Naloxone Continuous Infusion for Spinal Cord Protection in Endovascular Aortic Surgery Leads to Higher Opioid Administration and More Pain

•The purpose of this study was to assess postoperative opioid requirements in patients receiving naloxone continuous infusion as part of a multimodal regimen used to prevent spinal cord ischemia in patients undergoing aortic aneurysm repair.•This was a single-center, retrospective cohort review of 95 patients; 43 received naloxone continuous infusion while 52 patients were in the non-naloxone group.•In our study, patients receiving naloxone continuous infusion to prevent spinal cord ischemia required greater quantities of opioids and had higher postoperative pain scores during the immediate postoperative period compared to patients not requiring naloxone. Compare total perioperative opioid use in patients receiving naloxone continuousinfusion (NCI) for spinal cord ischemia prophylaxis, versus patients not receiving NCI, in endovascular aortic repair. Single-center, retrospective cohort review. Academic medical center. Patients undergoing elective thoracic, thoracoabdominal, or abdominal aortic endovascular repair. Patients were separated based on the use of naloxone continuous infusion as part of a spinal protection protocol. Primary endpoint was opioid requirements, in milligram morphine equivalents (MME), during the first 48 hours or during NCI. Secondary endpoints included: postoperative pain scores during the same interval; opioid requirements during hours 48 to 72; and pain scores during hours 48 to 72. Ninety-five procedures were included; 43 received naloxone continuous infusion and 52 patients were in the non-naloxone group. Opioid use from a linear mixed model was elevated across the entire continuum in the naloxone group (18 MMEs, 95% CI 13-24), with the greatest difference seen at the 24-to-48-hour interval (51 MMEs, 95% CI 26-75) after adjustment for age, incisions, and prehospital opioid use. In the naloxone group, pain score estimates were elevated at each postoperative interval of evaluation, with similar adjustment. Across the continuum this was 0.7 higher (95% CI 0.2-1.3); the zero-six-hour and six-to-12-hour intervals were 0.9 (95% CI 0.4-1.4) and 1.2 higher (95% CI 0.7-1.7). Patients receiving anloxone continuous infusion to prevent spinal cord ischemia required greater quantities of opioids and had higher postoperative pain, compared with patients not requiring naloxone.