Primary Hyperaldosteronism Flashcards
What is primary hyperaldosteronism?
Autonomous aldosterone overproduction from the adrenal gland with subsequent suppression of plasma renin activity
Give the 2 main causes of primary hyperaldosteronism?
Idiopathic bilateral adrenal hyperplasia (60%)
Adrenal adenoma: Conn’s syndrome (40%)
What rare causes are there for primary hyperaldosteronism?
Familial hyperaldosteronism
Aldosterone producing adrenal carcinoma
Describe the pathophysiology of primary hyperaldosteronism
Excess aldosterone causes increased Na+ + water retention
Leads to increased blood volume + HTN
Also causes increased renal K+ loss leading to hypokalaemia
Renin is suppressed due to NaCl retention
Describe the epidemiology of primary hyperaldosteronism
5-10% of hypertensive patients
Conn’s syndrome F > M
Bilateral adrenal hyperplasia M>F
List 7 symptoms hypokalaemia
Fatigue Muscle weakness Headaches Constipation Palpitations Polyuria + polydipsia (due to nephrogenic DI) Paraesthesia (metabolic alkalosis)
List 4 signs of primary hyperaldosteronism
HTN (drug resistant) Complications of HTN e.g. Headaches Facial flushing Hypertensive retinopathy
What screening tests can be used for primary hyperaldosteronism?
Low Serum K+ Normal/ mild hypernatraemia as Na+ reabsorption is matched by water reabsorption High Urine K+ High Plasma Aldosterone Concentration High aldosterone: renin activity ratio
What confirmatory tests can be used for primary hyperaldosteronism?
Salt Loading
Failure of aldosterone suppression following salt load
CT/MRI: to detect tumour or hyperplasia
Why perform a bilateral adrenal vein catheterisation?
Measures adrenal vein aldosterone levels
Conn’s syndrome: discrepancy between adrenal levels
Bilateral adrenal hyperplasia: no difference between sides
How does Radio-labelled cholesterol scanning differentiate between causes of primary hyperaldosteronism?
Unilateral uptake in adrenal adenomas
Bilateral uptake in bilateral adrenal hyperplasia
Describe the management of bilateral adrenal hyperplasia
Spironolactone or Eplerenone
Amiloride (K+ sparing diuretic)
Monitor serum K+, creatinine + BP
ACEi + CCBs may also be added
Describe the management of Conn’s syndrome
Adrenalectomy
Describe the management of an adrenal carcinoma
Surgery
Post-operative mitotane (antineoplastic)
What complications may arise due to primary hyperaldosteronism?
Complications of HTN