Journal of the American Medical Association
thesia, though its application has not been worked out in detail. (d) The Relation of Ether and of Nitrous Oxid to the Infections.-We have already referred to the pro¬ tective action of nitrous oxid in the presence of the stimuli of continued consciousness as in prolonged insomnia ; and other histologie studies have shown that morphin also protects the brain, suprarenals and liver from the destructive action of prolonged or intense stimuli. It follows, then, that since the effects of an
... fects of an infection on the brain, suprarenals and liver are identical with the effects of insomnia, emotion, etc., then the administration of nitrous oxid and morphin will in part protect the organism against the damaging effect of infection. Summary of Experimental Findings: Nitrous oxid and ether anesthesia alike cause an increase in the -ion concentration of the blood, the spinal fluid and the bile ; and progressively decrease the reserve alka¬ linity of the blood. Ether causes marked histologie changes in the brain, suprarenals and liver, these changes being identical in kind with the histologie lesions caused by acid injection, or activation of any kind. Nitrous oxid and morphin each measurably pro¬ tect the brain against histologie changes due to infec¬ tion, while ether increases the damaging effects of infection. (c) The Clinical Bearing of These Studies.-The identity of the phenomena of anesthesia with the suc¬ cession of clinical symptoms which accompanies an increasing acidosis, combined with the fact that the histologie changes produced by nitrous oxid and by ether are identical with those caused by acidosis, sup¬ ports the postulate that anesthesia is an induced acid¬ ity. If the acidity is slight, anesthesia is light and the patient responds to even slight stimulation. As the acidity increases, the anesthesia deepens-first, asso¬ ciative memory is lost, but the cutting of the skin still causes involuntary movements ; then muscular tone is lost, and even the strong contact stimuli of a surgi¬ cal operation cannot drive their impulses through the brain to the muscles ; and finally, the decreasing alka¬ linity may so nearly approach the neutral point that even the circulatory and respiratory centers, which are especially adapted to respond to the stimulus of increased -ion concentration, fail to respond ; respi¬ ration and circulation are suspended and acid deathanesthetic death-follows. These studies explain why a patient, whose reserve alkalinity has been seriously reduced by exertion, emo¬ tion, physical injury or infection, or, by reason of starvation, interference with respiration or impairment of the liver or kidneys, is approaching acidosis, does not take an inhalation anesthetic well ; why there is much nausea and slow recovery from anesthesia in some cases and death in others, and why, in particular, children who are near acidosis always pass into that state and die unexpectedly. These facts show how necessary it is for the sur¬ geon and the anesthetist alike to realize that during the operation each is draining the store of reserve alka¬ linity. If the surgeon employs a local anesthetic, uses gentle manipulation and produces the least possible trauma, he conserves his patient and demands from the anesthetist less 6t the damaging inhalation anes¬ thetic. The anesthetist in turn conserves the patient by using the lightest possible even anesthesia administered with the least psychic trauma. These studies show that for the bad risk patient, nitrous oxid anesthesia is to be preferred to ether, and that analgesia with local anesthesia should be employed, with general anesthesia only when it is demanded by certain phases of the operation. These researches suggest the value of a mechanistic view of the phenomena of anesthesia and attach a high importance to the work of the anesthetist. In my own clinic we have now administered nitrous oxid anesthesia in over 15,000 cases without a death ; and moreover, as our knowledge and experience accu¬ mulate, we are able with increasing accuracy to adapt the anesthetic to the individual.