The interplay of four factors determines the outcome in Acute Liver Failure (ALF). Current criteria used for prognosis address each of these factors. a. Hepatic regeneration: Age, poor prognostic etiologies (drug, idiopathic ALF), b. Hepatocellular failure: INR, Bilirubin, c. Encephalopathy and brain edema: Stage III/IV, hyperacute vs acute/subacute, d. Multiorgan failure (MOF): pH. 2. In hyperacute liver failure, exemplified by acetaminophen-induced injury, prognostic criteria have focused on the course of encephalopathy and of multiorgan failure. In non-acetaminophen induced ALF, prognostic criteria reflect a greater role of hepatic regeneration in outcome. 3. Prognostic indices combine features of these four factors. The Kings College criteria (KCC) have been shown to have a better performance than the Clichy criteria. The KCC appear to have a higher specificity than sensitivity for acetaminophen-induced ALF, while its negative predictive value for non-acetaminophen induced ALF is unfortunately low. 4. Newer prognostic markers have been proposed, including serum phosphate and alpha fetoprotein as markers of regeneration and blood lactate, a reflection of MOF and hepatocellular failure. They are likely to complement the KCC rather than replace them. 5. Clinical judgement is still needed to weigh management options in this disease.
