Elimination kinetics of sevoflurane and halothane from blood, brain, and adipose tissue in the rat.

Using the rat as an animal model, the elimination kinetics of sevoflurane and halothane from brain, blood, and adipose tissue were compared. Elimination of sevoflurane and halothane from blood and brain was biexponential. The rapid, alpha-elimination rates of sevoflurane from blood and brain were faster than the corresponding rates for halothane. However, the slower beta-elimination rates from brain and blood, as well as the elimination rates from adipose tissue, were similar for both volatile anesthetics. Thus, the potential for residual postoperative impairment from subanesthetic tissue concentrations of halothane and sevoflurane may be similar even though sevoflurane is initially eliminated more rapidly from blood and brain.