BURN SIZE DETERMINES THE INFLAMMATORY AND HYPERMETABOLIC RESPONSE

Background: Increased burn size leads to increased mortality of burned patients. Whether mortality is due to inflammation, hypermetabolism or other factors is not entirely determined. The purpose of the present study was to determine whether different burn sizes are associated with differences in the hypermetabolic and inflammatory response. Patients and Methods: Severely burned pediatric patients were divided into four burn size groups: 0-39% total body surface are burn (TBSA), 40-59% TBSA, 60-79% TBSA and 80-99% TBSA. Demographic and clinical data, serum hormones, and resting energy expenditure (REE) was obtained throughout acute hospital course. Inflammatory markers were determined using the Bioplex Array. Significance was accepted at P < 0.05. Results: Two-hundred twenty one patients were included into this study. Forty-three patients in the 0-39% TBSA, 79 in the 40- 59% TBSA, 78 in the 60-79% TBSA, and 21 in the 80-99% TBSA group. Patients with larger burns had more operations, greater incidence of infections and sepsis, and higher mortality rates compared to the other groups, P < 0.05. Measured REE and percent predicted REE was highest in the 80-99 % TBSA group followed by the 40-59% and 60-79% and lowest in the 0-39 %, P < 0.05. Children suffering from >80% burn lost the most body weight, lean body mass, muscle protein and bone mineral content when compared to the other groups, P < 0.05. Urine cortisol concentration was increased in all groups but highest in the 80-99% TBSA group, P < 0.05. Cytokine profile showed distinct differences in expression between groups with significant differences in almost all cytokines, P < 0.05. Summary: Morbidity and mortality in burned patients is burn size dependent and due to an increased hypermetabolic and inflammatory reaction. These data delineate the importance for anabolic and anti-inflammatory treatment to improve outcome for these patients.