Comparison of the Effects of 0.03 and 0.05 mg/kg Midazolam with Placebo on Prevention of Emergence Agitation in Children Having Strabismus Surgery

Background: Midazolam has been widely studied for preventing emergence agitation. The authors previously reported that in children with sevoflurane anesthesia, intravenous administration of midazolam (0.05 mg/kg) before the end of surgery reduced the incidence of emergence agitation but prolonged the emergence time. This study was designed to test the hypothesis that a lower midazolam dose could suppress emergence agitation with minimal disturbance of the emergence time in children with sevoflurane anesthesia. Methods: In this randomized, double-blind, placebo-controlled trial, 90 children (1 to 13 yr of age) having strabismus surgery were randomized to 1: 1: 1 to receive 0.03 mg/kg of midazolam, 0.05 mg/kg of midazolam, or saline just before the end of surgery. The primary outcome, the incidence of emergence agitation, was evaluated by using the pediatric anesthesia emergence delirium scale and the four-point agitation scale. The secondary outcome was time to emergence, defined as the time from sevoflurane discontinuation to the time to extubation. Results: The incidence of emergence agitation was lower in patients given 0.03 mg/kg of midazolam (5 of 30, 16.7%) and patients given 0.05 mg/kg of midazolam (5 of 30, 16.7%) compared with that in patients given saline (13/of 30, 43.3%; P = 0.036 each). The emergence time was longer in patients given 0.05 mg/kg of midazolam (17.1 +/- 3.4 min, mean +/- SD) compared with that in patients given 0.03 mg/kg of midazolam (14.1 +/- 3.6 min; P = 0.0009) or saline (12.8 +/- 4.1 min; P = 0.0003). Conclusion: Intravenous administration of 0.03 mg/kg of midazolam just before the end of surgery reduces emergence agitation without delaying the emergence time in children having strabismus surgery with sevoflurane anesthesia.