Postoperative breakthrough pain in paediatric cardiac surgery not reduced by increased morphine concentrations

• Published in: Pediatric research 2021-12, Vol.90 (6), p.1201-1206
• Main Authors: de Hoogd, Sjoerd, Goulooze, Sebastiaan C., Valkenburg, Abraham J., Krekels, Elke H. J., van Dijk, Monique, Tibboel, Dick, Knibbe, Catherijne A. J.
• Format: Article
• Language: English
• Subjects: Analgesics, Opioid - administration & dosage; Breakthrough Pain - drug therapy; Child; Clinical Research Article; Dose-Response Relationship, Drug; Female; Heart surgery; Humans; Male; Medicine; Medicine & Public Health; Morphine; Morphine - administration & dosage; Pain; Pain, Postoperative - drug therapy; Pediatric Surgery; Pediatrics
• ISSN: 0031-3998; 1530-0447
• DOI: 10.1038/s41390-021-01383-z

Background Morphine is commonly used for postoperative analgesia in children. Here we studied the pharmacodynamics of morphine in children after cardiac surgery receiving protocolized morphine. Methods Data on morphine rescue requirements guided by validated pain scores in children ( n  = 35, 3–36 months) after cardiac surgery receiving morphine as loading dose (100 μg kg −1 ) with continuous infusion (40 μg kg −1  h −1 ) from a previous study on morphine pharmacokinetics were analysed using repeated time-to-event (RTTE) modelling. Results During the postoperative period (38 h (IQR 23–46)), 130 morphine rescue events (4 (IQR 1–5) per patient) mainly occurred in the first 24 h (107/130) at a median morphine concentration of 29.5 ng ml −1 (range 7–180 ng ml −1 ). In the RTTE model, the hazard of rescue morphine decreased over time (half-life 18 h; P