Effect of Laparoscopic Colon Resection on Postoperative Glucose Utilization and Protein Sparing

Abstract

Using a stable isotope method to quantify postoperative changes in glucose and protein metabolism, patients undergoing laparoscopic-assisted colon resection and receiving 4 mg . kg(-1) . min(-1) of dextrose intravenously will (1) have more pronounced suppression of endogenous glucose production, leading to (2) a greater reduction in whole-body protein breakdown. Randomized protocol study. Tertiary health care center in Montreal, Quebec. Twelve patients scheduled for colonic resection were randomly allocated to undergo either laparoscopic (n = 6) or open (n = 6) surgery. Patients underwent a 6-hour stable isotope infusion study (3 hours fasted and 3 hours fed with dextrose infusion) on postoperative day 2. Whole-body protein breakdown and synthesis, amino acid oxidation, and endogenous glucose production and clearance were measured during the postabsorptive state using L-[1-(13)C]leucine and [6,6-(2)H(2)]glucose. Gas exchange and plasma concentrations of metabolites and hormones were also measured. Endogenous glucose production and whole-body protein breakdown during the fasted and fed states. In the fasted state, laparoscopy did not affect protein and glucose metabolism. Dextrose infusion suppressed endogenous glucose production in both groups, with the greatest extent in the laparoscopic group (P = .01). Higher respiratory quotients (P = .001) in the latter group also indicated increased exogenous glucose oxidation. Neither surgical approach nor nutrition affected aspects of protein metabolism. Laparoscopy for colon resection facilitates whole-body glucose uptake and utilization and oxidation of exogenous glucose with no protein-sparing effect. The laparoscopic approach modulates gluconeogenesis, although it is not sufficient in the presence of exogenous energy to promote nitrogen retention.