Analysis of factors responsible for continuing mortality after paracetamol overdose

To determine reasons for the continuing mortality in patients taking a paracetamol overdose, the presentation, drug ingestion history, patient background, use of antidote (N-acetylcysteine and methionine), clinical course and outcome were determined in 247 patients treated at King's College Hospital in 1982 and 1983. Patients (147) were referred from other centres because of severe liver damage and 100 were local patients seen in the accident and emergency department. Survival in the local patients was 100% and, for those with severe liver damage, 49 and 63% (1982 and 1983 values). Delay in initial presentation to hospital was a major factor in determination of an adverse outcome, with a median delay of 30 h in the referred patients and 8 h in the local cases. Such a delay precluded administration of antidote to the majority of patients in the referred group, but in 11 cases where antidote could have been given a full course was not provided and all 11 patients died. Included among these were four patients in whom the serum paracetamol concentration was in the 'non-toxic' range. One patient with a chronic alcohol-drinking history (greater than 200 g/day) received N-acetylcysteine at 12 h but died from liver failure. However, in the complete series prior alcohol consumption was not associated with a significantly worse prognosis and simultaneous ingestion of alcohol with paracetamol had no effect on outcome. The concomitant ingestion of dextropropoxyphene caused an early and marked impairment of consciousness unrelated to any hepatotoxicity but, in three cases where dextropropoxyphene combinations were used, death occurred subsequently from liver failure.