The Prognostic Value Of Extravascular Lung Water Index In Patients With Acute Respiratory Distress Syndrome

ObjectiveThe Berlin definition of ARDS has proposed a guideline for clinical diagnosis and treatment, and a study has been shown a close relationship between the severity of disease and EVLWI,PVPI.This study aims to evaluate the relationship between extravascular lung water index(EVLWI), pulmonary vascular permeability index(PVPI)and the severity categories defined by the Berlin definition, and investigate the reference value of EVLWI in ARDS patients.MethodsFifty-four patients with ARDS who received pulse index continuous cardiac output (PICCO) monitoring were analyzed retrospectively. The patients were divided into mild,moderate and severe groups according to oxygenation index(OI) at admission.Characteristics and acute physiology and chronic health evaluation Ⅱ (APACHEII) score in mild, moderate and severe groups were recorded, and the differences in EVLWI and PVPI among the severity categories of ARDS patients were analyzed. The receiver operating characteristic curve (ROC curve) was used to evaluate the prognosis accuracy of these indicators.ResultsOf54patients, there were18ARDS patients in mild group,22in moderate group and14in sever group. The28-day mortality rate was gradually increased with severity categories of ARDS, and mortality in moderate and sever groups were significantly higher than that in mild group (54.5%(12/22),57.1%(8/14) vs.22.2%(4/18),both P<0.05).216independent evaluation were measured in54patients within72hours, EVLWI was increased with severity categories of ARDS (EVLWI in mild,moderate and severe groups were11(10-13),14(11-16),17(12-23) mL/kg,P<0.05), as well as the change tendency in PVPI (PVPI in mild,moderate and severe groups were2.0(1.8-2.5),2.7(2.0-3.9),3.7(2.1-4.8),P<0.05).The negative correlation between EVLWI and OI was found (r=-0.599,P=0.000), as well as between PVPI and OI(r=-0.541,P=0.000). The positive correlation between EVLWI and PVPI was found (r=-0.811,P=0.000), as well as between EVLWI and ITBVI (r=0.168,P=0.041). The area under ROC curve (AUC) for EVLWI evaluating the prognosis at0,24,48,72hours was0.639±0.082,0.642±0.082,0.702±0.078,0.719±0.076respectively,95%confidence interval (95%CI) was0.479-0.799,0.483-0.802,0.551-0.852,0.570-0.869respectively,AUC for APACHEII was0.783±0.068,and95%CI was0.648-0.0.918.As EVLWI>13ml/kg at72hours, the sensitivity and the specificity of accurate judgment were81.8%and61.5%.ConclusionCombining the Berlin definition with EVLWI and PVPI,the severity of ARDS can be assessed accurately. Dynamic observation of EVLWI can be one of prognostic factors in the patients with ARDS.