The Effects Of Different Methods Of ICS/LABA Maintenance Therapy On Small Airway Function In Patients With Cough Variant Asthma And Clinical Evaluation

BackgroundCough variant asthma(CVA)is one of the most common causes of chronic persistent cough.Early treatment after confirming the diagnosis of CVA can prevent CVA developing into typical asthma(TA).In the treatment of CVA,guidelines recommend the drug combinations of inhaled corticosteroids(ICS)and long-acting beta 2-agonists(LAB A).Budesonide/formoterol SMART(Single inhaler maintenance and reliever therapy)protocol is a novel form of treatment.Studies suggest that SMART protocol has better efficacy and safety compared with standard ICS/LABA+SABA,while superiorities in the effectiveness of budesonide/formoterol(BUD/FM)SMART protocol in CVA patients is uncertain.As similar to TA,the pathogenesis of CVA is chronic airway inflammation involving many cells.Airway hyper-responsiveness and small airway dysfunction are common characteristics of patients with TA and CVA.Studies have shown that small airways dysfunction is correlated with uncontrolled asthma and acute exacerbation of asthma and can drive asthma disease progress,which suggest that small airways are crucial target of asthma treatment.While there is little studies about changes in CVA and TA patients after treatment of BUD/FM SMART protocol.In order to clear superiorities in the effectiveness of BUD/FM SMART protocol in CVA patients and the efficacy of BUD/FM SMART protocol in small airway function between CVA and TA patients.our study consists of two parts,namely:the effect of budesonide/formoterol SMART protocol and fixed-dose treatment on small airway in patients with cough variant asthma and analysis of clinical efficacy,evaluation in treatment of BUD/FM SMART protocol in small airway function of TA and CVA patients,in the aim to provide clinical evidence for drug uses of CVA and TA patients.Part I:the effect of budesonide/formoterol SMART protocol and fixed-dose treatment on small airway in patients with cough variant asthma and assessment of clinical efficacyObjective:Analyse the effect of budesonide/formoterol SMART protocol and fixed-dose treatment on small airway function in patients with cough variant asthma and clinical efficacy,to clear changes in small airway function of CVA patients and superiorities in the effectiveness of BUD/FM SMART protocol in CVA patients.Methods:A total of 60 patients with CVA visited at respiratory clinic of Zhujiang hospital of southern Medical University from October 2018 to June 2019 were enrolled according to the inclusion criteria and exclusion criteria.CVA patients were randomized into two groups and treated with one inhalation twice-daily BUD/FM 160/4.5 mg plus as-needed BUD/FM(SMART group,n=30)or one inhalation twice-daily BUD/FM 160/4.5 mg plus as-needed SABA(Standard group,n=30)for 6 months.Small airway function parameters,fractional exhaled nitric oxide(FeNO)and asthma symptom assessing questionnaires were evaluated.SPSS20.0 software was used for data analysis.Results:1.After 3-month and 6-month treatment,both groups showed significant improvement in IOS parameters from baseline(P<0.05).After 6-month treatment,the SMART group showed significant improvement in small airway parameter-Fres measured by IOS compared with the Standard group(P<0.05).2.After 3-month and 6-month treatment,both groups showed significant improvement in FeNO,ACT and ACQ-5 from baseline(P<0.05).After 6-month treatment,the SMART group showed significant improvement in FeNO,ACT and ACQ-5 compared with the Standard group(P<0.05).3.After 3-month and 6-month treatment,both groups showed significant improvement in pulmonary functions from baseline(P<0.05).there was no significant differences between two groups(P>0.05).Conclusions:budesonide/formoterol SMART protocol can be applied to treat CVA,significantly improved small airway function and it is more effective than fix-dose treatment.Part II:Evaluation in treatment of BUD/FM SMART protocol in small airway function of TA and CVA patientsObjective:To clear clinical efficacy of budesonide/formoterol SMART protocol in small airway function of TA and CVA patients.Methods:30 CVA patients and 20 TA patients using budesonide/formoterol SMART protocol.Anti-rhinitis and anti-allergic agent were allowed in all patients according to specific situation.Teaching them the knowledge of asthma and the correct use of drug device.We collected the baseline date and follow-up data of each visit.Primary content of follow-up were small airway function parameters(MMEF,MEF75,MEF50 and X5,R5-R20,AX,Fres),secondary content were FeNO values and ACT,ACQ-5 scores.SPSS20.0 software was used for data analysis.Results:1.small airway function improved significantly from baseline in CVA patients and TA patients at 6 month(P<0.05),but a significant difference between two groups was not observed(P>0.05).2.FeNO,ACT and ACQ-5 improved significantly from baseline in CVA patients and TA patients at 6 month(P<0.05),but a significant difference between two groups was not observed(P>0.05).Conclusion:1.Small airway dysfunction is found in both CVA and TA patients.2.The monitor of small airway inflammation and function should not be ignored,and IOS possess certain advantages in aspect of monitoring changes of Small airway dysfunction.