A client who has acute glomerulonephritis is hospitalized with hyperkalemia. Which information will the nurse monitor to evaluate effectiveness of the prescribed calcium gluconate IV?

A. Calcium level: Calcium gluconate administration can transiently increase serum calcium levels, but monitoring calcium is not the primary indicator of therapeutic effectiveness in hyperkalemia. The goal of therapy is not to correct calcium deficiency but to stabilize the myocardial cell membrane against the effects of elevated potassium. B. Urine volume: Urine output reflects renal function and potassium excretion, which are important in managing hyperkalemia long-term. However, calcium gluconate does not lower serum potassium or enhance excretion; it acts rapidly on cardiac cells, so urine output does not indicate its immediate effectiveness. C. Cardiac rhythm: Hyperkalemia alters cardiac conduction, leading to ECG changes such as peaked T waves, widened QRS complexes, and risk of life-threatening arrhythmias. Calcium gluconate works by stabilizing the cardiac membrane and reducing excitability, thereby protecting against dysrhythmias. Improvement or stabilization of cardiac rhythm is the most direct indicator of its effectiveness. D. Neurologic status: Neurologic changes can occur with electrolyte imbalances, but calcium gluconate is not primarily used to correct neurologic symptoms in hyperkalemia. Its main therapeutic action is cardioprotective rather than neurologic, making neurologic status a less specific indicator of treatment response.