Predictors of outcome after acetaminophen poisoning in children and adolescents.

Objective: Shortened courses of N-acetylcysteine may be acceptable in patients with acetaminophen poisoning who are at low risk for toxicity. The goal of this study was to determine which clinical findings best identified patients at lowest risk for acetaminophen-related hepatotoxicity after an acute overdose.

Study Design: This was a retrospective analysis, throughout 10 years, of hospital admissions for acute acetaminophen poisoning, with inclusion criteria being an acetaminophen concentration above the possible toxicity line by nomogram, arrival within 24 hours, and an initial prothrombin time (PT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) measured within 24 hours of ingestion. Clinical parameters capable of identifying patients most and least likely to have hepatotoxicity were evaluated by using sensitivity and specificity testing.

Results: Of 95 patient charts identified, 41 met all inclusion criteria, with 16 patients having hepatotoxicity. PT, AST, and ALT within the first 24 hours postingestion did not identify all patients who had hepatotoxicity. The best predictor of a low risk of toxicity was the presence of normal values for the PT, AST, or ALT within 48 hours of ingestion.

Conclusions: These data suggest that all patients with an acute acetaminophen overdose should be observed and treated for at least 48 hours postingestion.