Feasibility of Constant Work Rate Testing to Detect Exercise-induced Laryngeal Obstruction

Study Overview
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Brief Summary
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TITLE Feasibility of constant work rate testing to detect exercise-induced laryngeal obstruction DESIGN Prospective observational pilot study AIMS To investigate if constant work rate testing at different work rates will sufficiently induce detectable exercise-induced laryngeal obstruction (EILO) using CLE. POPULATION Adult patients with EILO DURATION 01.09.2022 - 30.06.2023

Official Title
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Feasibility of Constant Work Rate Testing to Detect Exercise-induced Laryngeal Obstruction

Conditions
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Exercise-induced Laryngeal Obstruction (EILO)

Intervention / Treatment
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* Diagnostic Test: Continuous laryngoscopy during exercise (CLE), incremental exercise protocol
* Diagnostic Test: Continuous laryngoscopy during exercise (CLE), continuous work rate protocol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant is willing and able to give informed consent for participation in the study. Male or Female, aged 18 or above with a clinical suspicion of having EILO. Individuals with concurrent asthma can participate in the study provided that their asthma is well-controlled, determined by a negative bronchoprovocation test. Exclusion Criteria: No EILO found in Clinical standard-of-care CLE test Not able to complete the exercise test for other reasons than breathlessness or leg fatigue (e.g. injury, disease or disability preventing cycling to maximal exertion). Comorbidities other than asthma, which, judged by the investigator, might confound the test results or pose a medical risk to the patient (e.g. cardiac disease, exercise-induced anaphylaxis). Current smokers (< 6 months of stopping) or individuals with a significant smoking history (>10 pack years). Pregnancy.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: Continuous laryngoscopy during exercise (CLE), incremental exercise protocol|The incremental work rate exercise test will be performed using a cycle-ergometer. The exercise protocol is initiated by a five-minute warm-up at 50 Watts (W). Subsequently, they will complete a stepwise protocol, which will begin at 100 W and increase by 2 W every 6th second, until exhaustion or until the patient is unable to continue exercise, for any reason.|
|Diagnostic Test: Continuous laryngoscopy during exercise (CLE), continuous work rate protocol|Within two weeks the participants will perform an additional CLE-test at various intensities. The new exercise protocol is designed to induce EILO at different exercise intensities. Using the participants' individually calculated exercise capacity, three different workloads (70 %, 80 % and 90 %) will be calculated. The exercise protocol will be initiated with a five-minute warm-up at 50 W, then the workload will increase to the watt equivalent to 70 % of the participant's maximal exercise capacity. This workload will be fixed for ten minutes and only terminated if the participant feels the need to stop due to exhaustion or breathing difficulties. Next, the participant will have a five-minute resting phase with a set workload of 50 W. This protocol will be repeated at a workload equivalent to 80 % and 90 %|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| prevalence and degree of glottic or supraglottic collapse in EILO patients | Laryngoscopic detection of supraglottic or a glottic obstruction of the same severity as observed during incremental testing, during a submaximal constant work rate exercise test (70 %, 80 % and 90 %) using a visual grade scale (0-3, with 0 reflecting no obstruction, and 3 being the most severe degree of obstruction). | Changes from baseline during the procedure and immediately after cessation of the exercise test. | 
| Time of onset of the laryngeal obstruction | A specific point in time where observed laryngeal obstruction is first discernible will be determined during the evaluation of the laryngoscopic videos. This is to descriptively quantify this outcome. | A time of onset determined during the procedures | 
| Observed duration of the laryngeal obstruction | The investigators will further evaluate the laryngoscopic videos and determine the duration of the participant's laryngeal obstruction. This duration is defined as the time period from the time of onset during submaximal exercise, until remission of the observed obstruction or end of the test. | Duration measured in seconds during the procedures | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient reported symptom score: Dyspnoea-12 | The patients will fill out the Dyspnoea-12 questionnaire before the first exercise test The questionnaire consists of 12 questions regarding dyspnoea. This is a descriptive measure | At baseline | 
| Patient reported symptom scores: Nijmegen | The participants will fill out the Nijmegen questionnaire before the first exercise test The questionnaire consists of 16 questions, with answers ranging from never to very often. A score is calculated from these answers. A higher score means that it is more likely that the participant suffers from hyperventilation syndrome. This is a descriptive measure | At baseline | 
| Patient reported symptom scores: Multidimensional Dyspnoea Profile (MDP). | The patients will fill out the Multidimensional Dyspnoea Profile (MDP) questionnaire before the first exercise test This profile consists of questions regarding both affective and sensory components of dyspnoea. This is a descriptive measure | At baseline | 
| Modified borg dyspnoea during exercise | Minimum score: 0 Maximum score: 10 The participant will be asked to rate dyspnoea at baseline and during the CLE tests at 1 minute intervals. The investigators will compare the scores between the incremental CLE tests and the constant work rate CLE tests. | At baseline and at one minute intervals during the CLE tests (up to 60 minutes) | 
| Leg fatigue scores during exercise | Minimum score: 0 Maximum score: 10 The participant will be asked to rate leg fatigue at baseline and during the CLE tests at 1 minute intervals. The investigators will compare the scores between the incremental CLE tests and the constant work rate CLE tests. | At baseline and at one minute intervals during the CLE tests (up to 60 minutes) | 
| Rate of perceived exertion (RPE) scores during exercise | Minimum score: 0 Maximum score: 10 The participant will be asked to evaluate their rate of perceived exertion at baseline and during the CLE tests at 1 minute intervals. The investigators will compare the scores between the incremental CLE tests and the constant work rate CLE tests. | At baseline and at one minute intervals during the CLE tests (up to 60 minutes) | 
| Inter-rater agreement of the prevalence and degree of glottic or supraglottic collapse in EILO patients | After obtaining laryngoscopic video data, the investigators will evaluate the severity of laryngeal obstruction using a visual grade scale (0-3). From these gradings we will calculate inter-rater agreement values (weighted kappa). | During data analysis (month 1). |