A pheochromocytoma is a tumor (usually benign) that originates from the chromaffin cells of the adrenal medulla. In 90% of patients, the tumor arises in the medulla; in the remaining patients, it occurs in the extra-adrenal chromaffin tissue located in or near the aorta, ovaries, spleen, or other organs. The tumor may occur at any age, but peak incidence is between 40 and 50 years; it affects men and women equally and has familial tendencies. Ten percent of the tumors are bilateral, and 10% are malignant. Although uncommon, it is one cause of hypertension that is usually cured by surgery, but without detection and treatment it is usually fatal.

• Triad of symptoms is headache, diaphoresis, and palpitations in the patient with hypertension.
• Hypertension (intermittent or persistent) and other cardiovascular disturbances are common.
• Other symptoms may include tremor, headache, flushing, and anxiety.
• Hyperglycemia may result from conversion of liver and muscle glycogen to glucose due to epinephrine secretion; insulin may be required to maintain normal blood glucose levels.

• The typical triad of symptoms is headache, diaphoresis, and palpitations in the patient with hypertension.
• Hypertension and other cardiovascular disturbances are common. The hypertension may be intermittent or persistent. If the hypertension is sustained, it may be difficult to distinguish from other causes of hypertension.
• The signs associated with the “five Hs”—hypertension, headache, hyperhidrosis (excessive sweating), hypermetabolism, and hyperglycemia—are assessed.
• Measurements of urine and plasma levels of catecholamines and metanephrine ([MN], a catecholamine metabolite) and vanillylmandelic acid (VMA) or free catecholamines are the most direct and conclusive tests for overactivity of the adrenal medulla.
• Total plasma catecholamine (epinephrine and norepinephrine) concentration is measured with the patient supine and at rest for 30 minutes.
• A clonidine suppression test may be performed if the results of plasma and urine tests of catecholamines are inconclusive.
• Imaging studies (e.g., CT and MRI scans, ultrasonography, ¹³¹I-metaiodobenzylguanidine [MIBG] scintigraphy) are used to localize the pheochromocytoma and to determine whether more than one tumor is present.
• Function of other endocrine glands is evaluated.

• Bed rest with the head of the bed elevated is recommended.
• The patient may be moved to the intensive care unit for close monitoring of ECG changes and careful administration of alpha-adrenergic blocking agents (e.g., phentolamine [Regitine]), sometimes in tandem with a beta-adrenergic blocker (e.g., propranalol [Inderal]). Smooth muscle relaxants (e.g., sodium nitroprusside [Nipride]) may be added to lower the blood pressure quickly.
• Preoperatively, the patient may begin treatment with a low dose of an alpha-adrenergic blocker (phenoxybenzamine [Dibenzyline]) 10 to 14 days (or longer) prior to surgery.
• Treatment is surgical removal of the tumor, usually with adrenalectomy; hypertension usually subsides with treatment. Patient preparation includes control of blood pressure and blood volumes, which is typically carried out over 4 to 7 days.
• Patient is hydrated before, during, and after surgery.
• Postoperative corticosteroid replacement is required as a long-term medication after bilateral adrenalectomy.
• Careful attention is directed toward monitoring and treating hypotension and hypoglycemia.
• Several days after surgery, urine and plasma levels of catecholamines and their metabolites are measured to determine whether the surgery was successful.

• Monitor ECG changes, arterial pressures, fluid and electrolyte balance, and blood glucose levels.
• Monitor for a hypertensive crisis, which may result from manipulation of the tumor during surgical excision; this causes a release of stored epinephrine and norepinephrine, with marked increases in blood pressure and changes in heart rate.
• Encourage patient to schedule follow-up appointments to ensure that pheochromocytoma does not recur undetected.
• Inform patient about the potential for adverse effects of the medications, which include orthostasis, nasal stuffiness, increased fatigue, and retrograde ejaculation in men.
• Educate the patient about the purpose of corticosteroid agents, the medication schedule, and the risks of skipping doses or abruptly stopping administration of the doses.
• Educate the patient and family about how to measure the patient's blood pressure and when to notify the physician about changes in blood pressure.
• Encourage patient to begin a high-sodium diet on the second or third day after the introduction of an alpha-adrenergic blocking agent.
• Provide verbal and written instructions on collecting 24-hour urine specimen.
• Refer to home care nurses, as indicated.
• Give encouragement and support, because patient may be fearful of repeated attacks.
• Educate patient on the importance of periodic checkups owing to high risk of hypertension recurrence, especially in young patients.

For more information, see Chapter 52 in Hinkle, J. L., & Cheever, K. H. (2018). Brunner and Suddarth's textbook of medical-surgical nursing (14th ed.). Philadelphia, PA: Lippincott Williams & Wilkins.