n-3 Fatty acids have clinical benefits. The primary aim of the present study was the assessment of infection in patients who underwent major high-risk elective gastrointestinal surgery receiving postoperatively fish oil (FO)-supplemented parenteral nutrition (PN), compared with those receiving a standard olive oil (OO) emulsion. The secondary aims were the assessment of anti-inflammatory response and evaluation of tolerance and safety of these emulsions. A prospective, randomised, double-blind study was performed in patients requiring at least 5 d of PN. An isoenergetic and isoproteic formula was administered: group A received OO alone, while group B received OO that was partially replaced with FO (16·6 %, w/w). End points were outcome measures (mortality, sepsis, infection, hospitalisation days and PN duration), inflammatory response (C-reactive protein (CRP), prealbumin and leucocytes) and safety (TAG and glucose metabolism, and liver and kidney function). Statistical analysis was done using Student's t test and Fisher's exact test (P < 0·05). Twenty-seven patients were evaluated, with thirteen patients receiving FO. In this group, a significantly lower incidence of infections was found (23·1 v. 78·6 %, P = 0·007). CRP, prealbumin and leucocytes were not significantly different between the groups. There were no differences in safety parameters. We conclude that high-risk surgical patients receiving FO-supplemented PN for 5 d present a lower incidence of infection. Emulsions were safe and well tolerated.

Major surgery induces an immuno-inflammatory response accompanied by oxidative stress that may impair cellular function and delay recovery. The objective of the study was to investigate the effect of an enteral supplement, containing glutamine and antioxidants, on circulating levels of immuno-inflammatory markers after major gastrointestinal tract surgery. Patients (n 21) undergoing major gastrointestinal tract surgery were randomised in a single-centre, open-label study. The effects on circulating levels of immuno-inflammatory markers were determined on the day before surgery and on days 1, 3, 5 and 7 after surgery. Major gastrointestinal surgery increased IL-6, TNF receptor 55/60 (TNF-R55) and C-reactive protein (CRP). Surgery reduced human leucocyte antigen-DR (HLA-DR) expression on monocytes. CRP decrease was more pronounced in the first 7 d in the treatment group compared with the control group. In the treatment group, from the moment Module AOX was administered on day 1 after surgery, TNF receptor 75/80 (TNF-R75) level decreased until the third post-operative day and then stabilised, whereas in the control group the TNF-R75 level continued to increase. The results of the present pilot study suggest that enteral nutrition enriched with glutamine and antioxidants possibly moderates the immuno-inflammatory response (CRP, TNF-R75) after surgery.