Jaundice

Question 1

What are the three main causes of jaundice?

Answer 1

Haemolysis
Failure to conjugate bilirubin in the hepatocyte
Obstruction of biliary system

Question 2

What is jaundice?

Answer 2

Yellow discolouration of skin and sclera - usually detectable when plasma bilirubin reaches 50 micromoles/L (normal plasma bilirubin is <22)

Question 3

What system does increased bilirubin affect?

Answer 3

Neurotoxin

can cause permanent brain damage in neonates

Question 4

Jaundice, pale stools and dark urine suggests what?

Answer 4

‘Surgical jaundice’ - extrahepatic blockage of bile duct

Bilirubin in gut normally -> stercobilinogen = brown. If no bilirubin/bile is getting into gut = pale stools

High serum bilirubin = high excretion = dark urine

Question 5

What is the most common inherited disorder of bilirubin metabolism?

Answer 5

Gilbert’s disease (unconjugated hyperbilirubinaemia)

Question 6

What is the term given to the condition that causes brain damage in neonates due to high bilirubin?

Answer 6

Kernicticus

Question 7

Why do you have a low urobilinogen in the urine in extrahepatic obstruction?

Answer 7

Stercobilinogen in the gut is reabsorbed via the portal vein to then enter the liver, and is converted to urobilinogen to be excreted by the kidneys. Extrahepatic obstruction = no stercobilinogen in gut.

Question 8

A high alk phos with a normal bilirubin is most likely to suggest what?

Answer 8

A partial biliary blockage due to a liver metastases