Application Of Exhaled Nitric Oxide In Pulmonary Hypertension Associated With Chronic Obstructive Pulmonary Disease

Objective:To explore the change of exhaled nitric oxide in patients with acute exacerbation of chronic obstructive pulmonary disease complicated with pulmonary hypertension and its correlation with pulmonary artery systolic pressure,PaO₂ and peripheral blood inflammatory markers,so as to provide a new idea for early prediction of pulmonary hypertension in patients with acute exacerbation chronic obstructive pulmonary disease.Methods:A total of 102 inpatients diagnosed with acute exacerbation of chronic obstru-ctive pulmonary disease were enrolled in the Department of Respiratory of the Fourth Affiliated Hospital of Nanchang University from October 2017 to October2019.Exhaled nitric oxide,arterial blood gas,peripheral blood routine test,CRP test and Doppler echocardiography were detected.According to the PASP,the patients were divided into PH group and non PH group.To compare the difference of FeNO?CaNO,arterial blood gas parameters,peripheral blood WBC,NLR,EOS%,RDW,CRP levels between the two groups,analyzed the correlation between FeNO,CaNO levels and PASP level,PaO₂ and peripheral blood inflammatory markers;Logistic regression analysis was performed to investigate the risk factors of AECOPD comlicated with pulmonary hypenension.The ROC curve was used to assess the optimal cut-off point value of exhaled nitric oxide level for predicting combined with PH in AECOPD patients.Results:1.There were no significant differences in age,gender,body mass index,smoking status and incidence of hypertension?14.27±7.12ppb vs 7.38±3.37ppb?;Compared with the non PH group,CaNO?14.27±7.12 PPB vs 7.38±3.37 PP B?,PaCO2?50.73±5.52 vs 45.72±5.35?,NLR[5.99?3.16-9.63?vs 3.53?2.14-5.61?]and RDW?16.28±3.74%vs 13.53±1.50%?were significantly increased in the PH group,while PaO₂?59.40±5.66mmHg vs 66.81±7.18mmHg?was significantl y decreased,The difference was statistically significant?P<0.05?.There were no significant difference between the two groups in FeNO,pH of arterial blood g as,WBC and EOS%levels in peripheral blood?P>0.05?.2.CaNO levels in the two groups was positively correlated with PASP level and RDW level[r=0.566,r=0.589,P<0.001?PH group?;r=0.357,r=0.503,P<0.05?non PH group?].There was no correlation with PaCO₂ in the two groups?P>0.05?.CaNO level in PH group was negatively correlated with PaO₂ level?r=-0.503,P<0.001?and positively correlated with NLR and CRP level?r=0.457,r=0.478,P<0.001?.There was no correlation between CaNO level with PaO₂,NLR and CRP level in the non PH group?P>0.05?.3.Logistic regression analysis showed that increased CaNO level?OR=1.218,95%CI 0.775⁰.969?and decreased PaO₂?OR=0.867,95%CI 1.050¹.413?were independent risk factors for AECOPD combined with PH.4.ROC curve showed that the optimal CaNO cut-off point for predicting whether AECOPD patients had combined with PH was 10.25 ppb,the sensitivity was 0.709,and the specificity was 0.851.Conclusion:1.The level of CaNO in the AECOPD with PH group was significantly increased,which was positively correlated with pulmonary artery systolic blood pressure and negatively correlated with PaO₂.It has reference value for predicting whether AECOPD patients had combined with PH and could indirectly reflect the severity of pulmonary hypertension.2.The CaNO level of patients with AECOPD combined with PH is positively correlated with NLR,RDW,and CRP,suggesting that CaNO level combined with blood inflammatory markers could be used to evaluate the inflammatory type in PH.3.CaNO and PaO₂ are independent risk factors for pulmonary hypenension in patients with COPD,but the significance of FeNO still needs to be confirmed by further studies.