A patient is experiencing hyperkalemia. Which of the following nursing interventions is the priority in this situation to prevent complications?

Hyperkalemia is serum potassium >5.0 mmol/L that alters cardiac membrane potential, decreases myocardial excitability threshold, and disrupts cardiac conduction, leading to peaked T waves, widened QRS complexes, ventricular arrhythmias, and potential cardiac arrest. Rationale: A. Encouraging high-potassium foods is contraindicated and worsens hyperkalemia. It further increases extracellular potassium concentration and exacerbates cardiac conduction abnormalities. This intervention increases risk of life-threatening dysrhythmias. B. Potassium-sparing diuretics are contraindicated in hyperkalemia because they reduce renal potassium excretion. They worsen serum potassium elevation and increase risk of arrhythmias. This does not correct electrolyte imbalance and is unsafe. C. Calcium supplements (specifically IV calcium gluconate) stabilize cardiac membranes but do not lower potassium levels. While protective, they are not the primary monitoring intervention. This does not directly address ongoing rhythm detection needs. D. Continuous cardiac rhythm monitoring is the priority to detect early signs of lethal arrhythmias caused by hyperkalemia. It allows immediate intervention when ECG changes occur. This directly prevents progression to cardiac arrest by enabling rapid response.