DI-ETHYL ETHER ANALGESIA: A DETAILED DESCRIPTION OF THE FIRST STAGE OF ETHER ANESTHESIA IN MAN

Ether”, defined a first and second degree of etherization that corresponds to the modern classification of this point of anesthesia as the stage of analgesia. At this level of anesthesia, Snow described surgical procedures without pain after the patient had emerged from a deeper stage of etherization. In 1921, Gwathmey, using rectal ether in oil in obstetrical patients, observed a similar analgesia. In 1937, Guedel defined the stages and planes of anesthesia that have since become classical indicators of the progressive depression of the central nervous system during inhalation of di-ethyl ether. In 1951, Harris challenged our thinking about these stages and planes. He proposed to interpret signs of anesthesia in terms of absorption of an effective concentration of the anesthetic by specific areas of the brain. All these workers referred to a stage in which analgesia is present. All descrip-tions indicate that this is one of the first events of anesthetic induction and that this analgesia is superseded by the ensuing loss of consciousness as administra-tion continues. Guedel dc-emphasized the practical use of this first stage for fea