Acute Adrenal Insufficiency
Causes:
➧ Usually presents as an acute process in a patient with underlying chronic adrenal insufficiency
➧ Causes of Primary adrenal insufficiency:
- Auto-immune
- TB of adrenals
- Metastatic malignancy to adrenals
➧ Causes of Secondary or Tertiary adrenal insufficiency
- Pituitary or hypothalamic disease
➧ Acute destruction of the adrenals can occur with bleeding in the adrenals:
- Sepsis
- Disseminated intravascular coagulopathy (DIC)
- Complication of anticoagulant therapy
Precipitating factors:
➧ Omission of medication
➧ Precipitating illness:
- Severe infection
- Myocardial infarction
- Cerebro-vascular accident (CVA)
- Surgery without adrenal support
- Severe trauma
➧ Withdrawal of steroid therapy in a patient on long-term steroid therapy (Adrenal atrophy)
➧ Administration of drugs impairing adrenal hormone synthesis e.g. Ketoconazole
➧ Using drugs that increase steroid metabolism e.g. Phenytoin and Rifampicin
Clinical picture:
➧ Nausea and vomiting
➧ Hyperpyrexia
➧ Abdominal pain
➧ Dehydration
➧ Hypotension and shock
Clues to underlying Chronic Adrenal Insufficiency:
➧ Pigmentation in unexposed areas of the skin:
- Creases of hands
- Buccal mucosa
- Scars
➧ Consider adrenal insufficiency if hypotension does not respond to pressors
Laboratory diagnosis:
➧ Hyponatremia and hyperkalemia (Hyponatremia might be obscured by dehydration).
➧ Random cortisol is not helpful unless it is very low (less than 5 mg/L) during a period of great stress.
➧ ACTH (Cosyntropin) stimulation test:
- Failure of cortisol to rise above 552 nmol/L 30 min after administration of 0.25 mg of synthetic ACTH IV
➧ Basal ACTH will be raised in primary adrenal insufficiency but not in secondary.
➧ CT of the abdomen will reveal enlargement of adrenals in patients with adrenal hemorrhage, active TB, or metastatic malignancy.
Management of Acute Adrenal Insufficiency:
➧ Hydrocortisone: 200 mg IV stat then 100 mg/8 h. for 24 h
-Taper slowly over the next 72 h.
-When oral feeds are tolerated change to oral replacement therapy.
-Overlap the first oral and last IV doses.
➧ Dexamethasone: 10 mg/6 h. IV
➧ Fludrocortisone: 0.05-0.3 mg/d. (if hydrocortisone less than 100 mg/d).
-Patients with primary adrenal insufficiency may require mineralocorticoid therapy (fludrocortisone) when shifted to oral therapy.
➧ 5% dextrose: IV for hypoglycemia
➧ Normal saline: IV for volume expansion
➧ Treat precipitating diseases