The relation of inhalation analgesia and anesthesia to asphyxia neonatorum

Abstract 1982 consecutive deliveries were reviewed from the aspect of asphyxia neonatorum in relation to inhalation analgesic and anesthetic agents. 1. 1. Nitrous oxide, ethylene, and cyclopropane, when used as analgesic agents, did not materially influence the incidence of asphyxia neonatorum. 2. 2. Nitrous oxide, properly administered, was given for long periods of time without significant effects on fetal asphyxia. 3. 3. Cyclopropane and other agents when used in concentrations sufficient for anesthesia by operative delivery were accompanied by an increase in the incidence of fetal asphyxia. 4. 4. The incidence of asphyxia neonatorum varied directly as the duration of administration of cyclopropane anesthesia. 5. 5. There seemed to be no relationship between asphyxia neonatorum and the type of anesthetic technique. 6. 6. Prematurity, complications of pregnancy and labor, method of delivery and misuse of analgesic agents were apparently of greater significance in asphyxia neonatorum than the various inhalation agents when properly administered.