Population-based surveillance for acute liver failure.

Objectives: Most U.S. studies of acute liver failure (ALF) patients have been conducted at tertiary care liver transplantation centers. The aim of this study was to conduct population-based surveillance for ALF.
Methods: We conducted population-based surveillance for ALF within the 8 counties comprising Metropolitan Atlanta between November 2000 and October 2004. ALF cases were defined as the presence of coagulopathy, any grade of hepatic encephalopathy within 26 wk of illness onset, and no history of underlying liver disease. A questionnaire was administered and medical records were reviewed to determine clinical features, etiologies, and outcomes.
Results: A total of 65 cases were enrolled, yielding an annualized incidence for all causes of ALF of 5.5 (95% CI 4.3-7.0) per million. Acetaminophen (APAP)-related ALF was the most common (41%) etiology in adults while ALF of undetermined etiology was most common (38%) in children, followed by APAP-related ALF (25%). Unintentional APAP overdose was the most common type (61%) of APAP-related cause. Blacks were more likely than other races to have ALF of undetermined etiology (32%vs 11%). Overall mortality was 40%, with 27 (42%) surviving with supportive care alone and 8 (12%) requiring orthotopic liver transplantation.
Conclusions: Our population-based study suggests approximately 1,600 ALF cases occur in the United States each year. Consistent with findings from studies conducted exclusively at liver transplantation centers, APAP-related ALF was the most common etiology. Increased awareness of APAP-related ALF in the medical community may limit future cases. More research is warranted into ALF of undetermined etiology, especially in children.