Effects of initial pain treatment on sedation recovery time in a pediatric emergency department

Abstract

Study objectives: The purpose of this study is to compare the sedation recovery times for children receiving ketamine/midazolam (K/M) versus K/M plus an opiate (morphine or meperidine) analgesic in a pediatric emergency department (ED). Methods: This was a retrospective cross-sectional study performed at an urban children's hospital pediatric ED with a yearly census of 36,000. Descriptive statistics and confidence intervals (CIs) were used to analyze the data. Results: During an 18-month period (July 1, 2002, to December 31, 2003), 136 children received ketamine for procedural sedation in the ED. Of these, 116 also received midazolam. For the purpose of this study, the following number of patients were excluded: 9 with altered mental status, 11 with level of sedation not recorded, 6 with inadequate sedation, 6 with ketamine dose greater than 2 mg/kg or less than 0.3 mg/kg, 1 given reversal agents (Narcan and flumazenil), 2 with medical records not available for review, and 1 with morphine given more than 4 hours before ketamine and midazolam. Of the remaining 80 patients, 33 patients received K/M only, 32 received K/M and morphine, and 15 received K/M and meperidine. Of the 80 patients, the mean age was 91.8 months (SD 47.2, range 12 to 215 months). There were 47 (58%) male patients. Indication for procedural sedation and analgesia was an injury in 70 (87.5%) of the patients. Injuries included 64 fractures (60 forearm fractures), 3 lacerations, and 3 joint dislocations. Other indications were 3 foreign body removals, 2 incision and drainage procedures, 2 vaginal examinations, 2 computed tomographic scans, and 1 hernia reduction. The mean ketamine dose for the study population was 1.08 mg/kg (SD 0.4l, range 0.3 to 2 mg/kg). The mean midazolam dose was 0.08 (SD 0.03, range 0.02 to 0.21 mg/kg). The mean recovery time was 38.1 minutes (SD 21.6, range 8 to 96 minutes). For the 32 children who received intravenous morphine, the mean dose was 0.09 mg/kg (SD 0.04, range 0.03 to 0.2 mg/kg). For the 15 children who received intramuscular meperidine, the mean dose was 1.01 (SD 0.1, range 0.85 to 1.19 mg/kg). Minor complications occurred in 5 (6%) patients. In the K/M-only group, 2 patients had transient hypoxia (room air pulse oximeter ≤92%), 1 patient required a neck roll to maintain a patent airway, and 1 patient had agitation for less than 1 minute. In the K/M morphine group, 1 patient had transient hypoxia. In comparing the K/M-only group with the K/M morphine, K/M meperidine, and K/M morphine or meperidine groups, the mean ketamine and midazolam doses (mg/kg) were not significantly different. In comparing the recovery times for the K/M-only group with the K/M morphine, K/M meperidine, and the K/M morphine or meperidine groups, there was a significant difference. The mean recovery times were 29.7 minutes (SD 15.7), 41.1 minutes (SD 22.4; 95% CI for differences –20.9 to –1.76); 50.1 minutes (SD 24.9; 95% CI for differences –32.2 to –8.4) and 44 minutes (SD 23.4; 95% CI for differences –23.5 to –4.9), respectively. Conclusion: Presedation analgesia (morphine or meperidine) is associated with a significantly longer recovery time for procedural sedation with ketamine and midazolam. This finding is not to suggest a discontinuation of presedation analgesia treatment but to help in estimating resources (staff time) for providing procedural sedation in a pediatric ED.