Improvement in immune function in ICU patients by enteral nutrition supplemented with arginine, RNA, and Menhaden oil is independent of nitrogen balance

: Hypermetabolism and multiple organ failure syndrome (MOFS) after trauma, surgery, or sepsis is associated with accelerated catabolism, the rapid onset of malnutrition, and immune system failure. Current nutritional support, enteral or parenteral, can achieve an acceptable nutritional response but appears unable to improve immune function. Nutrients such as arginine, refined menhaden oil, and RNA have been found to have immune-stimulating properties. This randomized blind prospective trial compared two nutritionally complete enteral formulas, one supplemented with arginine, menhaden oil, and RNA, on the disease-specific effects of anergy and suppression of in vitro tests of immune function in intensive-care patients and the nutritional outcome of nitrogen balance. After 7-10 days of enteral nutrition in patients with persistent sepsis syndrome, both formulas were associated with the achievement of net nitrogen retention and improved visceral protein status but with nonresolution of anergy. However, the supplemented formula was associated with marked stimulation of in vitro lymphocyte proliferative responses and a significant reduction in 3-methylhistidine excretion. Six and 12-mo follow-up data demonstrated no long-term effects. Nutrients targeted to effect the disease-induced in vitro suppression of immune function in MOFS appear to achieve that end independent of the nutritional outcome of nitrogen balance and without adverse clinical outcome.