Evaluating Respiratory Safety of Intraoperative Methadone -- A Comparative Analysis

Background: Methadone is widely used as a perioperative analgesic due to its long-lasting pain relief and multimodal mechanism of action. Despite its advantages, there are concerns regarding its potential for respiratory depression (RD) and excessive sedation postoperatively. Objective: To compare the incidence of postoperative naloxone administration between patients receiving intraoperative methadone and those receiving intraoperative morphine, and to evaluate the duration of stay in the postanesthesia care unit (PACU) as an indicator of excessive sedation. Design: Retrospective cohort study conducted at Aarhus University Hospital, Denmark. Participants/Methods: Adult surgical patients (aged ≥18 years) between March 2019 and March 2023 were included. A total of 14,522 patients were analyzed, with 2437 receiving intraoperative methadone and 12,085 receiving intraoperative morphine. Logistic regression was used to assess the odds of naloxone administration within 24 hours postoper more...