Intraoperative Intravenous Methadone and Postoperative Opioid Requirements in Adult Patients With Burns

Postoperative pain management is a significant challenge in patients undergoing burn excision. Pharmacologic pain management strategies include both opioid and non-opioid medications. Given the national overuse of opioids and the associated negative effects, it is prudent and essential to find ways to manage pain with fewer or no opioids. We hypothesize that intraoperative administration of intravenous methadone reduces total morphine milligram equivalents per weight used in the 36 h following surgery. This is a retrospective, single-center cohort study of adult burn patients who underwent a first excision of full thickness burn between January 2019 and January 2021. One group received intraoperative intravenous methadone while the non-exposure group did not. The primary outcome was total morphine milligram equivalents per weight utilized in the 36 h following surgery. Secondary outcomes included average pain scores in the post-anesthesia care unit and for 36 h postoperatively, as well as discharge opioid prescriptions. The methadone group contained 104 subjects, and the non-exposure group contained 119 subjects. Poisson regression, with adjustment for covariates, showed that the methadone group required fewer 36-h postoperative opioids (IRR = 0.89, P = .447) and were discharged with fewer opioid prescriptions (IRR = 0.86, P = .363) independent of the age and %TBSA differences. Post-anesthesia care unit pain scores were lower in the methadone group (IRR = 0.91, P = .350), as were 36-h postoperative pain scores (IRR = 0.92, P = .310). These trends toward improved pain control and reduced opioid requirements in patients receiving intraoperative, intravenous methadone did not reach statistical significance. Prospective, adequately powered randomized studies are needed to advance these findings.