[A case of carbamate poisoning in which GCMS was useful to identify causal substance and to decide the appropriate treatment].

We often have cases of insecticide poisoning where the patient is unconscious and the causal substances are unknown. We report an 83-year-old unconscious man who had apparently ingested several agricultural chemicals, possibly organophosphate or carbamate. According to his family, there were three kinds of containers of agricultural chemicals with their caps opened around him. When he was transferred to our hospital, he presented hypertension, hypersalivation, and muscle fasciculation. His pupils were markedly miotic. In order to identify the substances ingested we used a gas chromatographymass spectrometer (GCMS) using his gastric content. Within 30 minutes we were able to identify the causal substance as methomyl, one of the popular carbamates, thereby eliminating the need to use pralidoxime (PAM). GCMS makes it possible to identify unknown substances quickly and accurately and is therefore extremely useful in deciding the appropriate treatment.