Opioid and Methadone Prescribing for Infants with Surgical Management of Congenital Heart Disease

Opioids are commonly prescribed for infants after congenital heart disease (CHD) surgery, and prolonged exposure can lead to physiologic dependence requiring methadone treatment. The Risk Adjustment for Congenital Heart Surgery-2 (RACHS-2) categorizes operative mortality risk and may also help identify infants at greatest risk for methadone treatment. A retrospective cohort study of infants < 1 year undergoing CHD surgery between 2016-2022 at 48 U.S. children's hospitals using the Pediatric Health Information System was performed. Infants were categorized by RACHS-2 score (1 = lowest, 5 = highest risk). Multivariable hierarchical logistic regression evaluated associations between postoperative opioid days and methadone treatment, including an interaction between RACHS-2 and opioid exposure. Secondary analyses compared postoperative length of stay (LOS), ventilator days, and total parenteral nutrition (TPN) days by methadone status. Among 34,127 infants, higher RACHS-2 scores were associated with longer postoperative opioid exposure (p < 0.001). For infants who received < 17 days of opioids, increasing RACHS-2 scores predicted greater probability of methadone treatment. After 17 days, RACHS-2 score 1 infants had the highest probability of methadone treatment, though they represented a minority. Methadone was independently associated with longer LOS, ventilator days, and TPN days. Higher RACHS-2 scores were associated with increased likelihood of postoperative methadone treatment in the early postoperative period. Methadone treatment was associated with adverse short-term health outcomes. For infants with prolonged opioid exposure, those with lower RACHS-2 scores were more likely receive methadone treatment- highlighting subpopulations that may benefit from targeted opioid stewardship initiatives.