Sevoflurane elimination kinetics in children.

We compared the rates of elimination of sevoflurane and halothane in 29 children, aged between one and seven years, undergoing ambulatory anaesthesia. Analgesia was provided by fentanyl and muscle relaxation by atracurium. Anaesthesia was maintained by inhalation of one MAC of either sevoflurane or halothane, based on an equipotent concentration of each agent for the age of the child. Following simultaneous discontinuation of N2O and the inhalational agent, the equation describing N2O washout was identical in the presence of halothane and sevoflurane, showing that there was no effect of the volatile agent on the rate of N2O elimination. The elimination of sevoflurane and N2O give similar types of equations. Halothane elimination gives a logarithmic type of equation, showing a slower release, corresponding to residual tissue content.