Which adjunct is specifically used with CPR for hyperkalemia-induced cardiac arrest?

• A. Sodium bicarbonate
• B. Atropine
• C. Calcium chloride
• D. Dopamine

Answer: (C)

Hyperkalemia makes cardiac membranes unstable and slows conduction, which can drive a cardiac arrest scenario during CPR. Giving calcium directly stabilizes the cardiac cell membranes by increasing the threshold for depolarization, so the heart muscle becomes less irritable and more likely to maintain organized electrical activity during resuscitation. This immediate membrane stabilization is why calcium chloride is the adjunct of choice in hyperkalemia-induced cardiac arrest.

Sodium bicarbonate can help by correcting acidosis and shifting potassium into cells, but its effect is slower and not as immediate for membrane stabilization during CPR. Atropine targets bradycardia from vagal causes, not hyperkalemia, and dopamine is a vasopressor/inotrope without addressing the underlying membrane instability caused by high potassium.