What is the initial step in the workup of a patient suspected of having adrenal insufficiency?

From the Guidelines

The initial step in the workup of a patient suspected of having adrenal insufficiency is to evaluate morning (AM) levels of adrenocorticotropic hormone (ACTH) and cortisol, as well as perform a basic metabolic panel, including sodium, potassium, carbon dioxide, and glucose levels. This approach is supported by the most recent and highest quality study available, which emphasizes the importance of assessing both ACTH and cortisol levels in the morning to accurately diagnose adrenal insufficiency 1.

Key Components of the Initial Workup

• Evaluate AM levels of ACTH and cortisol
• Basic metabolic panel (Na, K, CO2, and glucose)
• Consider standard dose ACTH stimulation test for indeterminate results
• Evaluate for precipitating cause of crisis, such as infection
• Adrenal CT for metastasis or hemorrhage, if primary adrenal insufficiency is suspected

Rationale for the Recommended Approach

The rationale behind this approach is to quickly and accurately identify patients with adrenal insufficiency, who may require urgent treatment to prevent life-threatening complications. By evaluating both ACTH and cortisol levels, clinicians can differentiate between primary and secondary adrenal insufficiency, which is crucial for guiding further management and treatment. The basic metabolic panel provides additional information on the patient's electrolyte balance and glucose metabolism, which can be affected in adrenal insufficiency.

Importance of Recent and High-Quality Evidence

The study by 1 provides the most recent and highest quality evidence for the initial workup of adrenal insufficiency, and its recommendations should be prioritized in clinical practice. While other studies, such as 1 and 1, also provide valuable information on the diagnosis and management of adrenal insufficiency, they are either less recent or of lower quality, and therefore should not take precedence over the recommendations of 1.

From the Research

Initial Step in Adrenal Insufficiency Workup

The initial step in the workup of a patient suspected of having adrenal insufficiency involves assessing cortisol levels.

• A morning serum cortisol level can be used as a first-line test to rule out adrenal insufficiency 2, 3, 4.
• A morning serum cortisol level >13 mcg/dL reliably rules out adrenal insufficiency 2.
• If the morning serum cortisol level is <13 mcg/dL, further evaluation with the cosyntropin stimulation test (CST) is needed 2.
• The CST is commonly performed in patients suspected of having adrenal insufficiency when the basal serum cortisol levels are inconclusive 5.

Cosyntropin Stimulation Test (CST)

• The CST can be performed using a low-dose or high-dose of cosyntropin 2, 6.
• The low-dose CST has been shown to be more sensitive and specific than the high-dose test, but the high-dose test is preferred since the low-dose test has not been validated 6.
• The CST requires intravenous (IV) or intramuscular (IM) administration of cosyntropin and multiple blood draws 2.

Basal Cortisol Levels

• Basal cortisol levels can be measured in serum or saliva 3.
• Unstimulated early morning cortisol has been suggested as a first-line parameter to assess adrenal function in patients with suspected secondary adrenal insufficiency 3.
• A basal cortisol value of >236 nmol/l can predict adrenal sufficiency with sensitivity 84% and specificity 71% 4.
• To increase the specificity to 95%, a basal cortisol cut-off of >375 nmol/l is recommended 4.