Controversy of immunonutrition for surgical critical-illness patients.

Specific nutrients such as arginine, glutamine, dietary nucleotides, and omega-3 fatty acids have been shown to influence infectious morbidity, antibiotic use, and hospital length of stay. The combination of these nutrients into one enteral formulation has become known as immune-enhancing diets. Consensus guidelines developed by a number of clinical investigators and published in 2001 concluded that immune-enhancing diets were beneficial in moderate to severely malnourished patients undergoing elective gastrointestinal surgery and patients sustaining severe blunt and penetrating torso trauma. The purpose of this article is to review data published between February 1, 2001, and January 31, 2003, to determine whether new studies substantiated or refuted the current recommendations for the use of immune-enhancing diets in surgical, critically injured, and critically ill patients. Results confirmed the benefits of preoperative administration of immune-enhancing diets in surgical patients but also demonstrated that postoperative administration offered no advantages. Decreased infectious complications were also observed in critically ill patients receiving immune-enhancing diets. Accumulating evidence supports the use of immune-enhancing diets in these specific patient populations.