Objective To investigate the changes of small airway function and diffusing capacity in patients with mild asthma before and after bronchial provocation test (BPT).Methods BPT was performed in suspected asthma patients with chief complaints of paroxysmal wheeze,chest tightness and cough，but with normal chest X-ray and baseline pulmonary function.BPT positive group was regarded as asthma group，while BPT negative group as control group.Lung volume，ventilatory function and diffusing capacity were measured before and after BPT and compared between the asthma and control groups.Results （A）No statistical differences were found in FEV1%，FEV1/FVC，FVC%，VC%，TLC%，FRC%，RV%，RV/TLC between the asthma and control groups before BPT.FEV1/FVC and FVC% were significantly decreased (all Plt;0.01)，while FRC% (Plt;0.05)，RV% (Plt;0.01) and RV/TLC (Plt;0.01) increased significantly in the asthma group after BPT compared with the control group.The decline rate of FEV1/FVC and FVC% and the increase rate of TLC%，RV%，RV/TLC were significantly higher in the asthma group than those in the control group (all Plt;0.01).（B）Compared with the control group，FEF25%-75% (Plt;0.05)，Vmax75% (Plt;0.01) and Vmax50% (Plt;0.05) were significantly lowered before BPT，while the above parameters and Vmax25% were significantly decreased after BPT in the asthma group (all Plt;0.01).The decline rate of FEF25%-75%，Vmax75%，Vmax50% and Vmax25% was significantly higher in the asthma group than those in the control group (all Plt;0.01).（C）There was no statistical difference in DLCO in both groups before and after BPT.Conclusions Patients with mild asthma had small airways impairment before BCT which further declined after BPT.However,no impairment of diffusion capacity was found before or after BPT.
Objective To observe the decline ratio of FEV1 after inhaling 0. 9% saline to the baseline, and to explore its relation to the result of bronchial provocation test ( BPT) with methacholine.Methods 115 patients with chronic cough or chest tightness were collected in Shougang Hospital, Peking University from March 2008 to September 2009. They were all performed pulmonary function test and the decline ratio of FEV1 after inhaling 0.9% saline to the baseline( ΔFEV1 ) was measured. Then they were allperformed BPT with methacholine. The predictive value of ΔFEV1 measurement for BPT results was evaluated. Results 49 cases yielded positive results in methacholine BPT, with ΔFEV1 gt; 3% in 35 cases and gt;5% in 20 cases. 66 casess yielded negative results in methacholine BPT, with ΔFEV1 gt; 3% in 6 cases. The sensitivity and specificity were 71% and 91% respectively when ΔFEV1 gt;3% was set as a cutoff,and which were 40. 8% and 100% respectively when ΔFEV1 gt;5% was set as a cut-off. All the patients didn’t show any serious adverse reaction. Conclusion ΔFEV1 gt;3% after inhaling 0. 9% saline is a good predictor for BPT results. More caution should be paid to these patients when performing BPT.
Objective To investigate the changes of small airway function，airway resistance and responsiveness of extrathoracic airway in chronic cough patients before and after bronchial provocation test (BPT)．Methods 68 chronic cough patients were requested to conduct lung function test and BPT．The airw ay resistance were measured via forced oscillationary technology before and after BPT．Results BPT revealed airway hyperresponsiveness in 52％subjects．MEF50 and R0 before BPT were significantly different between the patients with or without airway hyperresponsiveness．Post BPT changes in MEF50(MEF50％) were correlated positively to the changes in FEV1(FEVl％)，and negatively to the changes in R0[Ro-d]． Extrathoracic airway hyperresponsivenes(EAHR)was f0und in13 patients，in which 6 patients were not revealed by routine BPT．Conclusion There is small airway function abnormalities in chronic cough patients．Extrathoracic airway responsiveness test is a valuable supplementary index to routine BPT．
ObjectiveTo investigate the diagnostic value of bronchial provocation test in patients with chronic cough. MethodsA total of 550 chronic cough patients were selected in the 452nd Military Hospital from March 2011 to February 2012. These patients all underwent the basic lung function test and the bronchial provocation test (BPT) to acetylcholine so as to assess the bronchial hyper-reactivity by inhaling methacholine. The diagnostic value of BPT was then evaluated. ResultsAll included patients had normal lung function. There were 267 patients (48.5%) who showed positive results in BPT, of whom, 236 BPT-positive patients were finally diagnosed as cough variant asthma. After regular treatment, the cough symptoms were well controlled. ConclusionCough variant asthma is one of the main causes of chronic cough. The BPT is an important method of aiding the diagnosis of cough variant asthma which helps early diagnosis of it.