Homicide with intramuscular cyanide injection: a case report

Abstract

Cyanide poisoning most commonly occurs from smoke inhalation, less commonly by oral ingestion for suicide or homicide. There are rare cases of intravenous or subcutaneous parenteral cyanide. We report a fatal case of intramuscular cyanide used as a homicidal agent. A 35-year-old female was assaulted and injected with an unknown substance in her left buttock using a syringe. She was unresponsive at ED arrival and underwent immediate endotracheal intubation. After near normal vital signs at arrival (BP 130/83 mmHg, HR 102 bpm), she rapidly became hypotensive and bradycardic with worsening acidosis (pH 6.95, lactate 7.7 mmol/L). Despite vasopressors, hydroxocobalamin, and sodium thiosulfate, she succumbed. Plasma cyanide concentrations from blood drawn 1 and 4 h post exposure were both in the lethal range (3.4 and 4.1 mg/L, respectively). Our case demonstrates that intramuscular injection can result in fatal cyanide poisoning, resulting in rapid absorption, severe toxicity, and death.