CASE

A 25-year-old male presented to the emergency department after an alleged assault. The patient was hit in the head several times but never lost consciousness. He complained of headache but no nausea. His injuries were isolated to the head and face and limited to lacerations and contusions. The patient was intoxicated; he had consumed as many as 12 cans of beer throughout the evening. A review of systems was otherwise negative for neck or back pain, chest pain, visual changes, shortness of breath, or syncope. Initial vital signs included pulse, 150 beats per minute, and BP, 210/130 mm Hg. Baseline laboratory studies and an ECG were ordered. Potassium level was 2.2 mmol/L, but all other values and CBC results were within normal limits; the blood alcohol level was 0.14 g/dL. CT of the brain was negative. ECG indicated a normal sinus rhythm. Coagulation and cardiac enzyme study results were within normal limits.

History The patient denied any medical problems and family history was negative. He had a one-pack-per-day smoking habit and a remote history of cocaine use. He was employed as a construction worker. During the past 4 months, the patient had lost 30 lb through an effort to stay in shape. He had no contributory night sweats or foreign travel.

Diagnostic studies The patient was admitted to the hospital for evaluation of his hypertensive urgency and hypokalemia. BP remained high; however, he had no sympathomimetic symptoms of anxiety or sweating. Renal ultrasonography was unremarkable. Low plasma renin levels and elevated aldosterone levels were appreciated as part of his admission evaluation. A high resolution CT of the abdomen revealed a 15-mm nodule on the right adrenal gland (Figure 1). Given his transient tachycardia and heavy alcohol use, magnesium and phosphorus levels were obtained; results were 2.5 mg/dL and 3.6 mg/dL, respectively (both within normal ranges).

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DISCUSSION

This patient has two working problems: hypertension and hypokalemia. The underlying cause for both is Conn's syndrome, the most common cause of secondary hypertension.1 The presence of an adenoma with potassium and BP abnormalities indicates a diagnosis of primary hyperaldosteronism, or Conn's syndrome. Low renin levels support the diagnosis in this setting. Diagnostic studies should also include tests for biochemical markers for pheochromocytoma. The patient's weight loss was noncontributory but may have been considered as a cause for the hypokalemia if he had not been hypertensive. Essential hypertension was excluded, as it should have been, during the evaluation for secondary causes.

Treatment After ruling out other causes, primarily pheochromocytoma, Conn's syndrome is treated via an adrenalectomy. Potassium levels must be replenished because the consequential effects of hypokalemia can increase the risk of ventricular arrhythmias. Potassium-sparing diuretics, such as spironolactone (Aldactone), correct the hypokalemia and predict the BP response to surgery.

Our patient was taken into surgery, and an adrenalectomy was performed. Pathology results demonstrated adenoma, confirming the diagnosis. He responded to the adrenalectomy, and follow-up evaluations reflected normotension without medical therapy.

Comment Conn's syndrome is rare; 0.03% to 1.2% of patients with hypertension have the condition.1 Aldosterone induces renal tubular reabsorption of sodium, enhancing secretion of potassium and hydrogen ions.2 An overproduction of aldosterone, as seen in patients with adenomas and hyperplasia, results in hypertension caused by sodium retention and potassium excretion. Patients often present with hypokalemic symptoms, such as fatigue, weakness, cramps, or headaches. Primary hyperaldosteronism may also be caused by bilateral adrenal hyperplasia.

Evaluation of hypertension should differentiate between essential (or primary) and secondary causes. Patients should also be evaluated for renal artery stenosis, coarctation of the aorta, Cushing's syndrome, and adrenal secretory disorders in the appropriate settings. The acuity of the evaluation is determined by the history, physical examination findings, and the affected targeted organs. JAAPA

Tom Vascik practices at Northwest Emergency Physicians of TeamHealth, Tacoma, Washington. The author has indicated no relationships to disclose relating to the content of this article.

Erich Fogg, PA-C, MMSc, department editor

REFERENCES

1. Jabbour SA. Conn syndrome. Emedicine Web site. http://emedicine.medscape.com/article/117280-overview. Updated May 21, 2009. Accessed November 4, 2009.

2. Tierney LM, McPhee SJ, Papadakis MA, eds. Current Medical Diagnosis and Treatment. 38th ed. Stamford, CT: Lange; 1999.