Randomized clinical trial of intravenous soybean oil alone versus soybean oil plus fish oil emulsion after gastrointestinal cancer surgery.

Background: Specific immunonutrients may reduce the incidence of postoperative complications and shorten recovery time. This randomized trial evaluated the clinical efficacy of a fish oil emulsion on outcome and immune function after gastrointestinal cancer surgery.

Methods: A total of 206 patients with gastrointestinal or colonic cancer were randomized to receive isocaloric and isonitrogenous intravenous infusions of either soybean oil alone (1.2 g per kg bodyweight per day; control group, 103 analysed) or soybean plus fish oil emulsion (1.0 and 0.2 g per kg per day respectively; treatment group, 100 analysed) over 20-24 h daily for 7 days after surgery.

Results: Baseline data were comparable in the two groups. There were fewer infectious complications (four versus 12 on day 8; P = 0.066), systemic inflammatory response syndrome (SIRS) was significantly less common (four versus 13; P = 0.039) and hospital stay was significantly shorter (mean(s.d.) 15(5) versus 17(8) days; P = 0.041) in the treatment group. Total postoperative medical costs were comparable in the two groups (mean(s.d.) US $ 1269(254) and 1302(324) in treatment and control groups respectively; P = 0.424). The median (interquartile range) difference in CD4/CD8 between days 1 and 8 after surgery was + 0.30 (0.06 to 0.79) in patients receiving fish oil and + 0.20 (-0.19 to 0.55) in controls (P = 0.021). No severe adverse events occurred in either group.

Conclusion: Fish oil emulsion-supplemented parenteral nutrition significantly reduced SIRS and length of hospital stay. These clinical benefits may be related to normalization of cellular immune functions and modulation of the inflammatory response.