a. Stage II, III or IV encephalopathy, and the presence of at least two of the following five criteria: i. Non-A/Non-B hepatitis or drug (non-acetaminophen) induced FHF; ii. Serum bilirubin >17 mg/dL; iii. Patient ≥10 or <40 years old; iv. Prothrombin time >25 seconds (INR > 3.5), AND/OR; v. Jaundice to encephalopathy time ≥7 days; OR