Overview on metabolic adaptation to stress.

The patients that we wish to feed properly are stressed in different ways and very often in more than one way. The word ‘stress’ appears in the nutrition and clinical nutrition literature attached to a wide variety of meanings. This usage is a simple reflection of the complexity and diversity of stressors and stress responses, which are often considered by individual investigators in a specific, somewhat narrow context. The primary ‘stress’ may be a surgical procedure [1–3], an inflammation [4] or injury such as a burn. The ‘stress’ is understood to have degrees: surgery is more or less invasive, and inflammation, infection and burn are more or less extensive. ‘Stress’ most often connotes a physiological response (neuro – endocrine – metabolic – immune) to an insult or injury. There are no universally used indicators or benchmarks of stress (table 1). The ‘stress response’ evaluated may be considered to be the activation of the hypothalamic-pituitary-adrenal (HPA) and sympathetic nervous system (SNS) associated with elevated secretion of adrenal hormones, particularly epinephrine and glucocorticoids. The ‘stress response’ may be considered to consist of inflammation and activation of the immune system with emphasis on the postoperative or postinjury ‘cytokine storm’ [5]. Oxidative ‘stress’, including reactive oxygen species and antioxidants, is another manifestation of inflammation and injury of various types [6]. ‘Nutritional stress’ refers to a suboptimal preoperative or predisease nutrient supply, as well as to a depleted state that may evolve secondarily to another stress type. Stress of all of these types includes the concomitant psychological response. Nicolaïdis [7] emphasizes the Cynober L, Moore FA (eds): Nutrition and Critical Care. Nestlé Nutrition Workshop Series Clinical & Performance Program, Vol. 8, pp. 1–13, Nestec Ltd.; Vevey/S. Karger AG, Basel, © 2003.