Effect of Mouth Breathing on Exercise Induced Bronchoconstriction.

Study Overview
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Brief Summary
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Introduction: Exercise induced bronchoconstriction (EIB) is a common finding in the pediatric population with and without asthma. EIB is suspected with a drop of 10-15% in Forced expiratory volume in the 1st second (FEV1) during exercise challenge test (ECT). Some researchers assume that oral breathing, in several mechanisms, increase hyper-responsiveness of the airways. Aim: Asses the effect of a nose clip and allergic rhinitis in EIB. Hypothesis: The use of a nose clip in exercise challenges will increase the rate of positive tests. However, we assume that children with symptomatic allergic rhinitis will not demonstrate similar trends. Methods: A prospective, single center cohort study in a pediatric pulmonology institute, at Ruth's children hospital, Rambam medical center, Haifa, Israel. Children referred for ECT will be registered to the study and will be evaluated in two separate visits. Visit 1 - ECT with a nose clip and visit 2 - ECT without a nose clip. Demographic and clinical data and measurements of serial vital signs, exercise data and lung functions will be taken, as well as Total Nasal Symptoms Score (TNSS) and Asthma Control Test (ACT) questionnaires.

Detailed Description
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Introduction: Exercise induced bronchoconstriction (EIB) is a common finding in the pediatric population with and without asthma. EIB is evaluated with serial measurements of lung functions during exercise protocol. EIB is suspected with a drop of 10-15% in Forced expiratory volume in the 1st second (FEV1) during exercise challenge test (ECT). Some researchers assume that oral breathing, in several mechanisms, increase hyper-responsiveness of the airways. Aim: Asses the effect of a nose clip and allergic rhinitis in exercise induced bronchoconstriction. Hypothesis: The use of a nose clip in exercise challenges will increase the rate of positive tests. However, we assume that children with symptomatic allergic rhinitis will not demonstrate similar trends. Methods: A prospective, single center cohort study in a pediatric pulmonology institute, at Ruth's children hospital, Rambam medical center, Haifa, Israel, during 2020-2021. Children referred for ECT will be registered to the study after signing an informed consent and will be evaluated in two separate visits. Visit 1 - ECT with a nose clip and visit 2 - ECT without a nose clip. ECT will be conducted according to the institute protocol, based on American Thoracic Society (ATS) guidelines. Demographic and clinical data and measurements of serial vital signs, exercise data and lung functions will be taken, as well as Total Nasal Symptoms Score (TNSS) and Asthma Control Test (ACT) questionnaires.

Official Title
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The Effect of Mouth Breathing on Exercise Induced Bronchoconstriction in Children.

Conditions
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Asthma in Children

Intervention / Treatment
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* Diagnostic Test: Exercise challenge test (ECT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Exercise challenge test as part of exercise induced asthma evaluation. Age 6-18 years. Exclusion Criteria: Other chronic lung disease Significant background illness Severe asthma exacerbation or systemic steroids - last 2 months Persistent use of inhaled steroids - last 2 weeks Use of short acting bronchodilators - last 24 hours.

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum 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

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Exercise challenge test (ECT) with and without nose clip (NC).<br>All participants after receiving informed consent were invited for 2 visits. Visit 1 - ECT performed with NC. Visit 2 - ECT performed without NC. Demographic and clinical data and measurements of vital signs, exercise data and lung functions were recorded. ECT completed on treadmill. Questionnaires: Total Nasal Symptom Score (TNSS 0-6). Asthma Control Test (ACT 5-25) . Positive ECT = drop in FEV1 >12% from baseline | Diagnostic Test: Exercise challenge test (ECT)<br>* Baseline demographic, clinical and rest lung functions were recorded. ECT was performed on treadmill according to fixed protocol. Clinical data during ECT was recorded. (visit 1- performed with nose clip, visit 2- performed without nose clip). Lung function were measured and recorded at fixed time after ECT and after bronchodilator administration.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Primary end point | Maximum drop of forced expiratory volume in one second - (FEV1) after exercise challenge test with and without Nose clip. | 15 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Secondary end point | Forced expiratory volume in one second - (FEV1) improvement after bronchodilators during exercise challenge test with and without Nose clip | 15 minutes |