Intraoperative ketorolac dose of 15 mg versus the standard 30 mg on early postoperative pain after spine surgery: A randomized, blinded, non-inferiority trial

Abstract Study objective The primary aim of this study is to show the non-inferiority of 15 mg intraoperative dose of ketorolac as compared to the standard 30 mg ketorolac by looking at the visual analog scale pain (VAS) scores 4 h after an adult spine surgery. Design The study design is a prospective randomized non-inferiority clinical trial looking at non-inferiority of intraoperative 15 mg ketorolac from the standard 30 mg dose. Setting Quaternary care center. Patients 50 adult (18–65 years of age) undergoing lumbar decompression spine surgery. Interventions Group A received a single intraoperative dose of 15 mg ketorolac at the end of surgery and group B received single intraoperative dose of 30 mg ketorolac. Measurements The primary outcome was the visual analog scale (VAS) pain scores 4 h after an adult spine surgery. Secondary measures were morphine usage in the first 8 and 24 h postoperatively, numeric rating scores (NRS) up to 24 h, sedation, nausea, vomiting, respiratory depression, pruritus and bleeding complications. Main results Intention to treat analysis showed a mean increase in 4 h VAS pain score of 7.9 mm (95% CI: − 4.5 mm to 20.4 mm) in patients administered 15 mg ketorolac. This difference was neither statistically (P = 0.207) nor clinically significant (< 18 mm on VAS scale). A similar increase in the 15 mg group was noted through a per protocol analysis, 6.9 mm (95% CI: − 6.6 mm to 20.5 mm, P = 0.307) greater in the 15 mg group. Non-inferiority of 15 mg was not confirmed. No significant difference was found in secondary endpoints. Conclusions Ketorolac 30 mg intravenous was not superior to 15 mg intravenous for post-operative pain management after spine surgery. However, 15 mg failed to meet the pre-specified criteria for non-inferiority to the 30 mg dose.