Intraoperative Methadone Versus Other Opioids: A Retrospective Review of Postoperative Outcomes in Pediatric...

Findings of randomized controlled trials indicate that intraoperative methadone administration reduces postoperative pain and opioid consumption compared to other opioids in many patient populations. While concerns about potential risks persist, large retrospective studies may be able to assess risks from methadone versus other opioids. Recent retrospective studies in adult patients found no association between methadone administration and adverse outcomes. Similar studies in pediatric patients are lacking. This retrospective study investigates the association of intraoperative methadone with postanesthesia care unit (PACU) pain scores and other relevant postoperative outcomes compared to other opioids.

We conducted a retrospective cohort study of pediatric patients (≤18 years of age) undergoing 1 of 6 surgeries from January 1, 2018 to February 29, 2024: spinal fusion for scoliosis, laparoscopic sleeve gastrectomy, bilateral mastectomy with nipple reconstruction, knee surgeries, Nuss repair for pectus excavatum, and cleft palate repair. The primary outcome was maximum PACU pain scores in patients receiving intraoperative methadone versus other opioids. Secondary outcomes were the incidence of moderate-severe PACU pain, opioid consumption, naloxone administration, emergence delirium, postoperative nausea and vomiting (PONV), and PACU length of stay (LOS). Results were analyzed using regression models, controlled for appropriate variables including procedure, age, sex, American Society of Anesthesiologists (ASA) score, body mass index (BMI), the number of pre/intraoperative adjuvants, and the use of regional anesthesia. Predefined subgroup analyses were conducted to compare patients who received methadone versus other opioids in the setting of (1) receiving preincision regional anesthesia; (2) receiving an intraoperative remifentanil infusion; and (3) in the methadone group, receiving a methadone dose ≥0.15 mg kg -1 .

1794 patients were included; 528 received methadone. Patients receiving methadone had a lower maximum PACU pain score (3.9 [95% confidence interval {CI}, 3.6-4.2] vs 4.5 [95% CI 4.3-4.6]; P = .007), decreased PACU opioid consumption (0.06 vs 0.09 MEU kg -1 ; P < .001), decreased emergence delirium (9.60% vs 16.90%; P < .001), and no statistically significant difference in naloxone administration, PONV, and PACU LOS compared to the other-opioid group.

In this large, single-center retrospective study, intraoperative methadone administered to pediatric patients was found to be associated with reduced postoperative pain scores, opioid consumption, and emergence delirium. Larger studies are needed to achieve the necessary power to assess adverse events in pediatric surgical patients who receive methadone versus other opioids.