Glucose and protein kinetics in patients undergoing colorectal surgery: perioperative amino acid versus hypocaloric dextrose infusion

Surgical injury provokes a stress response that leads to a catabolic state and, when prolonged, interferes with the postoperative recovery process. This study tests the impact of 2 nutrition support regimens on protein and glucose metabolism as part of an integrated approach in the perioperative period incorporating epidural analgesia in 18 nondiabetic patients undergoing colorectal surgery. To test the hypothesis that parenteral amino acid infusion (amino acid group, n = 9) maintains glucose homeostasis while maintaining normoglycemia and reduces proteolysis compared with infusion of dextrose alone (DEX group, n = 9), glucose and protein kinetics were measured before and on the second day after surgery using a stable isotope tracer technique. Postoperatively, the rate of appearance of glucose was higher (P < .001) and blood glucose increased more (P < .001) in the DEX group than in the amino acid group. The postoperative increase in the appearance of leucine from protein breakdown tended to be greater (P = .077) in the DEX group. We conclude that perioperative infusion of a nutrition support regimen delivering amino acids alone maintains blood glucose homeostasis and normoglycemia and tends to have a suppressive effect on protein breakdown compared with infusion of dextrose alone.