Nutrition Therapy in Critically Ill Patients

The occurrence of malnutrition in critical care patients is a frequent event, both before and after the intensive care unit (ICU) admission. It is characterized by the occurrence of muscle weakness, delayed wound repair, and frequent nosocomial infections, resulting in increased morbidity and mortality rates. All patients with an ICU length of stay greater than 48 h should be considered at risk of malnutrition. Therefore, adequate nutritional support is mandatory for these patients to allow the maintenance of physiological organ function, immunocompetence, and tissue repair; it also preserves protein synthesis and skeletal and respiratory muscle function. Nutrition therapy includes enteral or parenteral administration of adequate caloric, protein, fluid, electrolyte, vitamin, and trace element intake. As compared with parenteral nutrition (PN), enteral nutrition (EN) is less expensive and may better maintain intestinal mucosal structure and gut absorptive and barrier functions. In addition, EN is associated with fewer infectious, mechanical, and metabolic complications. As a consequence, early EN (within 48 h) in critically ill adult patients should be performed whenever possible. In the case of contraindications to EN, PN should be implemented within 3–7 days. In the case of severely malnourished patients with contraindications to EN, early and progressive PN should be provided. This review is intended to provide an update on nutrition therapy in critically ill patients.