Definition
Acute liver failure is defined as "the rapid development of hepatocellular dysfunction, specifically coagulopathy and mental status changes (encephalopathy) in a patient without known prior liver disease".page 1557The diagnosis of acute liver failure is based on physical exam, laboratory findings, patient history, and past medical history to establish mental status changes, coagulopathy, rapidity of onset, and absence of known prior liver disease respectively.page 1557The exact definition of "rapid" is somewhat questionable, and different sub-divisions exist which are based on the time from onset of first hepatic symptoms to onset of encephalopathy. One scheme defines "acute hepatic failure" as the development of encephalopathy within 26 weeks of the onset of any hepatic symptoms. This is sub-divided into "fulminant hepatic failure", which requires onset of encephalopathy within 8 weeks, and "subfulminant", which describes onset of encephalopathy after 8 weeks but before 26 weeks. Another scheme defines "hyperacute" as onset within 7 days, "acute" as onset between 7 and 28 days, and "subacute" as onset between 28 days and 24 weeks.page 1557

Treatment
General concerns
Because ALF often involves the rapid deterioration of mental status and the potential for multiorgan failure, patients should be managed in the intensive care unit. For patients not at a transplant center, the possibility of rapid progression of ALF makes early consultation with a transplant facility critical. Accordingly, plans for transfer to a transplant center should begin in patients with any abnormal mentation. Early institution of antidotes or specific therapy may prevent the need for liver transplantation and reduce the likelihood of poor outcome.
Trey and Davidson introduced the phrase fulminant hepatic failure in 1970, which they described as a "... potentially reversible condition, the consequence of severe liver injury, with an onset of encephalopathy within 8 weeks of the appearance of the first symptoms and in the absence of pre-existing liver disease". Later, it was suggested that the term fulminant should be confined to patients who develop jaundice to encephalopathy within 2 weeks. Phrases subfulminant hepatic failure and late onset hepatic failure were coined for onset between 2 weeks to 3 months and for 8 weeks to 24 weeks, respectively. The umbrella phrase of acute liver failure was proposed by Kings College group, which has been adopted in this article. Paradoxically, in this classification, the best prognosis is in the hyperacute group. References
External links
Fulminant Hepatic Failure at eMedicine