Renal injury at first presentation as a predictor for poor outcome in severe paracetamol poisoning referred to a liver transplant unit.

BACKGROUND: Paracetamol poisoning remains a leading cause of morbidity and mortality. Identifying indices of poor prognosis at first presentation is key to both improving clinical care and determining targets for intervention. Renal failure is a feature of severe paracetamol poisoning. The aim of this study was to investigate the relationship between renal function (serum creatinine, Cr) at first hospital presentation and time of tertiary referral to outcomes in severe paracetamol poisoning.
METHODS: This was a retrospective cohort analysis of patients referred to the Scottish Liver Transplant Unit due to paracetamol poisoning between 1992 and 2004. The relation between degree of renal injury and outcomes, including worst prothrombin time, Kings College Hospital Criteria (KCHC) and death were examined. The effects of age, nature (single or multiple) and stated size of overdose, hepatic enzyme induction (gamma-glutamyl transpeptidase, GGT), degree of liver injury (aspartate aminotransferase, prothrombin time), blood pressure and renal injury were assessed.
RESULTS: Data from 522 patients were included. Renal impairment (Cr >120 mmol/l) was present in 48.8% of patients with liver injury at time of first presentation. Creatinine at first admission predicted poorer outcome in terms of worse prothrombin time, KCHC and death (p < 0.001). Associated risk factors for renal dysfunction included later presentation, staggered ingestion, increased age, hypotension and elevated GGT at first admission.
CONCLUSIONS: Creatinine at first admission appears to be a predictor of poor outcome in paracetamol overdose. A better understanding of mechanisms involved in causing renal dysfunction may offer potential therapeutic targets for improving outcome in this common poisoning.