Unmasking Cyanide Toxicity: A Case of Encephalopathy and Ventilatory Support Following Smoke Inhalation.

Cyanide toxicity is an uncommon yet life-threatening consequence of smoke inhalation, particularly when synthetic materials burn in confined or poorly ventilated environments. Prompt recognition is essential, as delayed treatment can lead to rapid neurological decline and respiratory failure. We report the case of a 40-year-old incarcerated male who developed acute encephalopathy and respiratory compromise after exposure to dense smoke while working near a burning fuse in a prison yard. Worsening mental status and diminished respiratory effort necessitated endotracheal intubation and mechanical ventilation. Laboratory findings revealed a markedly elevated lactate level and a minimal arterial-venous partial pressure of oxygen (PaO₂) gradient, raising suspicion for cyanide poisoning. The patient demonstrated rapid clinical improvement following empiric administration of hydroxocobalamin, further supporting the diagnosis. This case underscores the importance of maintaining a high index of suspicion for cyanide toxicity in smoke inhalation victims, especially in high-risk, resource-limited environments such as correctional facilities. Early empiric administration of hydroxocobalamin may be life-saving and should not be delayed pending confirmatory testing.