Hepatobiliary System

Question 1

What causes increased unconjugated bilirubin

Answer 1

Increased break down of haem
Decreased hepatic uptake of bilirubin
Decreased conjugation by the liver
Increased enterohepatic circulation

Question 2

What causes increased conjugated bilirubin

Answer 2

Decreased hepatic excretion
Bile obstruction
Hepatocyte dysfunction

Question 3

Outline the classification of neonatal jaundice

Answer 3

Early: 1st 24 hours of life (usually bad/pathological)
Intermediate: 2 days to 2 weeks (often due to benign causes)
Late: persists over 2 weeks (bad/pathological)

Question 4

Outline the causes of jaundice in neonates

Answer 4

Early
Haemolytic: ABO incompatibility, RH isoimmunisation, G6P6 deficiency,
Congenital infection

Intermediate
-Physiological: breast feeding jaundice
-Sepsis
-Haemolysis
-Crigler-Najjar syndrome(glucoronyl transferase absent)
-Polycythemia, bruising

Late/Prolonged
Conjugated:
-Biliary atresia
-Choledochal cyst
-Alagille syndrome
-Neonatal hepatitis
-Galactosaemia
-Tyrosinaemia
-Alpha1 antitrypsine deficiency

Unconjugated
-Physiological
-Breastmilk jaundice
-Infection
-Hypotyroidism

Question 5

What is the difference between breastfeeding and breast milk jaundice

Answer 5

Breast feed jaundice is last of effective breastfeeding which causes inadequate milk and calorie intake and results in decreased stooling and increased enterohepatic circulation. Infants may be dehydrated

Breastmilk jaundice is unclear, possibly there are factors that inhibit the enzyme UDGT1. Assc/w East Asian infants who are more likely to have a UGT1A1 mutation and weight loss

Both forms will produce unconjugated hyperbilirubinaemia

Question 6

What drives or causes physiological jaundice

Answer 6

High bilirubin production
-fetal Hb,
-short life of fetal Hb,
-eneterohepatic recirculation)

Reduced bilirubin excretion
-UDPGT concentrations at term are 1% of adult concentrations

Question 7

What are the hallmarks of biliary obstruction

Answer 7

Pale stools
Dark urine