Sevoflurane is used in children because it affords rapid and smooth induction and emergence from anesthesia, promotes hemodynamic stability, and does not irritate airways. However, it is associated with a high incidence of emergence agitation. Midazolam is often used to prevent emergence agitation, using an intravenous (IV) dose of 0.05 mg/kg before the end of surgery, which then increases the emergence time. This randomized, double-blind, placebo-controlled, parallel-group trial was undertaken to determine whether a lower dose of midazolam could suppress emergence agitation without disturbing emergence time in children having sevoflurane anesthesia.

The 90 children, aged 1 to 13 years, were undergoing elective strabismus surgery and were randomized 1: 1: 1 to receive 0.03 mg/kg midazolam, 0.05 mg/kg midazolam, or isotonic saline, with 30 patients in each group. Anesthesia was induced with IV thiopental sodium and maintained with sevoflurane and nitrous oxide in oxygen. Intravenous rocuronium bromide was used to facilitate tracheal intubation. Just before the end of surgery, patients were given their assigned study drug. The patients’ standard hemodynamic status was monitored in the postanesthesia care unit. Behavior on emergence was assessed with the pediatric anesthesia emergence delirium scale and a 4-point agitation scale, recorded every 5 minutes for the first 30 minutes and then every 10 minutes during the postanesthesia care unit stay. The primary outcome was behavior on emergence, and the secondary outcome was the time to emergence, that is, the time from the discontinuation of sevoflurane to the time of extubation. Duration of surgery, anesthesia, and sevoflurane administration were also recorded. Postoperative pain was assessed using a numerical rating scale; IV fentanyl was given to treat pain. Adverse events were recorded. SPSS for Windows, version 12.0 (SPSS Inc, Chicago, Ill) was used for analyses; P< 0.05 indicated statistical significance.