Abstract: Objective  To investigate the changes of serum vascular endothelial cadherin(VE-Cad) and angiopoietin-2(Ang-2) levels in patients with sepsis complicated by acute respiratory distress syndrome(ARDS) and their relationship with prognosis. 
Methods   A total of 79 patients with sepsis complicated by ARDS diagnosed and treated in our hospital were selected as the research subjects. According to the oxygenation index(PaO2/FiO2), patients were divided into mild group(n=28), moderate group(n=30) and severe group(n=21); they were divided into survival group(n=46) and death group(n=46) according to prognosis after 4 weeks. The levels of VE-Cad and Ang-2 in each group were compared. Pearson correlation analysis was used to analyze the correlation between VE-Cad and Ang-2, and binary Logistic regression analysis was used to analyze the factors affecting the prognosis of patients with sepsis and ARDS. Receiver operating characteristic(ROC) curve was used to analyze the diagnostic value of VE-Cad and Ang-2 in prognosis of septic patients with concurrent ARDS. 
Results  Serum VE-Cad and Ang-2 levels were the lowest in mild group, followed by moderate group and severe group, and the difference was statistically significant(P＜0.05). The levels of VE-Cad and Ang-2 in the survival group were significantly lower than those in the death group(P＜0.05). After Pearson analysis, VE-Cad was positively correlated with Ang-2(r=0.632, P＜0.001). Binary logistic regression analysis indicated VE-Cad as an independent influencing factor for the prognosis of sepsis complicated with ARDS(P＜0.05). ROC curve analysis showed that the AUC of VE-Cad, Ang-2, and the combination diagnosis of sepsis and ARDS for the prediction of diagnosis were 0.906, 0.690, and 0.912, respectively. The diagnostic value of VE-Cad and the combination diagnosis of the two was higher; both The AUC of combination diagnosis and VE-Cad was significantly higher than that of Ang-2(Z=3.266, 3.071, P=0.001, 0.002). The corresponding sensitivity and specificity of VE-Cad and Ang-2 with respect to the optimal cut-off values were 87.9%, 84.8% vs. 45.5%, 89.1%, respectively, and those of the combination of the two were 84.8% and 80.4%, respectively. 
Conclusion  Serum VE-Cad and Ang-2 levels in patients with sepsis complicated by ARDS increase with the aggravation of the disease. The VE-Cad and Ang-2 levels in dead patients are higher than those in surviving patients, and VE-Cad and the combination of the two have a higher diagnostic value for the prognosis of sepsis complicated by ARDS. Specifically, VE-Cad combined with Ang-2 has the highest diagnostic value.

Key words: respiratory distress syndrome, adult, sepsis, angiopoietin-2