Maintenance and recovery characteristics of sevoflurane anaesthesia in adult patients. A multicenter, randomized comparison with isoflurane.

BACKGROUND

The goal of the present multicenter, prospective, randomized clinical investigation was to compare the clinical efficacy and safety of sevoflurane and isoflurane during maintenance of and recovery from general anaesthesia in adult patients.

METHODS

With the approval of the Ethical Committee and the patient informed consent, 143 ASA physical status I-II patients, aged 18-65 years, were randomized in order to receive either isoflurane (n = 71) or sevoflurane (n = 72) as the main general anaesthetic. After an oral diazepam (0.1-0.2 mg kg-1) and atropine (0.007-0.01 mg kg-1) premedication and a standardized intravenous induction, general anaesthesia was maintained by adjusting the end-tidal concentrations of the inhalational agent for the maintainance of cardiovascular stability. At the end of surgery the anaesthetic vapours were discontinued, and the neuromuscular block was reversed; the following times were recorded: time of eyes opening, time of command response and suitability for discharge from the recovery area. The occurrence of any untoward event was also recorded. Preoperatively and 24 hr after surgery, blood was collected in order to assess renal an hepatic functions.

RESULTS

No differences in demography, duration of surgery, exposure to the inhalational agent and haemodynamic effects were observed between the two groups. Patients receiving sevoflurane showed shorter times for the achievement of extubation (median: 9 min versus 13 min, p = 0.002), eyes opening (median: 10 min versus 13 min, p = 0.002), command response (11 min versus 15 min, p = 0.002) and suitability for discharge from recovery room (median: 19 min versus 22 min, p < 0.05) than those receiving isofluorane. No intra- and intergroup differences were observed in pre- and post-operative laboratory testing of renal and hepatic function.

DISCUSSION

We conclude that sevoflurane, when compared to isoflurane, provides a similarly safe maintenance but allows for a more rapid emergence from general anaesthesia.