NITROUS OXIDE-CURARE ANESTHESIA UNSUPPLEMENTED WITH CENTRAL DEPRESSANTS

IN a previous communication (Ruben and Andreassen,1951) it was stated that it was possible and satisfactory to use only pethidine and curare as supplementary agents to nitrous oxide anaesthesia for major operations, thus avoiding the administration of barbiturates. Applying what is considered a more rational nitrous oxide technique, out-lined in a paper by the author (Ruben, 1953) a study was undertaken to evaluate to what extent the use of this nitrous oxide technique may result in avoidance of supplementation apart from the use of relaxants. As a consequence morphine was also omitted in the premedication, which consisted of scopolamine or atropine. It was felt that the role played by a relaxant could more easily be studied when no other supplement was in use. Forty patients, mostly for major operations, were anaesthetized according to these principles. Nitrous oxide was used in a non-rebreathing system using 20 to 23 per cent of oxygen in the flow delivered from the machine. The rather small number of cases forming the basis for this report is balanced by the consistency of the results, which was good enough to give a clear picture of what was possible with this anaesthesia. Eighteen of the operations were upper laparotomies, 14 were lower laparotomies, and the rest were thyroid and orthopaedic operations. The average duration of anaesthesi