Primary hyperaldosteronism Flashcards
define primary hyperaldosteronism?
characterised by autonomous aldosterone overproduction from the adrenal gland with subsequent suppression of plasma renin activity
what are the causes of hyperaldosteronism?
• Adrenal cortex hyperplasia – MOST COMMON
• Adrenal adenoma (Conn’s syndrome)
• RARE:
o Aldosterone producing adrenal carcinoma
what is the pathophysiology of primary hyperaldosteronism?
o Excess aldosterone leads to increased Na+ and water retention
o This leads to hypertension
o It also causes increased renal K+ loss leading to hypokalaemia
o Renin is suppressed due to NaCl retention
what is the epidemiology of primary hyperaldosteronism?
- 1-2% of hypertensive patients
- Bilateral adrenal hyperplasia is more common in MEN and presents at an older age
- Conn’s syndrome is more common in WOMEN and YOUNG patients
main features of hyperaldosteronism?
hypertension, hypokalaemia
symptoms of hypokalaemia?
o Muscle weakness
o Polyuria and polydipsia (due to nephrogenic DI)
o Paraesthesia
o Tetany
what are the signs of primary hyperaldosteronism?
• Hypertension
first line investigation for hyperaldosteronism?
Aldosterone/renin ratio
next line investigation for hyperaldosteronism?
High resolution CT abdomen and adrenal vein cathertisation
- Measures adrenal vein aldosterone levels and allows you to distinguish between Conn’s syndrome (unilateral ) and bilateral adrenal hyperplasia (bilateral)
what might the bloods show?
o Low Serum K+
o Serum Na+ is usually normal
o High Plasma Aldosterone Concentration
what is the postural test?
- Measure plasma aldosterone, renin activity and cortisol when the patient is lying down at 8 am
- Measure again after 4 hrs of the patient being upright
- Aldosterone-producing adenoma - aldosterone secretion decreases between 8 am and noon
- Bilateral adrenal hyperplasia - adrenals respond to standing posture and increase renin production leading to increased aldosterone secretion
how to manage bilateral adrenal hyperplasia?
spironolactone
how to manage conns syndrome?
o Adrenalectomy
how to manage an adrenal carcinoma?
o Surgery
what are the complications of primary hyperaldosteronism ?
• Complications of hypertension