Which option correctly identifies the two chemical agent classes and their countermeasures commonly referenced in casualty management?

• A. Choking agents with bronchodilators; cyanide antidotes
• B. Nerve agents (atropine and pralidoxime) and cyanide (hydroxocobalamin or other antidotes)
• C. Nerve agents (atropine and pralidoxime) and cyanide (hydroxocobalamin)
• D. Nerve agents (epinephrine and pralidoxime) and cyanide (nitrite-based antidotes)

Answer: (C)

Two chemical agent classes commonly addressed in casualty management are nerve agents and cyanide. For nerve agents, the standard countermeasures are atropine and pralidoxime. Atropine blocks muscarinic effects such as bronchorrhea, bronchospasm, and secretions, while pralidoxime reactivates acetylcholinesterase to reduce nicotinic and muscarinic toxicity, helping reverse the cholinergic crisis. For cyanide, the widely referenced antidote in field settings is hydroxocobalamin, which binds cyanide to form non-toxic cyanocobalamin that the body can excrete. This pairing—nerve agents with atropine and pralidoxime, plus cyanide with hydroxocobalamin—is the most consistently taught and used in casualty management. Other options either mix in less common antidotes or pair the wrong classes, making them less aligned with standard emergency protocols.