Adrenal crisis, or acute adrenal insufficiency, is a potentially life-threatening emergency which occurs as a result of cortisol deficiency. Prompt identification of affected patients and early initiation of therapy can be life-saving.
A history of pre-existing adrenal insufficiency or recent discontinuation of steroids may be apparent but some patients present de novo, and a high index of suspicion for the diagnosis is needed. Underlying conditions include primary adrenal insufficiency (Chapter 20), secondary adrenal insufficiency (Chapter 20) and chronic exogenous glucocorticoid treatment (doses ≥5 mg prednisolone equivalent for >4 weeks). This can also include patients treated chronically with nasal, topical or inhaled glucocorticoids.
Symptoms and signs include fatigue, dizziness and hypotension (especially postural hypotension), collapse (including hypovolaemic shock), abdominal pain, nausea, weight loss, fever, confusion, delirium or even coma (Figure 35.1). Patients with primary adrenal insufficiency may be pigmented (Chapter 20), whereas patients with secondary adrenal insufficiency may be pale with symptoms of other pituitary hormone deficiency.
Biochemical findings include hyponatraemia, hyperkalaemia, anaemia, pre-renal failure and hypoglycaemia (predominantly in children).
The initial assessment should check blood pressure (including postural measurement) and fluid balance status (Figure 35.2). Blood tests should include measurement of electrolytes, renal function, FBC, glucose, thyroid function (thyrotoxicosis can trigger a crisis), and paired serum cortisol and plasma ACTH. Definitive confirmation of adrenal insufficiency usually requires a Synacthen test (Chapter 20) but unless the patient is haemodynamically stable, treatment should not be delayed to accommodate this.
Therapy should commence as soon as the diagnosis is suspected. Patients usually have significant reduction in fluid volume, hence immediate treatment should focus on rehydration with 1 L 0.9% saline IV in the first 1–2 hours, followed by further fluids as required (often 4–6 L in the first 24 hours). Care is needed in the elderly and in those with cardiac or renal failure. If present, hypoglycaemia should be treated with IV glucose.
Hydrocortisone should be given as an immediate IV (or IM) bolus of 100 mg, followed by either an infusion of 200 mg over 24 hours, or 50 mg IV/IM injection every 6 hours. Tapering of hydrocortisone can occur after clinical improvement. Because hydrocortisone has substantial mineralocorticoid activity in high doses, fludrocortisone is not needed until total doses of hydrocortisone are <50 mg/day, and only then in patients with primary adrenal insufficiency (Chapter 20).
A search for precipitants should include a screen for infection (treated as necessary with antibiotics), a review of the history for any recent abrupt discontinuation of chronic glucocorticoid therapy, and review of sick day rules (Chapter 20).
An endocrinologist should be contacted as soon as the diagnosis is suspected. Subsequent tests should look to establish the cause of the adrenal insufficiency as in the non-acute state (Chapter 20).
Before discharge from hospital, a check should be made to ensure that patients are educated about the need to increase their glucocorticoid doses at times of intercurrent illness, they are provided with a hydrocortisone emergency injection kit, they carry a st couraged to wear medical alert jewellery.