Liver blood tests - Kumar

Question 1

Why is serum albumin levels useful?

Answer 1

• Marker of synthetic function
• Good for gauging severity of chronic liver disease
• In acute liver disease albumin levels may be normal
• Other causes of hypoalbuminaemia (malnutrition, urinary protein loss or sepsis) can make interpretation difficult.

Question 2

What are the three liver function tests?

Answer 2

• Serum albumin
• Bilirubin
• Prothrombin time

Question 3

What needs to be excluded when analysing prothrombin time in a patient suspected with liver disease? How is this done?

Answer 3

• Vitamin K deficiency

* Give an intravenous bolus of vitamin K

Question 4

What is INR (The International normalised ratio)?

Answer 4

• The INR is calculation used to standardise the results from the PT time

Question 5

What are the two liver biochemistry tests?

Answer 5

• Aspartate aminotransferase (AST)

* Alanine aminotransferase (ALT)

Question 6

What conditions can cause high levels of AST?

Answer 6

• Hepatic necrosis
• Myocardial infarction
• Muscle injury
• Congestive cardiac failure

Question 7

How is ALT different to AST?

Answer 7

• ALT is a cytosol enzyme, more specific to the liver, so that a rise only occurs with liver disease

Question 8

In what scenario is ALT greater than AST?

Answer 8

• Viral hepatitis (unless cirrhosis is present)

Question 9

In what scenario is AST greater than ALT?

Answer 9

• Alcoholic liver disease

* Steatohepatitis

Question 10

In patients with viral hepatitis what does an ALT:AST ratio of more than one indicate?

Answer 10

• cirrhosis

Question 11

Patients with liver disease without cirrhosis that have a AST greater than ALT what are the 2 most likely aetiological agents?

Answer 11

• Alcohol

* Obesity