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 injuries, 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 gln 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 approximately 300 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 (dollar 7593 +/- 747 US dollars) in the gln group and 68996 +/- 8620RMB (dollar 8343 +/- 1042, p = .031) in controls, although the cost of the enteral nutrition was higher in the gln-supplemented patients.


CONCLUSIONS
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.
Zhou
Ye-Ping
YP
Department of Surgery, Peking Union Medical Collage Hospital, Beijing, China.
Jiang
Zhu-Ming
ZM
Sun
Yong-Hua
YH
Wang
Xiu-Rong
XR
Ma
En-Ling
EL
Wilmore
Douglas
D
D000293:Adolescent; D000328:Adult; D002056:Burns / Q000382:microbiology / Q000503:physiopathology / Q000628:therapy*; D002681:China; D019587:Dietary Supplements; D004064:Digestive System / Q000503:physiopathology*; D004311:Double-Blind Method; D004731:Endotoxins / Q000097:blood; D004750:Enteral Nutrition; D004927:Escherichia coli Infections / Q000453:epidemiology; D005526:Food, Formulated; D005973:Glutamine / Q000008:administration & dosage* / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000453:epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss; D014945:Wound Healing; D014946:Wound Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control
D004731:Endotoxins; D005973:Glutamine