Intravenous Ketorolac Substantially Reduces Opioid Use and Length of Stay After Lumbar Fusion: A Randomized Controlled Trial

Study Design. A randomized, double-blinded, placebo-controlled trial.Objective. To examine the effect of intravenous ketorolac (IV-K) on hospital opioid use compared with IV-placebo (IV-P) and IV acetaminophen (IV-A).Summary of Background Data. Controlling postoperative pain while minimizing opioid use after lumbar spinal fusion is an important area of study.Patients and Methods. Patients aged 18 to 75 years undergoing 1 to 2 level lumbar fusions between April 2016 and December 2019 were included. Patients with chronic opioid use, smokers, and those on systemic glucocorticoids or contraindications to study medications were excluded. A block randomization scheme was used, and study personnel, hospital staff, and subjects were blinded to the assignment. Patients were randomized postoperatively. The IV-K group received 15 mg (age > 65) or 30 mg (age < 65) every six hours (q6h) for 48 hours, IV-A received 1000 mg q6h, and IV-P received normal saline q6h for 48 hours. Demographic and surgical details, opioid use in morphine milliequivalents, opioid-related adverse events, and length of stay (LOS) were recorded. The primary outcome was in-hospital opioid use up to 72 hours.Results. A total of 171 patients were included (58 IV-K, 55 IV-A, and 58 IV-P) in the intent-to-treat (ITT) analysis, with a mean age of 57.1 years. The IV-K group had lower opioid use at 72 hours (173 +/- 157 mg) versus IV-A (255 +/- 179 mg) and IV-P (299 +/- 179 mg; P = 0.000). In terms of opiate use, IV-K was superior to IV-A (P = 0.025) and IV-P (P = 0.000) on ITT analysis, although on per-protocol analysis, the difference with IV-A did not reach significance (P = 0.063). When compared with IV-P, IV-K patients reported significantly lower worst (P = 0.004), best (P = 0.001), average (P = 0.001), and current pain (P = 0.002) on postoperative day 1, and significantly shorter LOS (P = 0.009) on ITT analysis. There were no differences in opioid-related adverse events, drain output, clinical outcomes, transfusion rates, or fusion rates.Conclusions. By reducing opioid use, improving pain control on postoperative day 1, and decreasing LOS without increases in complications or pseudarthrosis, IV-K may be an important component of "enhanced recovery after surgery" protocols.