Cannabis Use Is Associated With Increased Use of Prescription Opioids Following Posterior Lumbar Spinal Fusion Surgery.

Abstract

Retrospective review. Cannabis is an antinociceptive which has been evaluated as a possible adjunct or substitute for opioid use in the treatment of acute pain. The aim of this study was to evaluate the association between preoperative cannabis usage and consumption of opioids for postoperative analgesia. Patients who underwent one- or two-level posterior lumbar fusion surgery were categorized as cannabis users or non-cannabis users based on preoperative diagnoses of cannabis use. Total morphine equivalent dose was calculated for both in-house opioid consumption and postoperative prescription opioid usage. Age, ASA, BMI, depression, tobacco use, estimated blood loss, OR time, LOS, disposition to rehab, 30-day readmission, in-house opioid consumption and postoperative prescription opioid usage were compared between groups using t-tests. Of the 220 opioid naïve patients, 29 (13%) patients were identified as cannabis users while 191 (87%) were non-cannabis users. There were no significant associations between opioid naïve cannabis usage and ASA, BMI, tobacco use, EBL, OR time, LOS, disposition to rehab, or readmission. Opioid naïve cannabis users had greater association with depression (31.3% vs 13.7%, P=.017) and younger age (56.37 years vs 65.37 years, P<.001). Interestingly, cannabis use was associated with a lower Charlson Comorbidity Index (CCI), with 1.38 vs 2.49 (P=.002). Cannabis users were found to have increased postoperative prescription opioid usage (2545.41 POST-MED vs 1379.72 POST-MED, P=.019). Cannabis usage is associated with increased usage of opioids postoperatively, both while in-patient and post-discharge, after posterior lumbar spinal fusion surgery.