 Acute liver failure (ALF) is a rare, life-threatening condition characterized by rapid 

evolution from deranged liver function to coagulopathy and encephalopathy, occurring 

most commonly in younger adults without pre-existing liver disease 

 ALF is often defined according to the time interval from the development of jaundice to 

onset of hepatic encephalopathy (HE).  

 The commonly utilised O'Grady classification categorises ALF as  

✓ Hyperacute 

✓ acute  

✓ subacute  

 This classification is of prognostic value, as those with a hyperacute presentation, in 

whom coagulopathy and encephalopathy are most severe, paradoxically have the 

highest rates of survival with medical management alone

 ❖ Etiology: 

 The majority of ALF cases in the developing world are due to : 

1) acute viral infections from hepatitis A, B and E. Rare viral causes of ALF include herpes 

simplex virus, cytomegalovirus (CMV), Epstein–Barr virus, adenovirus and 

parvoviruses. 

2) Drug induced liver injury 

3) Ischaemic liver injury, such as may occur in critically ill individuals with circulatory 

failure or septic shock, can cause significant hepatic necrosis 

4) metabolic diseases, such as Wilson's, malignant infiltration, Budd–Chiari syndrome 

and heatshock.  

5) ALF can occur in pregnancy where causes include acute fatty liver of pregnancy and 

haemolysis, elevated liver enzymes and low platelets (HELLP syndrome).