Source:  Snow, John. BMJ 1 (May 2, 1857): 381. [ltr. to ed., April 1857] .

On some alleged ill effects of amylene

Letter from John Snow, M.D.

Sir,--I shall be obliged if you will allow me to make a few remarks on the case of operation for stricture by Mr. Syme's method, reported at page 331 of your last number. The operation was followed by some severe symptoms which the reporter of the case attributes to the amylene which had been inhaled. The symptoms, however, were such as are occasionally produced by operations on the urethra, more especially by the operation in question, and are not such as amylene, or any analogous substance has been known, or would be likely, to produce. I have seen very similar symptoms to those which occurred to Mr. Erichsen's patient follow the introduction of bougies, with some bleeding from the urethra--the convulsions only were wanting. I should wish, however, to call particular attention to the following passage in a paper by Mr. Syme on the treatment of strictures of the urethra by external incision. (Medico-Chirurgical Transactions, vol. 36, p. 260.) "A curious train of nervous symptoms sometimes present themselves, to the great consternation of all who have not previously witnessed them, or are unaware of their nature. They occur most frequently soon after the catheter is withdrawn, and appear to depend on the urine resuming its natural course, but have also been observed at an earlier period. They have never, so far as I know, lasted more than thirty hours, and seldom continue above half this time. They consist of rigors, bilious vomiting, coldness of the extremities, suppression of urine, and delirium. They require no treatment, and do not seem to admit of being alleviated or curtailed by opiates, stimulants, or other means of remedy, requiring merely a little time for their disappearance, so that the only cordial of any service is a confident assurance on the part of the surgeon that there is no ground whatever for the slightest alarm or uneasiness."

I have administered amylene in 146 cases without ever meeting with any of the symptoms which occurred in Mr. Erichsen's case, except simple vomiting without depression, and that not a quarter so often as happens after chloroform. Amylene has also been largely used in France without producing any such symptoms as those which Mr. Syme describes, and which occurred after the operation in question. Amylene resembles chloroform very closely in its effects--more closely, indeed, in one respect, than could be desired--that of its power to cause sudden accidents; but chloroform, so extensively as it has been used, has not been known to occasion suppression of urine, or the train of symptoms connected with, and caused by, the congestion of the kidneys and suppression of urine which occurred in Mr. Erichsen's case. Amylene bears a great resemblance to nitrous oxide gas, both in the symptoms it produces, and in the promptitude with which its effects come on and pass off; but although this gas has been breathed for amusement, during almost sixty years, it is not recorded to have produced such a train of symptoms in any case as were met with after the operation under consideration.

Apart from all the experience above alluded to, it would be extremely unlikely that a medicine, whose physical properties compel it to pass away in the breath, with the exception of a minute trace, in a few minutes, should produce a fresh set of serious symptoms hours afterwards, the patient having been well in the mean time. It would be as if the effects of alcohol or opium should return after a few weeks. With regard to the term poisoning of the blood which occurs in the report to which I have referred, the blood may be said to be poisoned as long as any trace of a medicine or condiment remains in it; but a few hours after a patient has inhaled amylene his blood is not more poisoned by it than that of the surgeon and his assistants was at the time of the operation. The important poisoning of the blood in Mr. Erichsen's patient arose from the retention of excrementitious materials which the kidneys failed to eliminate, and the convulsions seem to indicate that the urea was decomposed into carbonate of ammonia. Sufficient particulars are not related, with regard to the vomiting which followed the previous operations, to enable one to form an opinion as to whether it was caused by the chloroform or not; but it is not improbable that it was due in a great measure to the operation. Vomiting is a symptom which used to occur after operations, now and then, before chloroform was used; and this agent, besides the vomiting which it undoubtedly occasions, has often to take the blame of that produced by other causes, such as a dose of opium, loss of blood, morbid poisons, and derangement of the renal and other functions occasioned by an operation.

I am, etc.

John Snow

18, Sackville Street, April 1857.