22: Liver Enzymes And Jaundice

Question 1

Liver enzymes vs LFTs misnomer

Answer 1

Most people call AST/ALT/ALT/bilirubin LFTs - but they dont determine liver function - should be called liver enzymes/liver tests/liver chemistry

Question 2

Hepatocellular vs cholestatic injury: description and what is elevated

Answer 2

Hepatocellular: hepatocyte injury; AST/ALT elevation
Cholestatic: bile duct injury; ALP and bilirubin elevation

Question 3

Which is more specific for liver injury - AST or ALT?

Answer 3

ALT more specific

Question 4

Why is ALT more specific than AST for liver injury?

Answer 4

AST also found in striated muscle and other organs

Question 5

AST vs ALT in alcohol induced liver injury

Answer 5

more prominent AST elevation than ALT

Question 6

Four clotting factors that are vitamin K dependent

Answer 6

2, 7, 9, 10

Question 7

Three places you can see jaundice in its earlier stages

Answer 7

Sclera, oral mucosa, palms

Question 8

Three General causes of hyperbilirubinemia

Answer 8

1. Overproduction
2. Impaired uptake/conjugation/excretion
3. Regurgitation of bilirubin from damaged hepatocytes or bile ducts

Question 9

At what level of bilirubin do you see clinical jaundice?

Answer 9

2mg/dL +

Question 10

Fractionated bilirubin

Answer 10

Indirect vs direct

Question 11

How to fractionated ALP

Answer 11

Order GGT

Question 12

Six things to order on a patient with conjugated hyperbilirubinemia

Answer 12

1. Viral hepatitis serology
2. AMA
3. Ceruloplasmin
4. Iron studies
5. Lipase/amylase
6. US for obstructive jaundice

Question 13

Two things to order on a pt with unconjugated hyperbilirubinemia

Answer 13

1. CBC

2. Peripheral smear

Question 14

What type of hyperbilirubinemia does hemolysis cause?

Answer 14

Unconjugated

Question 15

What to specifically look for when ordering a CBC for a pt with unconjugated hyperbilirubinemia? (5 things)

Answer 15

1. Anemia
2. Thrombocytopenia
3. Haptoglobin
4. Reticulocyte count
5. LDH