Sarah's Liver Function Tests ppt

Question 1

Liver blood flow

Answer 1

Dual supply: 
Portal vein (intestines & spleen) = nutrients and drugs 
Hepatic artery = O2 

Outflow = hepatic vein

Question 2

Liver synthesizes what coagulation factors?

Answer 2

2, 7, 9, 10, 1, 5

Question 3

Liver functions

Answer 3

• produces hormones
• endocrine and exocrine
• synthesizes clotting factors
• degrades amino acids to urea
• carbohydrate metabolism
• conjugates indirect to direct bilirubin
• produces and secretes bile that breaks down fats (50% bile stored in gallbladder)

Question 4

3 classifications of liver injury

Answer 4

1) cytotoxic
2) cholestasis
3) impaired conjugation of bilirubin

Question 5

What do elevated AST and ALT indicate?

Answer 5

Acute hepatocyte injury/hepatic inflammation. They may not be elevated in chronic liver failure.

Question 6

In alcoholic liver disease, what is the ALT to AST ratio?

Answer 6

2:1 or 3:1 (AST>ALT)

Question 7

What other conditions cause elevated AST and where else in the body is AST found?

Answer 7

MI, PE, pancreatitis. Found in skeletal muscle, spleen, heart, kidneys, pancreas, brain…

Question 8

What is albumin? What is the half-life? How is it a liver marker?

Answer 8

Protein synthesized in liver, half-life 20 days, reliable marker of chronic hepatocellular injury.

Question 9

What is the most sensitive liver function test?

Answer 9

INR

Question 10

What clotting factors are deficient in hemophilia? What happens to PT?

Answer 10

Factor 7 & 9. PT increased.

Question 11

What are the markers of hepatocellular (cytotoxic) injury?

Answer 11

AST/ALT/albumin/PT/INR

Question 12

What are the markers of cholestasis?

Answer 12

bilirubin (total, direct/conjugated), Alk Phos (ALP), GGT

Question 13

Conjugated bilirubin is water soluble which is why it can be excreted by the kidneys. True/False

Answer 13

True.

Question 14

Blockage of extrahepatic or intrahepatic systems leads to increase in conjugated or unconjugated bilirubin or both?

What tests can be ordered to assess for this?

Answer 14

Both. Direct & total bilirubin and bilirubinuria.

• indirect/unconjugated bili is the difference between direct and total.

Question 15

What are some causes of elevated indirect bilirubin?

Answer 15

DIC, hemolysis, Gilbert’s disease (inability to convert)

Question 16

What percentage of direct bilirubin indicates a build up of conjugated bilirubin (as opposed to unconjugated)?)

Answer 16

> 50% direct bilirubin (of total) = conjugated bilirubin

Question 17

What enzyme converts indirect to direct bilirubin?

Answer 17

glucoronyl transferase enzyme

Question 18

What three conditions can increase ALP?

Answer 18

Cholestasis (obstructive jaundice, cholecystitis, choliangitis)
Pregnancy
Bone disease (osteoblastic cancers & Paget's disease).

Question 19

GGT is the differential diagnostic for in pregnancy and in bone disease. Why?

Answer 19

GGT is increased in cholestasis, but unlike ALP it is not increased in pregnancy or in bone disease

Question 20

Name three types of cholestatic liver injury.

Answer 20

Primary biliary cirrhosis (fatigue, chronic RUQ pain, FN, female)
Primary sclerosing choliangitis (seen in UC)
Large bile duct obstruction (pain, fever, unwell)