Evaluation of adrenal function

Question 1

Tests relevant for the evaluation of adrenal function

Answer 1

ACTH stimulation test, aldosterone suppression test

Question 2

ACTH stimulation test

Answer 2

250 microgram of Synacthen given IV will lead to a cortisol response 60 min after. The cortisol should exceed 495 mmol/L (18ug/dl).
If the response is abnormal, measure aldosterone levels.

Question 3

Aldosterone suppression tests

Answer 3

IV saline suppression, oral sodium chloride suppression, flurocortisone suppression test

Question 4

IV saline suppression test

Answer 4

500ml 0.9% NaCl per hour for 4 hours. Draw PAC (plasma aldosterone concentration) at 0’ to 240’ min for a short test. Aldosterone suppression if PAC is less than 8.5 ng/dl

Question 5

Oral sodium chloride suppression test

Answer 5

10g NaCl daily for 4 days. On day 4 collect 24 hours urine aldosterone and urine sample. Suppression occurred if aldosterone is less than 14 mpg and sodium more than 200 mEq/ 24 hours.

Question 6

Fludrocortisone suppression test

Answer 6

High salt diet and large doses of Florinef over 4 days of hospitalization.