Risk factors and outcomes for hyperbilirubinaemia after heart surgery in children

INTRODUCTION: Liver dysfunction, associated with morbidity and mortality, is common in patients with CHD. We investigate risk factors for and outcomes of hyperbilirubinaemia in neonates and infants after cardiac surgery. MATERIALS AND METHODS: In a retrospective analysis of neonates and infants undergoing cardiac surgery at our institution between January 2013 and December 2017, we identified those with post-operative conjugated hyperbilirubinaemia. We tested various demographic and surgical risk factors, and use of post-operative interventions, for an association with conjugated hyperbilirubinaemia. We also tested hyperbilirubinaemia for association with post-operative mortality and prolonged length of stay. RESULTS: We identified 242 post-operative admissions, of which 45 (19%) had conjugated hyperbilirubinaemia. The average conjugated bilirubin level in this group was 2.0 mg/dl versus 0.3 mg/dl for peers without hyperbilirubinaemia. The post-operative use of both extracorporeal membrane oxygenation (OR 4.97, 95% CI 1.89-13.5, p = 0.001) and total parenteral nutrition (OR 2.98, 95% CI 1.34-7.17, p = 0.010) was associated with conjugated hyperbilirubinaemia. No demographic variable analysed was found to be a risk factor. Hyperbilirubinaemia was associated with higher odds of mortality (OR 3.74, 95% CI 2.69-13.8, p = 0.005) and prolonged length of stay (OR 2.87, 95% CI 2.02-7.97, p = 0.005), which were independent of other risk factors. DISCUSSION: We identified the post-operative use of total parenteral nutrition and extracorporeal membrane oxygenation as risk factors for hyperbilirubinaemia. These patients were more likely to experience morbidity and mortality than control peers. As such, bilirubin may be marker for elevated risk of poor post-operative outcomes and should be more frequently measured after cardiac surgery.