The nurse is evaluating a client's response to hemodialysis. Which laboratory values will indicate the dialysis was effective?

A. White blood cells (WBCs) increase from 5000 to 8000/mm³ (5 to 8 x 10⁹/L): WBC count is not directly affected by hemodialysis and reflects immune status rather than dialysis effectiveness. Changes in WBCs are unrelated to solute removal or fluid balance achieved during the procedure. B. Serum potassium level decreases from 5.4 to 4.6 mEq/L (5.4 to 4.6 mmol/L): A reduction in serum potassium indicates effective removal of excess potassium by hemodialysis. Controlling hyperkalemia is critical in renal failure, and normalization of potassium demonstrates successful solute clearance during the session. C. Hemoglobin increases from 10 to 12 g/dL (100 to 120 mmol/L): Hemoglobin levels do not change acutely after a single dialysis session, as erythropoiesis and anemia management are long-term processes. An immediate rise in hemoglobin is not an indicator of dialysis effectiveness. D. Blood urea nitrogen (BUN) decreases from 110 to 90 mg/dL (39.3 to 32.1 mmol/L): Although BUN is reduced by dialysis, a decrease from 110 to 90 mg/dL is relatively small and may indicate incomplete removal of urea. A more significant drop is usually expected to demonstrate optimal dialysis efficacy.