Determination of total energy requirements in burned children using the Doubly‐Labeled Water Technique

Abstract

IntroductionSevere burn injury initiates a prolonged stress response which results in hypermetabolism and increased resting energy expenditure. While adequate nutritional provision is imperative to mitigate losses in weight and lean mass following burn trauma, typically total energy expenditure (TEE) and caloric requirements are indirectly estimated from resting energy expenditure (REE). The doubly labelled water (DLW) method allows the direct quantification of TEE in free‐living individuals. The aim of this study was to use DLW to calculate the TEE of severely burned children during their acute hospitalization and outpatient rehabilitation.MethodsFifteen children aged 6–15 years with at least 30% of total body surface area (TBSA) burned admitted to Shriners Hospital for Children – Galveston were recruited. Eight children were studied during their acute hospitalization. Seven children were measured after hospital discharge during their outpatient rehabilitation program. TEE was determined following a 1.5g– 3g/kg dose of 2H218O water (DLW). Urine was collected before DLW administration and then daily for a period of 5–7 days for the acute patients and 14 days for the outpatient group. The elimination of 2H and 18O from body water was used to determine whole body combustion (CO2 production) from which TEE was calculated. Resting energy expenditure was also measured by indirect calorimetry during the study period.ResultsOf the 15 total patients, there were 3 females in the acute and 2 in the exercise group. Mean age was 10 ± 3 years (range, 6–15), mean weight on first study day was 37.3 ± 13.2 kg (range, 20.6–55.3) and mean burn size was 51% ± 17% (range, 30%–83%) of TBSA. For the acute group, study started on average on 22 ± 6 days post burn and for the outpatient group on 52 ± 29 days. Acute patients had a daily TEE that was 1.46 ± 0.27 times greater than measured REE (range, 1.12–1.87). This amounted to an energy requirement of 61 ± 16 kcal/kg/day (range, 42–90). Acute patients with full thickness burns >60% of TBSA had a TEE 1.8 times greater than measured REE. Outpatients had average daily TEE measured as 1.32 ± 0.12 times REE (range, 1.12–1.53), equating to an energy requirement of 53 ± 11 kcal/kg/day (range, 45–74).ConclusionsAcutely injured burn patients have a TEE that is 40–50% greater than REE, despite being largely immobilized. Patients with very large burns (>60% TBSA) have a TEE that is up to 80% greater than REE during their acute hospitalization. Following hospital discharge, TEE is around 30% greater than REE in burned children despite the fact that these patients are now ambulated, suggesting resolution of burn induced hypermetabolism. These preliminary data may be useful in forming guidelines for nutritional therapy in patients with severe burns.Support or Funding InformationThis work was funded by NIH (P50 GM060338 and R01 GM056687) and SHC (84080 and 80490)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.