The adrenal glands produce four major classes of hormones: glucocorticoids, mineralocorticoids, sex hormones (i.e., estrogens, androgens), and catecholamines (primarily epinephrine). Catecholamines are produced in the adrenal medulla. Synthesis is impaired by disease processes that destroy the adrenal glands. Catecholamine synthesis requires cortisol and may be decreased in patients with hypothalamic–pituitary disease. Loss of sex hormone production is not required for recovery from critical illness. Thus, this article concentrates on disease processes of the adrenal cortex that decrease production of glucocorticoids and mineralocorticoids.

Cortisol is the major glucocorticoid produced by the adrenal cortex and is required for normal function of all cells in the body. Deficiency of cortisol is associated with increased morbidity and mortality during critical illness, and complete absence of cortisol production is incompatible with life. Cortisol is required for carbohydrate, protein, and lipid metabolism; immune function; synthesis and action of catecholamines and adrenergic receptors; cardiac contractility; wound healing; vascular tone, endothelial integrity, normal vascular permeability; and numerous other functions. Hemodynamic benefits of glucocorticoids also relate to their actions on beta-adrenergic receptor synthesis and cell density,<sup>51 Saito T., Takanashi M., Gallagher E. , e al. Corticosteroid effect on early beta-adrenergic down-regulation during circulatory shock: Hemodynamic study and beta-adrenergic receptor study Intsiv Care Med 1995 ;  21 : 204-210  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> prevention of beta-adrenergic receptor desensitization/uncoupling,<sup>4 Barnes P. Beta-adrenergic receptors and their regulation Am J Resp Crit Care Med 1995 ;  152 : 838-860

Cliccare qui per andare alla sezione Riferimenti</sup> and inhibition of nitric oxide synthase.<sup>59 Szabo C. Alterations in nitric oxide production in various forms of circulatory shock New Horizens 1995 ;  3 : 2-32

Cliccare qui per andare alla sezione Riferimenti</sup> Mineralocorticoids (i.e., aldosterone) are important in the maintenance of fluid and electrolyte balance. The body can compensate for loss of mineralocorticoid production.