The Value Of RDW,D-dimer And FIB In Assessing The Severity And Prognosis Of Community-acquired Pneumonia

Objective:To study the utility of red cell distribution width（RDW）,fibrinogen（FIB）and D-dimer for the severity assessments and predicting the prognosis of patients with community-acquired pneumonia.Methods:The clinical data of 154 patients with CAP in Department of Respiratory and critical Care Medicine of Ningxia Medical University General Hospital were analyzed retrospectively.According to the CURB-65 score,the patients were divided into low-risk groups.（N=59,score<2）,medium-risk group（N=41,score=2）and high-risk groups（N=54 score≥3points）.The data including respiratory failure,admission to ICU,mechanical ventilation,organ damage,hospitalization days,commonly used inflammatory indexes,RDW,FIB and D-dimer CRP)were compared among groups.According to the diagnostic criteria of severe pneumonia,they were divided into severe CAP group and normal CAP group.According to the survival condition of 30 days,they were divided into death group and survival group.The data including RDW,FIB,D-dimer and common inflammatory indexes were compared among the groups.Pearson correlation analysis was used to analyze the relationship between RDW,FIB,D-dimer and respiratory failure.Draw the operating characteristic curve of subjects（ROC）to analyze the prognostic value of inflammation index,CURB-65 score,RDW,FIB and D-dimer in patients of CAP.Results:A total of 154 CAP patients,105 males and 49 females,were enrolled in this study.According to the CURB-65 score,the low,medium and high-risk groups were:59.41.54 Cases;There were 101 cases of severe CAP and 53 cases of normal CAP.There was no significant difference in sex,past history,FIB and HGB levels among the groups in CURB-65 score.With the increase of risk stratification,the incidence of respiratory failure,admission to ICU,hospital stay,electrolyte disturbance,liver and kidney function damage,and hypoproteinemia were increased with the risk stratification（χ²=:84.071;40.795;10.631;16.451;14.531;40.463,all P<0.05）;The levels of RDW,FIB,D-dimer,CRP and WBC in middle and high risk group were higher than those in low risk group（F=32.978;31.302;21.191;12.919,all P<0.05）.There was no significant difference in FIB and HGB between severe CAP group and normal CAP group.The levels of RDW,D-dimer and WBC in severe CAP group were significantly increased,（Z=-4.876;-5.409;-3.360;-4.014,P<0.01）,the levels of ALB and PLT decreased significantly（Z=-5.357,-4.151,P<0.001）.Compared with the survival group,the death group is older（t=-3.971,P<0.01）,the levels of RDW,D-dimer and WBC increased significantly（Z=-5.121;-2.231;-2.483,all P<0.05）,the levels of PLT and ALB reduced significantly（Z=-2.427;-2.31,P<0.05）.Multivariate Logistic regression analysis showed that age（OR=1.085,P<0.05）and RDW（OR=1.523,P<0.05）were independent risk factors for recent death in CAP patients.It was shown by correlation analysis that the levels of RDW was negatively corelated with PaO₂（r=-2.32,P<0.01）,significant positively corelated with PaCO₂（r=0.395,P<0.001）.The area under the ROC curve of RDW,D-dimer,CURB-65 score and CRP were 0.816[95%confidence interval（95%CI）=0.740-0.878],0.640[95%CI=0.552-0.722],0.826[95%CI=0.750-0.886],0.629[95%CI=0.541-0.712].The sensitivity and specificity of RDW in predicting death respectively were 92.9%and 63.5%with the cut-of of greater than 13%,and those for D-dimer were 84.6%and 49.2%with the cut-of of greater than 1.681mg/L,75%and 73.8%for CURB-65 score with the cut-of of greater than 2,57.1%and 64.6%for CRP with the cut-of of greater than 98.5mg/L.Conclusion:RDW and D-dimer have high value in evaluating the severity and prognosis of CAP patients.