Opioid Weaning Protocol Using Morphine Compared With Nonprotocolized Methadone Associated With Decreased Dose and Duration of Opioid After Norwood Procedure

Pediatr Crit Care Med. 2022 May 1;23(5):361-370. doi: 10.1097/PCC.0000000000002885. Epub 2022 Jan 5.


Objectives: Opioids are used to manage pain, comfort, maintain devices, and decrease oxygen consumption around Norwood palliation (NP), but in high dose and prolonged exposure, they increase risk of tolerance and iatrogenic withdrawal syndrome (IAWS). Variability in practice for IAWS prevention potentially increases opioid dose and duration. We hypothesize that protocolized weaning with morphine (MOR) versus nonprotocolized methadone (MTD) is associated with reduction in opioid exposure.

Design: A before-versus-after study of outcomes of patients weaned with protocolized MOR versus nonprotocolized MTD including subset analysis for those patients with complications postoperatively. Primary endpoints include daily, wean phase, and total morphine milligram equivalent (MMEq) dose, duration, and, secondarily, length of stay (LOS).

Setting: Quaternary-care pediatric cardiac ICU.

Patients: Neonates undergoing single-ventricle palliation.

Interventions: Introduction of IAWS prevention protocol.

Measurements and main results: Analysis included 54 patients who underwent the NP in 2017-2018 including the subset analysis of 34 who had a complicated postoperative course. The total and wean phase opioid doses for the MTD group were significantly higher than that for the MOR group: 258 versus 22 and 115 versus 6 MMEq/kg; p < 0.001. Duration of opioid exposure was 63 days in the MTD group and 12 days in MOR group (p < 0.001). Subanalysis of the complicated subset also identifies higher total and wean dose for MTD group (293 vs 41 and 116 vs 7 MMEq/kg; p < 0.001) with a longer duration (65 vs 22 days; p = 0.001). Within the subset, LOS was 55% longer in the MTD group than that in the MOR group (150 vs 67 d; p = 0.01) and not different in the uncomplicated group.

Conclusions: After complex NP, a protocolized opioid weaning using MOR versus MTD is associated with 65% shorter opioid duration, 10-fold decreased dose, and shortened LOS.

MeSH terms

  • Analgesics, Opioid / therapeutic use
  • Child
  • Humans
  • Infant, Newborn
  • Methadone / therapeutic use
  • Morphine / therapeutic use
  • Norwood Procedures* / adverse effects
  • Substance Withdrawal Syndrome*


  • Analgesics, Opioid
  • Morphine
  • Methadone