• overall survival rate (spontaneous survival without transplant plus survival following transplantation) at one year following entry into the study. [ Time Frame: One year following entry into the study ] [ Designated as safety issue: Yes ]
  

• spontaneous recovery (survival without transplant), transplantation, length of hospital stay, number of organ systems failing, infectious complication, highest coma grade of hepatic ENC and the number of days until recovery or death. [ Time Frame: One year following entry into the study ] [ Designated as safety issue: Yes ]
  

Drug: N-acetylcysteine
The study drug is administered as a continuous infusion at a dose of 150 mg/kg/day for up to 7 days following entry into the study. The infusion is discontinued at the time of death, liver transplant or discharge.

The PALF study group will collect clinical, epidemiological and outcome data on children with ALF. This information will be used to develop methods to predict whether a child will recover from the illness without the need for a liver transplant or other life-saving procedure. We believe the methods to predict survival will vary with different patient age groups, but that diagnosis, multi-system organ failure, degree of encephalopathy and level of coagulopathy will be important regardless of patient age. Biological samples, such as blood plasma and liver tissue, will provide opportunities to identify subgroups of patients who have unique treatment requirements and outcomes.

In addition, we hope to identify unrecognized mechanisms of liver injury resulting in ALF in children including the role of fatty acid oxidation defects, the prevalence of NK cell and other immune cell dysfunction in children with ALF and examine the impact of unsuspected acetaminophen (APAP) toxicity in the pathogenesis of ALF.

Finally, we will continue and complete the double blind, randomized, placebo-controlled trial of intravenous (IV) N-acetylcysteine (NAC) vs. placebo for the treatment of non-acetaminophen ALF. The purpose is to examine the safety and efficacy of intravenous NAC in children with ALF for whom no antidote or other specific treatment is available.