From the Guidelines
The workup for adrenal insufficiency should begin with morning cortisol and ACTH levels, followed by an ACTH stimulation test if initial results are inconclusive, as recommended by the most recent guidelines 1. The diagnostic work-up for patients in whom adrenal insufficiency is suspected should include evaluating ACTH and cortisol levels, as well as a basic metabolic panel, including sodium, potassium, CO2, and glucose levels 1.
- Key initial tests:
- Morning cortisol and ACTH levels
- Basic metabolic panel (Na, K, CO2, glucose)
- If initial results are inconclusive, consider an ACTH stimulation test to further evaluate adrenal function, as suggested by 1.
- Additional testing may include:
- Renin and aldosterone levels
- Adrenal imaging with CT or MRI to identify structural causes in primary adrenal insufficiency
- Pituitary MRI in cases of suspected secondary adrenal insufficiency During acute presentations, it is crucial not to delay treatment while awaiting test results; administer hydrocortisone 100 mg IV immediately, followed by 50-100 mg every 6-8 hours, along with IV fluids and glucose, as recommended by 1. This comprehensive approach is necessary because adrenal insufficiency can be life-threatening if not promptly diagnosed and treated, with the specific tests helping to determine the underlying cause and guide appropriate long-term management 1.
From the Research
Adrenal Insufficiency Workup
The workup for adrenal insufficiency involves a combination of clinical evaluation, laboratory tests, and imaging studies. The following are key components of the workup:
- Clinical evaluation: A thorough medical history and physical examination to identify signs and symptoms of adrenal insufficiency, such as fatigue, weight loss, and hyperpigmentation 2, 3, 4
- Laboratory tests:
- Morning cortisol levels: A cortisol level above 350 nmol/l can safely rule out Addison's disease, while a level below 140 nmol/l in the presence of elevated corticotropin concentrations (>300 pg/ml) is indicative of primary adrenal insufficiency 2
- Adrenocorticotropic hormone (ACTH) levels: Elevated ACTH levels can indicate primary adrenal insufficiency, while low ACTH levels can indicate secondary or tertiary adrenal insufficiency 3, 5
- Cosyntropin stimulation test: This test is used to confirm the diagnosis of adrenal insufficiency and to distinguish between primary and secondary adrenal insufficiency 3, 5, 6
- Imaging studies: Imaging studies such as CT or MRI scans may be used to evaluate the adrenal glands and pituitary gland for signs of disease or damage 4, 6
Diagnostic Criteria
The diagnostic criteria for adrenal insufficiency include:
- Low baseline cortisol levels (<100 nmol/L) alongside raised adrenocorticotropic hormone (ACTH) levels 5
- Failure to respond to the cosyntropin stimulation test 3, 5, 6
- Presence of autoantibodies against 21-hydroxylase or other adrenal antibodies 6
Treatment and Management
The treatment and management of adrenal insufficiency involve:
- Replacement of mineralocorticoids and glucocorticoids 3, 4, 6
- Education and empowerment of patients to take control of their own medical management, including stress dosing and emergency administration of glucocorticoids 4, 5, 6
- Monitoring for concomitant autoimmune diseases, particularly autoimmune thyroid disease 6