Immune response is compromised, to varying extent, in patients who have surgery, trauma, burns, and injury. Massive activation of the inflammatory cascade, with alterations in both innate and adaptive immune functions, contributes significantly to increased susceptibility to infections. The resulting septic syndromes are associated with development of multiple organ failure and significant morbidity and mortality in most of the cases. Since nutrition and immunity are interrelated, the use of enteral feedings enriched with immuneenhancing ingredients was proposed for restoration of immune functions and reducing infection rates in critically ill patients. Several nutrients like arginine, glutamine, omega-3-fatty acids, and nucleotides (immunonutrients) have been added to standard nutritional support solutions, and the use of these formulations is known as “immunonutrition.” Immunonutrients, apart from being dietary components, influence immunologic response mechanisms. These immunonutrients may simply be acting as pharmacologic agents, much like a drug, when consumed in amounts above the accepted daily requirements. A new field in nutrition science has thus emerged, and a shift from immunonutrition to pharmaconutrition has occurred. Pharmaconutrition is expected to make a disease-state-specific nutrition therapy possible. In light of the contemporary scientific research, we will be able to answer the questions of how to administer the right nutrients, in the right amounts, at the right time to critically ill patients. However, whether giving immunonutrients to critically ill patients is beneficial remains controversial. Recent meta-analyses have yielded encouraging results in terms of reducing infection rates, fewer days on a ventilator and reduced length of intensive care unit and hospital stay. Although controversy exists regarding the use of immunonutrients, either alone or in the form of a mixture, in critically ill patients, they can be administered safely with minimal risk of adverse outcome on condition that the patients are selected properly. In patients suffering from systemic inflammatory response syndrome, great caution should be exercised when immune-enhancing substrates are involved, as they may aggravate systemic inflammation.

Keywords: immünonütrisyon, farmakonütrisyon, glutamin, arjinin, nükleotidler, omega-3 yağ asitleri, antioksidanlar