The effect of supplemental enteral glutamine on plasma levels, gut function, and outcome in severe burns: A randomized, double-blind, controlled clinical trial

Background: This research was conducted to evaluate the effect of enterally administered glutamine (gln) dipeptide on metabolic, gastrointestinal, and outcome parameters after severe burn injury. Methods: Forty thermally injured patients with total,body. surface burns ranging between. 50% and 80%, and. third-degree burns ranging between 20% and 40% and without respiratory injures, were randomized into a prospective, double-blind, controlled clinical trial. One, group received gln-enriched enteral. nutrition and the other group received the standard enteral formulation. Tube feedings were initiated on postburn day 1 (PBD +1), and isocaloric and isonitrogenous feedings were administered to both groups until PBD + 12. The kin was given as the dipeptide of alanyl-gln (Ajinomoto, Tokyo, Japan), which provided 0.35 g gln/kg body weight/d. Plasma amino acid profiles, serum endotoxin concentrations, and the lactulose/mannitol absorption ratio (which reflects gut permeability) were measured at specific times throughout the clinical course.. Wound healing. at day 30 was assessed, and length of hospital stay and total costs were determined at discharge. Results: The 2 groups were similar in terms of age and extent of injury. Plasma gln concentrations were similar to300 umol/L. in both groups on PBD +1 and remained low in the control group (399 +/- 40 umol/L, mean +/- SD) but increased toward normal in the supplemented group to 591 +/- 74 (p = .048). Lactulose/mannitol ratios were increased above normal on POD +1 (control, 0.221 +/- 0.169; gln, 0.268 +/- 0.202; not significant), reflecting increased intestinal permeability after burn injury. On POD +3, the ratio in the gln group was lower than control (0.025 +/- 0.008 versus 0.049. +/- 0.016; p = .0001), and both groups returned toward normal ratios with time. Endotoxin levels on PBD +1 were elevated in both groups (control, 0.089 +/- 0.023 EU/mL; gln, 0.103 +/- 0.037 EU/mL; NS) but decreased significantly on PBD +3 in the patients receiving gln. Hospital stay was significantly shorter in the gln group than controls (67 +/- 4 days versus 73 +/- 6; p = .026). On day 30, wound healing was 86% +/- 2% complete in the gln group compared with 72% +/- 3% in controls (p = .041). Total cost of hospitalization was 62794 6178 RMB ($7593 +/- 747 US dollars) in the gln group and 68996 +/- 8620RMB ($8343 +/- 1042, p = .031) in controls, although the cost of the enteral nutrition was higher in the gln-supplemented patients. Conclusion: Enteral gln supplementation using a commercially available dipeptide supported plasma gln levels, improved gut permeability, and initially decreased plasma endotoxin levels in severely thermally injured patients. These alterations were associated with a reduction in the length of hospitalization and lower costs.