• Experience with more than 200 patients, most of them between the ages of 70 and 95, showed that anesthesia with nitrous oxide, oxygen, and a relaxant of the curare group gave excellent results in major surgery, provided certain precautions were observed. Premedication consisted of secobarbital sodium, scopolamine hydrobromide, and either morphine or meperidine hydrochloride. The type of gas machine is important because of the superiority of the demand-flow, fractional, or nonrebreathing technique. The induction must allow a period of 15 to 30 minutes for denitrogenation, during which the patient settles down to an equilibrium that can be maintained, in some patients, with an oxygen percentage of 30 to 50%. The relaxants used were gallamine triethiodide, succinylcholine chloride, or tubocurarine, the last named being avoided in patients with pulmonary fibrosis, emphysema, or bronchial asthma. The relaxant was administered only when denitrogenation was believed to be complete.
The anesthesia was kept light, so that the electroencephalograms resembled the records from the wakeful state. Several experiences here described convinced the authors that deep anesthesia greatly increases the danger of hypotension and that changing from ether to nitrous oxide obviated the need for vasoconstrictor drugs. The fact that nitrous oxide does not depress the respiratory center, does not irritate the respiratory epithelium, and does give adequate alveolar ventilation was shown by detailed biochemical studies in 13 patients. It is believed that this type of anesthesia permitted more deliberate, extensive, and definitive operations in poor-risk patients.