EXPLAINING OF CONN`S SYNDROME

EXPLAINING OF CONN`S SYNDROME OR HYPERALDOERONISM

Definition

Hyperaldosteronism means increased secretion of aldosterone hormone in the blood which may divided into primary (conn`s syndrome) which is the most commonly caused by an aldosterone - producing adenoma or carcinoma in the zona glomerulosa of the cortex of the adrenal gland or secondary hyperaldosteronism due to stimulation of the renin - angiotensin system from the renal artery stenosis and to low blood flow states such as congestive heart failure and liver cirrhosis

Cause of hyperaldosternisom

Primary hyperaldosternism

Results from autonomous aldosterone secretion which in trun leads to suppression of renin secretion

Most common age 30-50 years

• Most common  causes aldosterone producing adenoma or solitary functioning adrenal adenoma or very rare carcinoma in the zona glomerulosa causing conn`s syndrome  account for 70% of causes
• Adrenocortical hyperplasia may bilateral 25-30%
• Adrenal carcinoma  less than1%
• Ovarian carcinoma
• Familial causes
• Glucocorticoid suppressible hyperaldosteronism is an autosomal dominant form of hypertension in which aldosterone secretion is abnormally regulated by ACTH  this condition caused by recombinations between linked genes encoding closely related isozymes

Secondary aldosteronism

• Congestive heart failure
• Liver cirrhosis

Symptoms and signs

• Patient typically present with increased blood pressure  (hypertension) which is long standing moderate to severe hypertension and may be difficult to control despite the patient using multiple drug therapy due to water and sodium retention accounts for 1% in patient with essential hypertension
• Patient feel by headache
• Patient feel increased the frequency of micturation polyuria nocturia means at night and feel by thirsty or polydipsia
• Easy fatigue and weakness due to hypokalemia
• Muscle wasting and tirdness

Investigations and diagnosis

Laboratory

Blood tests

increased  plasma aldosterone concentration PAC  hyperaldosternism

Increased sodium NA hypernatremia

decreased potassium K hypokalemic acidosis

Decreased plasma renin activity PRA levels due to negative feedback caused by increased blood pressure and aldosterone

PAC :PRA ratio of 25 to 30 :1 is strongly suggestive of the diagnosis  but false positive results may occur in patient with chronic renal failure

Patients with primary hyperaldosternism fail to suppress aldosterone levels with sodium loading this test can be performed by 24 hours urine collection for cortisol , sodium , and aldosterone after 5 days of a high sodium diet or by giving the patient a load of 2 litre of saline solution while in supine position 2 to 3 days after being on a low sodium diet

Plasma aldosterone levels less than 8.5 ng|ml or a 24 hours urine aldosterone less than 14 ug after saline loading essentially for rules out primary hyperaldosternism

Radiological studies

CT and MRI scanning of the abdomen

To showing adrenal adenoma

Adrenal vein sampling

Selective venous catherization to localize aldosteronoma in which the adrenal vein is cannulated and blood samples for aldosterone and cortisol are obtained from both the adrenal veins and inferior vena cava after administration of the adrenocorticotrophic hormone ACTH but this procedure is invasive one and may lead to injury of the adrenal veins or ruptured it so this  may used in specific cases such as when the tumors can not be localized and in patients with bilateral adrenal enlarged to determine whether there is unilateral or bilateral increased secretion of aldosterone

Adrenal gland scintigraphy

Using NP-59 which is taken by the adrenal cortex and adrenal adenoma appear as hot nodules with suppressed contralateral uptake while hyperplastic glands show bilaterally increased uptake

Treatment

Treatment of hyperaldosteronism depend on the causes

Adrenal gland removal which can be done either by open surgical or laparoscopic adrenalectomy

Male patient more than 50 years and patients with multiple adrenal nodules may not benefit from adrenlectomy

Preoperative control of hypertension and adequate potassium supplementation are important

Patients are generally treated with diuretic drugs such as spironolactone an aldosterone antagonist

amiloride a potassium sparing diuretic that block sodium channels in the distal nephron of the kidney

   nifedipine a calcium channel blocker or captopril an angiotensin converting enzyme inhibitors ACE

Glucocorticoid - suppressible hyperaldosteronism

 Treated by administering exogenous dexamethasone at doses of .5 to 1 mg daily  also with spironolactone 

Postoperative

Some patient may suffer from transient hypoaldosteronism and need to give mineralocorticoids for up 3 months

tags:conn`s,explaining,syndrome