The Discussion Of Diagnosis Value And Critical Value Of Bronchial Provocation Test For Cough Variant Asthma

Objective: Comparing the differences of lung function between the asthma patients(including typical bronchial asthma and cough variant asthma,CVA)with normal healthy peoples,To expolre the diagnostic value of bronchial provocation test for cough variant asthma,and to establish the bronchial provocation test,s optimal threshold or threshold range for the diagnosis of CVA.Methods : Each 78 patients with cough variant asthma and typical bronchial asthma were collected as observation group from september2015 to january 2017 from the department of outpatient and inpatient in Yueyang Second People,s Hospital.In addition 78 cases of healthy subjects were gathered as contorl group.All subjects must make the bronchial provocation tests by inhaling specific concentration acetyl choline after completing the routine lung function-lung ventilation function test.Retrospectively observed and compared with asthma and CVA patients of different FEV1%pred reduced values of bronchial provocation test,and the parameter values of each group of conventional pulmonary function examination.TO analyze the affect of gender,age,height and weight(this paper adopt a combination of the two factors that BMI(body mass index,BMI))on the positive values of bronchial provocation test.In the meantime receiver-operatingcharacteristic curve(ROC)was used to study the best threshold or threshold range of bronchial provocation test in the diagnosis of cough variant asthma.Results: There was no statistically significant difference(P>0.05)comparing the value of FVC,FEV1,FEV1/FVC%,FEV1% pred among the bronchial asthma,CVA and healthy group.but PEF,FEF25-75% of cough variant asthma,bronchial asthma group was lower(P<0.01)than healthy subjects,It is noteworthy that PEF,FEF25-75%,PD20 in bronchial asthma group was more lower than cough variant asthma group(P<0.05).Bronchial provocation tests showed it was little changes of FEV1%pred in the healthy control group after inhaling the maximum dose of methacholine(2.504mg),While FEV1%pred value declined in cough variant asthma group was(16±4%)and in Bronchial asthma was(24±3%),there was statistically significant difference among three groups(P<0.01).Furthermore,the bronchial provocation test administrated that FEV1%pred was a few change at the difference of digender,different age paragraph and BMI,there was no statistical significance(P > 0.05).And then if we set FEV1%pred drop value at12%,It was found that the sensitivity of the diagnosis of cough variant asthma and specific degrees were 97.4% and 71.8% respectively.Conclusion: The study display it is of great significance to the diagnosis of cough variant asthma adopting Bronchial Provocation Test(BPT),when the FEV1%pred drop value was set at 12%,Which can significantly increase the positive rate of the diagnosis of cough variant asthma,and reduced the ratio of failure diagnosis.