Hyperaldosteronism

Question 1

Aetiology of hyperaldosteronism

Answer 1

Bilateral idiopathic adrenal hyperplasia is the most common cause of primary hyperaldosteronism
Excess aldosterone may be secondary to an adrenal adenoma (Conn’s syndrome, 70%)
Hyperplasia of the adrenal cortex (30%)
Rare: Glucocorticoid-suppressible hyperaldosteronism (1-3%) or an aldosterone producing adrenal carcinoma

Excess aldosterone results in Increased sodium and water retention causing hypertension, increased renal potassium loss and hypokalaemia and suppression of renin due to NaCl retention

Question 2

Risk factor for hyperaldosteronism

Answer 2

Age 20-70
Family history of PA
Family history of early onset of hypertension and/or stroke

Question 3

Symptoms and signs of hyperaldosteronism

Answer 3

Usually asymptomatic

Nocturia, Polyuria (nephrogenic DI secondary to hypokalaemia)
Lethargy
Mood disturbance (irritability, anxiety, depression)
Difficulty concentrating
Paraesthesia’s, muscle cramp
Muscle weakness
Palpitations
Headache

Sign: hypertension

Question 4

Investigations for hyperaldosteronism

Answer 4

Urine potassium: high

Aldosterone/renin ratio: raised (done after stopping anti-HTN for 2 weeks)
U&Es: Hypokalaemia

HR-CT: visualise any adrenal masses
Bialteral adrenal vein catheterisation and sampling: distinguish between Conn’s syndrome and bilateral adrenal hyperplasia
Fludrocortisone suppression test: failure of aldosterone suppression
Salt loading: failure of aldosterone suppression
Postural test: aldosterone and renin levels increase (Bilateral adrenal hyperplasia)

Question 5

Management for unilateral adrenal masses causing hyperaldosteronism

Answer 5

Unilateral laparoscopic adrenalectomy
1. Aldosterone antagonists e.g. amiloride, spironolactone, epleronone
2. Stop K+ supplementation immediately before surgery
3. Discontinue aldosterone antagonists

Post-op fluids without KCl

Adrenal lesion ≥ 2.5cm → immediate unilateral laparoscopic adrenalectomy

Question 6

Management for bilateral adrenal masses causing hyperaldosteronism

Answer 6

1. Aldosterone antagonists e.g. amiloride 2.5-15mg orally once daily in 2 divided doses, spironolactone, eplerenone
2. Laparoscopic adrenalectomy

Question 7

Complications of hyperaldosteronism

Answer 7

Complications of hypertension
- Stroke
- Myocardial Infarction
- Heart Failure
- Atrial fibrillation
- Impaired renal function
Perioperative complications (e.g., bleeding, infection, wound hernia, cardiovascular events)
Aldosterone antagonist- or mineralocorticoid receptor antagonist-induced hyperkalaemia

Question 8

Prognosis for hyperaldosteronism

Answer 8

Surgery either cures hypertension (50%) or will make it more amenable to anti-hypertensive therapy in those who are not cured (usually elderly or those with long-standing HTN)
Recurrence of PA in those apparently cured after 12 months is uncommon
Hypertension is improved and control achieved in the majority undergoing aldosterone antagonist treatment, but this is not as dramatic as surgical treatment
Hypertension in familial hyperaldosteronism type I (FH-I) is frequently of early onset and may be severe enough to cause early death, usually from haemorrhagic stroke, unless specifically treated, but treatment with glucocorticoids is usually highly effective