ObjectiveTo investigate the correlations between lipopolysaccharide(LPS), phospholipase A2 (PLA2) and platelet-activating factor (PAF) with coagulopathy after severe chest and abdominal injuries and their mechanisms. MethodsClinical data of 82 patients with severe chest and abdominal injuries whose trauma index (TI) was greater than or equal to 17 points in No. 253 Hospital of People's Liberation Army from January 2009 to June 2012 were retrospectively analyzed (severe chest and abdominal injury group). Those patients who had concomitant traumatic brain injuries or died in the Emergency Department were excluded from this study. There were 58 male and 24 female patients with their age of 16-76 (43.59±16.33)years. There were 17 patients with open injuries and 65 patients with closed injuries. There were 23 patients with fall injuries, 47 patients with traffic injuries, 8 patients with blunt force injuries, and 4 patients with penetrating injuries. Forty-two healthy volunteers who received routine medical examinations in the outpatient department of our hospital were chosen as the control group, including 27 males and 15 females with their age of 24-47 (37.32±10.45) years. Blood platelet (PLT) count, D-dimer (D-D), activated partial thromboplastin time (APTT), LPS, PLA2 and PAF were compared between the 2 groups, and linear correlation analysis was performed. ResultsPLT of the severe chest and abdominal injury group patients were significantly lower than that of the control group[(83.44±38.52)×109/L vs. (191.52±23.31)×109/L]. D-D[(1 823.89±608.02) U/L vs. (105.78±44.53) U/L], APTT [(68.24±24.12) s vs. (22.47±9.41) s], LPS[(438.66±106.02) U/L vs. (87.38±46.51) U/L], PLA2 [(41.35±14.26) ng/ml vs. (7.47±5.27)ng/ml] and PAF[(15 765.31±4 431.65) ng/L vs. (3 823.45±529.72) ng/L] of the severe chest and abdominal injury group patients were significantly higher than those of the control group(P < 0.001). PLT was significantly negatively correlated with LPS, PLA2 and PAF with all the respective correlation coefficient(r)less than-0.933 5. D-D and APTT were significantly positively correlated with LPS, PLA2 and PAF with all the respective r larger than 0.921 6. ConclusionLPS, PLA2 and PAF participate in the pathogenesis of coagulopathy in patients with severe chest and abdominal injuries. Early intervention against LPS, PLA2 and PAF may improve coagulopathy and survival rate of patients with severe chest and abdominal injuries.