SECONDARY HYPERTENSION-PRIMARY HYPERALDOSTERONISM

SUMMARY

1. In the patient with hypokalemia and hypertension, screen for hyperaldosteronism: early morning aldosterone:renin ratio (ratio > 30 is considered positive).

2. Causes: adrenal adenomas (70%; AKA "Conn syndrome"), idiopathic bilateral adrenal hyperplasia (25%), adrenal carcinoma (rare).

3. Investigate positive screening test with IV NS (salt & fluid loading) over 3-4 hours and check aldosterone levels. Alternatively, give oral salt load over 3-4 days.

4. Subsequently investigate with CT abdomen.

5. Initial management: salt & fluid restriction, potassium-sparing diuretic.

6. Unilateral adrenal adenomas are surgically removed with excellent results, whereas patients with bilateral adrenal hyperplasia are managed with diuretics alone.

Reference(s)

Wilkinson, I. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].