In acute hyperkalemia, which measure is immediately used to stabilize cardiac membranes?

In acute hyperkalemia, which measure is immediately used to stabilize cardiac membranes?

• A. IV Calcium Gluconate
• B. Kayexalate
• C. Insulin plus Dextrose
• D. Inhaled Beta-Agonist

Answer: (A)

The key idea is that in acute hyperkalemia the first priority is to protect the heart from the electric instability caused by high potassium. Calcium given intravenously stabilizes the myocardial membrane quickly by raising the threshold for depolarization, which reduces excitability and prevents life-threatening arrhythmias. This protection occurs within minutes, giving you time to employ treatments that lower the potassium level itself. Importantly, calcium does not lower potassium—it simply buys time for other measures to work. Options that shift potassium into cells or remove it from the body (like insulin with dextrose or beta-agonists, or GI binders) act on potassium levels, not membrane stability, and Kayexalate has a slower onset. So, intravenous calcium gluconate provides the immediate cardiac membrane stabilization needed in acute hyperkalemia.

The key idea is that in acute hyperkalemia the first priority is to protect the heart from the electric instability caused by high potassium. Calcium given intravenously stabilizes the myocardial membrane quickly by raising the threshold for depolarization, which reduces excitability and prevents life-threatening arrhythmias. This protection occurs within minutes, giving you time to employ treatments that lower the potassium level itself. Importantly, calcium does not lower potassium—it simply buys time for other measures to work. Options that shift potassium into cells or remove it from the body (like insulin with dextrose or beta-agonists, or GI binders) act on potassium levels, not membrane stability, and Kayexalate has a slower onset. So, intravenous calcium gluconate provides the immediate cardiac membrane stabilization needed in acute hyperkalemia.