the fear they have of the anaesthesiaplus the forcible closure of the eyes by a towel,gauze, rubber, oil silk, the inflated cushion of the in-haler, and the like. Now since I had the mask madeso that it could not in any way interfere with theeyes, I have never had a patient complain of suffo-cation.

The second is that which determined its beingmade so that it would not go below the chin. It isnecessary only to place the forefinger over the nasalbone and at the same time the thumb below thechin, and then try to open the mouth, in order torealize how little pressure is necessary to preventthe free opening of the jaws even while we areawake and the voluntary muscles in action. If,however, the person is anaesthetized and the musclesrelaxed, such interference with the free movementof the lower jaw is had much more readily. Inoticed that during an anaesthesia many studentswhen using a Schimmelbusch or equally large maskwould keep their patient cyanotic unless some spe-cial provision for keeping the lips and jaws aparthad been made. I noticed further that this cyanosiswould pass away when the inhaler frame was so ad-justed that it could not encircle the mandible. Askeeping a large frame from going below the jaw isa very difficult matter, I made my mask so that thelower border would rest between the lower lip andthe mental process. Therefore with the Fergusonmask it is impossible to interfere in any way withthe free working of the lower jaw. A person withthe frame of the mask bound tightly on the facecan talk, laugh, or sing just as freely as if it werenot on the face at all. Therefore this mask pre-cludes the possibility of interference with the freeentrance of air through the mouth, and of the twoentrances of respiratory air-namely, that throughthe buccal cavity and that through the nose-I con-sider, even for patients with a clear nasal cavity, the

IO

airway through the mouth the more important foranaesthesia.

The second essential to a satisfactory anaesthesiaby open ether is that:

B. THE PATIENT DURING THE INDUCTION AND

THROUGHOUT TIHE ANJESTHESIA SHALL BE ALLOWED

TO HAVE ALL THE AIR NECESSARY FOR NORMAL RES-PIRATION. That anaesthesia is not necessarily due toanoxamia has been settled, I think, for all time, butthere are still some anaesthetists who seem to be re-luctant to give up the old idea, possibly because inthe way that ether is so frequently administered a de-privation of air plays some r6le in the anesthesia.To realize that a restriction of air is not essential foran anaesthesia it is necessary only to bear in mindthe excellent ether anaesthesia that may be inducedand maintained even while pure oxygen is adminis-tered simultaneously with ether, also that in rectalanaesthesia the sleep is induced and maintainedwhile the patient is breathing with his lungs notonly sufficient air for ordinary respiration, but evenan abnormally large quantity. For in rectal anaes-thesia, at the beginning of the induction, the patientis breathing and for a while continues to breathenormally, but as soon as the stimulating effect ofthe ether is had he breathes more deeply and morerapidly, thus increasing both the quantity of tidalair at one inspiration and also the number of in-spirations per minute. Ether vapour itself is a trueanaesthetic. All that is necessary for producinganaesthesia is to furnish a proper quantity of ethervapour to the cells of the body. Another proof ofthis fact is the method and results of intravenousether anaesthesia. In any anaesthesia it does notmatter how much air, oxygen, carbon dioxide, orchloroform vapour may be present, the ether doesits work independently although in conjunction withthem. This teaches us to allow the patient fromthe beginning to the end of the anaesthesia all theair he needs for normal respiration, yet in someway introduce with this air sufficient ether vapour.

II

Of an absorbent gauze having twenty threads to theinch, nine thicknesses are sufficient, and this is thenumber I use in my work. The rule is, the smallerthe mesh of the gauze the fewer the thicknesses thatshould be used, the larger the mesh the more thick-nesses that may be used, but never enough to em-barrass in any degree the respiration of the patient.

It may, upon first thought, seem as if this state-ment were contrary to that in the rule to rigidlyexclude all air from between the mask and the face.It is not so, however. The reason for preventingair from entering between the inhaler and the faceis not because air is undesirable for the patient, butbecause if air enters beneath the framework of themask it floods the mouth to the exclusion of theetherized air which should be in the chamber. Thismixture in the chamber is formed by a thoroughmingling of the atmospheric air as it passes throughthe gauze diaphragm and the ether vapour as theliquid ether evaporates from the same diaphragm.

FIG. 2.

The phrases "proper quantity of ether vapour"and "sufficient ether vapour" raise the question ofpercentage. Personally, I have never yet satisfiedmyself from my own experiments of the percentageof ether vapour actually administered by the open-drop method or of the percentage necessary to pro-duce anaesthesia by this method. My presentopinion is that for ether the percentage is not nearlyas definite as it is for chloroform, no matter in whatway the chloroform may be administered. The

12

percentage of ether vapour actually used in openether, both when no very careful attention is givento the quantity employed and also when the patientis kept close on the border line of consciousness,apparently varies very greatly, and this for severalreasons, of which I will note here only the principalones related to open ether according to my observa-tion.

First and foremost is the general physical make-up and also the present physical condition of thepatient. Males as a rule require more ether thanfemales, although males of ordinary spare build donot require as much ether as some women of largebuild, especially if they have thick necks. I feel,from my experience, that the larger percentage herereferred to is necessary more to put them fullyasleep rather than to maintain the anaesthesia afterit has been induced.

Second, alcoholics of either sex, provided nopreliminary morphine has been given, require astronger vapour both to induce and maintain anaes-thesia than do non-alcoholics. Anaemic patients willgo to sleep and remain anasthetic with a morediluted ether vapour than will those with a normalamount of haemoglobin.

Third, further, I have had patients, both men andwomen, who have fallen asleep with full surgicalanaesthesia by means of such an incredibly small,not only amount of ether, but also of percentage ofether vapour, that hypnosis would have seemed areasonable explanation of the narcosis did not aknowledge of the patient's idiosyncrasy and of thecondition of the induction render such a possibilityextremely unlikely. I need not extend the list ofcauses on the part of the patient, as all anaesthetistshave had many such cases, and careful attention tothe phenomena attending etherization of these willconvince the observer that the variation relates notmerely to the total quantity of ether required, butalso and chiefly to the percentage of ether vapouractually inhaled.

W 13

Some causes of variation in the percentage ofether vapour observed apart from those due to thepatient, are:

(a) The size of the chamber beneath the dia-phragm. If the same sized drops of ether be puton at equal rates on two masks of unequal size,other things being equal, the percentage of vapouris the smaller in the larger chamber. That is, underlike dropping and atmospheric conditions, I get agreater percentage of ether vapour with an Esmarchmask than I do using a Schimmelbusch or an Ochs-ner mask.

(b) Also I find the percentage of ether variesgreatly with the quantity of ether deposited on thegauze diaphragm. It will increase up to a certainpoint with an increase in the amount of liquid etherdropped steadily during any definite space of time,but beyond that the percentage diminishes on accountof a phenomenon, the setting forth of which I wishto reserve until I discuss further on the rate ofdropping necessary for a good anmesthesia by openether.*

(c) Further, all this about percentage, includingthe percentage itself, is modified by the temperatureand the humidity of the surrounding air, the baro-metric pressure, the vigour of the patient's respira-tion, and the quantity of the tidal air. It seems tome that by open ether the variation of the percent-age of ether vapour, not only actually administeredbut required for anmesthesia, is so large that it is animpossibility to reduce it to any practical limit forthis method. In general, however, I believe that amere saturation of the respiratory air with ethervapour is all that is necessary for an ordinary anaes-thesia, and this can be had approximately-that is,sufficient for all clinical work-by allowing theether to merely evaporate spontaneously under con-ditions that will preclude dispersion and at the sametime not unduly confine either the air or the ethervapour. The specific gravity of ether vapour is2.55, that is, it is over two and a half times as heavy

*See page 20.

'4

as atmospheric air. For this reason much of theether vapour that comes off from the ether on anordinary mask falls to the floor by its own weight,and draughts of air produced by the movements ofassistants in the operating room cause even moreof this vapour to be dissipated. This occasionsgreat disturbance in open-ether anasthesia. Notonly is the ether wasted, but also the anasthesia isdisturbed, because at one time the patient may getconsiderable vapour and at another time none at all;but, however large or small other advantages ofsuch administration may be, a great difficulty existsin the inability to keep the patient's respiratory airjust saturated with ether vapour, and thereforethere is brought to the front the third requisite fora good open-ether anaesthesia, namely:

C. SOME PROVISION MUST EXIST FOR CONSERVINGTIHE ETHER VAPOUR FOR THE PATIENT'S USE; thatis, for preventing the ether escaping from the sur-face of the mask.

There are various means in actual use in theendeavour to accomplish this. One is to cover themask with a towel as soon as the ether is droppedon the gauze, then to remove the towel and dropmore ether on the diaphragm, and so continue theremoval, dropping, and replacing until the end ofthe anaesthesia. This, however, does not serve thepurpose well, while it allows carbon dioxide toaccumulate beneath the diaphragm and producecyanosis. Another means is the enmeshing of theether vapour in the interstices of gauze. Ether isdropped on to the gauze diaphragm of the mask,then immediately a layer or two of gauze is laidover this and ether is dropped on to it, and thisprocedure is repeated until so much gauze has beenlaid upon the mask that the patient cannot breathethrough it easily. Then all the superimposed gauzeis removed and the process is repeated. All this isa laborious proceeding; it produces an irregular re-bounding anaesthesia, and to me is otherwise un-satisfactory.

15

My own method is to form a shallow chamber(K) above the convex gauze diaphragm of the mask.In this chamber there is an opening (G) so largethat much more air than the patient can use fornormal respiration will easily pass through it. Atthe same time the chamber is not large enough tocollect any appreciable amount of carbon dioxide.My experiments have convinced me that a lowerconcave chamber (M) of about two hundred cubiccentimetres capacity with a superimposed chamberhaving a re-entrant convex bottom and of aboutfour hundred cubic centimetres capacity, serves thepurpose of open ether the best. Consequently the

F, G

FIG. 3.

Ferguson mask for open ether is made to fulfilthese requirements. Any essential modification fromthis size has not yielded in my hands as satisfactoryclinical results as does a mask of these capacities.

With open ether and my mask I have never seenacapnia. A writer in an article in the MedicalCentury for October, 1912, calls attention to thefact that with the open-drop method, by means ofthe Ferguson mask, acapnia never occurs. He ac-counts for this by supposing that just enough car-bon dioxide collects in the chambers to overcomeover-oxygenation of the respiratory centres. It istrue acapnia does frequently accompany anaesthesiaby open ether when any of the ordinary masks areused, but I believe its absence with my mask is not

due to the presence of any carbon dioxide, but de-pends upon a simpler and more important condition.

For instance, if a Schimmelbusch mask is usedfor open ether, on account of the uncontrollable andincalculable amount of waste of ether vapour liquidether is put on to the mask in quantities out of allproportion to what is necessary to maintain anaes-thesia. In consequence of this a strong respiratorystimulation is produced which with the over-abun-dant supply of air following the spasmodic cessa-tions of the supply of ether, and therefore of ethervapour, over-oxygenates the centres to the extent ofacapnia.* With the Ferguson mask the ether is

FIG. 4.

dropped on so regularly and in such small quantities,and the narcosis is maintained so easily at the levelof surgical anaesthesia, that no marked stimulatingeffect is produced. Now as the respiratory air isnot limited during either the induction or the main-tenance of the anaesthesia, acapnia should not occurtheoretically and does not occur clinically any morethan it takes place in every-day life in the invalidwho wears an anti-cold-air respirator or the work-man who wears an anti-dust respirator.

*Further experiments have led the author to believe,what at the time he read this report he announced asprobable, viz., that the cessation of respiration calledacapnia is not due to an over-oxygenation of the respira-tory centers, but to central fatigue, in consequence ofthe highly labored breathing produced by hyperstimulationby excessive quantities of ether vapor.

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D. A fourth requisite is A CONTINUOUS SERIES OF

DROPS OF ETHER ON TO THE GAUZE DIAPHRAGM AT

SUCH A RATE AS MEETS THE DEMANDS OF THE PA-TIENT FOR THE TIME BEING. The ether should bedropped on to the gauze steadily, not sprinkled orpoured on at intervals. A spasmodic supply ofether produces an irregular anaesthesia, the depthsof which may be represented by convex lines ofvarying amplitude with the corresponding concavelines representing the intervals of partial recoveries.Even if such an anaesthesia serves the purpose ofthe operation the recovery is not as satisfactory asif an anaesthesia of even depth had been had.Nausea and vomiting occur after the anesthesia,when otherwise they would not be expected, and iffor any reason nausea seemed inevitable, it isapparently more severe.

At first the dropping should be very slow-aboutone minim delivered in three or four drops (thenumber of drops depending upon their size) everyfive or six seconds. This slow dropping does notadd to the anaesthesia proper. Its purpose is toanaesthetize the membranes of the posterior nares,the pharynx and the larynx, so that when the etheris dropped rapidly for the anesthesia proper therewill be no irritation from the ether vapour, therewill be no coughing, no strangling, no other dis-agreeable sensations, and, what is of considerableimportance for the reputation of the anaesthetist, nounpleasant remembrances of the induction after thepatient is awake.

The length of time to continue this initiatory slowdropping will depend upon the patient and the sensi-tiveness of his throat. Any person with a verysensitive mucous membrane will require more care-ful and a longer slow dropping than one in a differ-ent condition. As a rule, in from forty-five secondsto one minute and a quarter from the beginning ofthis initiatory dropping the respiratory passages willbe ready for the more rapid delivery of the ether.

In certain tonsil and adenoid cases it is of little18

use to seek this preliminary local anaesthesia. Theparts are hypersensitive to such a degree that notmuch impression can be made on them in a shorttime, and so with such patients it is best to proceedat once to the induction of the general anaesthesia.

As soon as the irritability of the membranes hasbeen allayed the general surgical anaesthesia shouldbe induced by a continuance of the dropping, butnow much faster than during this preliminary drop-ping. No rule for this rapidity can be given. Ex-perience alone can teach it. The ether should onlybe dropped, however, and if for any reason thereseems to be a demand for more ether vapour thanthe rapid dropping which is under way furnishes,the end may be attained by distributing the dropsover a larger surface of the gauze. For ordinarycases by such a procedure I find complete surgicalanaesthesia to be present on the average in aboutfour and a half to five minutes from the time of thebeginning of the dropping for the anaesthesia proper,With females the time is from three to fiveminutes; with males from four to six minutes.Variations in the time depend, however, upon otherfactors besides sex.

Also for continuing the surgical anaesthesia afterit has been induced, the ether should be onlydropped. And again for the rate of this dropping nodefinite rule can be given except that the droppingshould meet the demands of the patient at the time.This is the anaesthetist's only criterion.

Further, the physical condition of the patient, thedepth and vigour of respiration, the temperatureand humidity of the air of the room, the size of thedrops, the character of the operative procedure atthe time are all important factors in the problem ofhow fast to drop, and actually determine its rate.If a deeper anaesthesia is needed a dropping morerapid within certain limits will effect it, while if alighter anaesthesia is all that is required a less fre-quent dropping will keep the patient as desired. Itshould be remembered, however, that a continuous

19

series of drops should be maintained. Relativelylong cessations of dropping are to be avoided. Itis better to drop once in five seconds twelve timesa minute, than to drop once a second for twelveseconds and stop forty-eight.

The fifth requisite to which I now call your atten-tion is related more or less closely to all methods ofadministering ether, but as it is of especial impor-tance in connexion with open ether, it must be men-tioned here.

E. THE ETHER SHOULD NOT BE DEPOSITED ON

THE GAUZE FASTER THAN IT WILL EVAPORATE FROM

IT. The rate will vary with the temperature of theroom; the frequency and strength with which thepatient exhales through the gauze; and the volatilityof the ether.

The reason for this is that in whatever quantitiesthe ether may be put on the gauze, some of it willevaporate, and the evaporation of this portion willlower the temperature of what remains as also ofthe gauze. After more ether is deposited thisevaporation continues with a continuous loweringof temperature until the temperature becomes solow that not enough ether vapour can be given offto anaesthetize the patient or to keep him asleep,even if by a proper dropping he has once been infull surgical anaesthesia.

In saying that "the ether should not be droppedany faster than it will evaporate" is not meant nofaster than it will evaporate in the laboratory froma dish, or under ordinary conditions from gauze andthe like, but no faster than it will evaporate fromthe mask under the conditions.in which it is in use.A very warm operating room will increase the rateof evaporation. The exhaling of the patient throughthe gauze will blow some vapour away. So alsothe pressure and humidity of the atmosphere andthe strength of the respiratory act will make a dif-ference in the evaporation. Thus it is evident thatthis rule can mean nothing else than that the ethershould not be put on to the mask faster than it will

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evaporate at the time and under the circumstancesof the immediate administration. If the anesthetistputs it on faster than this he will contravene hisown purpose, because the patient will not remainasleep, for no other reason than that the liquidether on the gauze cannot furnish him with vapoursufficient to keep the patient anesthetized.

F. Finally, THE MASK MUST BE KEPT ON THE

FACE AND NOT CONTINUALLY REMOVED. Seldom isthere need to take the mask from the face. If thediaphragm is made of the right number of layers ofgauze removal gives no more air. If the ether isdropped correctly the taking of the inhaler off theface is not necessary to cause the patient to getless vapour. If the patient has been laid on thetable in a suitable posture the jaw and tongue willgive little trouble. A removal of the mask meansa stop in the dropping of ether, which in its turnmeans an uneven anaesthesia. Attention to a fewdetails will make a removal of the mask as a rule un-necessary.

In conclusion, by way of illustration of what hasbeen said and to make the subject clearer, let medescribe in detail what is known as the FergusonMethod Of Open Ether Anaesthesia.

First, I do not wish ordinarly any preliminaryopiate. Preliminary morphine slows the respira-tion, prevents pupillary and other reactions, andtherefore interferes with two of the most importantwaymarks for the anaesthetist. Since it has beenstated that a preliminary opiate is essential to openether, let me here say I require such in only threeclasses of cases.

The first is that of patients with exophthalmicgoitre. So many such patients have died while go-ing from the ward to the operating room on accountof fear and their highly nervous condition, that Iwish the patient who is to have a thyroidectomy forexophthalmic goitre to have enough morphine longenough before the anaesthesia to permit him to betaken to the anaesthetizing room with a tranquil mind.

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My second class is that of alcoholics who I thinkmay give trouble on the table. The fighting of analcoholic on the table during the induction of etheranaesthesia is not due to a special irritation of thepatient by the ether. As alcohol and ether affectthe cells of the body in somewhat the same way, thepatient who is used to large quantities of alcoholtheoretically ought to be affected less than the non-alcoholic patient with an equal amount of ether.The disturbance in the case of the fighting alcoholicis due to a dream. An alcoholic is very prone todream as he falls asleep in ordinary every-day life.He has exalted exciting ideas when he drinks alco-hol in moderate quantities; he has the fiendishdream of delirium tremens when he drinks to ex-cess. He dreams as he goes under the influence ofether. Now this dreaming is always an excitingpugnacious ideation. On the contrary the dreamfrom the use of opium is a quieting, pleasing state.It is the sense of well-being, of a life in Elysianfields, that fascinates the opium fiend. Now ex-perimental psychology teaches that the physical con-dition productive of the exciting idea in alcoholismcan be offset by the physical condition producing thetranquillity of morphinism. Therefore I wish thatalcoholic whom I suspect will be a disturber of hisanaesthesia to have enough morphine long enough be-forehand to counteract any alcoholic hypercerebra-tion and to reduce him to a normal subject foranaesthesia.

My third class consists of strong athletic youngmen of ages from fourteen to twenty-two or there-abouts. These I find are very likely, while inhalingonly small quantities of ether vapour, to secretea very minute amount of thick tenacious mucus.This is apt to span the lumina of the smaller tubes,bronchioles, and stomata of the alveoli, and formdiaphragms that prevent any interchange of vapourbetween the respiratory air and the blood. Conse-quently not enough ether vapour enters the bloodto produce anaesthesia, and perhaps not enough pure

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air can enter to maintain normal oxygenation. Herewe have that peculiar, and to some, a puzzling, pic-ture of a strong healthy young man, perhaps foronly an operation for hernia, after inhaling a littleether becoming cyanotic and remaining so althoughthe inhaler has been removed, and not only plentyof fresh air but also perhaps oxygen supplied.

Now to prevent this secretion of mucus I wishsuch patients to have one-hundred-and-fiftieth grainof atropine hypodermatically, half an hour beforethe anaesthesia. But such patients have a verystrong abdominal respiration. Normally the mus-cular action is powerful and the excursions of theabdominal parietes are great. Now under the stimu-lating action of the atropine the abdominal breath-ing becomes abnormally great, so that if the opera-tion is one for appendicitis or for hernia, that is, in-volving the abdominal wall or the tissues in itsvicinity, the movements of the abdomen are a seriousdisturbance to the surgeon. Therefore I wish sucha patient to have with his atropine one-eighth or one-sixth grain of morphine, not for any demandof the anaesthesia, but to counteract the hyper-stimulation of the atropine which was given for thepurpose of the anaesthesia and thus I prevent thesurgeon being disturbed in his work.

Having now treated my patient as regards a pre-liminary opiate according to these rules, he is putfor anaesthesia upon the table on which the opera-tion is to be performed. Transfer from a stretcherto the operating table just after the induction, al-though the patient may be fully under the ether,will almost always cause a partial recovery whichmay require quite as much time and trouble to doaway with as the previous induction.

This operating table should be in the anaesthetiz-ing room where there is nothing to disturb eye orear. Then when the patient has been put in aproper position upon it, that is with his head slightlyextended, with no straps over the body and no onetouching him, I begin by asking the question, "Did

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you ever take ether before ?" Whether the answerbe "yes" or "no," I say, "I have something to tellyou. Patients who take ether as a rule don't like it.Some find the odour very disagreeable, and youprobably will, but if you will breathe regularly anddeeply, then what is disagreeable will pass awaymore quickly."

By this frankness I assure myself of the con-fidence of the patient during the induction; heunderstands the conditions necessary to render theinduction the least disagreeable and he makes noeffort to remove the mask after it is in position. Inow place on his face the mask, which has beenfitted previously. No unguent is used on the skin,nor are the eyes covered. The ether is then droppedon to the convex gauze diaphragm of the mask, veryslowly at first and then more rapidly, as has beenset forth above.

As the dropping is very important I will describehere my method, which will never fail in givingsatisfactory results. I use the ether directly fromthe original can, which holds 4 ounces. I do nottransfer it to another container because I believethat by so doing a good ether loses a working mar-gin. I drop from this can by means of a wick, andfor the exit of the ether from the tin I depend uponthe capillary attraction of the wick and the pressureof the ether vapour in the can. The proper makingof the wick is an essential feature of my method. Itake a piece of gauze an inch or two wide, depend-ing upon the size of the mesh of the gauze. A gauzewith twenty threads to the inch will require a stripabout two inches wide. If it has more threads itshould be narrower. The length should be equal tothree or four times the depth of the can from whichthe ether is to be used. This strip of gauze is foldedacross the narrow part or width so that the twoends come together. The two layers should not lieflat against each other but loosely. Then one endof this folded strip is held tight in one hand, whilethe other end is pinched between the fingers and

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thumb of the opposite hand and all is twisted intoa firm wick. A wick made thus will give the maxi-mum amount of capillary attraction. This wick isnow put into the can, to the very botton, and aboutone-half inch left projecting beyond the mouth of thecan. Now an ordinary cork, whole-that is, withno slit or slits in it-is put into the neck of the can

FIG. 5.

so as to confine the wick between it and the neck,and then pressed down very tightly. If put in tight-ly enough it cannot be drawn out easily, cannot beshaken out, when the can. is tipped no ether willrun out, and if the container falls on the floor, noether can be spilled. Nevertheless if this can, withthe wick in it, is held upright and then tipped alittle, drops of ether will come from the end of thewick, very slowly at first but more rapidly as thecan is tipped more and more, but if the cork andwick are arranged as they should be the ether will

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not run out in a stream. This is known as theFerguson Method of Dropping, and is the simplestand at the same time the most efficient dropping ofether for anaesthesia that I know of. The materialsfor its construction are always on hand, it is easilyand quickly made, and as long as there is any etherin the tin it will always work.

By such an apparatus I drop the ether on to themask, at the same time giving further careful atten-tion to the psychical condition of my patient.

I do this by anticipating a prejudice against theodour of ether that a few patients have, and furtherby keeping below the threshold of consciousness twoideas which previous to an anesthesia practically allpatients have formed, and which, if not carefullycontrolled by the anaesthetist, are likely to come tothe front and disturb the induction.

Some patients who know the odour of ether andwho consider it disagreeable, anticipate the induc-tion as a repulsive experience. Others, for onereason or another, have a mere prejudice againstit, while still others who have formed no idea ofthe odour of ether seek to remove the inhaler at thefirst whiff of ether vapour. In the majority of casesthe frank statement concerning the odour and fulldirections how to breathe, as has been described, willarouse an effort of will that will cause the initiatorystage to be passed easily; but for some fastidiouspeople and children something more is desirable, al-though perhaps not necessary. In such cases I putupon the gauze of the mask, on the concave portionof the diaphragm, and in such a position on thegauze that it will not come in contact with the skin,about two minims of the terpeneless oil of orange.The odour of this oil is more than twenty times asstrong as the odour of ether; therefore, if at firstthe ether is dropped very slowly, as it should be, itsodour is masked sufficiently not to disturb the pa-tient, or perhaps the agreeableness of the odour willsurprise him to the extent of permitting a quiet in-duction.

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The r61le played in the anaesthesia by oil of orangeis merely an aesthetic one. There are three thingsthat render the inhalation of ether vapour disagree-able. The first is the mere contact of the non-oxygenating gas with the membranes. Quite likelythis is a complex of sensations. I call it the tactualelement. Then there is the direct irritation of thenerve-endings by the ether vapour. This I call thephysico-chemical element. The third is a mere per-sonal dislike to the odour of ether vapour. Thefact that a very large number, indeed the majorityof patients, find the odour of ether disagreeable doesnot remove the condition from the realm of aes-thetics. This, then, I call the wsthetic element.

At the beginning of the induction I get rid of thetactual and of the physico-chemical elements by theslow dropping as described above under "Thefourth requisite." I deal with the aesthetic elementby means of the oil of orange, and it is importantto bear in mind that it is only with this elementthat the oil of orange has to do. It masks to a cer-tain extent the odour of the ether, and does notaugment or diminish the anaesthetic value of theether vapour or modify otherwise the narcosis.*

The figures given are true only in regard to theoil of orange, and do not hold for the so-calledAmerican essences, which are not nearly as strong.I have used it now for over ten years and considerit a valuable adjunct to open ether.

The two ideas which I find it necessary to keepbelow the threshold of consciousness are the indefi-nite notion on the part of patients that somethingmay go wrong, and the idea that they may be cutbefore they are unconscious. These must be dealtwith separately and in different ways.

To meet the first I always talk to my patientduring the induction. I never ask a question, be-cause after the initial dropping of the ether co-ordination of the senses is very soon lost, and if

*Except that it seems to increase the percentage of post-aniesthetic nausea and vomiting.

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the patient replies to any question the speech centreretains its activity, and the reiterated answers ofthe patient, at first coherent, soon become inco-herent, and finally pass into a mere jabber. All thiswhile the patient does not breathe well, thereforethe induction is prolonged and otherwise disturbed.On the other hand, I make positive statements tothe patient about just what he wishes to know,namely, that "everything is all right." This idea Irepeat over and over again in as varied a phrase-ology as I can command, but always keeping certainfacts in mind, namely, that the patient becomesdrowsy, therefore a clear, clean-cut enunciation isnecessary; that the power of association is lost, con-sequently a long word cannot be guessed at fromone or two of its syllables, therefore monosyllablesshould be used; again, that the field of consciousnessnarrows very rapidly. Soon after the initial drop-ping only six short words or syllables are under-stood, as "Breathe deeply; you are doing fine."Then only five, as "Every thing is all right." Thenonly four, as "You are all right." Then three, as"All is right;" "You are fine." And just before con-sciousness goes out only two and one, as "All right,""Fine."

Talking to my patient steadily in this way Ikeep a perfect control over his mind and render theinduction shorter and easier than it would be other-wise.

The second disturbing idea, namely that theoperation will begin before the anaesthesia is com-plete, I prevent being brought from subconscious-ness by not allowing the patient to be touched inany way during the induction, with one exception.The rationale of this is as follows. The patient,very soon after the ether has begun to be dropped,is out of all reasoning relation with his surround-ings. We say co-ordination is lost. Now if thepatient is touched in even a friendly way, either bya relative or nurse, or if his position upon the tableis changed, or he is otherwise disturbed, he arouses

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somewhat and the subconscious idea that he is to becut before he is asleep leaps over the threshold intoconsciousness and he tries to let you know he is stillconscious. This he does according to his presentidea by making some small motion such as a move-ment of the feet or the hands. This, however, isonly as he interprets his action, for in reality he isthrashing all over the table. To prevent this dis-turbance, which is often considered as a necessarysecondary stage, I use no straps to hold the patienton the table and do not allow any one to touch him.

The exception to this has to do with the scrubbingup of the patient. I am willing the scrubbing upshould go on during the induction provided that ithas been begun and is well under way before anyether is given. Tell the patient plainly that thenurse will scrub him up, and that while she does itthe ether will be given, and act accordingly and notrouble will be had, but if the induction has evenbut just begun, then the patient must not betouched in any way until surgical anaesthesia ishad.*

As a rule patients will pass into the state of surgi-cal anaesthesia without moving upon the table. Aslight movement of legs or arms in the case of somepatients requires no attention. If, however, as inthe case of certain alcoholics, restraint is necessary,it should be employed. Such can be done most ef-fectively by grasping firmly the opposite side of thetable with one hand at a point which will permityour arm to span the front of both the thighs of thepatient, four inches above the upper border of thepatellae. Put the arm in this position, then stoop soas to bring firm pressure on the thighs, and thepatient, although very strong, will be effectually re-strained.

*For a full description of the psychical condition of thepatient during anesthesia and how to manage it, see "SomePsychic Factors of Surgical Anaesthesia," by Robert HenryFerguson, A.M., M.D., Sc.1)., in Illinois Medical Journal,August, 1914.

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Having now the patient unconscious, I continuethe anaesthesia as directed above by dropping theether faster or slower, according to the need of thepatient, until the mask is removed for good.

If the patient has been placed on the table proper-ly the tongue or the jaw usually gives no trouble.In the few cases in which the tongue did provetroublesome, I used to hold it forward by means ofa flat wick made of a three-inch gauze bandage. Ayear ago, 1912, however, I became acquainted withthe airway devised by Sir Frederick Hewitt, andsince then have used it with such success that I now

FIG. 6.

consider it an essential part of the anaesthetist'sarmamentarium. For use in the United States,however, I have made a slight modification, thereason for which is this: In America many anaes-thesias are conducted by inexperienced nurses orcareless internes. If now, for open ether, the air-way, as made in England, is used, there is dangerof liquid ether being poured through the gauze downthe airway, as the opening is like a funnel and opensdirectly below the middle part of the gauze dia-phragm on which this ether is dropped. While I

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have never had this accident happen, I have felt thepossibility of it, and have taken especial care that itshould not occur. It is not at all likely with thesemi-open method or with the closed method, andindeed not with open ether, in the hands of a skilledanaesthetist if a good dropper is used. It is, how-ever, a real danger with open ether if an inex-perienced or a careless person administers theether, or if a dropper which will sometimes allow astream to run is used and only a very thin gauzediaphragm is on the mask. Therefore to precludethis danger I have had the present opening to theairway closed and apertures for the ingress andegress of the respiratory air made around the sidesof the metal end, which makes the entrance of liquidether from a careless depositing of it upon the maskalmost impossible.

I may say in closing that with an open-etheranaesthesia conducted in the way I have outlinedsurgical anaesthesia is induced in a very short time,is easily maintained with a minimum quantity ofether, while nausea and vomiting seldom follow ifa good ether has been used.* My own percentage isabout eight of nausea, not all of whom vomit; fur-ther, the recovery is very rapid.

*It is worthy of note that post operative nausea and vom-

iting may be due to the operative procedure alone. Suchfrequently follow operation, on or about the gall bladder-decapsulation of the kidney, operations for strangulatedhernia, rough handling of the peritoneum, long or severetraction on the tubes and ovaries-or on the spermatic cord.

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