Snow Physical Properties and Human Ventilatory Response
Snow Physical Properties and Human Ventilatory Response
Sufficient oxygenation is critical for completely buried avalanche victims to avoid
 life-threatening consequences during hypoxic exposure. Snow contains a remarkable capacity to
 maintain air availability; it was suspected that the snow physical properties affect the
 development of hypoxia and hypercapnia. The aim of this study was to evaluate the influence
 of different snow physical properties on the development of hypoxia and hypercapnia in
 subjects breathing into an artificial air pocket in snow. Twelve male healthy subjects
 breathed through an airtight face-mask and 40cm tube into an artificial air pocket of 4L.
 Every subject performed three tests on different days with varying snow characteristics.
 Symptoms, gas and cardiovascular parameters were monitored up to 30min. Tests were
 interrupted at SpO2 <75% (primary endpoint); or due to subjective symptoms like dyspnea,
 dizziness, and headache (i.e. related to hypercapnia). Snow density was assessed via standard
 methods and micro-computed tomography (CT) analysis, and permeability and penetration with
 the snow micro-penetrometer (SMP).
Inclusion Criteria:

 -  Healthy volunteers with an age above 18yr-old, physically active.

 -  Volunteers have been informed and have signed consent.

 Exclusion Criteria:

 -  Lack of consent.

 -  Chronic previous illness of the respiratory tract or of the cardiovascular system.

 -  Acute disease at or immediately prior to the test (eg, flu-like infection, fever of
 unknown origin).

 -  Eurac employees.