From the Guidelines
The initial evaluation for adrenal insufficiency (Addison's disease) should involve a paired measurement of serum cortisol and plasma ACTH, with consideration of clinical presentation, including symptoms such as unexplained collapse, hypotension, vomiting, or diarrhea, as well as signs like hyperpigmentation, hyponatremia, hyperkalemia, acidosis, and hypoglycemia. When evaluating a patient for adrenal insufficiency, it is crucial to consider the clinical context, as outlined in the consensus statement on the diagnosis, treatment, and follow-up of patients with primary adrenal insufficiency 1. The diagnostic process should not be delayed, especially in cases of suspected acute adrenal insufficiency, where treatment should never be delayed by diagnostic procedures 1. Key laboratory tests include:
- Morning serum cortisol level
- Plasma ACTH level
- In cases where the diagnosis is unclear, a synacthen (tetracosactide) stimulated test can be diagnostic, with a peak serum cortisol <500 nmol L-1 indicating primary adrenal insufficiency 1. Additional considerations in the initial evaluation may include:
- Electrolyte imbalance (hyponatremia, hyperkalemia)
- Blood glucose levels (hypoglycemia)
- Complete blood count (anemia)
- Renin levels
- Adrenal antibody testing for primary adrenal insufficiency
- Imaging of the adrenal glands or pituitary, depending on whether primary or secondary adrenal insufficiency is suspected. It is essential to approach the diagnosis of adrenal insufficiency with a high index of suspicion, given its potential for morbidity and mortality, and to tailor the diagnostic workup based on clinical presentation and initial laboratory findings, as recommended by the consensus statement 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Initial Evaluation for Adrenal Insufficiency
The initial evaluation for adrenal insufficiency (Addison's disease) involves a combination of clinical assessment, laboratory tests, and imaging studies. The following are key components of the initial evaluation:
- Clinical presentation: A detailed clinical assessment, including a thorough medical history and physical examination, is essential to identify signs and symptoms of adrenal insufficiency, such as fatigue, weight loss, and hypotension 2, 3.
- Laboratory tests: Measurements of basal serum cortisol levels, adrenocorticotropic hormone (ACTH) levels, and electrolyte panels are crucial in the initial evaluation of adrenal insufficiency 4, 3, 5.
- Cosyntropin stimulation test: This test is used to confirm the diagnosis of adrenal insufficiency and to assess the function of the adrenal glands 4, 3, 5.
- Imaging studies: Imaging studies, such as computed tomography (CT) or magnetic resonance imaging (MRI) scans, may be necessary to evaluate the adrenal glands and to identify any underlying causes of adrenal insufficiency 2, 3.
Key Laboratory Tests
The following laboratory tests are essential in the initial evaluation of adrenal insufficiency:
- Basal serum cortisol levels: A morning cortisol level < 140 nmol/L or 5 mcg/dL is suggestive of adrenal insufficiency 3.
- ACTH levels: Elevated ACTH levels are indicative of primary adrenal insufficiency, while low ACTH levels are suggestive of secondary adrenal insufficiency 3.
- Electrolyte panels: Hyponatremia, hyperkalemia, and hypotension are common electrolyte imbalances in patients with adrenal insufficiency 2, 5.
Special Considerations
Certain patient populations require special consideration in the initial evaluation of adrenal insufficiency, including:
- Children and infants: Lower doses of cosyntropin are required for testing in pediatric patients 3.
- Pregnant women: Salivary cortisol tests may be used in pregnant women due to abnormal cortisol binding globulin (CBG) levels 3.
- Patients with autoimmune disorders: 21-hydroxylase antibodies should be evaluated to rule out autoimmunity 3.