A comparison of acute respiratory distress syndrome outcomes between military and civilian burn patients

Abstract

Background: The objective of this report was to compare the prevalence of acute respiratory distress syndrome (ARDS) and associated mortality between military service members with burns sustained during or in support of combat operations and civilian burn patients treated at a single burn center. Methods: Demographic and physiologic data were collected retrospectively on mechanically ventilated military and civilian patients admitted to our burn intensive care unit between January 2003 and December 2011. Patients with ARDS were identified and categorized as mild, moderate, or severe using the Berlin criteria. Demographics and clinical outcomes were compared. After initial comparison, propensity matching was performed and mortality compared. Results: A total of 891 burn patients required mechanical ventilation during the study period; 291 military and 600 civilian. The prevalence of ARDS was 34% (n = 304) for the entire cohort, 33% (n = 96) for military, and 35% (n = 208) for civilians (p = 0.55). For the entire cohort, despite more severe injury burden, military patients had a significantly lower overall mortality (17% vs. 28%; p = 0.0002) as well as ARDS mortality (33 vs. 48%, p = 0.02) when compared to civilians. This difference was not significant after propensity matching based on age. Conclusion: In a retrospective cohort study, burned military patients on mechanical ventilation had a significantly lower overall and ARDS mortality despite larger burns and more severe injury when compared to civilian burn patients. This difference appears to be largely because of age.