A multicenter comparison of maintenance and recovery with sevoflurane or isoflurane for adult ambulatory anesthesia

Sevoflurane was compared with isoflurane in 246 adult ASA class I-III patients undergoing ambulatory surgery. After administration of midazolam 1-2 mg and fentanyl 1 mu g/kg, anesthesia was induced with propofol 2 mg/kg and maintained with either sevoflurane of isoflurane in 60% nitrous oxide to maintain arterial blood pressure at +/- 20% of baseline. Fresh gas flows were 10 L/min during induction and 5 L/min during maintenance. Times to eye opening, command response, orientation, and ability to sit without nausea and/or dizziness were significantly faster after sevoflurane. Significantly more sevoflurane patients met Phase 1 of postanesthesia care unit (PACU) Aldrete recovery criteria (greater than or equal to 8) at arrival, 95% vs 81%. Also, significantly more sevoflurane patients were able to complete psychomotor recovery tests during the first 60 min postanesthesia. Discharge times were not different. Sevoflurane patients had significantly lower incidences of postoperative somnolence (15% vs 26%) and of nausea both in the PACU (36% vs 51%) and in the 24-h postdischarge period (9% us 24%). Patient satisfaction was high overall (sevoflurane 97%, isoflurane 93%). We conclude that sevoflurane is a useful inhaled anesthetic for maintenance of ambulatory anesthesia.