Primary hyperaldosteronism

2021-01-27 12:00 AM

Fasting overnight, lying down; intravenous infusion 2L 0.9% NaCl solution. The plasma aldosterone (PAC) is then measured. Diagnosis is confirmed when PAC> 10 ng / mL.

Reason

There are 5 main possible diseases:

Adenoma secretes aldosterone.

Idiopathic hyperaldosteronism.

Unilateral primary adrenal hyperplasia.

Hyperaldosteronism responds to glucocorticoids.

Aldosterone secreted by adrenal carcinoma.

Clinical

Clinical symptoms are nonspecific, patients feel weak; more severe causing headache, anxiety, drinking a lot, urinating a lot, nocturia and paraesthesia. Patients often come to the clinic for symptoms of hypokalaemia and hypertension.

Physical symptoms: mild to severe hypertension, fundus stages I, II; Severe hypokalaemia may result in orthostatic hypotension without tachycardia because of decreased pressure receptor perception. With severe alkalosis, there can be symptoms such as hypocalcaemia (Chvostek, Trousseau).

Subclinical

Blood potassium decreases in typical cases, blood sodium slightly increases, impaired glucose tolerance.

Diagnose

Screening

Screening for primary hyperaldosteronism should be performed in the presence of hypokalaemia with hypertension, and most of them with treatment-resistant hypertension.

Potassium blood:

Avoid high potassium intake and stop the diuretics for at least 3 weeks. 20% of patients have normal blood potassium or the low limit of normal.

Renin-angiotensin-aldosterone system evaluation:

Measurement of plasma renin activity any (PRA):  primary hyperaldosteronism.

Measurement of plasma aldosterone (PAC) concentration at 8 am after at least 4 hours lying down and eating enough salt a few days ago.

If PAC / PRA> 30 and PAC> 20 ng / mL: primary hyperaldosteronism with 90% sensitivity, 91% specificity.

Captopril Test:

Take 25mg of Captopril in the morning, 2 hours after the blood is drawn, the patient is in a sitting position. Normal: PAC decreases, PRA increases.

Primary hyperaldosteronism: unchanged PAC and PRA. PAC / PRA> 50, PAC> 15 ng / dL.

Implementing the quadrants

Use an aldosterone therapy test with oral NaCl or intravenous infusion to determine that aldosterone in urine and plasma is not inhibited.

Test for inhibition with oral NaCl:

Eat high doses of salt for 3-4 days, supplement with KCl 40-200mEq / day. On the last day, taking 24 hours of urine to measure aldosterone, sodium, and creatinine. Urine sodium> 200mEq / L and urinary aldosterone> 10-14 μg help confirm diagnosis.

NaCl intravenous infusion test:

Fasting overnight, lying down; intravenous infusion 2L 0.9% NaCl solution. The plasma aldosterone (PAC) is then measured. Diagnosis is confirmed when PAC> 10 ng / mL.

Treatment

Adenoma secretes aldosterone

Unilateral removal of the adrenal area where the adenoma is located.

It is necessary to treat preoperative hypokalaemia with Spironolactone. It is better to have endoscopic adrenalectomy.

Unilateral primary adrenal hyperplasia

Also responds well to surgical treatment like adenoma.

Idiopathic hyperaldosteronism

Increased blood pressure does not decrease after surgical treatment, although hypokalaemia can be improved, so the appropriate treatment, in this case, is internal medicine:

Eat less than 100 mEq Na + per day.

Keep an ideal weight, drink alcohol, exercise regularly.

Spironolactone: treatment of hypertension, first dose 200-300 mg/day; Reduce gradually to 100 mg/day as blood pressure and blood potassium improve.

Amiloride is also effective if the patient is intolerant to Spironolactone.

If blood pressure does not drop after the full dose, calcium inhibitors, ACE inhibitors or diuretics can be used.

Hyperaldosteronism responds to corticosteroids

Glucocorticoids with dose changes from physiological to pharmacological can control blood pressure and hypokalaemia. However, Spironolactone is similarly effective and safer than glucocorticoids in the long term.

K adrenal epithelial secretion of aldosterone

Surgical treatment. If K is left after surgery, it should be treated with Mitotane.

If the tumour is secreted cortisol can use Ketoconazole.

If the tumour is too much aldosterone can use Spironolactone.