Breathing Experiments into the Simulated Avalanche Snow: Medical and Technical Issues of the Outdoor Breathing Trials
Abstrakt
Avalanche burials represent one of the most dangerous risks associated with winter activities in the mountains. Asphyxiation occurs as a consequence of blocked airways; or, due to a severe hypoxia and hypercapnia resulting from rebreathing previously exhaled gas.
Recently, outdoor breathing experiments with healthy volunteers were conducted in order to investigate the gas exchange limitations and work of breathing effects on the probability of survival under avalanche snow. Ambient conditions during the experiments differ significantly from the recommended operating conditions of the medical devices.
Therefore, special measures need to be applied during the experiments not only to assure proper functioning of the devices used for the monitoring of the breathing subjects, but also ensuring their required precision and accuracy. As the subject starts to suffer from hypoxia and hypercapnia short after beginning of the breathing trial, careful and detailed monitoring and advanced safety precautions must be adopted.
Using our experience from real outdoor breathing trials, we aim to recommend both the technical and medical precautions that should be undertaken in future studies.