Primary aldosteronism

The Correct Answer is E


Explanation:

Primary aldosteronism, a disorder characterized by hypertension, hypokalemia, suppressed plasma renin activity, and increased aldosterone secretion, affects 0.05 to 2% of the hypertensive population. This disorder should be suspected in hypertensive patients in whom spontaneous or easily provoked hypokalemia develops that is slow to correct after discontinuation of diuretics.

As important as recognizing the presence of primary aldosteronism is the differentiation of lesions that are surgically curable (60-70% of the cases in some series) from those that are best treated medically.

In this patient, the presence of hypertension, hypokalemia, and alkalosis appropriately triggered screening for hyperaldosteronism, which led to the findings of an aldosterone-renin ratio of greater than 30, which constitutes a positive screening test.

Aldosteronism can be confirmed by the finding of a 24-hour urine aldosterone secretion of 12 μg in the salt replete state. Adrenal imaging is the next step to differentiate adrenal adenoma from adrenal hyperplasia, although adenomas smaller than 1.5 cm can be missed and thus mistaken for hyperplasia. In confusing cases, adrenal vein sampling for aldosterone measurements is used to localize adenoma with a 95% accuracy.

The finding of a lateralizing 10:1 aldosterone ratio in the presence of a symmetrical ACTH-induced cortisol rise diagnoses and localizes an adenoma. Other features suggestive of adenoma include plasma 18-hydroxy corticosterone of 100 ng/dL or more, spontaneous hypokalemia of less than 3 mEq/L, and an anomalous postural decrease of plasma aldosterone concentration.

Saline loading is inappropriate in this patient because of heart failure and hypertensive retinopathy.

Category: