INCREASE IN TOXICATION OF ETHER BY NEW METHODS OF ADMINISTRATION
Journal of the American Medical Association
necessarily mean syphilis, and that a diagnosis of syph¬ ilis cannot be based on weak and medium inhibitions when they are employed. We hold that weakly positive reactions with syphilitic liver-extract mean nothing but syphilis. Even though it were true that the cholesterin¬ ized antigens give a more delicate reaction and may furnish positive results in cases of syphilis that are neg¬ ative to the syphilitic liver-extract, it is a very much less serious error to overlook an occasional case of
... ccasional case of syph¬ ilis than to saddle a diagnosis of the disease with all it entails on a patient who does not have syphilis. Considerable harm is being done at present by the use of unreliable non-specific or artificial extracts, in two ways: 1. The marked discrepancies between the results of the Wassermann test and the clinical findings in many cases are causing skeptical clinicians to lose confidence in the value of the reaction, and thus they are beine; deprived of an important diagnostic and therapeutic aid. 2. A great many unfortunate persons are being treated for syphilis who have not and never had syphilis. as the result of weakly positive and doubtful reports of workers using these antigens. By all means let the experimental work go on, in the endeavor to improve the technic of the Wassermann reaction; but until the results obtained with innovations are proved to be more reliable than those with the gen¬ erally accepted methods, let us adhere to the technic and reagents that have withstood successfully the assaults of time and which are supported by clinical experience. The small amount of ether administered in the intravenous method, as compared to that used in the inhalation and insufflation methods, has led some to believe that this direct method of introduction lessens the amount of ether utilized by the patient in the maintenance of anesthesia, whereas the reverse is true. Anesthesia is maintained by keeping the ether and the blood at a certain ratio. When the blood remains constant in volume, increase or decrease in the percentage of ether deepens or lightens the anesthesia accordingly, and conversely, the amount of ether within the system remaining constant, an increase in the volume of the circulating fluid decreases the depth of the anesthesia. To maintain surgical anesthesia in the intravenous method, then, the amount of ether required is increased in the proportion that the saline solution bears to the original, total volume of blood. In the normal adult (150 pounds) the amount of blood varies from 4.58 to 4.65 liters, and from this can readily be calculated the extra burden of ether toxication thrust on the patient. In such a patient, using preliminary hypodermic medication, intravenous admin¬ istration requires for induction about 8 ounces of saline solution ; that is, at the end of induction there is being thrown into circulation about 5 per cent, more ether than is required in other methods; at the end of an hour's surgical anesthesia the excess is 15 per cent., and at the end of a prolonged operation, in which it is reported that 4*4 pints of saline solution were admin¬ istered, the excess was more than 40 per cent. It is futile to hold that this pronounced excess of ether does not increase ether toxication. While some of the saline solution transudes into body cavities and tissues, it carries ether with it, and this must subse¬ quently be excreted. The comparative freedom from postnarcotie nausea and vomiting does not necessarily indicate lessened ether toxicity, for the methods of administering ether that avoid passing a strong vapor continually over the olfactory nerves are likewise fol¬ lowed by less nausea and vomiting. The odor of ether, per se, is nauseating, and causes much of the vomiting in the cruder methods of administration. In the oil-rectal method of administering ether the same ultimate result increasing the amount of ether in circulation seems to follow, although the modus operandi is entirely different. Here, in the adult, about 6 ounces of ether, plus 2 ounces of olive-oil (both bv volume) are introduced into the rectum. All of the ether thus introduced reaches the patient's circulation, except that which is subsequently withdrawn, as there is no source of evaporation, such as occurs in other methods. It requires only \y2 ounces of ether in the patient's circulation without rebreathing to induce and maintain an hour's surgical anesthesia. The amount of ether withdrawn in the oil-rectal method shows that a much larger amount than this reaches the patient's cir¬ culation. The much larger amount of ether required in this method is probably due to the oil interfering with the anesthetic action of ether. Theoretically, of course, this is true, and it seems to be verified prac¬ tically. Not only is there very much more than li/2 ounces' difference in the original amount of ether intro¬ duced into the rectum and that withdrawn at the end of an hour of surgical anesthesia, but there is a decid¬ edly greater tendency toward respiratory paralysis with¬ out the corresponding depth of anesthesia that occurs in other methods. This indicates that while the oil may lessen the anesthetic action of ether it does not corre¬ spondingly decrease its toxic action on the respiratory center. Certain it is that the margin of safety between surgical anesthesia and respiratory paralysis is consid¬ erably reduced in the oil-rectal method. It is not contended that these methods are without value, for each possesses decided advantages; but the price that is exacted for these advantages should always be given proper consideration. Hotel Bretton Hall, Eighty-Sixth Street and Broadway.