Premedication with midazolam in out-patient general anaesthesia. A comparison with morphine-scopolamine and placebo.

Strong premedication may prolong recovery and cause side-effects after short surgical procedures in general anaesthesia. To be operated without premedication may be unpleasant for the patient. Midazolam is a water-soluble benzodiazepine with rapid onset and short half-life. In a randomized study with 193 female patients, we compared the effects and side-effects of three different premedicants i.m.: midazolam, morphine-scopolamine (Mo-Scop) and placebo. Midazolam and Mo-Scop had an equal and significantly better effect than placebo on preoperative anxiety and alertness. Side-effects like nausea, dry mouth and prolonged recovery occurred significantly more often in the Mo-Scop than the midazolam or placebo groups. The midazolam-premedicated patients had significantly more amnesia compared with the other two groups. Only 3% of the patients would prefer no medication before anaesthesia, whereas 80% would prefer a combination of an anxiolytic and hypnotic premedication. Sixty-three percent of the patients would prefer a premedicant administered by injection. The results indicate that midazolam i.m. is an effective premedicant, with few side-effects, for short procedures in general anaesthesia.