Enteral versus parenteral glucose as the sole nutritional support after colorectal resection. A prospective, randomized comparison.

Twenty consecutive patients undergoing resection for colorectal carcinoma were randomized to receive either a glucose polymer by nasojejunal tube or glucose by intravenous infusion as the sole postoperative nutritional support for 4 days. Identical amounts of glucose were given by the two routes. Brief infusions of insulin (10 mU kg-1) and glucose (25 g) were given before and 4 days after surgery for the purpose of metabolic evaluation. Blood glucose was consistently lower in the enteral than in the parenteral group (p less than 0.05). Glucose tolerance and the hypoglycemic response to insulin were impaired after surgery in the parenteral group (p less than 0.01 in both cases) but not in the enteral group. Clearance and release of insulin were similar before and after surgery and were similar in both groups. Patients receiving enteral glucose had less postoperative distress and required fewer doses of analgesic drug (p less than 0.05 in both cases). It is concluded that enteral infusion of glucose preserves insulin action and glucose tolerance after colorectal resection, whereas intravenous infusion of glucose does not. The favorable metabolic effects seen after enteral infusion are accompanied by a reduction of postoperative discomfort.