Isoflurane in paediatric anaesthesia

The characteristics of induction with and recovery from isoflurane anaesthesia were studied in 248 children. The mean time to loss of consciousness was 1.5 min (SD 0.5). Tracheal intubation, without interruption of spontaneous ventilation, was accomplished in a mean time of 4.2 min (SD 54 seconds). Movement and excitement, of 20-30 seconds duration, occurred in 23.9% children and 22 patients coughed during induction; 15 (12.6%) during the first 124 inductions; 7 (5.6%) subsequently. The mean half-times of reduction of alveolar isoflurane concentrations in 28 children whose lungs were ventilated with isoflurane and in 13 children who breathed isoflurane spontaneously during anaesthesia were: 45 sec after exposure for one hour, 70 sec after exposure of 2-3 hours and 110 seconds following exposures of 4-8 hours. The mean recovery times of the three groups were 6.5, 9.5 and 11.5 min respectively. In two further groups of nine children the mean half times of elimination of halothane and isoflurane were 220 seconds and 54 seconds respectively; recovery from isoflurane was markedly faster. Isoflurane is well accepted by children; induction is more rapid than with halothane, and the marked flexibility in the control of its effects are due to its relative insolubility. It has wide application in paediatric anaesthesia.