Free BCEN Certified Emergency Nurse (CEN) Practice Question

The correct answer is hydroxocobalamin (Cyanokit). The patient's presentation is consistent with cyanide poisoning, which can occur in firefighters exposed to smoke from burning synthetic materials. Cyanide inhibits cellular respiration, leading to lactic acidosis and central nervous system depression. Hydroxocobalamin is the preferred antidote in this scenario because it directly binds cyanide to form cyanocobalamin, which is then excreted in urine. It has a favorable safety profile and does not cause hypotension or methemoglobinemia.

Sodium thiosulfate, while effective, is typically used as a second-line treatment or in combination with other antidotes. It works more slowly than hydroxocobalamin. Amyl nitrite is part of the older cyanide antidote kit and is not the first choice due to its potential to cause methemoglobinemia and hypotension. Pralidoxime is used for organophosphate poisoning, not cyanide toxicity.