Comparison of propofol and antagonised midazolam anaesthesia for day-case surgery.

A technique of midazolam/fentanyl/isoflurane/nitrous oxide anaesthesia, in which the benzodiazepine was antagonised by the specific antagonist, flumazenil, was compared with propofol/fentanyl/nitrous oxide anaesthesia for minor outpatient urological surgery. No significant difference was found in the overall ease of anaesthesia; however, using subjective (linear analogue sedation scales) and objective (letter deletion and simple reflex time) tests, recovery was found to be significantly slower for the antagonised midazolam group. For both groups, the most frequent intraoperative problem was patient movement in response to surgical stimulation and, postoperatively, headache. The midazolam group displayed the greatest degree of residual sedation at the 4-hour time of discharge and on arrival home a significantly larger number of patients in the midazolam group slept for a period. It is likely that the dose of flumazenil chosen (1 mg) was inadequate to completely antagonise the dose of midazolam (mean 17 mg) for the full duration of recovery.