Ultrasound Evaluation of Alveolar Stress by Measurement of Ultrasound Pleural Strain in Healthy Subjects

Study Overview
=================
Brief Summary
-----------------
In the critical patient, lung ultrasound is routinely performed for acute respiratory distress, adult respiratory distress syndrome and for hemodynamic evaluation. Its diagnostic performance is superior to that of chest radiography in the context of pleuropulmonary parenchymal pathologies. The search for lung sliding is performed to diagnose a pneumothorax or to search for the correct placement of the endotracheal intubation tube. However, this analysis is qualitative and is sometimes difficult to interpret. At present, there is no global evaluation technique at the patient's bed allowing to analyze simultaneously the alveolar recruitment, the pulmonary over-distension and the quality of the lung sliding, whereas the pulmonary damage is most often heterogeneous. The justification of our research project is based on the need to develop and validate a means of global and regional quantification of the mechanical and aeration properties of the lung parenchyma by the analysis of the acoustic markers of the pleura (pleural strain) by the ultrasound technique of speckle tracking. The aim is to establish the normal values of the pleural strain in healthy volunteers, in spontaneous ventilation and then in non-invasive mechanical ventilation, in order to vary the lung volume.

Official Title
-----------------
Ultrasound Evaluation of Alveolar Stress by Measurement of Ultrasound Pleural Strain in Healthy Subjects

Conditions
-----------------
Ultrasound Strain Measurement

Intervention / Treatment
-----------------
* Device: Lung Strain


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: -Healthy volunteer male or female between 18 and 50 years old Exclusion Criteria: History of traumatic or spontaneous pneumothorax History of connective tissue disease Any history of chronic respiratory disease Presence of an ongoing clinical respiratory Ear-Nose-Throat (ENT) or pulmonary syndrome (rhinitis, sinusitis, bronchitis, lung disease) History of gastro-duodenal reflux or stomach surgery

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: healthy Volunteers<br>Healthy male or female volunteers between 18 and 50 years old | Device: Lung Strain<br>* The main objective of this study is to describe the physiological values of lung strain in healthy volunteers as well as its variations induced by non-invasive positive pressure ventilation and their correlation with tidal volume.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung Strain values | Lung strain values (%) in spontaneous ventilation and then under non-invasive mechanical ventilation (NIV) by varying tidal volume and PEEP | during the procedure (30 minutes) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ultrasound semiology and normal values | Description of the ultrasound semiology and the normal values of the different strain parameters (Global longitudinal strain and strain rate) during apnea | during the procedure (30 minutes) | 
| Variations of the strain under NIV in the different pulmonary zones tested | Description of the variations of the strain and strain rate (inspiratory and expiratory) according to the variations of the level of inspiratory support and positive expiratory pressure (PEEP) under NIV in the different pulmonary zones tested | during the procedure (30 minutes) | 
| Longitudinal and transversal values of lung strain in the different pulmonary zones tested | Description of the longitudinal and transversal values of the lung strain and lung strain rate in the different pulmonary zones tested | during the procedure (30 minutes) | 
| Variations of the strain under NIV in the right ventricle | Description of the variations of the strain and strain rate (inspiratory and expiratory) according to the variations of the level of inspiratory support and positive expiratory pressure (PEEP) under NIV of the right ventricle | during the procedure (30 min) | 
| Variations of the strain under NIV of the diaphragm | Description of the variations of the strain and strain rate (inspiratory and expiratory) of the diaphragm according to the variations of the level of inspiratory support and positive expiratory pressure (PEEP) under NIV. The evaluation of the diaphragmatic strain will be coupled and compared to the fraction of shortening of the diaphragm, which is currently the ultrasound reference method to measure the function of this muscle | during the procedure (30 minutes) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
lung strain, speckle tracking, lung stress