Age Differences in Inflammatory and Hypermetabolic Postburn Responses

OBJECTIVE: The aim of this study was to identify contributors to morbidity and death in severely burned patients <4 years of age. METHODS: A total of 188 severely burned pediatric patients were divided into 3 age groups (0-3.9 years, 4-9.9 years, and 10-18 years of age). Resting energy expenditure was measured through oxygen consumption, body composition through dual-energy x-ray absorptiometry, liver size and cardiac function through ultrasonography, and levels of inflammatory markers, hormones, and acute-phase proteins through laboratory chemistry assays. RESULTS: Resting energy expenditure was highest in the 10- to 18-year-old group, followed by the 4- to 9.9-year-old group, and was lowest in the 0- to 3.9-year-old group. Children 0 to 3.9 years of age maintained lean body mass and body weight during acute hospitalization, whereas children >4 years of age lost body weight and lean body mass. The inflammatory cytokine profile showed no differences between the 3 age groups, whereas liver size increased significantly in the 10- to 18-year-old group and was lowest in the 0- to 3.9-year-old group. Acute-phase protein and cortisol levels were significantly decreased in the toddler group, compared with the older children. Cardiac data indicated increased cardiac work and impaired function in the toddler group, compared with the other 2 age groups. CONCLUSIONS: Increased mortality rates for young children are associated with increased cardiac work and impaired cardiac function but not with the inflammatory and hypermetabolic responses.