A 45-year-old man is evaluated for treatment-resistant hypertension. His blood pressure remains consistently greater than 150/90 mm Hg despite documented compliance with a three-drug antihypertensive regimen that includes a thiazide diuretic. Recent laboratory testing revealed unprovoked hypokalemia with a serum potassium level of 2.9 mEq/L. The physician strongly suspects primary hyperaldosteronism and plans a complete diagnostic workup to determine if the patient is a candidate for surgical cure. Arrange the following diagnostic and management steps in the most appropriate chronological sequence for the evaluation of this patient.
- 1Measure the ratio of plasma aldosterone concentration to plasma renin activity
- 2Perform an intravenous saline infusion test
- 3Obtain a high-resolution computed tomography (CT) scan of the adrenal glands
- 4Conduct adrenal venous sampling
Cevap
The correct chronological sequence is to first screen with the aldosterone-to-renin ratio, confirm the diagnosis with a saline infusion test, localize the anatomy with an adrenal CT scan, and finally perform adrenal venous sampling to establish functional lateralization prior to surgery.
The evaluation of primary hyperaldosteronism follows a highly structured algorithm. The initial mandatory step is screening with the plasma aldosterone concentration to plasma renin activity ratio. If this ratio is elevated, the diagnosis must be biochemically confirmed with a suppression test, such as an intravenous saline infusion, which will fail to suppress aldosterone levels in patients with autonomous production. Once biochemically confirmed, the workup transitions to localization, beginning with a high-resolution adrenal CT scan. Because non-functioning adrenal incidentalomas are highly prevalent, particularly in middle-aged and older adults, an anatomic CT scan alone cannot reliably determine the source of aldosterone hypersecretion. Therefore, adrenal venous sampling is typically required in surgical candidates to functionally confirm unilateral disease (e.g., an aldosterone-producing adenoma) versus bilateral adrenal hyperplasia.
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Anahtar Kavram
The diagnostic algorithm for primary hyperaldosteronism follows a strict sequence: initial biochemical screening, confirmatory suppression testing, anatomic localization via CT scan, and functional lateralization via adrenal venous sampling.