Which agent is used to stabilize the myocardium in hyperkalemia?

• A. Albuterol inhalation
• B. Insulin with glucose
• C. Calcium gluconate
• D. Sodium bicarbonate

Answer: (C)

When potassium is elevated, the first priority is to protect the heart from the unstable electrical environment it creates. Calcium helps achieve this by stabilizing the cardiac cell membranes. Administering calcium gluconate raises the threshold for triggering action potentials, reducing excitability and preventing dangerous arrhythmias, even before potassium levels are lowered. This effect is rapid, giving critical time to implement measures that actually lower serum potassium, such as shifting potassium into cells with insulin plus glucose or beta-agonists, or removing potassium from the body. The other options can lower potassium or shift it intracellularly, but they do not provide the immediate membrane stabilization the heart needs in hyperkalemia.