Clinical Trial: Diagnostic Utility of Different Airway Resistance Assessment Techniques in the Methacholine Challenge Test

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Diagnostic Utility of Different Airway Resistance Assessment Techniques in the Evaluation of Bronchial Hyperreactivity by Methacholine Challenge Testing

Brief Summary:

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.


Detailed Summary:

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 ca
Sponsor: Medical University of Warsaw

Current Primary Outcome: The concentration of methacholine inducing a 20% fall in FEV(1) from post-diluent baseline [PC(20)] [ Time Frame: up to 2 hours ]

In case of FEV1 decrease of > 20% from baseline PC (20) will be calculated by logarithmic interpolation.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Change in FOT resistance and reactance from post-diluent baseline after inhalating consecutive methacholine aerosols [ Time Frame: within 6 minutes after methacholine aerosol inhalation ]
    Airway resistance and reactance will be measured by FOT after inhalating methacholine aerosols until FEV(1) fall of >20% from baseline
  • Change in plethysmographic airway resistance from post-diluent baseline after inhalating consecutive methacholine aerosols [ Time Frame: within 6 minutes after methacholine aerosol inhalation ]
    Airway resistance will be measured by plethysmography after inhalating methacholine aerosols until FEV(1) fall of >20% from baseline
  • Change in interrupter airway resistance from post-diluent baseline after inhalating consecutive methacholine aerosols [ Time Frame: within 6 minutes after methacholine aerosol inhalation ]
    Airway resistance will be measured by interrupter technique after inhalating methacholine aerosols until FEV(1) fall of >20% from baseline
  • Change in FEV(1) from from post-diluent baseline after inhalating consecutive methacholine aerosols [ Time Frame: within 6 minutes after methacholine aerosol inhalation ]
    FEV (1) will be measured by spirometry after inhalating methacholine aerosols until FEV(1) fall of >20% from baseline
  • Assessment of the difficulty level of FOT [ Time Frame: after methacholine challenge test (up to 2 hours two hours from the start of the methacholine challenge test) ]
    Patients will receive visual analogue scale form assessing difficulty level and problems related to performing each test
  • Assessment of the difficulty level of plethysmography [ Time Frame: after methacholine challenge test (up to 2 hours two hours from the start of the methacholine challenge test) ]
    Patients will receive visual analogue scale form assessing difficulty level and problems related to performing each test
  • Assessment of the difficulty level of interrupter technique [ Time Frame: after methacholine challenge test (up to 2 hours two hours from the start of the methacholine challenge test) ]
    Patients will receive visual analogue scale form assessing difficulty level and problems related to performing each test
  • Assessment of the difficulty level of spirometry [ Time Frame: after methacholine challenge test (up to 2 hours two hours from the start of the methacholine challenge test) ]
    Patients will receive visual analogue scale form assessing difficulty level and problems related to performing each test
  • Duration of the bronchial resistance assessment by FOT [ Time Frame: During methacholine challenge test (up to 2 hours) ]
    Duration of each pulmonary function test will be measured
  • Duration of the bronchial resistance assessment by plethysmography [ Time Frame: During methacholine challenge test (up to 2 hours) ]
    Duration of each pulmonary function test will be measured
  • Duration of the bronchial resistance assessment by interrupter technique [ Time Frame: During methacholine challenge test (up to 2 hours) ]
    Duration of each pulmonary function test will be measured
  • Duration of spirometry [ Time Frame: During methacholine challenge test (up to 2 hours) ]
    Duration of each pulmonary function test will be measured
  • Total duration of methacholine challenge test [ Time Frame: During methacholine challenge test (up to 2 hours) ]
    Total duration bronchial challenge will be measured


Original Secondary Outcome: Same as current

Information By: Medical University of Warsaw

Dates:
Date Received: December 1, 2014
Date Started: November 2014
Date Completion:
Last Updated: November 8, 2016
Last Verified: November 2016