Can we Improve Preoxygenation by Using Adjustable Pressure Limiting Valve (APL) ?

Study Overview
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Brief Summary
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The aim of this study is to investigate the effects of setting airway pressure release valve (APL valve) on the anesthesia workstation to 5 cmH2O during spontaneous breathing on preoxygenation. In this prospective study healthy volunteers are randomized in cross-over between spontaneous breathing with the APL valve on spontaneous position or spontaneous breathing with the APL valve on 5 cmH2O or CPAP (continous positive airway pressure) mode with 5 cmH2O PEEP (positive end expiratory pressure).

Detailed Description
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There are several methods to improve preoxygenation but most of them require advanced anesthesia workstations. Therefore the investigators planned an an experimental study on healthy volunteers to investigate the effects of a simple method on preoxygenation. Healthy volunteers are randomized in cross-over between spontaneous breathing with the APL valve on spontaneous position or spontaneous breathing with the APL valve on 5 cmH2O or CPAP mode with 5 cmH2O PEEP. The volunteers will breath through an anesthesia face mask. The fresh gas flow rate is 12 L/min, inspiratory fraction of oxygen is 100%. The exhaled gas (oxygen and carbon dioxide) are monitored. The inspiratory and end expiratory fraction of oxygen will be recorded every 10 seconds. The primary endpoint is the time to achieve end expiratory fraction of oxygen of 90% or more.The secondary endpoint is the proportion of subject with end expiratory fraction of oxygen of 90% or more after a 3 min period and the end expiratory fraction of oxygen at the third minute.

Official Title
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The Effects of Setting Adjustable Pressure Limiting Valve (APL) to 5 cmH2O on Preoxygenation

Conditions
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Preoxygenation

Intervention / Treatment
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* Procedure: preoxygenation with 100% O2, fresh gas flow rate 12 L/minute


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy volunteers Exclusion Criteria: any respiratory disease

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: spontaneous breathing<br>volunteers will breath via an anesthesia face mask spontaneously while the APL (airway pressure release valve) valve is on the spontaneous position. | Procedure: preoxygenation with 100% O2, fresh gas flow rate 12 L/minute<br>* volunteers will be placed in supine position, fresh gas flow rate will be set at 12 L/min and delivered oxygen concentration will be set at 100%.<br>|
| Active Comparator: spontaneous breathing with APL 5 cmH2O<br>volunteers will breath via an anesthesia face mask spontaneously while the APL (airway pressure release valve) valve is on the 5 cmH2O position. | Procedure: preoxygenation with 100% O2, fresh gas flow rate 12 L/minute<br>* volunteers will be placed in supine position, fresh gas flow rate will be set at 12 L/min and delivered oxygen concentration will be set at 100%.<br>|
| Active Comparator: CPAP 5cmH2O PEEP<br>volunteers will breath via an anesthesia face mask spontaneously on the CPAP mode of the anesthesia workstation with 5 cmH2O PEEP. | Procedure: preoxygenation with 100% O2, fresh gas flow rate 12 L/minute<br>* volunteers will be placed in supine position, fresh gas flow rate will be set at 12 L/min and delivered oxygen concentration will be set at 100%.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time to reach end expiratory fraction of oxygen of 90% or more |  | 5 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| proportion of volunteer with end expiratory fraction of oxygen of 90% or more after a 3 min period |  | 3 minutes | 
| End expiratory oxygen fraction at the 3th minute |  | 3 minutes | 
| Verbal rating Score | After completion of the whole arms of the study the volunteers will give a score between 0-10 to define the difficulty of breathing during the procedure | 5 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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preoxygenation, CPAP(continuous positive airway pressure), APL (airway pressure release) valve