A double blinded randomized clinical trial of perioperative ketorolac 15 mg versus 30 mg, evaluated by visual analog score in orthopedic and ear-nose and throat patients

Abstract

Elisabeth Arndal, Eva Rye Rasmussen, Pernille Vaabengaard

Objective: Ketorolac is a non-steroid anti-inflammatory drug for intravenous use, with analgesic and anti-inflammatory effects and known for its potent influence on moderate to severe postoperative pain. The literature has shown that 30mg i.v. perioperative ketorolac is efficient, well-tolerated and decreases postoperative pain scores. There is no consensus in the literature on whether or not non-steroid anti-inflammatory drugs increase postoperative bleeding. This rare but possibly severe adverse reaction justifies further research into ketorolac dose-dependant postoperative pain scores. The study aims were to evaluate the difference between 15mg and 30mg perioperative i.v. ketorolac on postoperative VAS scores and secondary analgesia consumption after orthopedic or ear, nose and throat surgery. Methods: A comparative double-blinded randomized controlled trial included 69 patients, aged 18-65 years, undergoing ear, nose and throat or orthopedic surgery. Patients were randomized to receive either 15mg or 30mg i.v. ketorolac 30 minutes prior to the end of the surgery. Postoperative pain was recorded at 0, 15, 30, 60 and 90 minutes after arriving at the post-anesthesia care unit. The total amount of supplement analgesia consumed was calculated when the patient left the postoperative care unit or after 90 minutes. Results: A two-sided t-test showed the following: VAS t0: p=0.068 (95% CI 1.564 - 2.780); VAS t15: p=0.078 (95% CI 1.641 - 2.868); VAS t30: p=0.056 (95% CI 1.751 - 3.070); VAS t60: p=0.210 (95% 1.600 - 3.119); and VAS t90: p=0.124 (95% 1.120 - 3.230). The mean postoperative oral morphine equivalent was 9.1mg [5-20 mg] in the 15 mg group and 7.9 mg [2.5-20 mg] in the 30 mg group (two-sided t-test, p=0.526 95% CI -2.21-4.25). Conclusion: Our study demonstrated that 15 mg i.v. perioperative ketorolac exerts the same postoperative pain relief as 30 mg and does not result in a higher secondary analgesia consumption.