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 determine the diagnostic value of fractional exhaled nitric ( FeNO)measurement in diagnosis of bronchial asthma. Methods The patients with unkown-cause respiratory symptoms including wheezing, cough, and breathlessness were enrolled from August to September in 2008.FeNO was measured by nitric oxide analyzer ( NIOX; Aerocrine AB; Solna, Sweden) . Bronchial challenge test ( BCT) or bronchodilator test was defined as golden standard for asthma diagnosis. The value of FeNO was assessed and the optimal operating point of FeNO testing was determined by the means of the receiver operating characteristic ( ROC) curves. Results A total of 101 patients were enrolled, in which 48 cases were diagnosed as asthma by positive yield in BCT ( in 38 cases) or bronchodilator test ( in 10 cases) . The severity of airway hyperresponsiveness ( AHR) judged by BCT was mild in 15 cases, moderate in 15 cases and severe in 8 cases. The levels of FeNO of asthma group were higher than those of non-asthma group [ ( 68. 19 ±43. 00) ppb vs ( 19. 52 ±10. 60) ppb, P lt; 0. 05] . A linear correlation of FeNO with lnPD20 FEV1 was revealed in the cases with AHR. Area under ROC curve was 0. 9. The optimal diagnostic cutoff point was 36. 5 ppb which was capable of differentiating asthma and non-asthma with sensitivity of 92. 7% ,specificity of 83. 3% , positive predictive value of 79. 17% , negative predictive value of 94. 34% and accuracy of 87. 13% . Conclusion FeNO test may be helpful in the diagnosis of asthma with high sensitivity and specificity.
Objective To evaluate the clinical value and safety of adenosine monophosphate( AMP)bronchoprovocation test in patients with asthma. Methods Sixty asthmatics, including 19 cases with uncontrolled asthma, 22 with partially controlled asthma, and 19 with controlled asthma were enrolled. Twenty-four healthy volunteers were enrolled as control and 20 patients with upper respiratory tract infection ( URI) were also included. AMP bronchoprovocation test ( AMP-BPT) was performed. PD20 FEV1-AMP lt;40 mg was set as a cut-off value of positive response to AMP. Positive rate, sensitivity, specificity, accuracy and adverse reactions of AMP-BPT were evaluated. Eleven cases with uncontrolled asthma and 12 cases with partially controlled asthma were followed up with AMP-BPT three months and six months after inhaledcorticosteroids treatment. Asthma symptom scores were recorded a week early before each challenge. The correlation between PD20FEV1 -AMP and asthma symptom score was analyzed. Values of PD20 FEV1 -AMP were represented as median and quartile range [ M( QR) ] . Results No positive responses to AMP were found in both healthy and URI subjects. On the other hand, positive responses to AMP were found in all the uncontrolled asthmatics ( 100% ) with PD20FEV1 -AMP as 0. 6 mg ( 0. 4 mg) , in 19 partially controlled asthmatics ( 86. 4% ) with PD20 FEV1 -AMP as 5. 38 mg ( 32. 67 mg ) , and in 5 controlled asthmatics( 26. 3% ) with PD20FEV1 -AMP as 40 mg ( 29. 3 mg) . There were negative correlations between the logarithms of PD20 FEV1 -AMP and logarithms of asthma symptom scores ( r = - 0. 598, P lt; 0. 01) . The sensitivity, specificity and accuracy was 72% , 100%, and 84% , respectively. Percentage of subjects who experienced wheezing, cough, dyspnea, swallows stimulation, chest tightness, expectoration and cyanosis during AMP-BPT were 37. 5%, 21. 2%, 15. 4%,7. 7%, 7. 7%, 4. 8%, and 1. 0%, respectively. No severe adverse reaction was found. Conclusions AMP-BPT is helpful to the diagnosis and differential diagnosis of bronchial asthma. It also can be used to evaluate the severity and control level, and to monitor the therapeutic efficacy in clinical practice. Moreover, AMP-BPT is well tolerated with little adverse reaction.
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 compare the value of fractional exhaled nitric oxide ( FENO) measurement and leukotriene D4 bronchial provocation test ( LTD4-BPT) in diagnosis and evaluation of asthma. Methods 20 uncontrolled,22 partially controlled, 20 controlled asthmatics, and 21 normal subjects were enrolled in the study. Measurement of FENO was performed followed by LTD4-BPT. The distribution characteristics and relationship of both results were analyzed, and the diagnostic value was compared using receiver operation characteristic ( ROC) curve.Results FENO was above 25. 0ppb in 80. 7% of the asthmatics. The proportion of asthmatics with FENO between 26.0ppb and 49.0ppb was larger in the uncontrolled and partially controlled subjects than that in the controlled subjects. Both the median and interquartile range of cumulative dosage ( PD20FEV1-LTD4) were much higher in the controlled asthmatics as compared with the uncontrolled and partially controlled asthmatics. The area under the ROC curve ( AUC) for PD20FEV1-LTD4 [ AUC: 0.914, 95% CI: ( 0.855, 0.974) ] was larger than that of FENO [ AUC: 0.820, 95% CI: ( 0.718, 0.921) ] . Higher sensitivity ( 0.8570 vs. 0.8065) and specificity ( 0.9048 vs. 0.7619) were in favor of PD20 FEV1 -LTD4 ≤ 4.800 nmol as compared with FENO ≥ 26.0ppb being the positive threshold. Conclusion Compared with FENO measurement, LTD4-BPT has higher sensitivity and specificity and is of higher diagnostic value for asthma.
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.