Diagnostic Performance Of Fractional Exhaled Nitric Oxide In Patients With Chronic Cough

Chronic cough refers to the duration of cough for more than eight weeks,and the results of X-ray examination showed that the patient does not have a cough.In chronic cough is often misdiagnosed as chronic bronchitis,patients with long-term use of antibiotics and cough medicine treatment effect is poor,Chronic cough has become the respiratory department and are the leading cause of hospitalization and patients with major cost.It is necessary for us to strengthen the understanding of this kind of disease.Can correct analysis of the patient’s cause,to the doctor to prescribe the right medicine,improve the therapeutic effect? ObjectiveTo explore the exhaled nitric oxide(FeNO)is applied to the detection of chronic cough patients with airway hyperresponsiveness of value.And to observe the changes of the effect of glucocorticoid treatment on exhaled NO.Methods1.The data of 300 cases of chronic cough in The Second Clinical of Zhengzhou University and XinYang Central Hospital from March 2014 to March 2015 were selected and analyzed.All the subjects were tested by FeNO and bronchial provocation test.Whether the patients with airway hyper-responsiveness were determined.by bronchial provocation test results,and to investigate the value of exhaled nitric oxide on bronchial hyperreactivity in patients with chronic cough.The patients for positive bronchial provocation test were treated with glucocorticoid inhalation and followed up.The changes of FeNO were monitored and compared before and after treatment for 2 weeks、3 months、6months.Results1.The bronchial provocation test results show that 192 cases(64.00%)patients showed negative,108 cases(36.00%)showed positive,respectively,as a negative group and positive group and negative group FeNO value(products 14.24±4.87)ppb was significantly lower than that of positive group(49.85±31.87)ppb(t=9.541,p=0.006).2.The best value of FeNO for the determination of airway hyperresponsiveness was 26.5ppb,the specificity and sensitivity were 88.74% and 65.21% respectively.The positive predictive value was 87.53% and the negative predictive value was 66.95%.3.The levels of FeNO after exhaled cortiosteroid therapy for 2 weeks were decreased significantly in patients with positive bronchial provocation test(t=19.37,p1<0.001);the values of FeNO concentration measured in treatment group were basically normal after treatment for 3 months and 6 months,and at the same time there was no significant difference between the treatment group and the untreated group(t=2.373,P>0.05;t=1.941,P>0.05).ConclusionFeNO detection can accurately determine the degree of airway reactivity with high specificity and sensitivity.Exhaled breath NO level is helpful to evaluate the effect of hormone therapy in patients with chronic cough,and it plays an important role in the diagnosis and prognosis of the disease.