Impact of Non-intentional Leaks on Noninvasive Ventilation

Study Overview
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Brief Summary
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The investigators hypothesized that increasing non intentional leaks could increase work of breathing and could lead to patient/non-invasive ventilation (NIV) asynchrony. The main objective is to compare ventilatory pattern (work of breathing, flow, pressure) under NIV with and without non-intentional leaks in 10 awakened healthy subjects and 10 awakened and asleep obese hypoventilation syndrome (OHS) patients. Methods: While the subjects will be under NIV, several levels of leaks will be simulated in a random order with an automatically opening valve. Breathing pattern (work of breathing,flow, pressure, thorax and abdominal movements) will be recorded by Polygraphy. Healthy subjects will be recorded only during awakened state. OHS patients will be recorded both during awake and sleep sates. Analysis: A repeated measures analysis of variance (ANOVA) will compare work of breathing according to the different levels of leaks.

Official Title
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Impact of Non-intentional Leaks on Breathing Pattern and Work of Breathing During Non-invasive Ventilation: Study in Awakened Healthy Subjects and Awakened Obesity Hypoventilation Syndrome(OHS)Patients and During the Sleep in OHS Patients.

Conditions
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Intermittent Positive-pressure Ventilation, Respiratory Physiological Phenomena

Intervention / Treatment
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* Other: Non intentional leaks during non invasive ventilation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: OHS patients, in stable stade, teated with nocturnal non invasive ventilation for at least three months. Healthy subjects without known pathology Exclusion Criteria: OHS patients: instable cardio-respiratory status and/or acute cardio-respiratory failure three month before the inclusion. Latex allergy, oesophageal varices.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 70 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 and OHS subjects<br>10 healthy subjects: 20 to 60 years old 10 patients with Obesity hypoventilation syndrome: 20 to 70 years old treated with nocturnal non invasive ventilation for at least three months. | Other: Non intentional leaks during non invasive ventilation<br>* During NIV sessions (in awake state for both the 10 healthy and the 10 OHS subjects and during sleep only for the OHS subjects), the investigators will create several levels of non intentional leaks in a random order<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Main outcome measure:Work of breathing assessed by measurement of oesophageal pressure according to the levels of non intentional leaks during non invasive ventilation |  | Oesophageal pressure will be assessed during all the duration of the study (2hours for the healthy subjects, overnight for the OHS patients) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Secondary outcome measure: Assessments of the pulse transit time (PTT) and measurement of the oral opening (JAWSENS-NOMICS)according to the levels of non intentional leaks during non invasive ventilation |  | PTT and oral opening will be assessed during all the duration of the study (2hours for the healthy subjects, overnight for the OHS patients) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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non-invasive intermittent positive-pressure ventilation, work of breathing, Pulse transit time