Midazolam does not reduce emergence delirium after sevoflurane anesthesia in children

Background: Behavioral disturbance in children following sevoflurane anesthesia is a relatively frequent event. The aim of this study was to evaluate whether a higher dose of preoperatively administered rectal midazolam compared with a lower would alleviate this phenomenon. Furthermore the impact of these two doses of midazolam on sedation at induction of anesthesia was compared. Methods: A total of 115 children presenting for minor surgery under anesthesia were included in the study. The children were randomized to receive rectally either 1 mg.kg(-1) midazolam (group H) or 0.5 mg.kg(-1) midazolam (group L). General anesthesia was induced with propofol or sevoflurane and maintained with 1.5% sevoflurane in the inspiratory limb. Prior to the start of surgery a regional block was performed to ensure adequate pain relief. Behavior on emergence was assessed using a three point scale. In case of severe agitation propofol was administered IV. Results: The children in group H were significantly better sedated preoperatively (P < 0.01). There was no significant difference in emergence behavior: 42.1% of children in group H compared with 36.2% of children in group L exhibited severe agitation requiring sedation with propofol (P = 0.37). However, regardless of the preoperative dose of midazolam more children under the age of 36 months (61.4%) were severely distressed at emergence compared with older children (16.7%) (P < 0.01). Conclusions: A higher dose of 1 mg.kg(-1) rectal midazolam results in much better sedated children on induction of anesthesia than 0.5 mg.kg(-1). This, however, does not result in a reduced incidence of emergence delirium after sevoflurane anesthesia. Regardless of the premedication negative behavioral changes occur more frequently in children younger than 3 years of age.