Which of the following is an indication for renal replacement therapy?

• A. Acute kidney injury that improves with fluids
• B. Mild azotemia that responds to medical therapy
• C. End-stage kidney disease with refractory volume overload
• D. Hypokalemia requiring no therapy

Answer: (C)

The main concept here is that renal replacement therapy is reserved for situations where the kidneys can no longer maintain fluid and waste balance, especially when dangerous complications or symptoms persist despite other treatments. End-stage kidney disease with refractory volume overload is a classic scenario: the kidneys can’t excrete enough salt and water, so fluid accumulates, leading to edema and possible pulmonary congestion. When this volume overload does not respond to diuretics or dietary measures, dialysis is needed to remove the excess fluid and restore balance.

Why this option fits best: in long-standing kidney failure, the problem isn’t just a temporary imbalance but a chronic inability to regulate fluids. If volume overload remains uncontrolled, it can cause high blood pressure, heart failure, and lung issues; dialysis directly removes the excess fluid, addressing the root problem in this context.

Why the others aren’t indications: acute kidney injury that improves with fluids suggests a reversible, prerenal type that may recover with proper perfusion and hydration, so RRT isn’t required. Mild azotemia that responds to medical therapy indicates the kidneys can manage waste products with treatment, so dialysis isn’t needed. Hypokalemia needing no therapy is not an indication for dialysis, and in fact dialysis is typically reserved for hyperkalemia or other severe metabolic derangements, not low potassium.