Acute liver failure

Question 1

Define acute liver failure

Answer 1

Acute liver injury, plus

• Encephalopathy
• Deranged coagulation (INR >1.5)
• Previously normal liver

Question 2

Define acute-on-chronic liver failure

Answer 2

Decompensation of chronic liver disease

Question 3

Define fulminant hepatic failure

Answer 3

Severe hepatic failure

• Encephalopathy within 2 weeks in a patient
• Massive necrosis of hepatocytes
• Previously normal liver

Question 4

Outline the grading of hepatic encephalopathy

Answer 4

1. Altered mood/behaviour, sleep disturbances, dyspraxia, poor arithmetic
2. Increased drowsiness, confusion, slurred speech, liver flap, personality change
3. Incoherent, restless, liver flap, stupor
4. Coma

Question 5

Give four presenting features of acute liver failure

Answer 5

• Jaundice
• Coagulopathy
• Hepatic encephalopathy
• Cerebral oedema; hypoalbuminaemia
• Fetor hepaticus (breath of dead)
• Hepatorenal syndrome; pancreatitis
• Altered liver size
• Hyper-reflexia
• RUQ tenderness
• Ascites; splenomegaly

Question 6

Give two complications of acute liver failure?

How are these managed?

Answer 6

• Cerebral oedema: 20% mannitol
• Ascites: fluid/salt restriction, diuretics, daily weight
• Bleeding: Vit K 10mg/d for 3 days
• Hypoglycaemia: 10% glucose IV
• Encephalopathy: head tilt, lactulose, regular enemas

Question 7

Why does cerebral oedema occur in acute liver failure?

Answer 7

• Nitrogenous waste products accumulate
• Removed by astrocytes (CNS)
  
  • Conversion to glutamine
• Glutamine creates as osmotic effect
  
  • drawing water into the brain

Question 8

Name three causes of acute liver failure

Answer 8

• Paracetamol overdose (50%)
• Alcohol
• Viral hepatitis A or B
• Acute fatty liver of pregnancy

Question 9

Request three investigations for acute liver failure

Answer 9

• FBC
• U+Es
• LFTs; albumin; bilirubin
• Coagulation screen
• Viral markers
• Serum paracetamol
• Consider
  
  • a-1-antitrypsin
  • Urinary copper
  • AFP

Question 10

Outline the initial management of acute liver failure

Answer 10

Requires specialised unit

• Treat any underlying causes
  
  • N-acetylcysteine: paracetamol OD
• PPI: prevent GI bleed
• Prophylactic ABX and anti-fungal
• Avoid drugs with hepatic metabolism

Question 11

Why are prophylactic ABX and anti-fungals routinely given in acute liver failure?

Answer 11

Infection is a frequent cause of death and may preclude liver transplantation

Question 12

What is the definitive treatment of acute liver failure?

Answer 12

Liver transplant

Question 13

How is the indication for liver transplantation assessed?

Answer 13

King’s College Hospital criteria for liver transplantation

Differs if induced by paracetamol or not

Question 14

Outline the King’s College Hospital criteria for liver transplantation in paracetamol-induced liver failure

Answer 14

Either:

• Arterial pH <7.3 at 24hr after ingestion
• All of the following:
  
  • Prothrombin time >100s
  • Creatinine >300 micromol/L
  • Grade III or IV hepatic encephalopathy

Question 15

Outline the King’s College Hospital criteria for liver transplantation in non-paracetamol-induced liver failure

Answer 15

Either:

• Prothrombin time >100s
• Any 3 of the following:
  
  • Age <10 or >40
  • Etiology: non-A/B hepatitis, halothane, drug
  • >1/52 jaundice prior to encephalopathy
  • Prothrombin time >50s
  • Serum bilirubin >18mg/dL