Analgesic efficacy and safety of single-dose intramuscular ketorolac for postoperative pain management in children following tonsillectomy

Abstract

The efficacy of ketorolac, a non-steroidal anti-inflammatory drug, in the management of moderate to severe pain in adults, has led us to conduct a trial of this analgesic in children following tonsillectomy. Children were randomized to receive intramuscular (i.m.) ketorolac (1 mg/kg, EXP group, n = 45) or saline (CTL group, n = 42) at the completion of surgery. Intravenous (i.v.) fentanyl (0.5 μg/kg/dose) was administered in repeated doses postoperatively. Pain intensity was measured using both the Oucher and the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) to allow for comparison between self-report and behavioral measures of pain intensity. Severity of postoperative bleeding was measured using a 4-point rating scale. The EXP group had a significant reduction in total fentanyl dose (mean: 35.9 μg) compared to the CTL group (mean: 48.3 μg, t = −2.21, P < 0.03). There was a statistically significant decrease in pre-fentanyl CHEOPS scores in the Post-Anesthesia Care Unit (PACU) in the ketorolac group ( F (2,30) = 5.34, P < 0.01), but not in the saline group ( F (2.24) = 2.46, P > 0.05). In the first hour postoperatively, the CHEOPS demonstrated significant decreases in pain intensity scores in response to opioids, in both groups. In the PACU, children were unable to provide a self-report of pain intensity potentially due to a variety of factors (e.g., emergence delirium, agitation, excitement, sedation, and/or pain). However, during the remainder of the postoperative stay, the photographic scale of the Oucher was a more valid measure of pain intensity than the CHEOPS. There were no differences between the 2 groups in the severity of postoperative bleeding. Children in the EXP group were discharged significantly earlier (i.e., 30 min, t = −2.22, P < 0.03). Our data demonstrate that i.m. administration of ketorolac, at the end of surgery, significantly reduces opioid requirements and shortens length of stay without any evidence of increased bleeding. In addition, our data suggest that the patient's altered level of consciousness and attention span may diminish the utility of self-report measures of pain intensity in the immediate postoperative period.