Fatal methaemoglobinaemia in a dental nurse. A case of sodium nitrite poisoning.

Methaemoglobinaemia may be caused by ingestion of a number of drugs, among them nitrites, some of which are remarkably toxic. This was tragically highlighted by the death of a 17 year old dental nurse after taking a single 1 g tablet of sodium nitrite. These tablets are widely used in the medical and dental profession to prevent rusting of instruments while immersed in disinfectant solutions. The toxicity of this chemical should be more widely recognized and its storage made correspondingly more secure. Methaemoglobinaemia should be considered as a diagnosis in any patient with significant central cyanosis in whom there is no obvious cardiorespiratory cause.