Adrenal Insufficiency (AI)

Info

🌱 來自: Huppert’s Notes

Adrenal Insufficiency (AI)🚧 施工中

Adrenal Insufficiency (AI)

•   Etiologies:

-   Primary:

•   Autoimmune: Antibody against adrenal enzymes (most common)

•   Vascular: Adrenal hemorrhage, thrombosis, trauma

•   Infectious: Tuberculosis (adrenal calcification), CMV, histoplasmosis

•   Medications: Ketoconazole, rifampin, etomidate

•   Deposition diseases: Amyloid, sarcoidosis, hemochromatosis

•   Metastatic disease: Lung/breast cancer can go to the adrenals

-   Secondary:

•   Hypopituitarism (any primary or secondary cause)

•   Glucocorticoid therapy (typically consider if >3 weeks of ≥20 mg prednisone or equivalent, or long-term use of ≥10 mg prednisone or equivalent); suppression of the HPA axis is the most common cause of AI

•   Clinical features:

-   Fatigue (most common), nausea/vomiting, lethargy, hypoglycemia, hypercalcemia, eosinophilia (rare), abdominal pain, anorexia

-   Primary only: Skin hyperpigmentation in areas of friction and/or sun exposure (MSH is a by-product of ACTH synthesis), hyperkalemia, hyponatremia (due to mineralocorticoid deficiency and diminished suppression of ADH by low cortisol)

•   Diagnosis:

-   Step 1: Check early AM cortisol

•   If AM cortisol <3 μg/dL very concerning, if >18 μg/dL rules out adrenal insufficiency

•   Random cortisol level within the reference range does not rule out adrenal insufficiency

-   Step 2: Perform a standard cosyntropin stimulation test with 250 mcg cosyntropin

•   Can be performed at ANY time of day

•   Normal response is cortisol >18 μg/dL 60 minutes after administration of cosyntropin

-   Step 3: Determine etiology: Check plasma ACTH, plasma renin, serum aldosterone

•   High ACTH, high plasma renin, low aldosterone suggests primary adrenal insufficiency. Consider adrenal imaging, adrenal autoantibodies (e.g., steroid autoantibodies, marker for adrenalitis).

•   Low-normal ACTH, normal plasma renin, normal aldosterone suggests secondary adrenal insufficiency. Consider pituitary MRI, check other pituitary hormones.

•   Treatment:

-   Primary: Oral corticosteroid (hydrocortisone or prednisone) and mineralocorticoid (fludrocortisone)

-   Secondary: Oral corticosteroid only; no mineralocorticoid needed

-   Stress-dose steroids:

•   Counsel patients to increase steroid dose 2–3× for minor stressors (e.g., minor illness)

•   For major stressors, often need 10× steroid dosing (aka “stress dose steroids”)