Effect of the preoperative infusion of fish oil parenteral lipid emulsion on postoperative immune response and immediate clinical outcome of patients with gastrointestinal cancer

BACKGROUND: Parenteral lipid emulsion composed by fish oil, rich in omega-3 fatty acids, is infused in addition to other standard lipid emulsions, as part of parenteral nutrition therapy. In surgical patients, the perioperative infusion of fish oil lipid emulsion is associated with immune functions preservation and favorably modulation of postoperative inflammatory mediators, with decreased infectious complications and length of intensive care unit and hospital stay. These reported benefits encourage the use of fish oil lipid emulsion alone, as a pharmacological adjuvant agent for the treatment of surgical patients, independent of parenteral nutritional therapy indication. AIM: This clinical trial assessed the effect of short-term preoperative infusion of fish oil lipid emulsion alone on postoperative immune response and immediate clinical outcomes of patients with gastroenterological cancer. METHOD: In a prospective, randomized, controlled and double-blind design, elective surgical patients with gastrointestinal cancer (n= 63) received, for the last 3 pre-operative days, peripheral infusion (0.2g fat/kg of body weight./d) of fish oil lipid emulsion (Omegaven® 10% - Fresenius-Kabi) or control lipid emulsion (Lipovenos MCT® 10% - Fresenius-Kabi). Peripheral blood samples were collected before and after lipid emulsion infusion at the 3rd and 6th (only for cytokines) postoperative days to analyze plasma concentration of IL-6 and IL-10, as well as leukocyte migration, phagocytosis, oxidative burst and expression of HLADR and CD32 molecules. Postoperative infections, length of intensive care unit and hospital stay were also measured. RESULTS: At postoperative period, patients treated with fish oil lipid emulsion had increase of IL-10 (day 3, p < 0.0001), decrease of IL-6 (day 3, p = 0.029) and IL-10 (day 6, p<0.0001), lower decrease of leukocyte oxidative burst (p=0.023), maintenance of the percentage of monocytes expressing HLA-DR (p=0.046) and CD32 (p=0,025) and increase of the intensity of CD32 expression on neutrophil surface (p=0,010), when compared to patients treated to control lipid emulsion. The leukocyte chemotaxis was not affected. No changes were observed on postoperative infections and length of intensive care unit and hospital stay. CONCLUSION: Short-term preoperative infusion of fish oil lipid parenteral emulsion alone improves postoperative immune response of patients with gastrointestinal cancer without benefit on infections frequency and length of intensive care unit and hospital stays.