Comparison of midazolam with thiopentone for outpatient anaesthesia

The water soluble benzodiazepine, midazolam, was compared with thiopentone as an intravenous induction agent in unpremedicated patients undergoing cystoscopy as out-patients. Induction time was longer with midazolam, though subsequent transition to halothane inhalation anaesthesia was smooth and uneventful. Both drugs had similar effects on the cardiovascular and respiratory systems and were without local irritation following intravenous injection. Recovery was more prolonged with midazolam, tests of memory and unaided mobility showing greater impairment one hour after anaesthesia. Notwithstanding a slower and less predictable onset of unconsciousness and somewhat slower recovery phase, midazolam provides a safe alternative to thiopentone as an induction agent suited to minor surgical procedures.