Immediate postoperative enteral feeding decreases weight loss and improves wound healing after abdominal surgery in rats

Objective: To determine the effect of immediate vs. delayed (72 hrs) postoperative enteral feeding on weight loss and wound healing after experimental abdominal surgery. Design: Prospective, randomized, controlled study. Setting: Laboratory of a large university-affiliated medical school. Subjects: Seventeen male Sprague-Dawley rats, each weighing 350 to 400 g. Interventions: Four-centimeter longitudinal midabdominal incisions were made and gastroduodenal feeding tubes were inserted in the animals. The abdominal wound was closed in two layers. Immediately after closure, animals were randomized to receive immediate enteral feeding (early-fed group) with a peptide-based enteral formula or 5% dextrose in water at 4 mL/hr. Seventy-two hours after surgery, the 5% dextrose in water group was switched to the peptide formula (late-fed group). Animals were weighed daily. On postoperative day 5, the strength of the abdominal wound was determined using a balloon-bursting pressure technique. Blood was also obtained for measurement of insulin growth factor 1 concentrations. Mucosal protein content of the small bowel was measured. Results: Total body weight loss was less in the early-fed group (26 ± 4 vs. 46 ± 5 g/5 days) and wound strength was increased in the early-fed group compared with the late-fed group (6 ± 0.4 vs. 2.9 ± 0.8 kPa; 45 ± 3 vs. 22 ± 6 mm Hg). There were no differences between groups for circulating insulin growth factor 1 concentrations or small intestinal mucosal protein concentrations. Conclusions: Immediate postoperative enteral feeding results in decreased weight loss and improved wound healing after abdominal surgery in rats.