Nephrotoxicity after acute severe acetaminophen poisoning in adolescents

Objective: To determine the rate of acetaminophen related nephrotoxicity in adolescents who present after acute severe acetaminophen intoxication and to identify potential predictors of this outcome. Study Design: Retrospective analysis of consecutive patients between the ages of 12 and 18 years who were admitted at a tertiary care children's hospital for treatment of acute severe acetaminophen intoxication with N-acetylcysteine. The main outcome measure was the frequency of acetaminophen-related nephrotoxicity, defined as abnormal blood urea nitrogen (>6.4 mmol/L or > 18 mg/dL) and/or elevated creatinine (97.2 mu mol/L or >1.1 mg/dL) in association with one or both of the following: elevated blood pressure (systolic blood pressure > 140 mm Hg/diastolic blood pressure > 85) or abnormal urinalysis (urinalysis with hematuria or proteinuria). Statistical analyses used were measures of central tendency, Student's t-test, Mann-Whitney, and multivariate logistic regression. Results: Fourty-five patients were included. Acetaminophen-related nephrotoxicity occurred in 4 (8.9%) cases. One victim developed severe renal injury in association with elevated hepatic transaminases. Intergroup analyses revealed no statistically significant association between acetaminophen-related nephrotoxicity and amount/kg of acute severe acetaminophen ingested, delay in treatment with N-acetylcysteine, or measures of hepatic function. Conclusions: Acetaminophen-related nephrotoxicity occurred in 8.9% [95% CI: 4.52, 20.48] of children with severe overdose. There are no obvious predictors of this complication of acetaminophen overdose. Because the occurrence of renal injury can not be predicted, serial blood pressure, blood urea nitrogen/creatinine, and urinalysis should be considered an integral part of the management of children with acute, severe acetaminophen intoxication.