Physiology

* RBC hemoglobin breakdown -> unconjugated (indirect) bilirubin* Unconjugated (indirect) bilirubin -> liver -> conjugated (direct) bilirubin* Conjugated (direct) bilirubin -> Eliminated in stool

Causes of Hyperbilirubinemia

* Increased RBC turnover* Sepsis* Rh incompatibility* RBC disorders* Maternal diabetes* Scalp hematoma* Decreased/slow conjugation by the liver* Peaks around day 5 of life* Congenital liver disorders* Gilbert/Crigler Najjar Syndromes* Breast milk jaundice* Breast milk inhibits conjugation of bilirubin* Decreased excretion* Bowel obstruction* Breast feeding failure (dehydration)* Decreased stool output results in reabsorbed bilirubin

Kernicterus

* Brain damage from severe hyperbilirubinemia (>25 mg/dL)* Compare measured bilirubin to established nomogram* Treatment is phototherapy* (Worst case scenarios require exchange transfusion)

Additional Reading

* Approach to Neonatal Jaundice (emDOCs)