Intraoperative Methadone in Adult Cardiac Surgical Patients and Risks for Postoperative QTc Prolongation

Abstract

Objectives: To evaluate the effect of intraoperative intravenous methadone within a standardized enhanced recovery after cardiac surgery pathway on the perioperative corrected QT interval (QTc).

Design: Retrospective cohort study.

Setting: Cardiac surgical patients from a tertiary academic medical institution.

Participants: Eligible 1,040 adult patients undergoing elective cardiac surgery from July 2020 through July 2023 using validated institutional electronic medical record data INTERVENTIONS: Patients were administered intravenous methadone (0.1 mg/kg) or received analgesics other than intravenous methadone as part of an enhanced recovery after cardiac surgery pathway.

Measurements and main results: The primary outcomes were change in QTc and the percent QTc change between preoperative QTc and postoperative QTc upon intensive care unit admission. Secondary outcomes include postoperative ventricular arrhythmias, postoperative atrial fibrillation, intensive care unit length of stay, 30-day mortality, 1-year mortality, and mortality days from surgery. Out of a total of 1,040 patients, 423 received intraoperative methadone and 617 did not receive methadone. Methadone QTc mixed models demonstrated that QTc is prolonged immediately postoperatively and normalized 24 hours after surgery in both methadone and nonmethadone groups. There were no significant differences in baseline QTc, immediate postoperative QTc, changes in QTc, or percent change in QTc between the methadone and nonmethadone groups. There were no significant differences in ventricular or atrial arrhythmias, 30-day mortality, 1-year mortality, or days to death.

Conclusions: A single intraoperative intravenous methadone dose did not prolong the QTc significantly or increase the incidence of arrhythmias and may be safe in adult cardiac surgical patients.

Keywords: QTc prolongation; cardiac risk; cardiac surgery; intraoperative methadone; opioid analgesia; perioperative care; postoperative pain.