The focus of nutritional support has shifted from solely maintaining caloric intake to modifying disease response. Immunonutrition, also known as pharmaconutrition, involves the use of specific nutrients to modulate the activity of the immune system. Arginine supplements, such as Resource Arginaid®, have been used for some time to promote wound healing. Mounting evidence now suggests that nutritional interventions may also be effective in reducing post-operative infection and length of hospital stay, particularly for surgical oncology and trauma patients. A recent study of radical cystectomy patients showed a 39% reduction in infection rates when immunonutrition was administered peri-operatively.
Malnourishment, associated with higher morbidity and mortality, is a significant concern in surgical oncology patients. Trauma patients are often well-nourished upon presentation, however prompt nutritional support may still be warranted. Major trauma and surgery results in an initial period of hyper-inflammation, followed by excessive compensatory immune suppression. This immunosuppression may be partly due to rapid expansion of myeloid-derived suppressor cell (MDSC) populations. MDSCs produce arginase, thereby inhibiting arginine-dependent biological functions, such as wound healing and T-cell activation.
Limitations of clinical data in this field include inconsistent volumes and quantities of specific micronutrients, and small sample sizes employed in clinical trials. Nutrients with the most robust evidence base include arginine, glutamine, branched chain amino acids, n-3 fatty acids, and nucleotides. Enteral products available in Australia include Cubitan® and Impact®; parenteral products include Kabiven® and OliClinomel®.
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- Pierre JF, Heneghan AF, Lawson CM, Wischmeyer PE, Kozar RA, Kudsk KA. Pharmaconutrition review: physiological mechanisms. J Parenter Enteral Nutr. 2013; 37(5): 51S-65S.
- Turnock A, Calder PC, West AL, Izzard M, Morton R, Plank LD. Perioperative immunonutrition in well-nourished patients undergoing surgery for head and neck cancer: evaluation of inflammatory and immunologic outcomes. Nutrients 2013; 5: 1186-99.