Rapid Administration of Ketamine for Abscess Drainage in Children-A Dose Finding Study.

Study Objective: To estimate the minimum dose and total sedation time of rapidly infused ketamine that achieves 3 to 5 minutes of effective sedation in children undergoing abscess incision and drainage in the emergency department.

Methods: The Up-Down method was used to estimate the dose of intravenous ketamine infused over 5 seconds or less that provided effective sedation in 50% (ED50) and 95% (ED95) for healthy children aged 2 to 5 years and 6 to 11 years undergoing abscess incision and drainage. None 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 determined when patients reached a Modified Aldrete score of 10.

Results: We enrolled 20 children in each age group. The estimated ED50 was 0.9 and 0.6 mg/kg for the 2 to 5 years and 6 to 11 years' groups and the estimated ED95 was 1.1 mg/kg for both groups. The median time to full recovery for the 2 groups was 20.5 and 17.5 minutes when only 1 dose of ketamine was administered and 27.5 and 35 minutes when additional doses of ketamine were administered. No participants experienced serious adverse events.

Conclusions: We estimated ED50 and ED95 for rapidly infused ketamine for 2 age groups undergoing abscess incision and drainage. Further studies are needed to get a more precise estimate of ED95. The total sedation time with this technique in the abscess group was shorter than most previous studies and is consistent with our previous observations in patients undergoing fracture reduction.