呼出气一氧化氮检测在支气管炎症性肺疾病中的临床应用

Fractional exhaled nitric oxide in bronchial inflammatory lung diseases

目的:探讨呼出气一氧化氮水平(fractional exhaled nitric oxide,FeNO)在支气管哮喘、慢性阻塞性疾病(chronic obstructive pulmonary diseases,COPD)中的变化情况及与肺功能中第1秒用力呼气量(forced expiratory volume in the first second,FEV1)、第1秒用力呼气量占用力肺活量的百分比(forced expiratory volume in the first second/forced vital capacity,FEV1/FVC)的相关性。方法:选取57例疑似支气管哮喘患者(21例为急性发作期、12例为非急性发作期、24例为非支气管哮喘)、38例COPD患者(25例为急性加重期、13例为稳定期)、26例正常对照者,分别测定FeNO,FEV1,FEV1/FVC,并进行统计学分析。结果:在FeNO诊断支气管哮喘中,若FeNO以20.15 PPb为切点,57例疑似支气管哮喘患者诊断为支气管哮喘的阳性预测值94.1%,阴性预测值95.7%,灵敏度97.0%,特异度91.7%;33例确诊为支气管哮喘患者的FeNO与26例正常对照者比较,差异有统计学意义(P<0.05);支气管哮喘非急性发作期患者FeNO较急性期显著下降,差异有统计学意义(P<0.05),FEV1和FEV1/FVC差异无统计学意义(P>0.05);支气管哮喘患者FeNO水平与FEV1和FEV1/FVC无明显相关性(r=-0.186,-0.236,均P>0.05);38例COPD患者的FeNO,FEV1,FEV1/FVC与26例正常对照者比较,差异有统计学意义(均P<0.05);25例COPD急性加重期患者FeNO,FEV1,FEV1/FVC与13例COPD稳定期比较,差异有统计学意义(均P<0.05);13例COPD稳定期患者FeNO与正常对照者比较,差异无统计学意义(P>0.05);COPD患者FeNO水平与FEV1和FEV1/FVC无明显相关性(r=-0.167,-0.285,均P>0.05)。结论:支气管哮喘患者FeNO水平显著升高,在用FeNO诊断支气管哮喘中,若FeNO以20.15 PPb为切点,则FeNO诊断该疾病有较高的灵敏度和特异性;急性发作期FeNO较非急性发作期明显升高,可用于评估支气管哮喘的控制程度。COPD患者FeNO在急性加重期升高,稳定期无明显升高。

Objective: To explore the change of fractional exhaled nitric oxide (FeNO) and its correlation with forced expiratory volume in the ifrst second (FEV1), the ifrst second forced expiratory volume percentage of forced vital capacity (FEV1/FVC) in bronchial asthma and chronic obstructive pulmonary disease (COPD). Methods: FeNO, FEV1 and FEV1/FVC were measured in 57 suspected asthmatics (21 acute onsets, 12 non-acute and 24 non-asthma), 38 COPD patients (25 acute exacerbations and 13 stable stages) and 26 healthy subjects. Results: In the 57 suspected asthmatic patients, when the optimal cut off value of FeNO was 20.15 PPb, which was used to diagnose asthma and differentiate asthma and non-asthma, the positive predictive value, the negative predictive value, the sensitivity and the speciifcity was 94.1%, 95.7%, 97.0%, and 91.7% respectively. hTere was signiifcant difference in the FeNO level between the 33 asthmatics and 26 healthy subjects (P<0.05). There was also significant difference in the FeNO level between the acute onset and the non-acute (P<0.05), but not in the FEV1 and FEV1/FVC level (bothP>0.05). hTere was no signiifcant correlation between FeNO and FEV1, FEV1/FVC in patients with asthma (r=-0.186,-0.236, bothP>0.05). hTere was signiifcant difference in the levels of FeNO, FEV1 and FEV1/FVC between the 38 COPD patients and the 26 healthy subjects (all P<0.05), and also between the 25 acute exacerbations and 13 stable COPDs (allP<0.05), but not between the 13 stable COPDs and 26 healthy subjects (allP>0.05). FeNO was not correlated with FEV1 and FEV1/FVC level in COPD patients (r=-0.167,-0.285, bothP>0.05). Conclusion: FeNO level is increased obviously in patients with asthma. hTe optimal cut off value of FeNO at 20.15 PPb can differentiate asthma and non-asthma with high sensitivity and speciifcity. FeNO is higher for the acute onset than non-acute, which may be useful to evaluate the control degree. FeNO level is increased in COPD patients in the acute exacerbations, but there is no change in stable COPD patients compared with the healthy subjects.