Physiological Values When Breathing in an Air-pocket. Mountain Lab 2019 (ML2019)

Study Overview
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Brief Summary
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The literature describes and report neurologic intact patients surviving an avalanche several hours after they were buried. The most important factor for surviving more than 15-35 min of burial is considered to be the presence of an air-filled space around the head and neck, termed an air pocket. Little is known how the inspired air is influenced by the patients breathing and how oxygen and carbon dioxide diffuse through snow.

Detailed Description
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In a controlled and simulated avalanche scenario the investigators want to investigate how oxygen (O2) and carbon dioxide (CO2) diffuse and how rebreathing of CO2 in addition to mild hypoxia influence standardized physiological parameters in two scenarios: Fresh air and no fresh air delivered into the air pocket. The project is a field study designed to measure and document gas diffusion through snow. The outcome measures are: (1) Concentration of O2 and CO2 in the air pocket and 50 cm from the pocket. (2) Time interval for development of threshold values for concentration of O2 and CO2. The investigators will also monitor physiologic measures such as: Electrocardiogram (ECG), continuous invasive blood pressure, cerebral oximetry, continuous pulse oximetry, transthoracic impedance, and gas content in expired air. Subjective evaluation of comfort will also be scored. Twenty healthy young volunteers with written consent to participate will be used as test subjects. The study may have a clinical consequence for better outcome, for victims of avalanches by providing additional air or oxygen close to the patient. We will also measure specific body measures and spirometry.

Official Title
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Gas Diffusion in and Out of an Air Pocket After a Simulated Snow Avalanche and Its Impacts on Human Physiological Parameters.

Conditions
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Accident Caused by Snow Avalanche

Intervention / Treatment
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* Other: Fresh air


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy, non smoking, normal BMI Exclusion Criteria: None
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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: A field study designed as a crossover clinical trial.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Fresh air<br>2 litres of fresh air | Other: Fresh air<br>* Fresh air insufflation of 2 L/min toward mouth/nose.<br>|
| No Intervention: no fresh air<br>no supply of fresh air | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time | Time to reaching a threshold of physiology parameters or time limit | 25 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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avalanche, survival, physiology