Study objective: To compare sevoflurane-nitrous oxide with propofol-nitrous oxide for the induction and maintenance of anesthesia, and to determine the rates of recovery following each anesthetic.
Design: Randomized, controlled study.
Setting: Teaching hospital.
Patients: 50 ASA physical status I and II patients, ranging in age from 18 to 70 years.
Interventions: General anesthesia was induced with either sevoflurane or propofol and maintained with 60% to 70% nitrous oxide and either sevoflurane or a propofol infusion and supplemental fentanyl. At the conclusion of surgery, the oxygen flow was increased to 6 L/min and all anesthetics were discontinued simultaneously. Patients were monitored for the nature and speed of induction and emergency from anesthesia.
Measurements and main results: Induction of anesthesia was significantly slower in the sevoflurane group than in the propofol group (2.0 +/- 1.1 vs. 0.8 +/- 0.5 min, respectively). The ease of induction and the time required for emergence from anesthesia were the same in both study groups (eye opening: 9.0 +/- 4.4 min vs. 8.0 +/- 5.0 min; following commands: 11.2 +/- 5.0 min vs. 9.8 +/- 6.9 min; extubation: 9.1 +/- 4.5 min vs. 8.6 vs. 5.1 min in the sevoflurane and propofol groups, respectively). Patients in the sevoflurane group experienced nausea and vomiting more frequently than patients in the propofol group (13 and 5 patients vs. 3 and 0 patients in the sevoflurane and propofol groups, respectively), which were not related to the administration of neostigmine or intraoperative opioids.
Conclusion: Sevoflurane allows for rapid inhalation induction of, and emergence from, general anesthesia.