INTRODUCTION

Acute liver failure is characterized by acute liver injury, hepatic encephalopathy (altered mental status), and an elevated prothrombin time/international normalized ratio (INR). It has also been referred to as fulminant hepatic failure, acute hepatic necrosis, fulminant hepatic necrosis, and fulminant hepatitis. Untreated, the prognosis is poor, so timely recognition and management of patients with acute liver failure is crucial [1]. Whenever possible, patients with acute liver failure should be managed in an intensive care unit at a liver transplantation center.

This topic will review the etiology, clinical manifestations, and diagnosis of acute liver failure in adults. The prognosis and management of patients with acute liver failure is discussed separately. (See "Acute liver failure in adults: Management and prognosis".)

The discussion that follows is consistent with society guidelines from The American Association for the Study of Liver Diseases (AASLD) and European Association for the Study of the Liver (EASL) for the management of acute liver failure [2,3].

DEFINITIONS

Acute liver failure refers to the development of severe acute liver injury with impaired synthetic function (INR of ≥1.5) and altered mental status in a patient without cirrhosis or preexisting liver disease [2-4]. A commonly used cutoff to define acute liver failure is an illness duration of <26 weeks.

Acute liver failure may also be diagnosed in patients with previously undiagnosed Wilson disease, vertically acquired or reactivation of hepatitis B virus, or autoimmune hepatitis, in whom underlying cirrhosis may be present, provided the disease has been recognized for <26 weeks. On the other hand, patients with acute severe alcohol-associated hepatitis, even if recognized for <26 weeks, are considered to have acute-on-chronic liver failure since most have a long history of heavy alcohol use causing liver fibrosis. The approach to such patients is discussed elsewhere. (See "Management of alcohol-associated hepatitis".)