Investigation on the predictive value of the dynamic changes of EVLWI and PVPI on the prognosis of ARDS patients

Abstract

To investigate the dynamic changes of extra vascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) on the prognosis of acute respiratory distress syndrome (ARDS), and predict the risk factors affecting prognosis of ARDS. 70 patients meeting ARDS Berlin definition, who were admitted to the ICU from July 2012 to July 2014, were analyzed with a prospective method. The patients were divided into a survival group and a death group according to their survival situation in 28 days. EVLWI (EVLWI1-EVLWI4), PVPI (PVPI1-PVPI4), DeltaEVLWI (subtracting EVLWI day 4 from day 1), and DeltaPVPI (subtracting PVPI day 4 from day 1) of the two groups of patients from the 1st day to the 4th day were monitored by the pulse indicator continuous cardiac output (PiCCO). Parameters including the acute physiology and chronic health evaluation (APACHE II) score, sequential organ failure assessment (SOFA) score, EVLWI, PVPI, DeltaEVLWI, DeltaPVPI, oxygenation index (OI), CVP, the number of organ dysfunction were compared between the two groups. Univariate analysis and multivariate logistic regression were used to analyze the independent risk factors associated with prognosis. Receiver operating characteristic curve (ROC curve) was drawn to evaluate the prediction performance of those risk factors in the prognosis of ARDS. Comparison of EVLWI and PVPI between the survival group and the death group of ARDS patients at different time points: EVLWI and PVPI showed no statistical difference from the 1st day to the 2nd day after admission, but those two parameters in the death group were higher than those in the survival group form the 3rd day to the 4th day after admission (P<0.01). The comparison of the dynamic changes of EVLWI and PVPI within the two groups: the EVLWI and PVPI in the survival group declined gradually from 1st day to 4th day after treatment, but that changing trend in the death group showed no statistical difference. DeltaEVLWI and DeltaPVPI changes in the survival group were higher than in the death group (P<0.01). They were independent risk factors of patients 28-day prognosis (P<0.05). ROC curve and 28-day survival curve showed that the area under ROC curve of DeltaPVPI predicting prognosis of patients with ARDS was 0.812, when the optimal cut off value was 1.2, and the median survival period in DeltaPVPI>1.2 group was longer than that in the Delta PVPI≤1.2 group. The continuous dynamic observation of EVLWI and PVPI changes is better than that of a single detection. DeltaEVLWI and DeltaPVPI are independent risk factors and can be used as an auxiliary indicator for the prognosis of patients with ARDS.