Ultrasound Imaging of the Larynx and Diaphragm During NIV and Cough Assist

Study Overview
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Brief Summary
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The study examines if diagnostic ultrasound imaging of larynx and diaphragm can be as accurate as transnasal fiberoptic laryngoscopy in visualizing the larynx during NIV and Mechanically Assisted Cough interventions.

Detailed Description
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Transnasal fiberoptic laryngoscopy (TFL) is gold standard for visualising the larynx. TFL has been used to visualize the laryngeal response patterns during non-invasive therapeutic interventions, as during Mechanically Assisted Cough in patients with Amyotrophic Lateral Sclerosis. The examinations revealed that the larynx adducted during the application of positive pressures, which restricted the airflow and reduced the efficacy of the treatment. The higher treatment pressures resulted in ineffective interventions as a result of the adducted vocal cords obstructing flow. This knowledge has changed the treatment approach for patients with possible upper airway instability by individualizing the treatment pressures and flow due to laryngeal responses. TFL may cause slight discomfort when placing the laryngoscope. Diagnostic ultrasound is non-invasive easily applicable technique that has gained increasing popularity in diagnosing cardiopulmonary and laryngeal conditions during the recent times. The aim of the study is to investigate whether the diagnostic ultrasound of the larynx can be as accurate as TFL during Mechanically Assisted Cough and Non-Invasive Ventilation (NIV). The present study will include healthy participants. Hypothesis is that diagnostic ultrasound of larynx can provide clinical valuable information of the laryngeal response patterns during Mechanically Assisted Cough and NIV. The aims of the study are: To evaluate the feasibility of diagnostic ultrasound imaging of the larynx, and to compare to the gold standard of TFL used during ongoing NIV and Mechanically Assisted Cough in healthy subjects. To evaluate the feasibility of ultrasound imaging if the diaphragm during ongoing NIV and Mechanically Assisted Cough in healthy subjects.

Official Title
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Can Ultrasound Imaging of Both Upper Airways and Diaphragm be Used to Guide Efficacy on Non-invasive Ventilation and Cough Assist

Conditions
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Healthy Persons

Intervention / Treatment
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* Diagnostic Test: Diagnostic Ultrasound
* Diagnostic Test: Transnasal Fiberoptic Laryngoscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy subjects Exclusion Criteria: history of laryngospasm or pneumothorax

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy persons<br>Noninvasive ventilation and Cough Assist | Diagnostic Test: Diagnostic Ultrasound<br>* To investigate if Ultrasound imaging can visualize the larynx during NIV and Cough Assist, and be as accurate as laryngoscopy<br>Diagnostic Test: Transnasal Fiberoptic Laryngoscopy<br>* To investigate if Ultrasound imaging can visualize the larynx during NIV and Cough Assist, and be as accurate as laryngoscopy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Opening movements in larynx on transnasal fiberoptic laryngoscopy (TFL) during inspiration | Number of participants. | Day 1 | 
| Obstructive movements in larynx on TFL during inspiration | Number of participants. | Day 1 | 
| Closure in larynx on TFL during the compression phase of cough | Number of participants. | Day 1 | 
| Opening movements in larynx on TFL during expiration | Number of participants. | Day 1 | 
| Narrower movements in larynx on TFL during expiration | Number of participants. | Day 1 | 
| Obstructive movements in larynx on TFL during expiration | Number of participants. | Day 1 | 
| Opening movements in larynx on Anterior Ultrasound (USA) during inspiration | Number of participants. | Day 1 | 
| Obstructive movements in larynx on USA during inspiration | Number of participants. | Day 1 | 
| Closure in larynx on USA during the compression phase of cough | Number of participants. | Day 1 | 
| Opening movements in larynx on USA during expiration | Number of participants. | Day 1 | 
| Narrower movements in larynx on USA during expiration | Number of participants. | Day 1 | 
| Obstructive movements in larynx on USA during expiration | Number of participants. | Day 1 | 
| Opening movements in larynx on Lateral Ultrasound (USL) during inspiration | Number of participants. | Day 1 | 
| Obstructive movements in larynx on USL during inspiration | Number of participants. | Day 1 | 
| Closure in larynx on USL during the compression phase of cough | Number of participants. | Day 1 | 
| Opening movements in larynx on USL during expiration | Number of participants. | Day 1 | 
| Narrower movements in larynx on USL during expiration | Number of participants. | Day 1 | 
| Obstructive movements in larynx on USL during expiration | Number of participants. | Day 1 | 
| Comparison of observed movements in the larynx on transnasal fiberoptic laryngoscopy (TFL) and Anterior Ultrasound (USA) imaging. | The chi-square test will assess differences between examination methods. | Day 1 | 
| Comparison of observed movements in the larynx on transnasal fiberoptic laryngoscopy (TFL) and Lateral Ultrasound (USL) imaging. | The chi-square test will assess differences between examination methods. | Day 1 | 
| Comparison of observed movements in the larynx on Anterior Ultrasound (USA) and Lateral Ultrasound (USL) imaging. | The chi-square test will assess differences between examination methods. | Day 1 | 
| Ultrasound imaging of diaphragm excursion | Measurements will be performed in quiet breathing, NIV and Cough Assist. Diaphragm excursions are recorded in M-mode, and will be presented in millimeters. | Day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjects perception of the examination with TFL - VAS scale | Participant's experience of the examination will be evaluated on a Visual Analog Scale (VAS) from 0-10 where higher number indicate more discomfort. | Day 1 | 
| Subjects perception of the examination with Laryngeal ultrasound - VAS scale | Participant's experience of the examination will be evaluated on a Visual Analog Scale (VAS) from 0-10 where higher number indicate more discomfort. | Day 1 | 
| Airflow registration | A pneumotachograph inserted in the Circuit between the facemask and the therapeutic device will register airflow during the interventions. Interruptions of the airflow will verify the possible laryngeal adductions. | Day 1 | 
| Pressure registration | A pressure transducer inserted in the Circuit between the facemask and the therapeutic device measures the pressure and verify the settings of the NIV and Mechanically assisted Cough. | Day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Transnasal Fiberoptic Laryngoscopy, Diagnostic Ultrasound, Cough Assist, Noninvasive ventilation