Nutritional support in ICU patients: position of scientific societies.

The most prominent metabolic alterations which characterize the systemic inflammatory response syndrome and sepsis include hypermetabolism, hyperglycemia with insulin resistance, accelerated lipolysis and net protein catabolism [1–3]. The combined effect of these metabolic alterations associated with bed rest and lack of nutritional intake can lead to a progressive depletion of lean body mass. Even if nutritional support in critically ill patients cannot fully prevent or reverse the metabolic alterations and, consequently, the disruption in body composition and the erosion of the body cell mass, it can nevertheless slow the rate of net protein catabolism by providing an exogenous load of energy and nitrogen [2, 4]. Recent publications demonstrate increased non-resting energy expenditure (i.e. activity) after the first week of critical illness [5]. Total energy expenditure in septic patients was in fact 25 5 kcal/kg/day during the first week of critical illness and increased to 47 6 kcal/kg/day during the second week. However, it remains to be determined if administering more than 25–30 kcal/kg/day is beneficial to these patients, and if providing more than 1 g amino acid/kg/day (a quantity sufficient to minimize loss of body protein during the initial 2 weeks of critical illness) carries further benefit [6]. We reviewed the official statements of some national and international scientific societies regarding the nutritional support of intensive care unit (ICU) patients: the Italian Society for Parenteral and Enteral Nutrition (SINPE) 1995 [7]; the French Speaking Society for Enteral and Parenteral Nutrition (SFNEP) 1996 [8] that only considered septic patients; the American College of Chest Physicians (ACCP) 1997 [9]; the French Speaking Society of Enteral and Parenteral Nutrition (FSNEP) 1998 [10]; the European Society of Intensive Care Medicine (ESICM) 1998 [11] that also published a position