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.