Acute Respiratory Distress Syndrome in the forward environment. Retrospective analysis of ARDS cases among French Army war casualties.

BACKGROUND: According to the Joint Theater Trauma Registry, 26-33% of war casualties develop Acute Respiratory Distress Syndrome (ARDS), with high mortality. Here we aimed to describe ARDS incidence and severity among patients evacuated from war zones and admitted to French intensive care units (ICUs). METHODS: We performed an observational retrospective multicentric review of all patients evacuated from war zones and admitted to French ICUs between 2003-2018. Our analysis included all medical and trauma patients developing ARDS according to the Berlin definition. We evaluated ARDS incidence, and determined ARDS severity from arterial blood gas analysis. Analyzed parameters included invasive ventilation duration, ARDS treatments, ICU stay length, and 30-day and 90-day mortality. RESULTS: Among 141 included patients (84% military; median age, 30 years), 57 (42%) developed ARDS. ARDS was mild in 13 patients (22%), moderate in 24 (42%), and severe in 20 (36%). Evacuation occurred in <26 hours for 32 war casualties, 17 non-war-related trauma patients, and 8 medical patients. Among severe trauma patients, median ISS was 34, and AIS thorax was 3. Upon French ICU admission, median PaO2/fiO2 ratio was 241 [144-296]. Administered ARDS treatments included intubation (98%, n = 56), protective ventilation (87%, n = 49), neuromuscular blockade (76%, n = 43), prone position (16%, n = 9), inhaled nitric oxide (10%, n = 6), almitrine (7%, n = 7), and extracorporeal life support (ECLS) (4%, n = 2). Median duration of invasive ventilation was 13 days, ICU stay was 18 days, 30-day mortality was 14%, and 90-day mortality was 21%. CONCLUSIONS: ARDS was frequent and severe among French patients evacuated from war theaters. Improved treatment capacities are needed in the forward environment-for example, a specialized US team can provide ECLS for highly hypoxemic war casualties. LEVEL OF EVIDENCE: Prognostic and epidemiological study, level III.