The Characteristics Of Small Airway Disease In Cough Variant Asthma(CAV)

Objective:This research aims to discuss the relation between small airway lesion and CVA patients and improve the cognition and diagnosis consciousness by systematically analyzing the expiratory flow indicator of CVA and typical asthma patients and each indicator of the airway provocative test. Methods:Collect the clinical data of CVA and typical asthma patients in the respiratory outpatient department of the First Hospital of Shan Xi Medical University from January 2015 to November 2015, 138 cases in total. These two groups above are divided into medium group, mild group and very mild group according to the airway responsiveness. Compare each expiratory flow indicator and airway provocative test indicator by applying statistical methods such as T-test, variance analysis and multiple linear regressions. Results:Compared with asthma group, the FEF25-75%, FEF75% and FEF50% that reflect small airway function of the expiratory flow indicator of CVA group is obviously higher than that of the asthma group and the difference is significant(P<0.001). The PD20 of CVA group is higher than that of the asthma group and the difference is statistical(P<0.05). In CVA group, the FEV1% normal predicated value, FEV1/FVC% and FEF25-75% of the very mild group are obviously lower than that of the medium and mild groups. In asthma group, the FEV1% normal predicated value, FEV1-FVC%, FEF25-75% and FEF75% of the medium group are obviously higher than that of the mild and very mild groups. The FEF50% and PEF value of medium group are higher than that of the very mild group. The Dmin and PD20 which reflect the airway responsiveness have positive correlation with FEF25-75%/FVC% and the minimum concentration(Cmin) and reactivity SGrs at the beginning of the resistance rising have negative correlation with BMI. Conclusion:The small airway lesion damage and airway sensitivity of CVA group is lighter than that of the asthma group. And the diseases with higher airway responsiveness, the severer of the small airway lesion damage will be. The indicator that reflects the small airway lesion and BMI have some certain predictive value for CVA patients. When the FEF25-75%/FVC gets smaller and the airway responsiveness gets higher, hint of focusing on the small airway indicator for CVA patents has certain predictive value for CVA. When the BMI gets higher and the airway responsiveness gets lower, hint of losing weight appropriately for asthma patients is helpful to improve the living quality of the patients.