Diagnostic Utility of Different Airway Resistance Assessment Techniques in the Evaluation of Bronchial Hyperreactivity by Methacholine Challenge Testing
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 46
- 试验地点
- 2
- 主要终点
- The concentration of methacholine inducing a 20% fall in FEV(1) from post-diluent baseline [PC(20)]
研究概览
简要总结
The aim of the study is to compare standard spirometric evaluation of methacholine challenge test with plethysmographic, interrupter technique and forced oscillation technique (FOT) evaluation of the airways resistance.
The study group will consist of patients referred for methacholine challenge test. All patient will undergo spirometric, plethysmographic, interrupter technique and FOT examinations - before and after inhalation of aerosols. Patients will also undergo the measurement of nitric oxide concentration in exhaled air and laboratory tests, including: blood count, measurement of serum C-reactive protein, sodium, potassium, creatinine, immunoglobulin E and N-Terminal pro-brain natriuretic peptide (NT-proBNP) concentration.
The investigators intend to assess, if plethysmographic, and/or interrupter, and/or FOT measurement of bronchial reactivity can replace standard spirometric assessment. Plethysmography, interrupter technique and FOT are much more easier to perform for patients. Furthermore, those two techniques are less dependent on patient's motivation and cooperation ability. Thus, usage of FOT, interrupter technique and/or plethysmography in bronchial hyperreactivity testing could make methacholine challenge test more comfortable and available for more patients. The investigators are also going to analyze the relationship between exhaled nitric oxide and functional indices of bronchial hyperreactivity.
详细描述
Bronchial hyperreactivity is defined as the increased respiratory tract responsiveness to multiple stimuli, which results in bronchial muscles constriction and bronchial lumen narrowing. Bronchial hyperreactivity is a hallmark of asthma, however it may also be present in other diseases, e.g. chronic obstructive pulmonary disease (COPD). Methacholine challenge test is one of the bronchial reactivity assessment methods. Methacholine acts directly on bronchial smooth muscles receptors and causes bronchoconstriction. Bronchial reactivity is increased in the presence of active inflammation. Methacholine challenge testing is commonly performed in patients with symptoms suggestive of asthma and negative result of spirometry reversibility test. The measurement of methacholine concentration which causes 20% forced expiratory volume at one second (FEV1) decrease in post-inhalation spirometry (PC20) is a standard method of hyperreactivity evaluation. However, above method could be used among patients who are able to perform acceptable spirometry. Furthermore, results of spirometry might be influenced by level of compliance and motivation of patients. Moreover, whereas spirometric methacholine challenge test has high negative predictive values, its positive predictive value is relatively low. Thus, diagnostic utility of other pulmonary function tests should be assessed in methacholine challenge test evaluation.
In plethysmography airway resistance is performed during tidal breathing. The increase of specific airway resistance of 200% and the decrease of specific airway conductance of 40% after methacholine inhalation, respectively, are proposed as a cut-off levels for bronchial hyperreactivity diagnosis.
In forced oscillation technique (FOT), sinusoidal oscillations are emitted by membrane into airway lumen and airway resistance is calculated on the basis of changes in air flow induced by oscillations. The increase of resistance and decrease of reactance in FOT are typical for bronchoconstriction.
Finally, also interrupter technique (IT) allows for airway resistance assessment during tidal breathing. In IT, airway resistance is calculated on the basis of mouth pressure measured directly after airway occlusion and airflow measured directly before occlusion.
The aim of the study is to compare standard spirometric evaluation of methacholine challenge test with plethysmographic, interrupter technique and forced oscillation technique (FOT) evaluation of the airways resistance.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Diagnostic
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •presence of asthma symptoms without confirmation of diagnosis by standard methods
- •dyspnea and/or cough of unknown etiology
排除标准
- •FEV1 <1.2 L or <60% of predicted value
- •acute heart failure
- •myocardial infarction in last 3 months
- •transient ischaemic attack or stroke in last 3 months
- •aneurysms
- •methacholine allergy
- •pregnant and lactating women
- •administration of β2-mimetic, anticholinergic agent or theophylline before methacholine challenge test in 6, 8 and 24 hours, respectively
- •respiratory tract infection in last 6 weeks
- •patient inability to cooperate
结局指标
主要结局
The concentration of methacholine inducing a 20% fall in FEV(1) from post-diluent baseline [PC(20)]
时间窗: up to 2 hours
In case of FEV1 decrease of \> 20% from baseline PC (20) will be calculated by logarithmic interpolation.
次要结局
- Change in plethysmographic airway resistance from post-diluent baseline after inhalating consecutive methacholine aerosols(within 6 minutes after methacholine aerosol inhalation)
- Change in interrupter airway resistance from post-diluent baseline after inhalating consecutive methacholine aerosols(within 6 minutes after methacholine aerosol inhalation)
- Assessment of the difficulty level of plethysmography(after methacholine challenge test (up to 2 hours two hours from the start of the methacholine challenge test))
- Duration of the bronchial resistance assessment by interrupter technique(During methacholine challenge test (up to 2 hours))
- Change in FEV(1) from from post-diluent baseline after inhalating consecutive methacholine aerosols(within 6 minutes after methacholine aerosol inhalation)
- Duration of the bronchial resistance assessment by FOT(During methacholine challenge test (up to 2 hours))
- Total duration of methacholine challenge test(During methacholine challenge test (up to 2 hours))
- Change in FOT resistance and reactance from post-diluent baseline after inhalating consecutive methacholine aerosols(within 6 minutes after methacholine aerosol inhalation)
- Assessment of the difficulty level of spirometry(after methacholine challenge test (up to 2 hours two hours from the start of the methacholine challenge test))
- Duration of spirometry(During methacholine challenge test (up to 2 hours))
- Assessment of the difficulty level of FOT(after methacholine challenge test (up to 2 hours two hours from the start of the methacholine challenge test))
- Assessment of the difficulty level of interrupter technique(after methacholine challenge test (up to 2 hours two hours from the start of the methacholine challenge test))
- Duration of the bronchial resistance assessment by plethysmography(During methacholine challenge test (up to 2 hours))