Efficacy of First-Line Sodium Thiosulfate Administration in a Case of Potassium Cyanide Poisoning

Abstract

Cyanide poisoning may occur following accidental fire-smoke inhalation or deliberate ingestion of salts. Hydroxocobalamin represents a first-line life-saving antidote. Although hydroxocobalamin represents a first-line lifesaving antidote, it is still not promptly available in the emergency department. Sodium thiosulfate can be administered in association with hydroxocobalamin whereas the delayed onset of clinical response makes sodium thiosulfate less suitable for emergency use. We describe a case of cyanide intoxication of a 43-year-old man who ingested an unknown amount of potassium cyanide, purchased via the Internet, in an attempted suicide. At admission to the emergency department, the patient presented GCS 3 with severe lactic acidosis. Orotracheal intubation, gastric lavage and oral activated charcoal were applied. Sodium thiosulfate was available in the emergency department and 10 grams were infused over a 30 minute period. Hydroxocobalamin was prescribed by the poison control centre and 5 grams were infused 2 hours after admission. Following sodium thiosulfate administration the patient was arousable and lactate concentration improved. No adverse effects were noted. Metabolic acidosis completely resolved 12 hours later. Cyanide concentration performed on blood samples collected at admission confirmed high cyanide blood levels (15 mg/L). This report highlights as the first-line administration of sodium thiosulfate, in rapid infusion, resulted effective and safe for cyanide poisoning. Our report suggests that sodium thiosulfate should be considered when hydroxocobalamin is not promptly available in an emergency setting.