Rapid administration technique of ketamine for pediatric forearm fracture reduction: a dose-finding study.

Study Objective: We estimate the minimum dose and total sedation time of rapidly infused ketamine that achieves 3 to 5 minutes of effective sedation in children undergoing forearm fracture reduction in the emergency department.

Methods: We used the up-down method to estimate the median dose of intravenous ketamine infused during less than or equal to 5 seconds that provided effective sedation in 50% (ED50) and 95% (ED95) of healthy children aged 2 to 5, 6 to 11, or 12 to 17 years who were undergoing forearm fracture reduction. Most patients were pretreated with opioids. Three investigators blinded to ketamine dose independently graded sedation effectiveness by viewing a video recording of the first 5 minutes of sedation. Recovery was assessed by modified Aldrete score.

Results: We enrolled 20 children in each age group. The estimated ED50 was 0.7, 0.5, and 0.6 mg/kg and the estimated ED95 was 0.7, 0.7, and 0.8 mg/kg for the groups aged 2 to 5, 6 to 11, and 12 to 17 years, respectively. For the group aged 2 to 5 years, an empirically derived ED95 was 0.8 mg/kg. All patients who received the empirically derived ED95 in the group aged 2 to 5 years or the estimated ED95 in the groups aged 6 to 11 and 12 to 17 years had effective sedation. The median total sedation time for the 3 age groups, respectively, was 25, 22.5, and 25 minutes if 1 dose of ketamine was administered and 35, 25, and 45 minutes if additional doses were administered. No participant experienced serious adverse events.

Conclusion: We estimated ED50 and ED95 for rapidly infused ketamine for 3 age groups undergoing fracture reduction. Total sedation time was shorter than that in most previous studies.