3. Liver function and LFTs

Question 1

What are the liver functions

Answer 1

Metabolic - carbohydrates, hormones, lipids, drugs, proteins
Storage - glycogen, vitamins, iron
Protective - detoxification and elimination of toxic compounds
Bile - production and excretion

Question 2

Define acute and chronic liver failure

Answer 2

Acute: development of severe hepatic dysfunction within 24wks of onset of disease

Chronic: progressive decline in liver function with established disease

Question 3

What are the causes and outcomes of acute hepatitis

Answer 3

Causes:
Poisoning - paracetamol
Infection -hep a-c
Inadequate perfusion

Outcome:
Resolution - majority of cases
Progression to acute hepatic failure
Progression to chronic hepatic damage

Question 4

Consequences of chronic liver disease

Answer 4

Cirrhosis - irreversible shrinkage of liver and fibrosis
Portal hypertension - increased blood pressure in portal vein
Ascites - accumulation of fluid in peritoneal cavity
Renal failure

Question 5

Name some causes of liver failure (4)

Answer 5

Inadequate synthesis of albumin
Inadequate synthesis of clotting factors
Inability to elimate bilirubin
Inability to elimate nitrogenous waste

Question 6

Describe the current liver function tests

Answer 6

Aminotranferases - ALT and AST for liver cell damage
Bilirubin - for cholestasis
ALP and gamma-GT - for biliary epithelial damage and obstruction
Albumin - for synthetic function

Question 7

Describe the liver enzymes

Answer 7

AST and ALT - sensitive, non specific markers of acute damage to hepatocytes
ALP - increased in liver diseases due to increased synthesis in response to cholestasis
Gamma-GT - raised in cholestasis, also affected by ingestion of alcohol and drugs such as phenytoin