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Abstract

Introduction: Post-traumatic Acute Respiratory Distress Syndrome (ARDS) has historically been associated with high rates of morbidity and mortality. The incidence of post-traumatic ARDS is decreasing. Hypothesis: We hypothesize that, despite improvements in care, the associated morbidity and mortality have not declined. This study was undertaken to determine trends in the incidence of post-traumatic ARDS and its associated morbidity and mortality over the last decade. Methods: This retrospective cohort study assessed all trauma patients admitted to the Surgical Intensive Care Unit (SICU) at a Level I academic trauma center from 2001 – 2010. Patients requiring mechanical ventilation were screened for the development of ARDS. Demographics, injury data, fluid and blood component use, ventilator parameters, and outcomes were identified from the SICU, blood bank, and trauma databases. Results: A total of 3954 patients met study inclusion criteria, and 319 (8.1%) developed ARDS. The incidence of ARDS declined in a linear fashion (R2 = 0.76) from 14% in 2001 to 1.9% in 2010. Traditional risk factors including peak inspiratory pressures (PIP), blood component transfusion and positive fluid balance continue to be associated with the development of ARDS. Mean PIP, units of blood, and 48-hour fluid balance declined throughout the study period. After adjusting for age, injury severity, initial hemodynamics, blood component transfusions, fluid balance, and ventilator parameters, the development of ARDS continues to be associated with a 2.7 fold greater risk of death (95% CI 1.8, 4.2), decreased ventilator free days (p < 0.01), and increased length of ICU stay (p<0.01). Overall mortality each year remained stable at 29 – 33% throughout the decade. Conclusions: Though once relatively common after severe trauma, the incidence of ARDS has declined dramatically over the last decade. The cause of this decline is multifactorial, however despite improvements in care, the mortality associated with the development of ARDS remains high. Continued efforts to prevent the development of ARDS have lead to a near disappearance of this highly morbid complication.