SPLIT (FRACTIONATED) BILIRUBIN AND CHOLESTASIS ASSESSMENT (NO DRUG THERAPY)
Prolonged neonatal jaundice - disease-level clinical article (prolonged-neonatal-jaundice-full.txt)
Jaundice that outlasts two weeks is a laboratory question before it is anything else. The biliary atresia article sets the trigger: past 14 days, jaundice should not be called physiological, and it needs prompt evaluation for cholestatic liver disease. The jaundice article sets the stakes: a conjugated hyperbilirubinaemia in an infant is always pathological, and always points to something medical or surgical underneath. The single test that separates them is the split bilirubin.
- THE TEST IS A SPLIT BILIRUBIN, NOT A TOTAL. A transcutaneous meter cannot read the direct fraction, and it is that fraction the diagnosis of neonatal cholestasis turns on. (Neonatal Jaundice - StatPearls - NCBI Bookshelf, NBK532930) A transcutaneous reading, or a total serum bilirubin on its own, cannot answer this question.
- WHAT A RAISED DIRECT FRACTION MEANS - the biliary atresia article's laboratory picture is a conjugated hyperbilirubinaemia, with the total and the direct bilirubin both up. (Biliary Atresia - StatPearls - NCBI Bookshelf, NBK537262)
- Suspect neonatal cholestasis readily, read the split bilirubin, the liver enzymes and the imaging without delay, and get the baby to paediatric surgery and hepatology quickly. (Biliary Atresia - StatPearls - NCBI Bookshelf, NBK537262)
- THE REST OF THE WORKUP, as the jaundice article sets it out: the serum aminotransferases can show injury to the hepatocytes where the hyperbilirubinaemia is conjugated; a raised alkaline phosphatase and GGT point to obstruction in the biliary channels; and the prothrombin time (PT), the international normalised ratio (INR) and the serum albumin are the measures of what the liver is still synthesising and how it is functioning. (Neonatal Jaundice - StatPearls - NCBI Bookshelf, NBK532930)
- ASK ABOUT THE NAPPY AND THE URINE - the assessment of a jaundiced newborn opens with a careful history: what complicated the pregnancy, what runs in the family, how the delivery went, when the symptoms started, whether feeding is going well, and the mother's serology. The colour of the stool and of the urine can itself indicate which kind of jaundice this is. (Neonatal Jaundice - StatPearls - NCBI Bookshelf, NBK532930)
- NO PHOTOTHERAPY DOSE IS PRINTED HERE. Unconjugated hyperbilirubinaemia is treated principally by phototherapy and by exchange transfusion - both given as an inpatient, both dosed off a nomogram, and neither a primary-care prescription. A baby who needs them needs a hospital.
- Prolonged jaundice with a NORMAL split bilirubin still needs an explanation. The article's causes of unconjugated jaundice include hypothyroidism present from birth; the sulfa drugs, ceftriaxone and the penicillins; obstruction of the intestine and pyloric stenosis; jaundice of breast milk; and simply not taking enough at the breast. (Neonatal Jaundice - StatPearls - NCBI Bookshelf, NBK532930) Check the newborn thyroid screen before calling it breast-milk jaundice.