Adrenal Insufficiency
Tyler Schubert, Griffin Bullock
Differential diagnosis for adrenal insufficiency (AI)
- Glucocorticoid-induced (most common): typically >10mg prednisone equivalent for >3 weeks with physiologic stress or abrupt discontinuation.
- Primary (adrenals): autoimmune (Addison’s), infection (TB, fungal), infiltration (sarcoidosis, malignancy), hemorrhage (Waterhouse-Friedrichsen), medications (high-dose azoles), immune checkpoint inhibitors.
- Secondary (pituitary): Pituitary mass/neoplasm, infarct, infiltration, surgery, medications (opioids, immune checkpoint inhibitors).
Presentation
- Presentation: Generalized weakness, abdominal pain, nausea, weight loss, fatigue, orthostatic hypotension. Hyperpigmentation and salt craving suggest primary disease.
- Labs: hyponatremia, hyperkalemia (only in primary AI), hypoglycemia, eosinophilia.
Evaluation
- Inpatient: if no recent glucocorticoid exposure, draw AM cortisol and ACTH (ideally 8am) -> 250ug cosyntropin -> cortisol 1h after. Cortisol level ≥14 is normal.
- Outpatient: draw AM cortisol level for screening; <5 suggests AI; >10 AI unlikely. Complete ACTH stimulation if 5-10.
- If ACTH stimulation is abnormal, consult endocrine.
Management
- Chronic replacement:
- Glucocorticoid: hydrocortisone 15-25 mg daily, split between two doses at 8am and ~2-4pm to mimic physiology. Prednisone 3-5 mg once daily is alternative. Dose must increase in acute illness (below).
- Mineralocorticoid (primary AI): fludrocortisone 0.05-0.3 mg daily.
- Adrenal crisis (treat first, test later): IV hydrocortisone 100 mg immediately, followed by IV hydrocortisone 50 mg q6h; give 1L NS in first hour or D5NS if hypoglycemic; avoid hypotonic saline. Obtain BMP, glucose, ACTH level, serum cortisol prior to treatment if able but do not delay treatment.
- Stress dose steroids for known AI:
- Stress dosing: temporary increase in glucocorticoid dose above physiologic replacement to match cortisol response during physiologic stress, including illness or surgery.
- Minor illness: double home dose for 2-5 days or until acute illness is resolved.
- Surgery with local anesthesia: hydrocortisone 40 mg total in 3 divided doses (20 mg 1h pre-op, 10 mg 6h post-op, 10 mg 6h later).
- Surgery with general/regional anesthesia: intraop IV hydrocortisone 100 mg bolus at induction, then IV hydrocortisone 50 mg q6h. Postop resume PO hydrocortisone at 40 mg daily for 48h if uncomplicated course, followed by return to baseline dose.
| Drug Name | Equivalent doses (mg) | Activity relative to hydrocortisone | Duration of action (hrs) |
|---|
| Hydrocortisone | 20 | 1 | 8 to 12 |
| Cortisone acetate | 25 | 0.8 | 8 to 12 |
| Prednisone | 5 | 4 | 12 to 36 |
| Prednisolone | 5 | 4 | 12 to 36 |
| Methylprednisolone | 4 | 5 | 12 to 36 |
| Triamcinolone | 4 | 5 | 12 to 36 |
| Dexamethasone | 0.75 | 30 | 36 to 72 |
| Betamethasone | 0.6 | 30 | 36 to 72 |
