Low-dose ketorolac improves analgesia and reduces morphine requirements following posterior spinal fusion in adolescents

Abstract

Purpose: To determine if low-dose ketorolac would improve analgesia while minimizing unwanted side effects in adolescents following posterior spinal fusion (PSF).

Methods: A prospective randomized double-blind placebo-controlled trial assessed the analgesic effects of low-dose ketorolac following PSF. Thirty-five adolescents aged 11-17 yr were randomly assigned to receive placebo or 0.5 mg x kg(-1) ketorolac (maximum of 15 mg) six hourly postoperatively for 36 hr in conjunction with standard morphine patient controlled analgesia (PCA). Pain and sedation were assessed twice daily for the first three postoperative days (POD). The incidence of side effects related to both non-steroidal anti-inflammatory agents and opioids were recorded.

Results: Adolescents in the ketorolac group received an average dose of 0.2 mg x kg(-1) (average exposure 1.2 mg x kg(-1)), had lower pain scores on POD one and two (P < 0.05) and consumed less morphine in the postanesthesia care unit and on POD two. There was no difference in the incidence of pruritus, nausea, vomiting or constipation, but patients in the ketorolac group tolerated activity better on POD one (P < 0.05). There were no differences between groups with regard to postoperative blood loss or transfusion requirements. Fourteen patients were followed for two years and the incidence of curve progression, hardware failure or back pain at final follow-up was not different.

Conclusion: Low-dose ketorolac in conjunction with morphine PCA improved the quality of analgesia and reduced morphine requirements following PSF compared to placebo without increasing the incidence of non-steroidal anti-inflammatory side effects.