[A comparative study of the use of sevoflurane and propofol in ambulatory surgery]

Cost-containment strategies increase the demand for day-case surgery. In outpatients, a short time of stay in the post-anaesthesia care unit and a short interval to discharge home are of great importance. After general anaesthesia, mental and psychomotor functions are impaired to varying degrees by different anaesthetics. Therefore, the choice of anaesthetic may influence the discharge times of outpatients. In this study, the recovery characteristics of sevoflurane versus propofol anaesthesia were compared in adult outpatients.

With ethics committee approval and written informed consent, a total of 50 patients undergoing day-case ophthalmological or urological surgery were randomised into two groups. After a priming dose of vecuronium 0.015 mg/kg, anaesthesia was induced in all patients with propofol 2.0-2.5 mg/kg and fentanyl 2 micrograms/kg. Suxamethonium 1 mg/kg was used to provide muscle relaxation for endotracheal intubation. According to the randomisation, anaesthesia was maintained with either sevoflurane 1-3 vol.% (group 1, n = 25) or propofol (group 2, n = 25). The immediate postoperative recovery was assessed by the time to the appropriate response to different verbal commands. The quality of the overall postoperative recovery was classified by visual analogue scales, the digit-symbol substitution test (DSST), a modified Aldrete score, and the time until the ability to sit upright and walk. Overall side effects and postoperative behaviour were evaluated by a telephone interview on the day after surgery.

Neither the study groups nor the duration of surgical procedures differed significantly. The total doses of anaesthetic used were 1.7 +/- 1.1 MAC-h sevoflurane and 631 +/- 261 mg propofol, respectively. The time intervals from the end of anaesthesia to extubation of the trachea were significantly shorter after sevoflurane than after propofol (6.6 +/- 2 min vs. 9.8 +/- 6 min). Similar results were obtained for the intervals to eye opening (7.2 +/- 2 min vs. 12.6 +/- 9 min) and hand squeezing (8 +/- 2 min vs. 13.8 +/- 11 min). The recovery of cognitive functions was significantly faster after sevoflurane when compared to propofol as evidenced by the DSST. The modified Aldrete score was significantly better in the sevoflurane group at all assessment times. Except for 30 min after anaesthesia, when sevoflurane patients complained of significantly more nausea, VAS scores were not different. No significant difference in the ability to sit and walk was found. The side effects did not differ between both groups.

The results indicate that in urological and ophthalmological day surgery, the early recovery and the return of mental and psychomotor function in the first 60 min after anaesthesia is faster following sevoflurane than after propofol. No differences in ambulation times became evident. Sevoflurane may offer clinical advantages over propofol when used for maintenance of anaesthesia during outpatient surgical procedures.