Study On Correlation Between Red Cell Distribution Width And The Severity Of Patients With Chronic Obstructive Pulmonary Disease

Object This paper aims to understand the possible correlation between the red blood cell volume distribution width(RDW) and assessments of chronic obstructive pulmonary disease(COPD), and thus it can help us to find an objective biomarker for assessments of COPD.Methods We selected 166 patients who were admitted to respiratory department of The First Affiliated Hospital of Anhui Medical University for AECOPD at the time of hospitalization from January 2014 to February 2016. Detailed medical history collection and physical examination were carried on all patients, and the demographic information, LOS, CAT, acute exacerbation frequency as well as the result of examination were recorded in detail. We collected the parameters of routine blood test, BNP,lung function test as well as color doppler echocardiography. There were 30 patients were followed up 3 months after discharged in stable period. Respectively according to the RDW and the complications, we categorized the 166 AECOPD patients into elevated RDW group, non-elevated RDW group; neither respiratory failure and right heart failure(1) group, simple respiratory failure(2) group, simple right heart failure(3) group, both respiratory failure and right heart failure(4) group. Respectively according to the acute episodes and the lung function grading, we categorized the 30 patients stable with COPD into acute exacerbation high-risk group, the low risk of exacerbation group; mild to moderate group, severe to very severe group.Results 1. In comparison patients with an elevated RDW(>15%) value and with a non-elevated RDW(<15%) value were more likely to have a higher CAT, LOS, WBC, CRP, BNP,RVSP, Pa CO2 levels and a lower Pa O2 levels(P<0.05). The incidence of respiratory failure and right heart failure in patients with an elevated RDW value were all increased compared with those patients with a non-elevated RDW value(c2 value were 18.931,35.650,respectively, P<0.001). 2. The RDW values of groups 2,3,4 were all significantly higher than that of group 1(P<0.001). 3.RDW levels positively correlated with CRP,CAT,LOS as well as BNP levels; and it was negatively correlated with Pa O2 levels(P<0.05). 4. RDW levels were predictive for the presence of respiratory failure and right heart failure in AECOPD patients,with a sensitivity of 55.1% and specificity of 93.2%,with a cutoff value higher than 14.750%. 5. The RDW value of severe to very severe group was higher than that of mild to moderate group(t=2.238,P=0.033). RDW was negatively correlated with FEV1(r=-0.364, P=0.048), and it was no correlations with FEV1% Pred and FEV1/FVC(P>0.05). 6.The RDW value of 30 patients who were followed up in acute exacerbation was higher(1.26+0.43)% than that of them in stable period, and the difference is significant(t=4.820, P< 0.001). The rate of increased RDW in acute exacerbation was higher than that in stable period,the differences were significant(P = 0.039).Conclusion In patients with COPD who had a higher RDW levels, the clinical symptoms and inflammatory response were heavier, the lung function was poorer, and the rates of respiratory failure and heart failure were higher. RDW levels of patients in acute exacerbation were higher than that of patients in stable period of COPD. So we speculated that RDW may be used for the assessment of COPD.