Neonatal Jaundice

Question 1

what is neonatal jaundice?

Answer 1

Elevated total serum bilirubin
w/ clinical features of jaundice

Question 2

tell me about etiologies and how unconjugated hyperbilirubinemia occurs

Answer 2

can be physiological where its simply due to the fetus having more RBCs with a shorter lifespan so more break down into bilirubin, and the liver not being efficient enough to conjugate it as it is being produced

pathological reasons could be
- genetics: UGT enzyme deficiency or defect
- hemolytic anemia - immune or not immune
- sepsis
- hemoglobinopathies: thalassemia

other:
- congenital hypothyroidism
- fetal macrosomia
- breastmilk jaundice - protein in the milk stops conjugation
- breast-feeding jaundice - not enough nutrition from feeding

Question 3

tell me about etiologies and how conjugated hyperbilirubinemia occurs

Answer 3

is always pathological
a hepatobiliary issue

• biliary atresia
• increased enterohepatic circulation, more bilirubin is being recycled vs excreted
• infections - HIV, CMV
• genetics

Question 4

how do you ix neonatal jaundice

Answer 4

1. universal screening with transcutaneous scan for bili
2. if suspect, do total serum bilirubin - see conjugated vs unconjugated
3. do other ix for potential etiologies

• hemolytic anemia - LDH, CBC, DAT, maternal/fetal blood types, reticulocyte counts
• genetics - genetic testing for inborn errors of metabolism
• imaging for structural defects
• liver enzymes: ALT/ALP/GGT and albumin and PT/INR
• TORCH titers
• other infectious cultures/titers
• liver biospy

Question 5

how do you tx neonatal jaundice?

Answer 5

1. wait and watch
2. phototherapy - unconjugated bili only
3. exchange transfusion
4. tx underlying cause
   - IVIG - immune hemolytic anemia
   - structural - fix it
   - infectious - abx
   - liver transplant

Question 6

what are some complications of unconjugated jaundice?

Answer 6

spectrum of bilirubin-induced neurologic disorders (BIND)
acute bilirubin encephalopathy: poor feeding, lethargy, hypotonia (↓ muscle tone) and muscle contractions, or frank seizures

kernicterus (chronic bilirubin encephalopathy): hypotonia, exaggerated deep tendon reflexes, obligatory tonic neck reflexes, delayed motor milestones

Question 7

what are some cx of conjugated jaundice?

Answer 7

vitamin deficiencies of vitamin DEAK (lipid soluable) - failure to thrive

Question 8

what are some red flag s/s for neonatal jaundice?

Answer 8

S/s of bilirubin encephalopathy: poor feeding, lethargy, altered sleep, abnormal tone, seizures, high pitched cry, s/s of hemolysis (pallor, anemia, tachycardia), dehydration (dry mucous membrane, sunken fontanelle), fever

Question 9

how is bilirubin broken down/produced?

Answer 9

RBC destruction → release of heme → degraded into unconjugated (indirect) bilirubin → taken to liver by carrier protein ➔ hepatocytes convert it into conjugated (direct) bilirubin via UDP-glucuronosyltransferase → excreted into bile to feces or to be excreted via urine

a portion is also reabsorbed into the liver