Laboratory Testing and Management of Addisonian Crisis

Essential Labs to Draw Immediately

The American College of Physicians recommends drawing blood for cortisol, ACTH, and basic metabolic panel immediately before administering hydrocortisone, but never delay treatment to wait for results 1, 2
Serum cortisol levels <250 nmol/L with elevated ACTH during acute illness are diagnostic of primary adrenal insufficiency, according to the Endocrine Society 3, 5
Plasma ACTH is markedly elevated in primary adrenal insufficiency, helping to distinguish primary from secondary causes, as stated by the American Association of Clinical Endocrinologists 3, 4, 5

Hyponatremia is present in approximately 90% of cases, though levels may be only marginally reduced, according to the European Society of Endocrinology 3, 4, 5
Hyperkalemia occurs in only 50% of cases, so its absence does not exclude the diagnosis, as noted by the American College of Physicians 3, 4, 5
Creatinine and BUN are elevated due to prerenal renal failure from volume depletion, as stated by the National Kidney Foundation 4, 5
Hypoglycemia is common in children but less frequent in adults, according to the Pediatric Endocrine Society 4, 5

The underlying cause of Addisonian crisis should be determined, including testing for 21-hydroxylase autoantibodies (21OH-Ab), which are positive in autoimmune Addison disease, accounting for approximately 85% of cases in Western Europe, as stated by the European Society of Endocrinology 1, 4
A CT scan of the adrenals should be performed if 21OH-Ab is negative, to evaluate for hemorrhage, tumor, tuberculosis, or infiltrative processes, according to the Radiological Society of North America 1, 4
Very long chain fatty acids (VLCFA) should be tested in males to screen for adrenoleukodystrophy, as recommended by the American Academy of Neurology 1
Plasma renin activity is increased in primary adrenal insufficiency, according to the American Heart Association 5
Serum aldosterone and DHEAS are low in primary adrenal insufficiency, as stated by the Endocrine Society 5

The American College of Emergency Physicians recommends immediately administering hydrocortisone 100 mg IV bolus, 0.9% isotonic saline at 1 liter over the first hour, and continuing hydrocortisone 100 mg IV every 6-8 hours until recovered 2, 4