Safety profile of intraoperative methadone for analgesia after major spine surgery: An observational study of 1,478 patients.

OBJECTIVE

To investigate the incidence of perioperative adverse events in patients receiving intravenous methadone for major spine surgery.

DESIGN

Retrospective review of perioperative records from March 2011 and February 2016.

SETTING

University of Virginia Healthsystem.

PATIENTS: Adult patients undergoing elective spinal fusion of two or more levels.

MAIN OUTCOME MEASURES: Incidence of respiratory depression, time to extubation, hypotension, hypoxemia, reintubation, cardiac complications, and death.

RESULTS

Reviewed 1,478 patient records. Mean intraoperative methadone dose was 0.14 ± 0.07 mg/kg. A total of 1,142 patients (77.4 percent) were extubated in the operating room, 543 (36.8 percent) experienced respiratory depression, 1,180 (79.8 percent) hypoxemia, and 22 (1.5 percent) required reintubation. Cardiac complications included arrhythmias (289 patients, 29.9 percent), QTc prolongation (568 patients, 58.8 percent), and myocardial infarction (16 patients, 1.1 percent). Two in hospital deaths occurred (0.14 percent).

CONCLUSIONS

Mild-moderate respiratory depression is observed following a one-time dose of intraoperative methadone, and monitoring in an appropriate postoperative setting is recommended.