Acute liver failure is rapid deterioration of liver function causing an acute alteration in mental status (hepatic encephalopathy) and coagulopathy. The condition can result from damage to the liver parenchyma, usually secondary to drugs (acetaminophen overdose or, rarely, therapeutic doses of acetaminophen in patients who fasted for ≥ 24 hours or drank excessive alcohol), viral infections, and hypotensive and subsequent fulminant hepatitis from septic shock. Signs and symptoms include acute onset of jaundice, abdominal pain, nausea, vomiting, anorexia, hepatomegaly, ascites, edema, and mental status changes, without a previous history of liver disease. Infants may initially present with irritability, sleep disturbance, hyperbilirubinemia, and failure to thrive. A life-threatening condition, acute liver failure can lead rapidly to hepatic encephalopathy, cerebral edema (increased intracranial pressure, brainstem herniation), gastrointestinal bleeding, infection, multi-organ failure, and ultimately, death.

The demographics of acute liver failure are difficult to define, as different etiologies (viral, pregnancy-induced, septic shock, drug-induced) are seen in widely different ages and subsets of the population.

Management is largely supportive: repletion of blood product and clotting factors to temporize against bleeding, lactulose and rifaximin for hepatic encephalopathy, hemodynamic stabilization, and antibiotics if there is a suspected underlying infection. Ultimately, the liver will either regenerate and restore synthetic function or liver failure will progress, resulting in death or the need for transplantation. There will be recovery from acute liver failure in approximately 40% of patients, with the remaining 60% either deceased or recipients of a liver transplant.

In pregnant patients presenting with acute liver failure, acute fatty liver of pregnancy and HELLP syndrome (hemolysis, elevated liver function tests, low platelets) should be considered as etiologies. Acute fatty liver of pregnancy is rare, occurring in approximately 1/20 000 deliveries, and presents with abdominal pain, nausea and emesis, and jaundice. Women with multiple gestations and low body mass index are at higher risk of developing acute fatty liver of pregnancy. The diagnosis is primarily clinical, distinguished from HELLP syndrome due to the absence of hemolysis and more evidence of synthetic liver dysfunction (elevated international normalization ratio [INR], elevated bilirubin), although a liver biopsy can be confirmatory by demonstrating microvesicular fatty infiltration in the hepatocytes. Treatment requires supportive care and prompt delivery of the baby.

Pediatric patients with hepatitis of unknown etiology: A 2022 outbreak of severe hepatitis in children in several countries, with the majority in Great Britain, may be associated with an adenovirus, including subtype 41F, but further studies are needed to determine the cause. Signs and symptoms include dark urine; jaundice; scleral icterus; light-colored stools; loss of appetite, abdominal pain, nausea, diarrhea, and vomiting; and joint pain. The US Centers for Disease Control and Prevention (CDC) has requested that physicians consider adenovirus testing for pediatric patients with hepatitis of unknown etiology and report any possible cases of hepatitis of unknown origin to CDC and state public health authorities. CDC also recommends testing for past or present SARS-CoV-2 infection in children with acute hepatitis, although the possible association is uncertain and under investigation. See also adenovirus infection.

Related topic: drug-induced hepatotoxicity