Comparison of psychomotor skills and amnesia after induction of anesthesia with midazolam or thiopental.

In two groups of 31 healthy patients undergoing minor elective surgery, anesthesia was induced intravenously with either midazolam maleate, 0.2 mg/kg, or thiopental, 3.5 mg/kg. All subjects received 2 micrograms/kg fentanyl 5 min before the induction agents. Induction time with midazolam was significantly longer than with thiopental (97.1 +/- 10.9 sec vs 59.4 +/- 5.0 sec) and time to orientation postoperatively was significantly longer after midazolam (31.7 +/- 4.2 min vs 11.0 +/- 1.1 min). Continued recovery after orientation, measured by a series of psychomotor tests, was also significantly longer with midazolam than with thiopental. Anterograde amnesia was evident in 84.8% of the midazolam treated patients and in only 31.4% of the thiopental group. This degree of absence of recall was acknowledged positively by the affected patients. The protracted recovery period may limit the use of midazolam in short surgical procedures.