Snow Properties and Its Modeling for Studying Gas Exchange Under the Simulated Avalanche Snow

Not Applicable

• Conditions: Accident Caused by Snow Avalanche
• Interventions: Other: Breathing in the simulated avalanche snow

• Registration Number: NCT03413878
• Lead Sponsor: Czech Technical University in Prague

Brief Summary

The aim of the study is to investigate respiratory parameters of a person in the simulated avalanche snow and consequent use of the measured data for development of a mathematical-physical model of breathing during increasing hypercapnia in the avalanche.

Detailed Description

The study is a part of a university research project aimed at studying physiological conditions and development of breathing parameters of a person breathing in the simulated avalanche snow. Presence of an air pocket and its size play an important role in survival of victims buried in the avalanche snow. Even small air pockets facilitate breathing, yet they do not provide a significant amount of fresh air for breathing. The investigators hypothesize that the size of the air pocket significantly affects the airflow resistance and work of breathing. The aim of the study is to investigate the effect of the air pocket volume on gas exchange and work of breathing in subjects breathing into the simulated avalanche snow.

Study Timeline

• Study First Submitted: 2018-01-22
• Study First Submitted QC: 2018-01-22
• Study Start: 2018-01-29
• Study First Posted: 2018-01-29
• Status Verified: 2021-02
• Last Update Submitted: 2021-02-24
• Last Update Posted: 2021-02-25
• Primary Completion: 2022-05-20
• Study Completion: 2022-05-20

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 45

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Dry snow/Small air pocket	Breathing in the simulated avalanche snow	Breathing in the simulated avalanche snow. Breathing into model of dry avalanche snow with a small air pocket
Wet snow/Large air pocket	Breathing in the simulated avalanche snow	Breathing in the simulated avalanche snow. Breathing into model of wet avalanche snow with a large air pocket
Dry snow/Large air pocket	Breathing in the simulated avalanche snow	Breathing in the simulated avalanche snow. Breathing into model of dry avalanche snow with a large air pocket
Wet snow/Small air pocket	Breathing in the simulated avalanche snow	Breathing in the simulated avalanche snow. Breathing into model of wet avalanche snow with a small air pocket

Primary Outcome Measures

Name	Time	Method
The length of breathing	Continuously within 30 minute interval from the beginning of the breathing experiment	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.

Trial Locations

Locations (2)

Czech Technical University, Faculty of Biomedical Engineering; 🇨🇿 Kladno, Czechia

Charles University, Czech Republic; 🇨🇿 Prague, Czechia