Effect of halothane, enflurane, and nitrous oxide on tracheal ciliary activity in vitro

Effects of halothane, enflurane, and nitrous oxide on ciliary beats were evaluated using a photoelectric system in dissected rabbit tracheal segments. Dose-dependent suppression of the frequency of ciliary beats of moderate degrees was observed after exposure of tracheal segments to warmed and humidified vapors of halothane and enflurane. No suppression, however, was noted after exposure to nitrous oxide. These findings suggest that halothane and enflurane directly suppress ciliary activity.