The nurse caring for a patient with Cushing's symdrome explains to her patient about the dexamethasone suppression test scheduled for tomorrow. What does the nurse explain that this test will involve?

Question

A) Administration of dexamethasone orally, followed by a plasma cortisol level every hour for 3 hours
B) Administration of dexamethasone intravenously, followed by an x-ray of the adrenal glands
C) Administration of dexamethasone orally at 11 PM, and a plasma cortisol level at 8 AM the next morning
D) Administration of dexamethasone intravenously, followed by a plasma cortisol level 3 hours after the drug is administered

Answer 1

Ans: C

Feedback: Dexamethasone (1 mg) is administered orally at 11 pm, and a plasma cortisol level is obtained at 8 AM the next morning. This test can be performed on an outpatient basis and is the most widely used and sensitive screening test for diagnosis of pituitary and adrenal causes of Cushing's syndrome. Options A, B and D are incorrect as they do not correctly describe the test.