Midazolam Premedication Delays Recovery After Propofol Without Modifying Involuntary Movements

Midazolam has GABAergic effects in children that may modify propofol-induced involuntary movements, yet delay recovery. In a double-blind, randomized study, 24 children (2-7 yr of age, ASA physical status I or II) undergoing short surgical procedures received midazolam 0.5 mg/kg (Group M) or placebo (Group P) per os 20-30 min before propofol anesthesia (5 mg/kg intravenously followed by an infusion). Blind observers scored sedation and anxiety levels (scale 1-4) before premedication, at separation from parents, and at induction of anesthesia. Induction and emergence were videotaped, and body movements were recorded. During recovery, times to eye opening and maximum Steward (SS = 6) and Vancouver Sedative Recovery (VSRS = 22) scores were noted. Parents were questioned about side effects that may have occurred during the following week. Both groups were similar in age, sex, weight, timing of premedication, propofol dose, and duration of surgery. The incidence of involuntary movements did not differ between groups but was higher at induction (79%) than on emergence (25%) (P < 0.05). Anxiety and sedation scores were similar in Group P and Group M, but recovery took longer after midazolam, with eye opening (mean +/- SD) 24 +/- 7 vs 43 +/- 18 min, maximum SS (median and range) 27 (13-37) vs 55 (24-138) min, and maximum VSRS 51 (30-100) vs 80 (50-130) min. Children returned to normal activity in 1 (0-5) day, and none exhibited neurological complications. We conclude that an oral premedicant dose of midazolam prolongs recovery from anesthesia in children without affecting dystonic movements after propofol.