The Clinical Value Of Fraction Exhaled Nitric Oxide In Patients With Chronic Obstructive Pulmonary Disease And Its Complication Of Pulmonary Hypertension

Objectives: To explore the clinical value of Fraction Exhaled Nitric Oxide in Patients with Chronic Obstructive Pulmonary Disease and chronic obstructive pulmonary disease with pulmonary hypertensionMethods: Outpatients with COPD visiting the second affiliated hospital of soochow university from April 2014 to July 2015 were enrolled. Lung function Pulmonary artery systolic pressure(PASP) and FENO were detected. According to the PASP, patients can be divided into simple COPD and COPD with PH. According to the FEV1 / FVC and FEV1 pre% after inhaling bronchi relaxation, patients can be divided into groupsⅠ; Ⅱ; Ⅲ; Ⅳ. A total of 25 healthy cases were selected as control group. The value of FeNO was assessed and the optimal operating point of FeNO testing for the diagnosis COPD with PH was determined by the means of the receiver operating characteristic(ROC)Results: 1. The levels of FeNO in COPD(24.79±4.19ppb) were significantly higher than in healthy cases(13.91±3.45 ppb, P<0.05). 2. FeNO of groups Ⅱ, Ⅲ, Ⅳ were lower than those of group Ⅰ, FeNO of groups Ⅲ, Ⅳwere lower than those of group Ⅱ,FENO of group Ⅳ were lower than those of group Ⅲ(P<0.05). 3. A total of 81 patients with COPD were recruited, among whom 51 were diagnosed as PH. The levels of FeNO in COPD with PH(19.20±4.55ppb) were significantly lower than in COPD(25.72±6.93 ppb, P=0.000) The levels of FeNO in COPD with PH showed a negative liner correlation with PASP(r=-0.713, P=0.000). The levels of FeNO in mild PH(20.95±3.29) ppb were significantly higher than in moderate PH(14.97±3.65 ppb P=0.000). The levels of FeNO in mild PH showed a negative liner correlation with PASP(r=-0.367, P=0.003). The levels of FeNO in moderate PH also showed a negative liner correlation with PASP(r=-0.648, P=0.046). The area under ROC curve was 0.76. The optimal diagnostic cutoff point was 22.5 ppb which was capable of differentiating COPD with PH and non- COPD with PH with a sensitivity of 88.2%, and a specificity of 60%.Conclusion: FeNO is obviously elevated in patients with COPD,and it is associated with degree of airflow obstruction. The level of FeNO was lower in COPD with PH compared to COPD. FeNO may be helpful in the diagnosis of PH in COPD with high sensitivity and specificity.