Cyanide overdose: survival with fatal blood concentration without antidotal therapy.

Cyanide poisoning is an uncommon emergency department problem. It has a high mortality, and specific antidotal therapy can be lifesaving. We describe a 23-year-old man who ingested potassium cyanide and survived without antidotal therapy. His blood cyanide concentration was 4.65 mg/L, which is within the lethal range. The arterial venous oxygen saturation gradient was considered in the decision regarding antidote administration. Our experience underscores the importance of supportive care.