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Midazolam premedication delays recovery after propofol without modifying involuntary movements
J C Bevan1, G R Veall, A J Macnab
1Department of Anaesthesia, British Columbia's Children's Hospital, Vancouver, Canada.
Insights
Oral midazolam premedication in children undergoing anesthesia did not alter involuntary movements but did prolong recovery time. This study investigated midazolam
Area of Science:
- Anesthesiology
- Pediatric Anesthesia
- Pharmacology
Background:
- Midazolam exhibits GABAergic effects in children.
- These effects may influence propofol-induced involuntary movements and recovery duration.
Purpose of the Study:
- To evaluate the impact of oral midazolam premedication on propofol-induced involuntary movements and recovery time in pediatric patients.
- To assess sedation and anxiety levels and side effects associated with midazolam.
Main Methods:
- A double-blind, randomized study involving 24 children (2-7 years) receiving midazolam or placebo orally before propofol anesthesia.
- Observers scored sedation and anxiety; videotaping recorded body movements during induction and emergence.
- Recovery was assessed by time to eye opening and standardized sedation/recovery scores.
Main Results:
- The incidence of involuntary movements did not differ between groups but was higher at induction than emergence.
- Midazolam premedication significantly prolonged recovery times, including eye opening and sedation/recovery scores.
- Anxiety and sedation scores were similar between the midazolam and placebo groups.
Conclusions:
- Oral midazolam as a premedicant prolongs anesthesia recovery in children.
- Midazolam did not affect the incidence of dystonic movements following propofol anesthesia.
- Children returned to normal activity within one day with no neurological complications.
Abstract:
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.