The patient's potassium level is 6.2 mEq/L. Which of the following signs should the nurse monitor most closely?

A. Blood pressure changes are incorrect because although hyperkalemia can indirectly affect cardiac output, blood pressure is not the most sensitive indicator of elevated potassium. Blood pressure may remain normal even when dangerous arrhythmias are developing. B. Electrocardiogram abnormalities is correct because hyperkalemia directly affects cardiac conduction. At a potassium level of 6.2 mEq/L, patients are at high risk for life-threatening arrhythmias. Typical ECG changes include peaked T waves, prolonged PR interval, widened QRS complex, flattened P waves, and a sine wave pattern, which may progress to ventricular fibrillation or asystole. Continuous cardiac monitoring is essential because these changes can occur rapidly, and early detection allows immediate intervention to prevent cardiac arrest. C. Respiratory rate is incorrect because hyperkalemia typically does not initially affect respiration. Severe hyperkalemia can lead to muscle weakness, including the diaphragm, which may reduce ventilation, but these complications occur after cardiac effects and are not the most urgent concern. D. Level of consciousness is incorrect because neurological changes such as confusion, weakness, or paresthesia are usually late signs of hyperkalemia. While important to monitor, altered mental status is less immediately life-threatening than cardiac effects.