To evaluate the prognosis value of plasma soluble vascular endothelial growth factor receptor (sFlt-1) combined with extravascular lung water index (EVLWI) in acute respiratory distress syndrome (ARDS) complicated with septic shock caused by severe pneumonia.

A retrospective analysis was conducted in Respiratory Intensive Care Unit of the Affiliated Zhengzhou Central Hospital of Zhengzhou University from January 2015 to July 2017. The study included 52 severe pneumonia patients with ARDS complicated with septic shock, who was performed by measurement of pulse index continuous cardiac output (PICCO) and survived more than 3 days after admission. According to the 28-day mortality, these patients were divided into the survival group (31 cases) and the death group (21 cases). PICCO was used to record the EVLWI level. The plasma level of sFlt-1 was measured by enzyme-linked immunosorbent assay (ELISA). Acute physiology and chronic health evaluation II (APACHE II) score and sequential organ failure assessment (SOFA) score were calculated. Independent risk factors were analyzed by multiple logistic regression. Correlation analysis between plasma sFlt-1 and EVLWI and APACHE II values was performed on the 1st, 2nd and 3rd day after admission. Receiver operating characteristic curve (ROC) was calculated, and the prognostic value of each parameter was assessed.

The blood lactate, APACHE II score and SOFA score in the death group were significantly higher than those in the survival group at RICU admission (P<0.05), and the length of RICU stay was significantly shorter than that in the survival group (P<0.05), while differences in other clinical characteristics between the two groups were not statistically significant. The levels of EVLWI, sFlt-1 and blood lactate, APACHE II score and SOFA score in the death group were significantly higher than those in the survival group on the 1st, 2nd and 3rd day (all P<0.05), whereas the PaO₂/FiO₂ was significantly lower than that of the survival group on the 2nd and 3rd day (all P<0.05). Logistic regression analysis showed that sflt-1 level and EVLWI were significantly related with the patient mortality. The levels of sFlt-1 on day 1, 2 and 3 after RICU admission were positively related to EVLWI and APACHE II score (all P<0.01). The sensitivity and specificity of sFlt-1 combined with EVLWI in prognosis evaluation were 89.7%, 78.2% and 86.3%, 75.7%, respectively. The AUC of sFlt-1 combined with EVLWI was 0.875 and 0.856 on the 1st and 3rd day, respectively (all P<0.01), which had a better prognostic value than each of them.

SFlt-1 could be used as a biomarker of mortality for severe pneumonia patients with ARDS complicated with septic shock. The combination of sFlt-1 and EVLWI might be important in early prediction of the prognosis of the 28-day mortality in patients with ARDS complicated with septic shock caused by severe pneumonia.

sFlt-1; PICCO; Extravascular lung water index; Septic shock; Prognosis