The term acute liver failure (ALF) refers to the acute (<26 weeks) and severe worsening in liver function associated with encephalopathy in a person with no underlying chronic liver disease. ALF constitutes a critical clinical syndrome that is potentially reversible but has a very variable prognosis. No specific treatment is available, and liver transplantation (LT) is the treatment of choice in many cases. However, the challenge remains of identifying those patients with a poor likelihood of spontaneous recovery of liver function and for whom the indication and time of LT in order to guarantee survival (based on identification of prognostic factors) need to be established. In Europe, 8% of LT are due to ALF. Although the results of LT due to ALF have improved over recent years, they are still far from those seen after elective LT
