To treat hyperkalemia in ARF, which combination of therapies is used?

• A. Hypertonic glucose, insulin infusions, and sodium bicarbonate
• B. Potassium-lowering diuretics alone
• C. High-dose potassium supplements
• D. Calcium channel blockers alone

Answer: (A)

The key idea is rapidly lowering extracellular potassium by shifting it into cells while correcting the underlying acidosis. Insulin, given with glucose, drives potassium into cells via the Na+/K+-ATPase, and the glucose prevents hypoglycemia from the insulin. Adding sodium bicarbonate helps raise pH, which also promotes potassium movement into cells. Together, this combination provides a quick reduction in circulating potassium, which is crucial in acute renal failure where the kidneys can’t excrete potassium effectively. Other options aren’t as helpful: diuretics alone rely on kidney function and may not work in ARF; giving potassium would worsen the problem; and calcium channel blockers don’t lower potassium at all.