Clinical and Economic Outcomes Associated With Postoperative Intravenous Ketorolac Use After Posterolateral Lumbar Fusion: A Retrospective Cohort Study

Abstract

Background: Intravenous ketorolac is commonly used as part of multimodal analgesia following posterolateral lumbar fusion. However, evidence regarding its clinical and economic outcomes in patients undergoing posterolateral lumbar fusion remains limited.

Objective: To compare the clinical and economic outcomes between patients who received postoperative intravenous ketorolac and those who did not receive ketorolac following posterolateral lumbar fusion.

Methods: A retrospective cohort study was conducted by reviewing medical records of patients who underwent lumbar fusion surgery at Surin Hospital between 1^st. January 2020 and 31^st. December 2025. Patients who received intravenous ketorolac 30 mg every 12 hours postoperatively were compared with those who did not receive ketorolac. Outcomes of interest included postoperative pain scores, blood loss, length of hospital stay, and treatment costs.

Results: A total of 127 patients were included in the study, comprising 82 patients in the ketorolac group and 45 patients in the control group. After adjustment for potential confounders, no significant differences were observed in postoperative pain scores, intraoperative blood loss, or postoperative drain output. However, the ketorolac group had a significantly shorter postoperative length of stay by 0.88 days p = 0.049 and lower total treatment costs by 8,299 THB p = 0.002 compared with the control group.

Conclusion: Short-course postoperative intravenous ketorolac after posterolateral lumbar fusion was not associated with significant differences in postoperative pain or blood loss. Although shorter postoperative hospitalization and lower treatment costs were observed, these associations should be interpreted cautiously given the retrospective study design.