ACTH stimulation test


ACTH stim·u·la·tion test

a test for adrenal cortical function; ACTH administered by bolus, continuous intravenous infusion, or intramuscularly, evokes an increase in plasma cortisol in normal persons; in adrenal cortical insufficiency, the expected increase in plasma cortisol is limited or nonexistent.

ACTH stimulation test

A test to determine the presence of adrenal insufficiency.

Patient care

Synthetic adrenocorticotropic hormone (ACTH) is injected intravenously, and the serum cortisol level is measured at timed intervals (30 or 60 min after the injection). A patient with normal adrenal function will respond to the test with increased serum cortisol levels above 18 µg/dl. Serum cortisol levels < 15 µg/dl are diagnostic of adrenal insufficiency. The test has been traditionally performed with an injection of 250 µg of ACTH, but studies have shown that 1 µg is an equally effective test dose.

 Synonym: Cortrosyn stimulation test; cosyntropin stimulation test

ACTH stim·u·la·tion test

(stimyū-lāshŭn test) Measurement of adrenal cortical function.