Key Points
����Acute liver failure (ALF) is a rare condition in which rapid deterioration
of liver function results in altered mentation and coagulopathy in
individuals without known preexisting liver disease. U.S. estimates are
placed at approximately 2000 cases per year.
����The most prominent causes include drug-induced liver injury, viral
hepatitis, autoimmune liver disease and shock or hypoperfusion. Many
cases (~ 15%) have no discernible cause.
����Acute liver failure often affects young persons and carries a high
morbidity and mortality. Prior to transplantation, most series
suggested less than 15% survival. Currently, overall short-term
survival (one year) including those undergoing transplantation is
greater than 65%.
����No single therapy has been found to improve the outcome of all
patients with ALF, with the possible exception of N-acetylcysteine
(NAC).
Definitions
����The most widely accepted definition of ALF includes evidence of
coagulation abnormality, usually an International Normalized Ratio
(INR) ��� 1.5, and any degree of mental alteration (encephalopathy) in a
patient without preexisting cirrhosis and with an illness of < 26 weeks���
duration.
����Patients with Wilson disease, vertically-acquired hepatitis B virus
(HBV), or autoimmune hepatitis may be included in spite of the
possibility of cirrhosis if their disease has been recognized for
< 26 weeks.
