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 unknown chronic liver disease.

Epidemiology

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

Clinical presentation

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

Pathology

Etiology

Causes of acute liver failure include ^1,3,4:

• viral infection, hepatitis B is probably the most common ^5,6

• idiopathic (15%), i.e. cause unknown

• drug toxicity, e.g. acetaminophen 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 acute 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

Vascular assessment with Doppler ultrasound is useful in determining the patency of the hepatic artery, hepatic vein, and portal vein. A diagnosis of Budd-Chiari syndrome, ischemic hepatitis, and portal vein thrombosis may be confirmed or excluded during workup ⁸.

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

The goals of management include identification of reversible causes of acute liver failure, provide organ support to maximize the probability of recovery as well as to perform risk stratification and identify patients for consideration of early liver transplantation, as they may not survive supportive care ⁸. Consideration for transfer to a center with expertise in liver transplantation may be appropriate ⁸.