Positive Pressure and Gravity Affect Volumetric Capnography

Study Overview
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Brief Summary
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Volumetric capnography is an interesting and non-invasive tool for monitoring ventilation in mechanically ventilated patients. The aim of this study was to test the effect of positive pressure ventilation and different body positions on volumetric capnograms.

Detailed Description
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In this interventional study awake and healthy volunteers will be submitted to spontaneous, pressure support and control pressure ventilation using a tight nasal mask. Volumetric capnography and electrical impedance tomography (EIT) will be continuously recorded during the protocol. Different body positions were randomly tested. Analysis of global and regional distribution of ventilation using EIT will be matched with changes observed in volumetric capnography-derived parameters.

Official Title
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The Effect of Positive Pressure and Body Position on Volumetric Capnography Assessed by Electrical Impedance Tomography

Conditions
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Hypoventilation

Intervention / Treatment
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* Other: body positions


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society Anesthesia physical status I. Age between 25-39 years old, Body mass index between 23-28 kg/m2, Non-smokers. Exclusion Criteria: Presence of pulmonary or cardiac diseases. Abnormal spirometry.

Ages Eligible for Study
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Minimum Age: 28 Years
Maximum Age: 39 Years

Sexes Eligible for Study
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Male

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: non-invasive ventilation<br>Non-invasive positive pressure at different body positions: sitting - supine - prone - right lateral and left lateral. | Other: body positions<br>* positive pressure ventilation at different body positions<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Analysis of the changes in volumetric capnographic parameters with changes in body positioning and positive pressure ventilation. | The volunteers are breathing spontaneously with and without positive pressure support. Capnographic parameters were registered at each studied condition. | 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electrical impedance images of the distribution of ventilation with changes in body positioning and positive pressure ventilation. | The volunteers are breathing spontaneously with and without positive pressure support. Electrical impedance images were taken at each studied condition. | 4 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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volumetric capnography, gravity, mechanical ventilation, EIT