Laboratory Findings in Adrenal Crisis

Electrolyte Abnormalities

Hyponatremia is present in approximately 90% of newly presenting cases, though serum sodium levels may be only marginally reduced 2, 3
Hyperkalemia is found in approximately 50% of patients at diagnosis, caused by aldosterone deficiency, impaired glomerular filtration, and acidosis 2
In the presence of severe vomiting, patients may paradoxically present with hypokalaemia and alkalosis rather than the expected hyperkalemia 2
Mild to moderate hypercalcemia occurs in 10-20% of patients at presentation 2

Increased creatinine and BUN due to prerenal renal failure from volume depletion 1, 4
Hypoglycemia is common in children but less frequent in adults 2
Metabolic acidosis may be present due to impaired renal function and aldosterone deficiency 1, 2
Elevated liver transaminases can occur in some patients 2
Anemia, mild eosinophilia, and lymphocytosis may also be present 2

These laboratory abnormalities should raise suspicion of adrenal crisis in patients presenting with unexplained collapse, hypotension, vomiting, or diarrhea 3
Treatment should never be delayed by diagnostic procedures when adrenal crisis is suspected 3
Initial treatment includes immediate IV hydrocortisone 100 mg bolus and rapid intravenous administration of 0.9% saline (1 L over an hour) 1

In suspected acute adrenal insufficiency, serum cortisol <250 nmol/L with increased ACTH is diagnostic of primary adrenal insufficiency 2
Serum cortisol <400 nmol/L with increased ACTH during acute illness raises strong suspicion of primary adrenal insufficiency 2
Blood for diagnostic testing (cortisol, ACTH, electrolytes, glucose) should be drawn before treatment, but treatment must not be delayed waiting for results 1