INTRAVENOUS PETHIDINE IN ANESTHESIA (A Report on 330 Cases)

THE first series of cases in which pethidine hydrochloridewas used to supplement nitrous oxide-oxygen anaes-thesia was conducted in America (Neff, Mayer and Perales, 1947), and reports of its use in this country followed two years later (Mushin and Rendell-Baker, 1949). Subsequent reports from both sides of the Atlantic indicate that there is a wide variation in the actual quantities of pethidine administered by different anaesthetists. Neff, Mayer and Thompson (1950) stated that the total dose used by them decreased as experience in the use of the method was gained, but that this was possibly due, in part at least, to the use of ether supplementation and curare for endotracheal intubation in extensive procedures. In cases not requiring intubation they used a slow induction tech-nique giving nitrous oxide with 20 per cent oxygen until the anaesthesia was stabilised before injecting pethidine. Using this method, their average dose was at the rate of 30 mg. an hour, whereas in those cases in which thiopentone was used for induction the average hourly requirement was 37 mg. Griffiths (1950) reported that, in 150 administrations, 25 mg. was adequate for procedures lasting as long as one and a half hours. The proportion of oxygen in the gas mixture was not stated nor the method of its administration