Definition
• Yellowish discoloration of the skin/tissue/body fluids caused by ↑ bilirubin production or ↓ excretion
Approach
• Bilirubin: Formed from degradation of hemoglobin → bound to albumin in blood (unconjugated/indirect) → conjugated in liver by glucuronyltransferase (conjugated/direct) → excreted in bile
History
• Differential depends on age (neonates ≤4 wk), gestational age, breast-feeding status
• Time of onset of sx: Yellowing of skin, dark urine
Physical Findings
• Scleral icterus, jaundice
Labs
• Total/fractionated bilirubin (visible >5 mg/dL in neonates), LFTs, CBC (hemolysis/anemia → Coombs test, smear, ABO/Rh type), reticulocyte count, serum haptoglobin
• Neonates → unconjugated (can be physiologic, treat to prevent kernicterus)/conjugated (always pathologic)
PHYSIOLOGIC JAUNDICE
Definition
• Elevated unconjugated bilirubin in the 1st wk of life, 60% newborns will be jaundiced (peaks 2–5 d), due to low activity of glucuronyltransferase
Evaluation
• Total/fractionated bilirubin, CBC (hemolysis/anemia → Coombs test, smear, ABO/Rh type), total bilirubin usually <6 mg/dL, up to 12 mg/dL in premature infants
Treatment
• No tx necessary
Disposition
• Home
Pearls
• Pathologic: In the 1st 24 h of life, peak >17 mg/dL in breast-fed/>15 mg/dL in formula-fed infants, persists beyond 1st wk of life, ↑ bilirubin >5 mg/dL/d
• Cx of severe hyperbilirubinemia: kernicterus (bilirubin deposition in basal ganglia → neurodevelopmental deficits)
• Sepsis can rarely present as jaundice
BREAST-FEEDING JAUNDICE
Definition
• ↑ unconjugated bilirubinemia in breast-fed infants possibly due to hormonal mediators or altered intestinal secretion/absorption of bile, early onset after birth
Evaluation
• Total/fractionated bilirubin, CBC
Treatment
• No tx necessary if bilirubin <17 mg/dL, continue breast feeding, phototherapy
Disposition
• Home
BREAST MILK JAUNDICE
Definition
• Due to substances in breast milk that prevent conjugation & excretion of bilirubin. Occurs after 3–5 d of life, persists for weeks.
Evaluation
• Total/fractionated bilirubin, CBC
Treatment
• If bilirubin <17 mg/dL, continue breast feeding, phototherapy
• If >17 mg/dL, stop breast feeding, will not recur when resumed
Disposition
• Home
ABO AND RH INCOMPATIBILITY/HEMOLYTIC DISEASE
Definition
• Hemolytic dz caused by maternal antibodies against fetal A or B type proteins or maternal Rh antibodies (sensitized from previous pregnancy) against Rh-positive fetus (Rh incompatibility)
History
• Yellowing of skin w/i 1st 24 h of life, dark urine, lethargy
Physical Findings
• Severe jaundice, scleral icterus, ill appearing
Evaluation
• Total/fractionated bilirubin, CBC (hemolysis/anemia → Coombs test, smear, ABO/Rh type)
Treatment
• Phototherapy, exchange transfusion (see table)
Disposition
• Admit
CONJUGATED HYPERBILIRUBINEMIA
Definition
• Pathologic increase in direct bilirubin leading to jaundice (conjugated bilirubin >20% of total, or >2 mg/dL)
History
• Yellowing of skin, dark urine, lethargy, ±genetic syndrome/metabolic syndromes/sepsis
Physical Findings
• Severe jaundice, scleral icterus, ill appearing
Evaluation
• Total/fractionated bilirubin, CBC, blood cultures, blood smear, LFTs, blood type, KUB if signs of obstruction, U/S: Biliary obstruction, UA, Ucx
Treatment
• Hydration, tx based on cause (see below)
Disposition
• Admit
