Analysis Of Small Airway Function In Adult Asthma Patients

Objective:To investigate the correlation and Clinical Implications between small airway function,airway hyper-responsiveness,and lung function before and after treatment in adults with asthma.Methods:Using retrospective analysis,67 asthma patients newly diagnosed at the Department of Respiratory Medicine of the Second Hospital of Shanxi Medical University from December 2015 to June 2017 were selected as the study subjects,and the selected patients met the diagnostic criteria for bronchial asthma and the bronchial provocation test was positive at the first visit.According to whether the small airway function was normal before treatment,it was divided into A and B groups.In group A(44 cases),the small airway function was abnormal before treatment.In group B(23 cases),the function of small airway was normal before treatment.Patients in both groups were given a powder inhalation of budesonide/formoterol 160/4.5 μg according to the GINA guidelines.After 6months of treatment,the relationship between small airway function,airway hyper-responsiveness,and lung function before and after treatment was analyzed and compared between the two groups.Results:1、Before treatment,the comparison of lung function indexes between group A and group B showed that all lung function indexes in group A were lower than those in group B;the difference in FVC between the two groups was not statistically significant(P>0.05),and the differences of FEV1,PEF and FEF25 were statistically significant(P<0.05).Before treatment,FVC and ΔFEV1 in group A were slightly higher than those in group B,but the difference was not statistically significant(P>0.05).The differences of FEF75,FEF50 and FEF25-75 in the two small airway indexes were statistically significant(P< 0.05).2、After treatment,the comparison of lung function indexes between group A and B showed that the FEV1,FEV1/FVC,FEF75,FEF50,FEF25,and FEF25-75 in group A were all lower than those in group B,and the difference was statistically significant(P<0.05).The decline rate of FEV1 caused by bronchial provocation test in group A and B was expressed by ΔFEV1 and the ΔFEV1 in group A was slightly higher than that in group B,and the difference was not statistically significant(P>0.05).3、Comparison of various lung function indexes before and after treatment in group A,after treatment,FEV1,ΔFEV1,FEV1/FVC,PEF,FEF75,FEF50,FEF25,and FEF25-75 in group A were significantly higher than those before treatment,and the difference was statistically significant(P < 0.05).4、The results of comparison of various lung function indicators before and after treatment in Group B showed that in group B,all lung function indexes after treatment were higher than those before treatment,and the difference in ΔFEV1 before and after treatment in group B was statistically significant(P<0.05).Before and after treatment,there was no significant difference in lung function parameters of FVC,FEV1,FEV1/FVC,PEF,FEF75,FEF50,FEF25,FEF25-75(P >0.05).5、In cases with small airway function abnormalities(Group A),the abnormal rate of FEF25-75 was significantly higher than that of FEF50 and FEF75(P < 0.05),ie,FEF25-75/FVC can qualitatively predict the presence of airway hyper-responsiveness.6、After treatment in groups A and B,the positive rate of provocation test was lower than that before treatment,and the positive rate of provocation test in group A was lower than that in group B,and the difference was not statistically significant(P>0.05).7、The Pearson correlation results showed that there was a correlation betweenΔFEV1 and FEF25-75/FVC after treatment in group A,where r=0.319,P=0.035.8、Pearson correlation results showed that there was no correlation between FEV1 and ΔFEV1(P>0.05),but there was significant correlation with other pulmonary ventilation function indexes(P<0.01);there was no correlation between ΔFEV1 and other lung function indicators(P>0.05).FEV1/FVC had significant correlation with PEF and small airway indexes(P<0.01),among which FEV1/FVC had higher correlation with small airway indexes,with r values above 0.7,and the correlation coefficient r of FEV1/FVC and PEF is 0.440.There was a correlation between PEF and small airway indexes(P<0.05).FVC correlated only with FEF75 in the small airway index(P<0.05).Each of the small airway indexes had a significant correlation with each other(P<0.01).Conclusion:1、Inhalation of budesonide-formoterol can effectively improve lung function.2、Among the three indexes of FEF50,FEF25-75 and FEF75,FEF25-75 can be used as the first reference index for evaluating small airway dysfunction.3、FEF25-75/FVC can qualitatively predict the presence of airway hyper-responsiveness.4、Each of the small airway indicators has a positive correlation with FEV1,FEV1/FVC,and PEF,and the correlation between each of the small airway indexes and FEV1,FEV1/FVC is more significant;There is a significant positive correlation between each of the small airway indicators.