Calcium is considered cardioprotective in hyperkalemia.

• A. True
• B. False
• C. Not sure
• D. It depends on context

Answer: (A)

In hyperkalemia, calcium is used to protect the heart by stabilizing the cell membranes. When potassium rises outside the cell, the resting membrane potential becomes less negative, which can inactivate sodium channels and lead to slowed conduction and dangerous arrhythmias. Calcium counters this by increasing the threshold for depolarization, making cardiac cells less jumpy and helping to maintain stable electrical activity.

Importantly, calcium doesn’t lower the potassium level itself; it’s a rapid, temporary safeguard that buys time for definitive potassium-lowering treatments such as insulin with glucose, beta-agonists, bicarbonate if indicated, diuretics, or dialysis. Its use is particularly emphasized when there are ECG changes or high potassium with risk of dysrhythmia, making it a recognized cardioprotective step.

So, the statement is true: calcium is considered cardioprotective in hyperkalemia.