[Perioperative nutrition for gastrointestinal surgery].

In elective gastrointestinal (GI) surgery, the patients' nutritional status should be assessed and if protein-energy malnutrition exists, preoperative nutritional support should be scheduled 7 to 14 days before surgery. In malnourished patients in particular, preoperative nutrition with total parenteral nutrition (TPN) reduces postoperative complication rates of infection. Preoperative enteral nutrition (EN) is considered to be as effective as TPN in improving postoperative surgical outcome. Many prospective randomized trials or meta-analyses comparing postoperative EN and TPN have revealed that postoperative EN improves surgical outcomes and lowers postoperative complication rates of infection to a degree similar to TPN. Although two recent prospective multicenter randomized trials in malnourished patients undergoing elective GI cancer surgery are controversial, no evidence that EN was less effective than TPN was recognized. Thus postoperative EN, prior to TPN, is recommended in patients with malnutrition or insufficient oral intake for 7 days or more after surgery. When TPN is administered, hyperglycemia due to overfeeding should be carefully controlled. Patients who undergo distal gastrectomy or colectomy can start oral intake 3 to 4 days after surgery, with pertinent peripheral infusion. Immunonutrition containing immune-enhancing nutrients such as arginine, n-3 polyunsaturated fatty acid, glutamine, etc., especially administered preoperatively, is a promising nutritional therapy for reducing postoperative infectious complications.