Nutritional support in critical illness.

Critically ill patients, almost by definition, are catabolic and often hypermetabolic. Although it is generally accepted that such patients would benefit from nutritional support, there are remarkably little data to support this premise. Several experts believe that prospective, randomized, controlled studies to document the efficacy of nutrition support in improving outcome in critically ill patients are unlikely to occur for a variety of reasons. It is difficult to recruit acceptable (large) numbers of patients that can be matched in terms of diagnosis, severity of illness and nutritional status prior to intensive care unit (ICU)b admission. With the broad acceptance of early nutritional support amongst physicians, ethical dilemmas are created in proceeding with trials in which control groups receive no nutritional support. Finally, as Soeters et al. [1] point out, it is likely that those patients who are most severely ill will receive the least benefit in terms of outcome because of overwhelming illness. Nevertheless, nutritional depletion is generally associated with increased morbidity and mortality, and intuitively the correction of these deficiencies should minimize the component of the adverse outcome attributable to malnutrition.