Work of Breathing Under Extreme Hypercapnia Induced by Ventilation Insufficiency

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.

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.

Breathing in the simulated avalanche snow. Breathing into model of wet perlite 2L air pocket with resistance compensation

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.

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

Roubik K, Sieger L, Sykora K. Work of Breathing into Snow in the Presence versus Absence of an Artificial Air Pocket Affects Hypoxia and Hypercapnia of a Victim Covered with Avalanche Snow: A Randomized Double Blind Crossover Study. PLoS One. 2015 Dec 14;10(12):e0144332. doi: 10.1371/journal.pone.0144332. eCollection 2015.