From the Guidelines
The initial work-up for a patient suspected of having adrenal insufficiency should include evaluating morning ACTH and cortisol levels, as well as a basic metabolic panel, with consideration of an ACTH stimulation test for indeterminate results, as recommended by the most recent guidelines 1.
Initial Evaluation
The diagnostic work-up for patients in whom adrenal insufficiency is suspected involves several key steps:
- Evaluate morning (AM) levels of ACTH and cortisol, with specific thresholds guiding further investigation, such as an AM cortisol level less than 3 mg/dL 1.
- Perform a basic metabolic panel to assess sodium, potassium, CO2, and glucose levels, which can help identify electrolyte imbalances and hypoglycemia associated with adrenal insufficiency 1.
Further Testing
For indeterminate results, such as an AM cortisol level between 3 mg/dL and 15 mg/dL, consider a standard dose ACTH stimulation test to confirm the diagnosis of adrenal insufficiency, as this test can help differentiate between primary and secondary adrenal insufficiency 1.
Special Considerations
In cases where primary adrenal insufficiency is suspected or confirmed, evaluate for precipitating causes of crisis, such as infection, and consider an adrenal CT to rule out metastasis or hemorrhage, which are common causes of primary adrenal insufficiency 1.
Additional Recommendations
It's also important to be aware of the potential for corticosteroid use to cause isolated central adrenal insufficiency and the need for careful management when planning hormone replacement therapy for multiple deficiencies, including instructing patients on stress dosing and the use of a medical alert bracelet 1.
From the FDA Drug Label
2 DOSAGE AND ADMINISTRATION
2.5 Administration Information • Obtain blood sample for baseline serum cortisol. Obtain blood samples again for assessment of cortisol levels exactly 30 minutes and 60 minutes after administration of cosyntropin for injection.
2.6 Interpretation of Plasma Cortisol Levels after Cosyntropin for Injection • Stimulated plasma cortisol levels of less than 18 mcg/dL at 30- or 60-minutes post cosyntropin for injection are suggestive of adrenocortical insufficiency.
The initial work-up for a patient suspected of having adrenal insufficiency involves:
- Obtaining a baseline serum cortisol level
- Administering cosyntropin for injection (0.25 mg IV or IM in adults)
- Obtaining blood samples for assessment of cortisol levels exactly 30 minutes and 60 minutes after administration of cosyntropin for injection
- Interpreting stimulated plasma cortisol levels to determine if they are suggestive of adrenocortical insufficiency (less than 18 mcg/dL at 30- or 60-minutes post cosyntropin for injection) 2
From the Research
Initial Work-up for Adrenal Insufficiency
The initial work-up for a patient suspected of having adrenal insufficiency involves several steps, including:
- Measuring morning serum cortisol levels to rule out adrenal insufficiency, as a level >13 mcg/dL reliably rules out the condition 3
- If the morning serum cortisol level is ≤13 mcg/dL, further evaluation with the cosyntropin stimulation test (CST) is necessary 3
- The CST can be performed using either a 250 mcg or 1 mcg dose of cosyntropin, with the 1 mcg test having better diagnostic discrimination but requiring an extra step to dilute the cosyntropin 3
Interpretation of Test Results
When interpreting the results of the ACTH stimulation test, clinicians should consider the clinical presentation and likelihood of adrenal insufficiency before testing, as well as technical factors that can affect cortisol values and diagnostic accuracy 4
- The corticotropin-releasing hormone (CRH) stimulation test may also be useful in evaluating patients with adrenal insufficiency, particularly in differentiating between hypothalamic and pituitary causes of the condition 5
Special Considerations
In patients with glucocorticoid-induced adrenal insufficiency, the diagnosis is made with a stimulation test such as the ACTH test, and treatment should follow the principles for treatment of central adrenal insufficiency 6
- In patients with established glucocorticoid-induced adrenal insufficiency, education and awareness are crucial to prevent delayed glucocorticoid administration in the acute setting and to improve self-management 6