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The adrenal gland synthesizes steroid hormones in the cortex and catecholamines in the medulla. Adrenal insufficiency refers to a state of deficiency of adrenal gland hormone production in the cortex. It affects about 1 to 4 people per 100,000 in the U.S.1

Adrenal crisis is a life-threatening exacerbation of adrenal insufficiency due to increased physiologic demand (e.g., infection) or decreased supply (e.g., discontinuation of steroid therapy) of cortisol. It usually occurs in response to a major stress, such as acute myocardial infarction, sepsis, surgery, major injury, trauma, or other illnesses in any patient with primary or secondary adrenal insufficiency. In this situation, the adrenal gland fails to mount a stress response via increasing circulating cortisol levels.

The most frequent iatrogenic cause of acute adrenal crisis is rapid withdrawal of steroids in patients with adrenal atrophy secondary to long-term steroid administration. About 20% of acquired immunodeficiency syndrome patients eventually develop adrenal insufficiency.2,3 Currently, patients with major head trauma develop pituitary insufficiency much more frequently than previously recognized.4 Head trauma affects adrenocorticotropic hormone (ACTH) production, which decreases secretion of cortisol from the adrenal gland.

Primary adrenal insufficiency, or Addison disease, is due to intrinsic adrenal gland dysfunction and results in decreased cortisol and aldosterone production. Approximately 90% of the gland must be destroyed for clinical adrenal insufficiency to develop.5 The causes include infection [e.g., tuberculosis, human immunodeficiency virus (HIV)], drugs, adrenal hemorrhage (from use of warfarin, sepsis, and trauma), sarcoidosis, autoimmune disorders, metastases, and congenital adrenal hyperplasia.

Secondary adrenal insufficiency is due to hypothalamic-pituitary dysfunction causing inadequate ACTH production. This results in cortisol deficiency only. This may be caused by withdrawal of prolonged steroid therapy, pituitary disease, head trauma, or postpartum pituitary necrosis (Sheehan syndrome).

The adrenal gland is made up of the cortex (outer layer) and medulla (inner layer) producing steroid hormones and catecholamines, respectively. The adrenal cortex produces three categories of steroids. These include the glucocorticoids (cortisol), mineralocorticoid (aldosterone), and gonadocorticoids (sex hormones: testosterone and estrogen). Glucocorticoids are produced from the zona glomerulosa, whereas the latter two groups of steroids are produced from both the zona fasciculata and zona reticularis.

Cortisolis secreted from the cortex of the adrenal gland in response to direct stimulation by ACTH. ACTH secretion is stimulated by the hormone corticotropin-releasing factor released from the hypothalamus. This occurs in a diurnal rhythm, with higher levels secreted in the morning and lower levels in the evening. Plasma cortisol suppresses the release of ACTH by negative feedback inhibition. Cortisol facilitates the patient’s stress response, affecting the heart, vascular bed, water excretion, electrolyte balance, potentiation of catecholamine action, and control of water distribution. It affects the fat, protein, and carbohydrate metabolism by producing the glucose by glycogenolysis and neoglycogenesis. It is involved in immunologic and inflammatory responses and affects calcium metabolism. It ...

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