A -year-old male is evaluated in the ambulatory clinic for newly discovered hypertension. During a health screening two weeks ago, his blood pressure was recorded at mmHg. Today, his vitals show a blood pressure of mmHg with a regular pulse of /min. The patient takes no daily medications and has no family history of early-onset cardiovascular disease. He mentions experiencing intermittent muscle cramps and generalized weakness over the past few months. Physical examination is unremarkable, with no abdominal bruits, abnormal facies, or purple striae. Initial basic metabolic panel results demonstrate a serum sodium of mEq/L and a serum potassium of mEq/L. Which of the following is the most appropriate next step in laboratory evaluation?
- AIntravenous saline suppression test
- Measurement of plasma aldosterone concentration and plasma renin activityCevap
- CComputed tomography of the adrenal glands
- DAdrenal venous sampling
- E24-hour urine collection for fractionated metanephrines
Cevap
Measurement of plasma aldosterone concentration and plasma renin activity
The correct next step is the measurement of plasma aldosterone concentration (PAC) and plasma renin activity (PRA). This patient's presentation of newly discovered hypertension accompanied by spontaneous hypokalemia and muscle cramps is highly suspicious for primary hyperaldosteronism. The diagnostic algorithm for primary hyperaldosteronism requires strict sequencing. The very first step is biochemical screening utilizing the PAC/PRA ratio. In primary hyperaldosteronism, autonomous aldosterone secretion suppresses renin production, resulting in a significantly elevated ratio.
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Anahtar Kavram
The diagnostic workup for primary hyperaldosteronism begins with screening via the plasma aldosterone concentration to plasma renin activity ratio, followed by confirmatory suppression testing, and finally localization imaging.