Immunonutrition and sepsis        ZHANG Zhi-dan.  Department of Critical Care Medicine， the First Affiliated Hospital of China Medical University， Shenyang 110001， China
Abstract    Septic patients are often in a catabolic state with increased energy requirements and depletion of specific nutrients which can provoke organ dysfunction. Artificial feeding is highly recommended for septic patients. Some specific nutrients including glutamine, arginine, omega-3 fatty acids, nucleotides, vitamines and trace elements can exert not only nutritional support but also immunomodulation effects to improve the host’s defence and facilitate recovery. Glutamine attenuates pro-inflammatory cytokine responses as well as improves mucosal barrier function and cellular defence. Arginine produces metabolic, immunological and haemodynamic effects via nitric oxide dependent and independent pathways. Omega-3 fatty acids can attenuate the inflammatory response. Vitamines and trace elements can improve the antioxidant defences. However, immunonutrition in critically ill septic patients is still a controversy between rationalism and empiricism. No recommendations about the routine use of specific immunonutrition for septic patients can be concluded. Clinicians should carefully consider the composition of the nutrition support depending on the patient’s conditions and other influencing factors to make the optimal use of immunonutrition for septic patients.