Ketorolac analgesia for inguinal hernia repair is not improved by peripheral administration

Abstract

It has been suggested that ketorolac, a non-steroidal anti-inflammatory drug (NSAID) available for parenteral use, may result in prolonged (24 hr) postoperative analgesia through a peripheral mechanism when added to local anesthetic infiltration. Our objective was to assess this effect by controlling for systemic absorption of the drug. This randomized, double-blind trial studied 40 men undergoing elective inguinal hernia repair under spinal anesthesia. All patients received 19 mL of lidocaine 1% infiltrated in the operative field before incision. Patients were randomized into two groups of 20. The surgical site group received ketorolac 30 mg added to the lidocaine infiltration. In the control group, ketorolac 30 mg was injected subcutaneously in the contralateral abdominal wall. Numeric rating scores (0-10) of pain at rest and with movement were recorded at the time of discharge from the recovery room and at 24 hr postoperatively. Time to first analgesia, postoperative iv morphine use, total time in the recovery room, and total oral analgesic use in the first 24 hr were also compared. There were no significant differences between groups with respect to any of the measured variables. In both groups, pain scores were low at rest (1.9 +/- 1.4 vs 2.2 +/- 1.8, surgical site and systemic groups, respectively) and moderate with movement (5.3 +/- 2.2, 5.0 +/- 1.8) after anesthetic recovery. Pain scores were similar at 24 hr (1.1 +/- 1.3, 1.9 +/- 1.6 at rest; 5.7 +/- 2.0, 6.2 +/- 2.2 with movement). Adding ketorolac to lidocaine infiltration for hernia repair does not improve or prolong postoperative analgesia compared to systemic administration.