Source: Snow, John. Medical Times, vol. 22, Aug. 31, 1850, pp. 228-31. [letter to ed.] .

Remarks on the administration of chloroform, in answer to Professor Lizars

By John Snow, M.D.

Vomiting under the Influence of Chloroform attended with no Danger.--The Glottis not Paralyzed.--Safety and Advantages of Chloroform in large Operations, involving the Mouth.--Objection to Administering it on a Handkerchief.--Necessity and Advantages of an Apparatus.--List of Deaths from Chloroform.--Means of Avoiding all Danger in giving it.

I regret to differ in opinion from Professor Lizars on some practical points of his letter in the last number of the Medical Times, respecting the administration of chloroform; but, however unpleasant it may be to differ from so deservedly eminent a surgeon, it becomes the more a duty to correct what one believes to be erroneous, on account of the increased attention which his fame must command for his statements. What I conceive to be the errors in question appear to have arisen from Professor Lizars not having given the subject the amount of study and attention that it requires. He says, that those administering chloroform "have only to attend to two important points in order to insure safety to the patient. The first indication is to give directions to the patient that his stomach be kept empty." He proceeds to say, "for that reason operations should be performed before breakfast, as chloroform always produces vomiting when the stomach is full, and the rejected fluid is liable to enter the paralysed glottis and produce suffocation. To this cause I apprehend the great proportion of those who have died under the influence of chloroform may be ascribed." The italics are his own. I entirely agree in the propriety of an empty stomach preparatory to the inhalation of chloroform; but if any one thinks this a means of avoiding danger, he might be seriously disappointed in a case in which danger should really exist. I, as well as others, had been in the habit of directing patients not to take food for two or three hours before inhaling ether, and the same directions have been given since the introduction of chloroform. But it constantly happens that I have to give it to patients whom I have not seen before, and to whom the surgeon has omitted to give directions on the point, and not [228/229] unfrequently the patient has taken a meal just before I arrive; yet in no case has the inhalation been either postponed or omitted on that account. The patient is, indeed, liable, though by no means certain, to vomit when the stomach is full, but the vomiting has not, in any case, been attached with ill consequences of any kind, and I have seen, at least, two hundred patients vomit whilst partially under the influence of chloroform. In two or three cases, in fact, the patient who had eaten a very full meal, vomited and inhaled by turns during the whole operation. If the rejected fluid were liable to enter the glottis, of course there would be some inconvenience, either at the time or afterwards. As Professor Lizars is so afraid of the patient having food in the stomach before inhaling, it may safely be assumed, that his experience of vomiting, after chloroform, is by no means so large as that stated above. As regards his apprehension, that the great proportion of deaths are due to this cause, the simple answer to it is, that the patients who have died from the effects of chloroform did not vomit, and that nothing was found in the windpipe to obstruct respiration, in such of them as were examined after death.

Having stated the facts bearing on the question of vomiting, I may proceed to the theory of the subject, and, for an explanation, need not go further than Professor Lizars's own letter. At the concluding part, he says, "in the administration of chloroform, I have stated, that the constant production of retching, proves that the pneumogastric nerves are excited." Now, although retching occurs only occasionally, and never whilst the patient is deeply narcotised; yet, if it prove that the pneumogastric nerves are excited, it explains why the glottis, which is supplied by branches of these nerves, is not paralysed. The truth is, that the glottis is one of the organs of respiration, and retains more or less sensibility as long as the patient has sensibility enough to breathe. And so long as there are sensibility and energy sufficient to effect the complicated act of vomiting, the functions of the glottis appear to be unimpaired. When the narcotism from chloroform is confined within reasonable bounds, there is as little danger of blood getting into the windpipe, in operations involving the mouth, as of vomited matters in other cases. When the first fatal instance of inhalation of chloroform occurred in a girl near Newcastle, Dr. Simpson hastily asserted that she had been suffocated by some brandy given to her when dying, although but a teaspoonful was given which was swallowed, and ever since that time there has been a prejudice in Edinburgh against giving chloroform in large operations involving the mouth. Severe pain, has consequently, been inflicted in many such cases in that city; whilst in London probably nine-tenths of these operations have been performed under chloroform. If much blood flow into the throat there will always be some embarrassment to the respiration, whether a patient be insensible or not. The practice in such cases always was to lean the patient's head forward now and then, and, if this be still attended to[,] the blood does as little harm under the proper influence of chloroform as without it. I cannot but think that Professor Lizars must have been mistaken in the case of tooth-drawing, in which he supposed that the blood trickled down the glottis. I have given chloroform in many cases, in which from eight to twelve teeth were removed at one operation; and, although subsequent vomiting, in some of the cases, revealed a good deal of blood which had been swallowed or flowed down the pharynx and esophagus, there were never any symptoms of a drop having entered the windpipe or lungs. That the glottis is fully competent to take care of the air passages, and that suffocation is not very readily caused under the influence of chloroform, I have further ascertained by putting the heads of animals under water whilst insensible. These experiments will be given in detail on another occasion; but I may mention that a cat lay, in one instance, exactly two minutes with its head under the liquid, and readily recovered soon after being withdrawn.

It may be interesting to some of the readers of the Medical Times, if I enumerate some of the more important operations about the mouth in which I have administered chloroform. I may preface the account by mentioning an operation performed by the late Mr. Liston, in which ether was the agent employed, as showing that he was not afraid of narcotism in operations involving the mouth. The operation consisted in the removal of a very large tumour occupying the central part of the lower jaw, in a young lady. The bone was divided far back on each side.

Mr. Tatum removed a very large tumour of the lower jaw in a man in St. George's Hospital, and one by Mr. Fergusson in King's College Hospital; also one in a gentleman, in private practice, by that surgeon. The superior maxillary bone was removed on two occasions, in St. George's Hospital, in which I gave chloroform, and also, on three occasions, by Mr. Fergusson also removed the superior maxillary bone in the case of a lady. In these, and similar operations on the face, the patients were first made insensible by means of the inhaler, and the insensibility was kept up during the operation by means of a sponge applied near the mouth from time to time; not more than about fifteen or twenty minims of chloroform being put on the sponge at once. Besides the prevention of the dreadful pain, the chloroform has the further advantage, in large operations on the face, of greatly diminishing the tendency to syncope from the unavoidable loss of blood. I have seen no ill effects from it in any case. One patient died soon after the operation, and I have explained the cause of death at some length in the Medical Gazette for February 9, 1849.

In the operations for nasal polypi, and for epulis, a good deal of blood generally flows backwards into the throat, but without any injurious consequences. In the operation for hare-lip, when the child is laid on its back, the blood also flows into the throat, if more than a few drops be lost, and is either all swallowed, or part of it is allowed to flow out by turning the child quickly round for a moment now and then. Mr. Fergusson operates with the child in this position, and I have administered chloroform in twelve of his operations for hare-lip within the last two years. Two of the children were but three weeks old, and two or three of the others were under three months.

Besides having the stomach empty, the other point to which Professor Lizars considers it necessary to pay attention, in order to avoid danger, "is the allowing the patient to breathe atmospheric air along with the chloroform." He adds, that "an experienced assistant is required to administer the chloroform, and to do nothing else. He must watch its effects, allowing fresh atmospheric air to enter the nostrils and mouth occasionally during its administration and influence, otherwise the blood may become too greatly carbonised, and death ensue." These remarks are, on the whole judicious; but it is not easy to understand his exact meaning respecting the atmospheric air. If he considers that patients can inhale the vapour of chloroform unmixed with air, that is an error into which a great part of the speakers at the Académie de Médécine fell, in a discussion which took place last year. No human being has breathed unmixed vapour of chloroform, or ever will, as it can only exist in a separate state, at the ordinary pressure of the atmosphere, when raised to the temperature of 140°; or at the ordinary temperature, when the atmospheric pressure is reduced to about one-sixth the usual amount. The experiment of inhaling pure vapour of chloroform could only be tried on a small animal under the receiver of an air-pump. Professor Lizars, perhaps, means, however, that the mixture of vapour and air must be intermitted, and breathed by turns with air surcharged with vapour. This, however, is not at all requisite if the vapour be diluted to a sufficient point. If, for instance, the patient be breathing 95 to 96 per cent of air, with 4 or 5 per cent of vapour of chloroform, it will be unnecessary to intermit the process till insensibility be complete. It is not sufficiently understood, or, at least, borne in mind, that the vapour of chloroform requires to be largely diluted with air, not for the purpose of respiration, (its physical constitution ensures that,) but to prevent its operating with dangerous rapidity. In proof of this, it is only necessary to state the circumstance, that, in giving ether, only 70 to 80 per cent of air is breathed with 20 or 30 per cent of vapour; whilst, in the case of chloroform, there should be 95 or 96 per cent. of air; and, in the case of hydrocyanic acid, which I have administered in the Hospital for Consumption, there must be over 99 per cent of air, with much less than 1 per cent of vapour.

Professor Lizars recommends chloroform to be administered by putting two drachms or so upon a handkerchief. [229/230] This is the plan of Dr. Simpson. I have taken every proper opportunity, since the time when chloroform was first introduced, of opposing its use on a handkerchief in the way recommended; but I cannot hope that anything that I can write will receive one-tenth the circulation of the pamphlet issued by the Physician-Accoucheur to the Queen in Scotland, and copied into all the newspapers in the kingdom, when he first tried the effects of chloroform in an undiluted state, on the recommendation of Mr. Waldie, of Liverpool. The small amount of safety attending the use of the handkerchief may be judged of from Professor Lizars's estimate of that safety, notwithstanding his two points which he supposes to secure it. He admits that chloroform is a valuable agent in large operations, but others, attended with a not much less amount of pain, as the amputation of a finger or toe, he would have to be performed without it. Now others, as well as I, who have formed our opinion of it, from its use with a suitable inhaler, have no hesitation in recommending it in the smallest operations, being sure that with skill and care it is quite free from danger. I have twice taken chloroform to have a tooth drawn, and would not undergo a similar operation without it, so long as I could get a skilful person to administer it with a suitable apparatus.

Professor Lizars considers an instrument indispensable for giving chloroform to horses, but says, "in human surgery no inhaler or any instrument should ever be used; it is highly reprehensible--many lives must have been sacrificed to its employment." Now, an inhaler is not necessary for the horse any more than for man, except as a means of rendering the process more agreeable, manageable, certain, and safe; all which points it is our duty to consult in the human subject, as much as in the horse, although, perhaps, the former is the less deserving creature. Professor Lizars must have seen some very imperfect form of inhaler, perhaps with a tube to enter the mouth. He can hardly be aware that a former pupil of his own, who is now justly eminent, not less for his observations on ether and chloroform than on many other subjects--I allude to Dr. Francis Sibson--contrived an inhaler whilst at the Nottingham Infirmary, and disapproves of the handkerchief. With respect to the inhaler which I employ, it allows of such easy respiration that a person might wear it day and night for an indefinite period, uncharged with chloroform, and removing it to take his meals, without injury to his health. To prove that the handkerchief and not the use of inhalers has been the chief cause of the deaths from chloroform, it is only necessary to enumerate the fatal cases.

1. Jan. 28, 1848. Hannah Greener, aged 15, near Newcastle. Toe-nail operation. Handkerchief.

2. Feb. 23, 1848. Mrs. Simmons, of CincinattiU.S. Extraction of teeth. Inhaler; no medical man present.

3. A young woman at Hyderabad, in Hindostan. Distal phalanx of a finger. Handkerchief.

4. May, 1848. Madlle. Stock, aged 30, at Boulogne. Opening an abscess. Handkerchief.

5. Dec., 1848. Young gentleman at Govan, near Glasgow. Intended toe-nail operation. Handkerchief.

6. Jan. 24, 1849. J. Verrier, aged 17, Lyons. Intended amputation of finger. Handkerchief.

7. Feb. 20, 1849. Samuel Bennett, Westminster. Amputation of toe. Handkerchief.

8. Aug. 23, 1849. Mdme. Labrune, Langres, France. Intended extraction of tooth. Handkerchief.

9. Oct. 10, 1849. John Shorter, aged 48, St. Thomas's Hospital. Toe-nail operation. Inhaler; given by a non-medical person.

10. Nov., 1849. Girl Jones, Shrewsbury. Removal of eyeball. Not stated.

11. Young lady, Berlin. Intended extraction of tooth. Napkin.

12. Feb., 1950. Artilleryman, Mauritius. Amputation of last phalanx of middle finger. Handkerchief.

13. Alex. Scott, aged 34, Guy's Hospital. Removal of portion of hand. Handkerchief.

These, I believe, comprise all the recorded cases in which death was clearly due to the administration of chloroform.

In one of the cases it is not stated that a handkerchief was used, though, from the context of the report, that seemed to be the case. Of the other twelve an inhaler was used in only two of the cases, and in neither of them was it used by a medical man, whilst, in the ten instances in which death was caused by chloroform on a handkerchief, it was administered by a qualified medical man in every instance but one. There have been four cases in which death was accidentally cause by chloroform taken by the deceased parties when no one else was present. Two of these deaths occurred in Scotland. A handkerchief was used in each instance, and, but for the practice of taking chloroform on a handkerchief, these persons would probably never have taken it at all. However, I have not included these cases in the above list. There was a death commonly attributed to chloroform which I have not included in the list--that which occurred at Mr. Robinson's the dentist; for I believe that that was case of fatal syncope, due to mental emotion in a subject with fatty degeneration of the heart, and great enlargement of the liver. He was only just beginning to inhale, when he suddenly died. In that case an inhaler was employed.

Other supposed causes of the deaths from chloroform have been suggested by various writers, besides those above mentioned, only one of which I shall notice. Many persons, especially in Edinburgh, have attributed the fatal cases to the impurity of the chloroform employed; but, in the first place, it has been examined in nearly all the cases, and found, to be quite good. And, again: although it might contain impurities which would cause irritation at the time, and subsequent disagreeable effects, it could not become contaminated with anything likely to cause sudden death; and, before this assertion is repeated, we ought to be told with what substance stronger than itself chloroform is liable to be contaminated. I fully admit the necessity of having chloroform, as well as other medicines, quite pure; as its adulteration, though not liable to cause death, may cause disappointment, and other disagreeable consequences; and it must also be admitted, that this, as well as other drugs are liable to impurity, both in London and elsewhere. I am of opinion, however, that impure chloroform has not been supplied by the respectable houses of this metropolis. I generally use Mr. Morson's chloroform; but have, at one time or other, used that of Mr. Squire, Mr. Jacob Bell, Mr. Bullock, Mr. Hooper, Mr. Taylor, and others, and always found it good. I have also used the chloroform of Messers. Duncan, Flockhart and Co., of Edinburgh, and cannot give it any better praise than by saying it was equally good. If the Edinburgh people wish to assert that they can produce something better than pure chloroform, they must call it by another name, for it must be a different medicine.

The real cause of deaths from chloroform undoubtedly is, that in each case the patient has had an overdose; I mean more than was necessary to render the patient, or one of similar size and strength, insensible. By a dose of chloroform, however, must be understood, the quantity inhaled during an operation. For instance, when the inhalation is left off for two or three minutes, a great part of the chloroform exhales by the breath, and the patient perhaps requires to inhale a little more. This should be considered a repetition, and not an increase of the dose.

The necessary points to be observed, in order to avoid the risk of giving an overdose, are, 1st, that its vapour be systematically diluted with a sufficient quantity of air, by means of a suitable apparatus--when no accident can happen, without the continued neglect of evident warning symptoms; and, 2nd, that the person exhibiting the chloroform should keep his whole attention directed to the patient, and be able to understand all the signs that occur. I have not space here to go fully into the description of the signs which indicate when the inhalation should cease, and an operation begin, but would refer to some papers of mine, "On Narcotism by Inhalation," in the Medical Gazette, 2nd vol. for 1848, and also to some papers on "Chloroform," by Dr. Sibson, in the same volume. I may state, however, that it is chiefly by attention to the state of the respiration and the eye, that danger is to be avoided. The pulse may be felt as a physiological inquiry, or with reference to the operation, but gives no guiding information concerning the chloroform, for the following reasons:--When the vapour is diluted to a safe extent, it might be continued till death, as I have ascertained in animals, and the pulse would still beat distinctly for many seconds after the respiration had ceased; and if, on the other hand, the vapour be of dangerous strength, the heart might suddenly cease to beat, and the first intimation of danger from the pulse would come only too late.

If chloroform be given on a handkerchief at all, not more [230/231] than from fifteen to twenty minims(a) should be put on at once ((a) Drops of chloroform are widely different from minims, being extremely small). In this way it may be given in midwifery, as that quantity, and often much less, suffices for each application; but in surgery, where the full effect is required, this would be insufficient.

Frith-street, Soho-square, Aug. 27, 1850.

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