Conns Syndrome Flashcards
What is Hyperaldosteronism
Hyperaldosteronism is caused by excessive levels of aldosterone caused by the abnormal release of extra aldosterone (primary hyperaldosteronism) or in response to increased level of renin (secondary hyperaldosteronism)
Aldosterone usually acts in the distal renal tubule to promote sodium retention and potassium excretion (to increase blood pressure). In hyperaldosteronism the increased fluid uptake levels, brought about by increased Na+ reuptake) cause too much volume expansion and lead to hypertension. The increased potassium excretion can cause also cause hypokalaemia
Primary Hyperaldosteronism is most common form of secondary hypertension.
What are the causes of Hyperaldosteronism
Common: Conns Syndrome (Adrenal Adenoma), Bilateral adrenal hyperplasia
Other: Familial Hyperaldosteronism, Adrenal Carcinoma, Renovascular Disease (Reduced blood supply to kidney causes unnecessary RAAS activation and secondary hyperaldosteronism)
What will you find on a histroy taking of Hyperaldosteronism
Symptoms:
Hypertension –May cause headaches or vision problems
Hypokalaemia – Weakness, Cramps, Lethargy, Paraesthesia, (Metabolic Alkalosis and Arrhythmias in severe hypokalaemia)
Polyuria/Polydipsia - Kidneys cannot concentrate urine
Risk Factors:
Family History of hyperaldosteronism or early onset hypertension – Indicates familial hyperaldosteronism
Specific Questions to ask:
Hypertension + Hypokalaemia = Think hyperaldosteronism
Think specifically in patients <40 with hypertension or patients with treatment resistant hypertension (>3 drugs)
Differentials:
Cushing’s Disease - Will also have hypertension and hypokalaemia but Renin/Aldosterone levels with be normal
What will you find on examination of Hyperaldosteronism
Hands:
Weak pulses – Peripheral vascular disease (complication of chronic with hypertension)
Weakness – Hypokalaemia
Hypertension
Arrhythmias – Hypokalaemia
Neck:
Carotid bruits - may indicate carotid artery stenosis and warrant further duplex imaging
Face:
Examination of optic fundi - Papilledema, Hypertensive retinopathy (retinal haemorrhages, micro aneurysms, cotton-wool spots) (complication of chronic with hypertension)
Chest:
Look for signs of heart failure – Pulmonary crackles at lung bases, Gallop Rhythm (complication of chronic with hypertension)
Abdomen:
Renal Bruit - renal artery stenosis
Feel for an AAA - (complication of chronic with hypertension)
Legs:
Weak pulses – Peripheral vascular disease (complication of chronic with hypertension)
Weakness – Hypokalaemia
What investigations will you order in Hyperaldosteronism
Bedside:
Bedside:
ECG - Hypokalaemia can cause arrhythmias
Bloods:
U&E – Hypokalaemia (however can be normal) and hypernatremia (However can be normal). Renal impairment may be seen in renal artery stenosis.
Renin and aldosterone levels - Aldosterone raised and renin either low (primary hyperaldosteronism) or high (secondary hyperaldosteronism). An Aldosterone:Renin ratio of >800 indicates primary hyperaldosteronism.
Imaging:
CT Adrenal Glands - Looking for adrenal adenoma (only ordered once diagnosis of hyperaldosteronism confirmed as there are many incidentalomas)
Renal US - May show asymmetrically sized kidney in renal artery stenosis
Special Tests:
Adrenal Venous sampling – Blood taken from each kidney and aldosterone levels measured of each sample. If there is a difference (>3x) between the Aldosterone:Renin ratio of each side, it is almost diagnostic of an adrenal adenoma
Renal arteriogram - Diagnostic of renal artery stenosis
Genetic Testing – If familial Hyperaldosteronism suspected
What is the treatment of Hyperaldosteronism
Medical:
Benign Adrenal Hyperplasia - K+ sparing diuretics (Amiloride) and Aldosterone antagonists (E.g. Spirinolactone) used long term for management of BP and K+ levels.
Familial Hyperaldosteronism - Steroids to induce remission
Surgical:
Conns Syndrome - Laparoscopic adrenalectomy with pre-surgical Spirinolactone used during the referral period
