Coma and metabolic acidosis early in severe acute paracetamol poisoning

Coma and profound metabolic acidosis early in acute paracetamol poisoning have been described in three patients. Of five further patients (four female, one male, aged 17-80 years) with severe poisoning (plasma paracetamol concentration greater than 800 mg/l, 4-12 h postingestion), four were deeply unconscious on admission and two had a severe metabolic acidosis. Signs of hepatorenal damage were minimal and no additional poisons were detected except salicylates (plasma concentration 290 mg/l) in one instance. Plasma paracetamol half-lives were prolonged (median 9.4 h, range 4.8-39 h) and one patient sustained massive hepatic damage and a further patient died despite treatment with intravenous acetylcysteine. Paracetamol poisoning, when associated with exceptionally high plasma concentrations, can give rise to coma and metabolic acidosis in the absence of hepatic failure or other drugs. Although unusual, other such presentations may not have been recognized because a toxicology screen was not performed.