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Characterisation of Large Airway Collapse During Exercise (LACE) (LACE)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT04264052
Recruitment Status : Suspended (Due to COVID-19 Royal Brompton Hospital's internal imposed restrictions)
First Posted : February 11, 2020
Last Update Posted : August 3, 2020
Royal Brompton & Harefield NHS Foundation Trust
Information provided by (Responsible Party):
Imperial College London

Brief Summary:

The large central airways (i.e. trachea and bronchi) act as a conduit to enable lower airway ventilation but also facilitate airway clearance during dynamic manoeuvres, such as coughing. It is becoming increasingly well recognised however, that in a significant proportion of individuals with chronic airway disease (e.g. chronic obstructive pulmonary disease-COPD or chronic asthma) and in those with an elevated body mass index (BMI), that the large airways may exhibit a tendency to excessive closure or narrowing. This large airway collapse (LAC) can be associated with exertional breathlessness and difficulty clearing airway secretions. A variety of terms have been used to describe LAC including excessive dynamic airway collapse (EDAC) or if the cartilaginous structures are involved then tracheobronchomalacia (TBM).

One clear limitation of the current approach to diagnosis is the fact that many of the 'diagnostic' tests employed, utilise static, supine measures +/- forced manoeuvres. These are somewhat physiologically flawed and differ markedly from the reality of the heightened state of airflow that develops during exertion. i.e. forced manoeuvres likely induce very different turbulent and thoracic pressure changes, in contrast to the hyperpnoea of real-life physical activity (i.e. walking or cycling). A current unanswered question is therefore, what happens to the large airway dynamic movement of healthy individuals (and ultimately patients) during real-life exercise and how does this compare with the measures taken during a forced manoeuvre, either during a bronchoscopy or during an imaging study such as CT or MRI scan.

The key aim of this study is therefore to evaluate and characterise large airway movement in a cohort of healthy adults during a real-life exercise challenge and to compare this with findings from a dynamic expiratory MRI and MRI during exercise. In order to achieve this, the investigators proposes to develop and test the feasibility of an exercise-bronchoscopy protocol.

Condition or disease Intervention/treatment
Airway Disease Diagnostic Test: CBE & MRIE

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Study Type : Observational
Estimated Enrollment : 40 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: The Feasibility of Continuous Bronchoscopy During Exercise in Healthy Adults in Assessing Large Airways Collapse
Actual Study Start Date : February 1, 2020
Estimated Primary Completion Date : September 2021
Estimated Study Completion Date : November 2021

Resource links provided by the National Library of Medicine

Group/Cohort Intervention/treatment
Forty healthy volunteers split in different age ranges (20-30 years n=10, 30-40 years n=10, 40-50 years n=10 and 50-60 years n=10) will undergo two airway assessments at rest and during exercise. The exercise assessments will be a continuous bronchoscopy during exercise (CBE-1st visit) and magnetic resonance imaging during exercise (MRIE-2nd visit) separated by at least three days to ensure for a sufficient cardiorespiratory and musculoskeletal recovery.
Diagnostic Test: CBE & MRIE

The diagnostic tests will be consisted by two visits.

In the first visit participants will undergo a medical history assessment and they will complete questionnaires related to the lung function (MRC Dyspnoea score, Dyspnoea-12 questionnaire, and Visual Analogue Scale). A spirometry will be performed to assess the lung function. Bronchoscopy will be performed at rest in a semi-supine position (on a reclined bed) and then during exercise on a treadmill.

In the second visit, spirometry and questionnaires will be performed prior to resting and during exercise measurements on a magnetic resonance imaging (MRI) scan.

Rest: Structural imaging of the neck and chest will be performed followed by dynamic imaging of the airways during several inspiratory and expiratory manoeuvres. No IV contrast media will be used.

Exercise: After obtaining the baseline images, the participants will be asked to cycle using a programmable supine ergometer placed on the MRI.

Primary Outcome Measures :
  1. Feasibility of continuous bronchoscopy during exercise (CBE): questionnaire [ Time Frame: 12 months ]

    Primary outcome will be the feasibility of continuous bronchoscopy during continuous exercise in healthy adults. Feasibility will be assessed via a post CBE tolerability questionnaire.

    The post exercise tolerability questionnaire aims to evaluate the upper airways function during exercise and the discomfort that the participant might experience during the test. It consists of 5 questions (Part A) where the score ranges from 1 (strongly disagree) to 5 (strongly agree), and 2 questions (Part B) where the score ranges from 1 (None at all) to 10 (Unbearable amount).

    The total score that will confirm the feasibility of CBE should be < 3 or < 5, for Part A and B, respectively.

    The questions relate to the tolerability of the CBE test (e.g., Exercise with the camera in place cause discomfort, 1 (strongly agree) to 5 (strongly disagree).

Secondary Outcome Measures :
  1. Diagnostic capacity of CBE and MRIE [ Time Frame: 12 months ]

    To evaluate the degree of large airway collapse (LAC) apparent in normal subjects via continuous bronchoscopy during exercise (CBE) and to compare this with static forced expiratory manoeuvres in magnetic resonance imaging (MRI) and MRI during exercise (MRIE).

    Flexible bronchoscopy and MRI at rest will be performed using dynamic inspiratory and expiratory manoeuvres.

    CBE will be performed on a treadmill utilising a linear individualised ramp protocol. Heart rate and electrocardiogram will be monitored throughout the test.

    MRIE will be performed on the MRI with and feet will be placed on a cycle ergometer fitted on the MRI (MR Pedal, Lode, Netherlands).

    The degree of LAC will be estimated in percentage reduction of the airway lumen in several sites of the trachea and main bronchi. In bronchoscopy the reduction will be classified as 0 to 50% / 50 to 75% / 75 to 100% / 100% airway closure. In MRI LAC will be diagnosed as >50% airway closure.

  2. Comparing dynamic versus physical exertion large airway collapse in CBE and MRIE [ Time Frame: 12 months ]

    To estimate the percentage of LAC from MRI in normal subjects during forced expiratory manoeuvres at rest and during exercise for both modalities.

    More specifically, the reduction (%) of LAC will be estimated in bronchoscopy at rest and will be compared with CBE to evaluate whether physical exertion can induce the similar response to dynamic expiratory manoeuvres. Similarly, percentage of LAC will be estimated in MRI at rest and compared with MRIE.

    Comparisons will be performed using statistical tests (e.g., Paired sample T-tests).

  3. Exploring the diagnostic capacity of different exercise modalities to assess LAC [ Time Frame: 12 months ]

    To compare findings between modalities (treadmill vs supine cycling).

    The percentages of LAC between CBE and MRIE will be compared (via statistical tests such as t-tests and Pearson's correlation tests.

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population

Subjects will be healthy and ≥ 20 to 60 years old.

The total sample size will be 40 subjects. 10 for each age group (20-30; 30-40; 40-50; 50-60 years).


Inclusion Criteria:

  • Subjects will need to be within the age range of 20-60 years old
  • have no known respiratory disease and normal spirometry
  • be able to exercise without medical reason for limitation.

Exclusion Criteria:

  • Subjects who have a significant comorbidity that prohibit exercise
  • have had a respiratory infection within the last month
  • known respiratory disease
  • current smokers or are pregnant.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04264052

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United Kingdom
Royal Brompton Hospital
London, United Kingdom, SW3 6NP
Sponsors and Collaborators
Imperial College London
Royal Brompton & Harefield NHS Foundation Trust
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Principal Investigator: James Hull, Dr Royal Brompton Hospital-Imperial College London
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Responsible Party: Imperial College London Identifier: NCT04264052    
Other Study ID Numbers: 19IC5362
First Posted: February 11, 2020    Key Record Dates
Last Update Posted: August 3, 2020
Last Verified: July 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Imperial College London:
excessive dynamic airway collapse
large airways collapse
Additional relevant MeSH terms:
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Pathologic Processes