During the preoperative period for adrenalectomy due to pheochromocytoma, the priority nursing action would be to monitor:

• A. Vital signs
• B. Intake and output
• C. Blood urea nitrogen (BUN) level
• D. Urine for glucose and acetone

Answer: (A)

The key idea is that managing hemodynamic stability is crucial in the preoperative period for pheochromocytoma. This tumor can release large amounts of catecholamines, especially during manipulation or stress, leading to sudden spikes in blood pressure and heart rate and risking life-threatening hypertensive crises or arrhythmias. Therefore, continuously monitoring vital signs—particularly blood pressure and pulse—to detect and respond to these changes is the top priority. This allows timely administration of antihypertensive or rate-controlling medications and adjustments to the anesthesia plan to keep the patient stable before and during surgery.

While intake and output, BUN, and urine glucose/acetone are useful parts of overall preop assessment, they do not address the immediate threat posed by catecholamine surges. They are less critical for guiding urgent intraoperative hemodynamic management compared with ongoing vital signs monitoring.