Acute Liver Failure

Question 1

What are the two types of acute liver failure?

Answer 1

ACUTE – no background of liver disease.

ACUTE-ON-CHRONIC – decompensated liver disease.

Question 2

How does acute liver failure present?

Answer 2

Jaundice.
Asterixis.
Constructional apraxia.
Fetor hepaticus.
Hepatic encephalopathy.

Question 3

What is fetor hepaticus and why does it occur?

Answer 3

Breath smells like pear drops as portal hypertension allows thiols to pass into the lungs.

Question 4

What is the pathophysiology behind hepatic encephalopathy in acute liver failure?

Answer 4

Ammonia can’t be cleared by the liver so it passes to the brain where astrocytes use it to convert glutamate to glutamine which causes an osmotic shift, leading to cerebral oedema.

Question 5

What are the symptoms of hepatic encephalopathy?

Answer 5

Altered mood.
Sleep disturbance.
Drowsiness.
Confusion.
Slurred speech.
Stupor.
Incoherence.
Restlessness.
Coma (if decreasing consciousness, then other causes e.g. sepsis, hypoglycaemia and seizure activity should be ruled out).

Question 6

What are the possible causes of acute liver failure?

Answer 6

Infection e.g. viral hepatitis, yellow fever.
Drugs e.g. paracetamol overdose, isoniazid, ecstasy.
Toxins.
Ischaemia.
Chronic causes.

Question 7

What investigations should be performed if acute liver failure is suspected?

Answer 7

FBC.
Blood cultures.
Serology.
Ferritin.
A1 antitrypsin.

Question 8

When should an ascites tap be performed?

Answer 8

On anyone deteriorating with ascites. Fluid sent for urgent MC&S to check for spontaneous bacterial peritonitis.

Question 9

How is acute liver failure managed?

Answer 9

Treat cause and complications:
-	Paracetamol OD – N-acetylcysteine. 
-	Infection – Abx.
-	Cerebral oedema – Mannitol.
-	Hepatorenal syndrome – IV albumin and arterial vasoconstrictors.
Thiamine and folate supplements. 
? transplant if fit criteria.

Question 10

What drugs should be avoided when prescribing in liver failure?

Answer 10

Avoid diuretics (increases encephalopathy risk), opiates, oral hypoglycaemics, saline IVIs.
Warfarin effects are also enhanced and should also be cautious of hepatotoxic drugs e.g. MTX, paracetamol, isoniazid, azathioprine.