Primary Hyperaldosteronism Flashcards
outline the typical presentation for primary hyperaldosteronism?
HTN (not being controlled by drugs and young pts)
hypokalaemia symp: headaches, tiredness, polyuria/ polydipsia, muscle weakness and parasthesia
Define primary hyperaldosteronism?
autonomous aldosterone overproduction from the adrenal gland with subsequent suppression of plasma renin activity
outline the 2 main causes of primary hyperaldosteronism?
Adrenal adenoma (Conn’s syndrome) - responsible for 70% of cases
Adrenal cortex hyperplasia (30% of cases)
outline the pathophysiology of primary hyperaldosteronism?
Excess aldosterone leads to increased Na+ and water retention
This leads to hypertension
It also causes increased renal K+ loss leading to hypokalaemia
Renin is suppressed due to NaCl retention
summarise the epidemiology of primary hyperaldosteronism?
1-2% of hypertensive patients
Conn’s syndrome is more common in WOMEN and YOUNG patients
Bilateral adrenal hyperplasia is more common in MEN and presents at an older age
what are the presenting symptoms of primary hyperaldosteronism?
Symptoms of Hypokalaemia
- Muscle weakness
- Polyuria and polydipsia (due to nephrogenic DI)
- Paraesthesia
- Lethargy
- Tetany
- Mood disturbances
- Difficulty concentrating
what are the signs of primary hyperaldosteronism on physical examination?
signs of hypertension
what are the possible complications of primary hyperaldosternoism ?
Complications of hypertension e.g. stroke, MI, HF< AF, impaired renal function
summarise the prognosis for patients with primary hyperaldosteronism?
Surgery may cure hypertension
Or it may make the hypertension easier to treat with anti-hypertensive medication
what is management for bilateral adrenal hyperplasia?
Spironolactone – primary choice
OR
Eplerenone can be used if the spironolactone side-effects are intolerable – secondary choice
OR
Amiloride (potassium-sparing diuretic)
Amiloride and spironolactone can also be used in combination to minimise the dose of spironolactone and the risk of sex-steroid-related adverse effects. Eplerenone (in countries where available as a subsidised treatment for PA) is another option for patients in whom spironolactone is poorly tolerated and where amiloride is unable to achieve sufficient aldosterone blockade.
Monitor serum K+, creatinine and BP
what are the screening tests for primary hyperaldosteronism?
24 Hr Bp monitoring ( rule out primary HTN)
Low Serum K+
- NOTE: Serum Na+ is usually normal because the Na+ reabsorption is matched by water reabsorption
High Urine K+
High Plasma Aldosterone Concentration
High aldosterone: renin activity ratio
- RENIN must be suppressed but need to check the meds which will suppress renin (e.g. bet-blockers artificially suppress) so you don’t get a false positive
What are the confirmatory tests for prmary hyperaldosteronism?
Salt Loading - Failure of aldosterone suppression following salt load confirms primary hyperaldosteronism
Postural Test - Measure plasma aldosterone, renin activity and cortisol when the patient is lying down at 8 am and measure again after 4 hrs of the patient being upright
CT adrenal/MRI
Bilateral adrenal vein catheterisation - Measures adrenal vein aldosterone levels and allows you to distinguish between Conn’s syndrome and bilateral adrenal hyperplasia
- Sample from left and right renal vein and IVC – need to have XS production from one side which suppresses the other side and less from the IVC – can confirm the diagnosis and say that it is lateralised (so less likely to be bilateral adrenal hyperplasia)
Radio-labelled cholesterol scanning
what does the postural test show for primary hyperaldosteronism?
Measure plasma aldosterone, renin activity and cortisol when the patient is lying down at 8 am and 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
describe radio-labelled cholesterol scanning results for adrenal hyperplasia?
Unilateral uptake in adrenal adenomas
Bilateral uptake in bilateral adrenal hyperplasia
