Pheochromocytoma

Pheochromocytoma is a catecholamine-secreting tumor of the adrenal medulla that triggers episodic, severe hypertension. The hallmark triad is sudden-onset hypertension, pounding headache, and profuse diaphoresis, often with tachycardia and a sense of impending doom. Episodes can be provoked by physical pressure on the abdomen, stress, exercise, or certain drugs (beta-blockers given alone, opioids, contrast dye). Diagnosis relies on 24-hour urine collection for catecholamines, metanephrines, and vanillylmandelic acid (VMA) — instruct the client to avoid caffeine, vanilla, citrus, and vigorous exercise during collection as these falsely elevate results. Surgical removal (adrenalectomy) is definitive treatment. Preoperatively, alpha-adrenergic blockers (phenoxybenzamine) are given first to control hypertension; only after adequate alpha blockade are beta-blockers added. Reversing this order causes unopposed alpha stimulation, worsening the hypertensive crisis. Nursing priorities center on avoiding anything that triggers catecholamine surges: do not palpate the abdomen, keep the environment calm, and monitor blood pressure frequently. Postoperatively, monitor for hypotension and hypoglycemia as catecholamine levels suddenly drop.