ABSTRACT
Objective To explore the value of simple exercise provocation test ( 6?minute running test) combined with small airway function test in early diagnosis of cough variant asthma ( CVA ) in children.Methods Ninety?four children with chronic cough from September 2017 to September 2018 in the pediatric clinic of the Affiliated Hospital of Xuzhou Medical University were selected for routine pulmonary ventilation function examination,simple exercise stimulation test and questionnaire survey.The differences of pulmonary function,clinical manifestations and allergens between positive and negative children with simple exercise stimulation test were compared and analyzed.Results The forced expiratory volume in one second (FEV1) of 94 children with chronic cough were all more than 70% by routine pulmonary function test,and the exercise provocation test was successfully completed.Among them,32 (34.04%) were positive in simple exercise provocation test.Among the positive patients,30 cases ( 93.75%) were diagnosed as CVA after further examination,clinical treatment and follow?up.In CVA group, FEV1 ( 81.52 ± 14.22)%,forced vital capacity (FVC) (89.00 ± 14.31)%, peak expiratory flow ( PEF) ( 65.05 ± 15.10)%, one?second rate (FEV1／FVC) (92.18±13.59)%,and instantaneous flow at 50% forced expiratory flow were observed after exercise.The vital capacity ( FEF50 ) ( 57.57 ± 22.49 )%, forced expiratory flow at 75% vital capacity (FEF75) (41.15±18.28)%,maximum expiratory flow ( MMEF75／25) (53.14±22.53)% were significantly lower than those before exercise ((94.07±9.69)%,( 92.30± 13.60)%,(80.73± 17.85)%,(101.07± 13.79)%,(66.71±19.29)%,(51.32±18.38)%,(63.75±19.43)%),(t values were 8.592 ,2.617 , 10.246 ,5.428,3.590 ,3.646 ,3.687 ,respectively,all P＜0.05)) In routine examination of pulmonary ventilation function,FEF50 (66.71 ± 19.29)% and FEF75 ( 51.32 ± 18.38)% in the positive group were significantly lower than those in the negative group (( 79.75 ± 21.94)%、( 69.08 ± 29.28)%),( t values were －2.841,－3.123,all P＜0.01).The proportion of night cough,morning cough and severe dry cough in positive group was significantly higher than that in negative group,while the proportion of day cough and wet cough was significantly lower than that in negative group ( P＜0.01).The proportion of eczema history in positive group was significantly higher than that in negative group ( P＜0.01).Conclusion Patients with CVA have high airway responsiveness and small airway dysfunction.Combination of simple motor stimulation test and small airway function test has important clinical value in the early diagnosis of CVA.