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Acute Adrenal Insufficiency

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