Work of Breathing Under Extreme Hypercapnia Induced by Ventilation Insufficiency

Study Overview
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Brief Summary
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The aim of the study is to investigate Work of Breathing of a person in simulated avalanche snow and consequent use of the measured data for judging which one of three simulated scenarios are alike while increasing hypercapnia in the simulated avalanche snow.

Detailed Description
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The study is a part of a university diploma thesis aimed at studying physiological conditions and development of breathing parameters of a person breathing in the simulated avalanche snow. The Investigator is measuring Work of Breathing in three scenarios: a) 2L air pocket, b) 2L air pocket with resistance compensation and c) no air pocket. The investigator hypothesize that the Work of Breathing during compensation of air pocket will be alike with no air pocket scenario, thus proving significance of the resistance reduction for survival. The aim of the study is to investigate the effect of Work of Breathing on gas exchange in subjects breathing into the simulated avalanche snow scenarios.

Official Title
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Work of Breathing Under Extreme Hypercapnia Induced by Ventilation Insufficiency

Conditions
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Accident Caused by Snow Avalanche

Intervention / Treatment
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* Other: extreme hypercapnia induced by ventilation insufficiency


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy and fit volunteers, classified as The American Society of Anesthesiologists class I without a smoking history Exclusion Criteria: Tiffeneau Index less than 0.70 any cardiovascular or respiratory condition

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 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: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Wet Perlite, 2L air pocket<br>Breathing in the simulated avalanche snow. Breathing into model of wet perlite with 2L air pocket | Other: extreme hypercapnia induced by ventilation insufficiency<br>* extreme hypercapnia<br>|
| Experimental: Wet Perlite 2L air pocket with resistance compensation<br>Breathing in the simulated avalanche snow. Breathing into model of wet perlite 2L air pocket with resistance compensation | Other: extreme hypercapnia induced by ventilation insufficiency<br>* extreme hypercapnia<br>|
| Experimental: Wet Perlite, no air pocket<br>Breathing in the simulated avalanche snow. Breathing into model of wet perlite with no air pocket | Other: extreme hypercapnia induced by ventilation insufficiency<br>* extreme hypercapnia<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The length of breathing | Time to termination of the breathing experiment due to the decision of the tested subject, or determined by high end-tidal carbon dioxide value or by the order by the clinician assessing the health status of the subjects. | Continuously within up to 7 minute interval from the beginning of the breathing experiment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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snow, avalanche, hypercapnia, work of breathing