Ketorolac for early postoperative analgesia

Study Objective: To determine the efficacy and speed of onset of analgesia of a single dose of intravenous (IV) or intramuscular (IM) ketorolac tromethamine following major orthopedic surgery. Study Design: Double-blind, randomized, placebo-controlled trial. Setting: A district general hospital in England. Patients: 112 patients aged 18 to 80 years suffering moderate or severe pain following orthopedic surgery. Interventions: Patients were randomized to receive 30 mg ketorolac IV, 30 mg ketorolac IM, or placebo following surgery. Measurements and Main Results: Verbal pain intensity scores were performed prior to admission to the study, then frequently for the first 45 minutes following administration of study medication, and subsequently at hourly intervals. Times to request for further analgesia were noted. Patient assessment of overall acceptability and pain relief of the study medication was recorded. There was no statistical difference in speed of onset of analgesia between the ketorolac groups and placebo. Median (range) times to first analgesic following study drugs were: ketorolac IV 45 minutes (9 to 1440 minutes), ketorolac IM 34 minutes (10 to 1440 minutes), placebo 24 minutes (10 to 615 minutes). There was a statistically significant difference between the ketorolac groups and placebo (ketorolac IV vs. placebo, p < 0.01; ketorolac IM vs. placebo, p = 0.03). Patient assessment of overall acceptability and pain relief was significantly better for IV ketorolac compared with placebo ( p < 0.01). By 6 hours, 78% of the IV ketorolac group and 95% of the IM ketorolac and placebo groups required further analgesia. Conclusions: Despite high patient acceptability compared with placebo, the use of ketorolac as the sole analgesic failed to control postoperative pain following major orthopedic surgery. IV administration of ketorolac conferred no advantages over the IM route with regard to efficacy or speed of onset.