Pheochromocytoma

A patient's blood pressure spikes to 250/140 during abdominal palpation — the tumor you didn't suspect just announced itself. Knowing what NOT to do next saves a life.

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.

Key Distinctions

Don't confuse pheochromocytoma's episodic hypertensive crises with essential hypertension — essential hypertension is sustained and gradual, not paroxysmal with diaphoresis and panic. Students commonly select beta-blockers as first-line treatment; alpha-blockers must come first — giving a beta-blocker alone removes the vasodilatory beta-2 effect, leaving alpha vasoconstriction unopposed. Don't confuse the 24-hour urine for VMA/metanephrines with the dexamethasone suppression test, which diagnoses Cushing's.

Clinical Pearl

Alpha before beta — think alphabetical order. Give phenoxybenzamine first; adding a beta-blocker without alpha blockade can kill the client.