Examining Obesity and Its Association With Burn Injury: A Secondary Analysis of the Transfusion Requirement in Burn Care Evaluation Study

Abstract

IntroductionLiterature examining the connection between obesity and burn injuries is limited. This study is a secondary analysis of a multicenter trial data set to investigate the association between burn outcomes and obesity following severe burn injury. Materials and methodsBody mass index (BMI) was used to stratify patients as normal weight (NW; BMI 18.5-25), all obese (AO; any BMI>30), obese I (OI; BMI 30-34.9), obese II (OII; BMI 35-39.9), or obese III (OIII; BMI>40). The primary outcome examined was mortality. Secondary outcomes included hospital length of stay (LOS), number of transfusions, injury scores, infection occurrences, number of operations, ventilator days, intensive care unit LOS, and days to wound healing. ResultsOf 335 patients included for study, 130 were obese. Median total body surface area (TBSA) was 31%, 77 patients (23%) had inhalation injury and 41 patients died. Inhalation injury was higher in OIII than NW (42.1% versus 20%, P = 0.03). Blood stream infections (BSI) were higher in OI versus NW (0.72 versus 0.33, P = 0.03). Total operations, ventilator days, days to wound healing, multiorgan dysfunction score, Acute Physiology and Chronic Health Evaluationscore, hospital LOS, and intensive care unit LOS were not significantly affected by BMI classification. Mortality was not significantly different between obesity groups. Kaplan–Meier survival curves did not significantly differ between the groups (χ2 = 0.025, P = 0.87). Multiple logistic regression identified age, TBSA, and full thickness burn as significant independent predictors (P < 0.05) of mortality; however, BMI classification itself was not predictive of mortality. ConclusionsNo significant association between obesity and mortality was seen after burn injury. Age, TBSA, and percent full- thickness burn were independent predictors of mortality after burn injury, while BMI classification was not.