Hyperaldosteronism Flashcards
What are the effects of aldosterone?
Increase sodium reabsorption from distal tubule
Increase potassium secretion from distal tubule
Increase hydrogen secretion from collecting ducts
What is primary hyperaldosterone called?
Conn’s syndrome
What causes Conn’s syndrome?
Adrenal glands producing too much aldosterone:
- adrenal adenoma (most common)
- bilateral adrenal hyperplasia
- familial hyperaldosteronism (rare)
- adrenal carcinoma (rare)
What effect does primary aldosteronism have on the serum renin level?
Will be LOW –> suppressed by the high BP
What is secondary hyperaldosteronism?
Excessive renin stimulates the adrenal gland to produce more aldosterone –> renin will be HIGH
What causes the high renin levels –> secondary hyperaldosteronism?
Occurs when the BP in the kidneys is lower than the BP in the rest of the body:
- renal artery stenosis
- renal artery obstruction
- heart failure
What causes renal artery stenosis and how is it diagnosed?
Atherosclerosis of the renal artery
–> doppler US, CT angiogram or MR angiogram
What is the best screening tool for suspected hyperaldosteronism?
Renin:aldosterone ratio
How should the renin:aldosterone ratio be interpreted?
High aldosterone + low renin –> primary hyperaldosteronsim
High aldosterone + high renin –> secondary hyperaldosteronism
What are the effects of hyperaldosteronism and how should they be investigated?
Hypertension –> measure BP
Hypokalaemia –> U&Es +/- ECG
Alkalosis –> blood gases
If a high aldosterone level is found, how should you investigate for the cause?
CT/MRI to look for adrenal tumour
Renal doppler US, CT angio or MR angio for renal causes
Which features might prompt you to check for hyperaldosteronism in a patient?
Patient with hypertension that is not responding to treatment
(most common cause of secondary hypertension)
What is the management of hyperaldosteronsim?
Aldosterone antagonists:
- eplerenone
- spironolactone
Treat the underlying cause
How is an adrenal adenoma treated?
Surgical removal
How is renal artery stenosis treated?
Percutaneous renal artery angioplasty via the femoral artery
