Acute on Chronic Liver Failure-What is in a 'Definition'?

Acute on chronic liver failure (ACLF) is a recently recognized syndrome and its definition has been evolving over last two decades. Currently, there is no universal consensus about the definition as kind of cases being seen in the Western world appear to be somewhat different from those that are seen in Asia Pacific region. But every one agrees that definition of ACLF should include following components. (a) The status of pre-existing liver disease, (b) defining the acute insult that leads to rapid deterioration of liver status, (c) time frame during which the acute insult can lead to rapid deterioration, (d) the quantification and definition of liver failure status after deterioration, which will determine the severity of ACLF, and (e) prediction of prognosis after analyzing first four components in the short and long terms. There is some consensus that number of organ failures may be the main determinant of prognosis. Whatever the definition is being used, the central role that superadded infections play in ACLF cannot be denied and need to be tackled aggressively. Apart from that, recovery may be possible if the acute insult or the baseline disease is curable, i.e. with the use of nucleoside analogs for hepatitis B, and corticosteroids for severe autoimmune hepatitis. Development of dynamic criteria with observations in Hospital may improve our understanding of prognosis as well as our approach to the management of ACLF.