Multiple Casualty Incidents at a Level I Trauma Center: A 15-year Analysis.

INTRODUCTION: Limited evidence regarding multiple casualty outcomes exists. Given resource strain with increasing patient load, we hypothesized that patients involved in a multiple casualty incident have worse outcomes compared to standard trauma patients. METHODS: Multiple casualty victims from 2006 to 2021 at our institution were identified; admission data and trauma outcomes were then compared to standard trauma patients. Chi-square tests and Mann-Whitney U-tests were performed for categorical and non-normal continuous data, respectively. Logistic regression was performed to evaluate associations with mortality and intensive care unit (ICU) admission. RESULTS: We identified 39,924 patients, of which 612 were multiple casualty patients (1.5%). Multiple casualty involvement was associated with younger age (29 y versus 44 y, P < 0.001) and higher rates of penetrating trauma (26.1% versus 21.4%; P < 0.001). Multiple casualty involvement was associated with higher injury severity score (ISS) (11.6 versus 7.9, P < 0.001), mortality (2.4% versus 1.5% P < 0.005), and ICU admission (17% versus 13%, P < 0.005). On logistic regression analysis, age, ISS, shock index, presence of the COVID-19 pandemic, and mechanism all independently predicted mortality (P ≤ 0.003), while multiple casualty involvement did not (P = 0.302). CONCLUSIONS: Although multiple casualty incidents are associated with patient factors that increase hospital resource strain, when controlling for age, ISS, shock index, presence of the COVID-19 pandemic, and trauma mechanism, involvement in multiple casualty incident was not independently associated with ICU admission or mortality. Improved understanding of the impact of high-volume trauma may allow us to improve our care of this at-risk population.