Acute liver failure

Acute liver failure (ALF), also known as fulminant hepatic failure, refers to sudden severe liver dysfunction from injury without underlying chronic liver disease (CLD), although sometimes it presents as decompensation of an unknown CLDchronic liver disease. 

Epidemiology

ALFAcute liver failure is rare, with < 1;1 case per 100,000 in the developed world ⁵.

Clinical presentation

Symptoms and signs of hepatic encephalopathy and/or coagulopathy areis the most common presentation. 

Pathology

Aetiology

There are many causes for ALFacute liver failure ^1,3,4:

• viral infection, hepatitis B is probably the most common ^5,6
• idiopathic (15%), i.e. cause unknown
• drug toxicity, e.g. paracetamol/acetaminophenacetaminophen toxicity, chemotherapeutic agents
• toxin exposure, e.g. toxic mushrooms, carbon tetrachloride (industrial chemical), aflatoxin ⁷
• metabolic disease, e.g. Wilson disease, Reye disease, acute fatty liver of pregnancy, HELLP syndrome
• vascular causes, e.g. Budd-Chiari syndrome, right heart failure, shock
• autoimmune hepatitis

Radiographic features

General features may include: 

• hepatomegaly
• gallbladder wall thickening
• ascites (may be small volume ³)

Features of cirrhosis (i.e. splenomegaly, enlarged collateral vessels, liver surface nodularity) are present in 20-30% of patients with ALFacute liver failure (ALF), although it should be stressed that patients with ALF do not have cirrhosis ³.

Ultrasound

• early: decreased liver echogenicity (cf. right kidney)
• late: the liver becomes heterogeneously echogenic ¹

CT

CT may demonstrate the general imaging features along with heterogeneous enhancement on portal venous phase imaging ³. 

Treatment and prognosis

Mortality is high in ALFacute liver failure at ~50% (range 30-70%) with orthotopic liver transplant considered the definitive treatment ^3,4.