ObjectiveTo evaluate the diagnostic value of sTREM-1 level in bronchoalveolar lavage fluid (BALF) for diagnosing early lung infection of patients with post-traumatic acute respiratory distress syndrome. Methods64 patients with post-traumatic ARDS,who were admitted in ICU from emergency department or other trauma surgery department from January 2010 to December 2012,were divided into a pulmonary infection group (n=34) and a non-pulmonary infection group(n=30).30 healthy volunteers aged over 18 years were taken as healthy control group.The ROC curve was used to analyze the diagnostic value of C-reactive protein (CRP),procalcitonin (PCT) and sTREM-1 in early pulmonary infection of patients with post-traumatic ARDS. ResultsGender and age composition showed no significant difference among the healthy control group,the pulmonary infection group,and the non-pulmonary infection group(P>0.05). Injury severity scale(ISS),APACHEⅡ and the mortality in 28 days showed significant difference between the groups of pulmonary infection and non-pulmonary infection(P<0.05).Oxygenation index (PaO2/FiO2),tracheal intubation time,mechanical ventilation time and length of ICU stay also showed significant difference between the groups of pulmonary infection and non-pulmonary infection(P<0.01).Compared with the healthy control group,levels of serum CRP,PCT and sTREM-1 increased significantly in the groups of pulmonary infection and non-pulmonary infection(P<0.001).Compared with the non-pulmonary infection group,the levels of CRP,PCT and sTREM-1 in serum,and sTREM-1 in BALF increased significantly in the pulmonary infection group (P<0.05).The area under the ROC curve (AUC) of serum CRP was 0.67 with the sensitivity of 0.68 and the specificity of 0.70.AUC of serum PCT was 0.67 with the sensitivity of 0.70 and the specificity of 0.64.AUC of serum sTREM-1 was 0.73 with the sensitivity of 0.73 and the specificity of 0.68.AUC of sTREM-1 in BALF was 0.90 with the sensitivity of 0.90 and the specificity of 0.82. ConclusionsTREM-1 in BALF can be used as a diagnostic indicator for early pulmonary infection in patients with post-traumatic ARDS.Its sensitivity and specificity are higher than serum CRP,PCT and sTREM-1.