Hepatic Failure

Question 1

Acute liver failure describes the rapid onset of hepatocellular dysfunction leading to a variety of systemic complications.

What are the primary causes of acute liver failure?

Answer 1

• Viruses (A, B, E)
• Paracetamol
• Non-paracetamol meds (statins, carbamazepine, ecstasy)
• Toxin-induced (eg. amanita phalloides)
• Budd-chiari syndrome
• Pregnancy-related (fatty liver, HELLP)
• Autoimmune hepatitis
• Wilson’s disease

Question 2

What are features of acute liver failure?

Answer 2

• Altered mentation, confusion + hepatic encephalopathy
• Asterixis
• Jaundice / Bruising
• RUQ pain
• Hepatomegaly / Ascites
• GI Bleeding
• Hypotension + tachycardia
• Raised ICP

ALF is characterised by jaundice, confusion and coagulopathy

Question 3

How can hepatic encephalopathy be graded?

Answer 3

West Haven criteria

• Grade I → change in behaviour with minimal change in level of consciousness. May have mild asterixis or tremor.
• Grade II → gross disorientation, drowsiness, asterixis and inappropriate behaviour
• Grade III → marked confusion, incoherent speech, sleeping most of the time but rousable to verbal stimuli. Asterixis less noticeable, elements of rigidity.
• Grade IV → coma that is unresponsive to verbal or painful stimuli. Evidence of decorticate or decerebrate posturing.

Question 4

Early transfer to a transplant centre is imperative in patients with ALF.

The initial workup for a patient with suspected ALF involves formal clinical assessment alongside urgent blood tests, non-invasive liver screen and imaging.

What are the urgent blood tests for acute liver failure?

Answer 4

• FBC / U+Es / LFTs
• Bone profile
• Blood glucose
• Arterial ammonia
• ABG (pH + lactate)
• Coagulation - urgent INR
• Lactate dehydrogenase
• Lipase/amylase
• Blood cultures

Question 5

Non-invasive liver screen refers to a series of tests that are critical to determine the aetiology (e.g. viral, autoimmune). If they are all negative, an alternative cause for ALF needs to be determined (e.g. Drug induced liver failure).

What constitutes the non-invasive liver screen?

Answer 5

• Toxicology of serum and urine
• Paracetamol serum level
• Autoimmune markers → ANA / autoantibodies / Igs / ANCA
• Hepatitis A-E
• Other → CMV / EBV / HSV / VZV / Parvovirus

Question 6

Which imaging modalities are useful for ALF?

Answer 6

• Doppler USS → assess patency of hepatic and portal veins / pre-existing cirrhosis
• Cross-sectional imaging of abdo (CT Abdo pelvis) → liver architecture / vascular integrity / exclude complications (pancreatitis)

Question 7

What is the key difference between acute liver injury and acute liver failure?

Answer 7

• Hepatic encephalopathy
• Carefully screen for HE, which may involve clinical assessment, cognitive tests, arterial ammonia and electroencephalogram (EEG)
• Can lead to coma

Question 8

Which criteria is used to select patients to undergo emergency liver transplantation?

Answer 8

• King’s College criteria