Which is the earliest marker of hepatocellular failure ?

The PT and/or the international normalized ratio (INR) are used to determine the presence or severity of coagulopathy. They are earliest and sensitive markers of hepatic synthetic failure. The serum ammonia level may be elevated dramatically in patients with fulminant hepatic failure. The aerial serum ammonia level is most accurate, but venous ammonia levels are generally acceptable. An elevated serum ammonia level does not exclude the possibility of another cause for mental status changes. Albumin:globulin ratio commonly decreases in hepatic failure.