A 40 years old male presented with uncontrolled hypertension of two years duration. Despite receiving beta blockers, calcium channel blockers, and an ACE inhibitor, his blood pressure remains elevated. He also complains of polyuria, polydipsia, and generalized muscle weakness.
On examination, his BP is 180/110 mmHg. Funduscopy reveals grade III hypertensive retinopathy. Rest of the examination is normal. Labs show:
Serum Sodium: 147 mEq/L
serum Potassium: 2.9 mEq/L
Bicarbonate: 26 mmol/l
RFTs, BSR and Urine R/E: Normal
- What is the likely diagnosis?
- What is the differential diagnosis?
- What further investigations are required?
- How would you treat this patient?
Key to the above questions and a brief discussion of the topic is given below. New candidates should try to solve the case before looking at the key.
What is the likely diagnosis?
Primary hyperaldosteronism/ conns syndrome
What is the differential diagnosis?
Essential hypertension, pheochromocytoma, renal artery stenosis, Cushing’s syndrome
What further investigations are required?
Aldosterone and renin levels, CT scan of adrenals, bilateral adrenal vein sampling to determine if the cause is unilateral or bilateral
How would you treat this patient with uncontrolled hypertension?
For bilateral adrenal hyperplasia, spironolactone is given.
For a unilateral adenoma, spironolactone or laparoscopic adrenalectomy is required
Hyperaldosteronism or conns syndrome:
Conn’s syndrome or primary hyperaldosteronism is a condition of excess aldosterone secretion by the adrenal glands. It is characterized by uncontrolled hypertension, hypokalemia, and metabolic alkalosis.
Hyperaldosteronism can be due to adrenal adenoma, adrenal hyperplasia (unilateral or bilateral) or rarely adrenal carcinoma.
Clinical features of hyperaldosteronism:
Patients with hyperaldosteronism primarily present with hypertension, hypokalemia, hypernatremia, metabolic alkalosis, and hypomagnesemia.
Because of the effects of hypokalemia patient scan present with muscle weakness. Muscle weakness is more profound in patients with a potassium level of less than 2.5 mEq/L.
Patients with hyperaldosteronism are at increased risk of cardiovascular diseases and strokes compared to other causes of hypertension like essential hypertension Cushing’s syndrome and pheochromocytoma.
Diagnosis of hyperaldosteronism:
Hyperaldosteronism is diagnosed by doing the aldosterone and renin levels. Aldosterone-renin ratio is usually elevated in primary hyperaldosteronism.
Computed Tomographic scans of the adrenal may be done to look for adrenal hypertrophy or a mass/ adenoma. In patients with adrenal hyperplasia, bilateral adrenal vein sampling should be done to differentiate between a unilateral and bilateral disease.
Patients with adrenal adenoma have more profound hypertension, hypokalemia and postural increase in aldosterone levels compared to patients with adrenal hyperplasia. This is also the basis of the postural stimulation test.
Treatment of uncontrolled hypertension and hyperaldosteronism:
Surgery is curative only in unilateral disease. All patients and specifically patients with bilateral adrenal hyperplasia may benefit from aldosterone receptor antagonists like spironolactone and eplerenone.
Laparoscopic adrenalectomy is the procedure of choice. Patients should have plasma aldosterone levels measured one day after surgery to assess for the cure. Patients should be monitored for hyperkalemia after surgery because of transient hypoaldosteronism.
Serum potassium levels should be measured at least weekly for four to six weeks. The preferred intravenous fluid after surgery is isotonic saline without potassium. Patients, when discharged should be advised a sodium-rich diet.
Patients who are not candidates for surgical treatment should be given spironolactone or eplerenone. Since spironolactone has anti-androgen properties, men may be advised eplerenone to reduce chances of painful gynecomastia.
Amiloride is an alternative potassium-sparing diuretic for patients not responding or tolerating both the drugs.