For hyperkalemia with ECG changes in CKD, what is the first-line management step?

• A. IV calcium to stabilize the myocardium.
• B. Immediate dialysis without stabilization.
• C. IV bicarbonate alone.
• D. Oral potassium binders first.

Answer: (A)

The immediate threat in hyperkalemia with ECG changes is the risk of lethal cardiac arrhythmias, so the first move is to stabilize the heart with IV calcium (calcium gluconate or calcium chloride). Calcium quickly protects myocardial cells by raising the threshold for depolarization, buying time to lower the potassium level. It does not reduce serum potassium itself, so after stabilization you proceed to shift potassium into cells (for example, insulin with glucose, and possibly beta-agonists or bicarbonate if acidotic) and then remove potassium from the body (diuretics if any remaining function, potassium binders, or dialysis in CKD). The other options don’t provide immediate myocardial protection or rapid, definitive control in this acute setting.