Deficiency in peripheral glutamine production in pediatric patients with burns

Plasma glutamine levels decrease in association with severe injury, which suggests that the consumption of glutamine exceeds the production of glutamine or possibly represents a deficit in the release of glutamine from skeletal muscle. The goal of this study was to assess the peripheral glutamine kinetic response to prolonged stress in children with critical injuries. To accomplish this purpose, we quantitated peripheral glutamine kinetics in vivo with the use of 5N¹⁵ glutamine in 5 children with severe burns (total body surface area, 74% ± 14%; mean ± SEM) and 3 children who underwent elective scar reconstruction. In the children with severe burns, leg blood flow was significantly elevated (16.2 ± 2.1 vs 7.5 ± 0.3 mL/min/100 mL leg volume, P < .02) and the arterial concentration of glutamine was significantly reduced (0.31 ± 0.04 vs 0.84 ± 0.05 mmol/L, P < .001). The rate of glutamine turnover within the leg was significantly reduced in the patients with acute burns, whereas the net efflux of glutamine was similar between the 2 groups. These findings suggest that plasma glutamine concentrations decrease during severe stress as a result of a deficit in peripheral glutamine release in conjunction with an increased central consumption. This preliminary study supports the notion that exogenous glutamine supplementation in pediatric patients with severe injuries may be needed because of this inadequate skeletal muscle response.