Conn's syndrome - mx

Question 1

What is the screening test for Conn’s syndrome called?

Answer 1

Plasma aldosterone conc to plasma renin activity

Question 2

Explain the results of PAC:PAR

Answer 2

1. PAC/PRA ratio increased
   - high plasma aldosterone concentration
   - low plasma renin activity

Question 3

Explain the ‘confirmatory test’ for conn’s syndrome

Answer 3

oral sodium loading test

1. high sodium diet/tablets for 3 days
2. 24 hour urine measurements of aldosterone

Question 4

oral sodium loading test - result in healthy indivisuals

Answer 4

1. RAAS is physiologically suppressed

2. inhibition of aldosterone secretion

Question 5

oral sodium loading test - result in primary hyperaldosteronism

Answer 5

1. failure to suppress aldosterone secretion in primary hyperaldosteronism

Question 6

Investigations - Imaging?

Answer 6

1. Adrenal CT - initial test after biochemical tests
   - check for hyperplasia/tumor
2. Adrenal venous sampling

Question 7

Explain the method ‘adrenal venous sampling’ and why is done?

Answer 7

1. used to differentiate between unilateral adenoma and bilateral hyperplasia
2. Measure plasma aldosterone concentration from right adrenal vs left adrenal vein
3. • unilateral disease : 4 x increase in PAC
   • bilateral disease : no difference in PAC between two sides

Question 8

Tx of UNILATERAL aldosterone adenoma/carcinoma

Answer 8

1. surgery - adren