Adrenal Insufficiency in the Critically Ill

• Adrenal insufficiency (AI) is estimated to occur in up to 30% of critically ill patients
• The most common causes of AI in the critically ill are SIRS and sepsis
• In most cases of critically ill patients, AI is functional (i.e relative) - the adrenal response is insufficient to respond to the degree of stress
• Diagnostic clues include hyponatremia, hyperkalemia, hypoglycemia (rare), and hemodynamic instability despite IVFs and vasopressors
• Although still controversial, most feel that AI is present in critically ill patients with either a basal cortisol < 15 mcg/dl, an increase in < 9 mcg/dl after ACTH stimulation, or a random cortisol < 25 mcg/dl
• IV hydrocortisone, methylprednisolone, and dexamethasone are the 3 glucocorticoids most commonly administered
• Hydrocortisone is usually the preferred agent because it is the synthetic equivalent of cortisol (and has both glucocorticoid and mineralocorticoid activity)