Range of NICU Practice in England and Wales Regarding Thresholds for Neonatal Conjugated Hyperbilirubinaemia and Relevant Investigations

Abstract

Objectives and Study: Conjugated jaundice is not an uncommon problem in a neonatal intensive care setting and is generally seen as a reversible complication of prolonged parenteral nutrition. However, several investigations are performed to exclude underlying liver disease. Opinion differs on diagnostic value of such investigations. The aim of the study was to evaluate practice related to investigation of conjugated jaundice in neonatal units across England and Wales. Methods: Questionnaire survey of lead neonatal consultants from all neonatal units in England and Wales. Questions included definition of conjugated jaundice, bilirubin cutoff that prompted investigations and tests performed. Clinicians were also requested to give their opinion on the yield from these investigations. Results: 102/194 neonatal units (52%), responded to the survey of which 33 were level 3 units, 50 level 2 and 19 level 1 units. 96 units (94%) performed conjugated jaundice screen and 6 units (6 %) did not. 77 units (75%) had a written policy. 49% of responders defined conjugated jaundice as conjugated bilirubin >20% of total bilirubin and 46% as >15% of total bilirubin and 5% of units did not have a clear definition. Conjugated bilirubin levels that prompted investigations varied between units with 28 (30%) using conjugated bilirubin >20% of total, 33(36%) a conjugated bilirubin >15% of total and 20 (21%) with no definite threshold. Majority (>76%) of units performed liver and thyroid function tests, Galactosaemia screen, a-1 antitrypsin and liver ultrasound. In addition to above investigations, 65% of units performed urine culture and hepatitis serology, 32% performed urine organic acids, NH3 and lactate. 19 units performed CF genetics and 23 HIDA scan. 71% of responders (which included 2 out of 3 neonatal units with in-house paediatric hepatology services) thought "diagnostic yield" from these tests were "poor" and 44% based this on their personal view, 29% on local data and 27% on anecdotal evidence. Conclusion: Our study identified a wide variation in definition and investigation of conjugated jaundice in neonates. Most neonatal pediatricians believe yield from these investigations is poor. Further studies are needed to support or refute this view. National consensus guidelines are required to standardize practice.