Recovery and pharmacokinetic parameters of desflurane, sevoflurane, and isoflurane in patients undergoing urologic procedures

Study Objective: To compare the pharmacokinetics and the speed of recovery after inhalation anesthesia with desflurane, sevoflurane, and isoflurane in elective surgery. Design: Prospective, randomized study. Setting: University medical center. Patients: 30 ASA physical status I and II adults presenting for elective su rgery. Interventions: Anesthesia was induced with etomidate and maintained with de sflurane (n = 10), sevoflurane (n = 10), or isoflurane (n = 10) and nitrous oxide. The inhalation drugs were titrated until an adequate clinical depth of anesthesia was reached. At the end of anesthesia, the patients breathed oxygen via the endotracheal tube and after extubation via a face mask. Measurements and Main Results: The groups were similar with respect to age, weight, duration of anesthesia, and mean arterial pressure. Mean end-tidal concentration (F-A = F-Ao) at the end of anesthesia was 6.34 +/- 1.15% aft er desflurane, 1.85 +/- 0.42% after sevoflurane, and 1.10 +/- 0.24% after i soflurane. F-A/F-Ao decreased significantly faster with desflurane than wit isoflurane, while there was little difference between desflurane and sevof lurane. As for the terminal half-life (t(1/2)), there were no differences a mong the groups (8.16 +/- 3.15 min after desflurane, 9.47 +/- 4.46 min afte r sevoflurane, and 10.0 +/- 5.57 min after isoflurane). The time until a co mmand was followed for the first time was the same in all three groups (13. 0 +/- 4.7 min after desflurane, 13.4 +/- 4.4 min after sevoflurane, and 13. 6 +/- 3.4 min after isoflurane). There was no significant correlation betwe en duration of anesthesia and the time until recovery. Conclusions: There are only minor differences with regard to the recovery p hase in premedicated patients who receive clinically titrated inhalation an esthesia with desflurane, sevoflurane, or isoflurane. (C) 1999 by Elsevier Science Inc.