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)
