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

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

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03911011
Enrollment
20
Registered
2019-04-10
Start date
2019-03-07
Completion date
2021-06-20
Last updated
2025-02-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Accident Caused by Snow Avalanche

Keywords

avalanche, survival, physiology

Brief summary

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

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. The study will also measure specific body measures and spirometry.

Interventions

OTHERFresh air

Fresh air insufflation of 2 L/min toward mouth/nose.

Sponsors

Ullevaal University Hospital
CollaboratorOTHER
Haukeland University Hospital
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

A field study designed as a crossover clinical trial.

Eligibility

Sex/Gender
ALL
Healthy volunteers
Yes

Inclusion criteria

* Subject must be Healthy * Subject must be non smoking * Subject must have normal BMI

Exclusion criteria

* None

Design outcomes

Primary

MeasureTime frameDescription
Time25 minutesTime to reaching a threshold of physiology parameters or time limit

Other

MeasureTime frameDescription
Physiology25 minutesValues of Physiology parameters

Countries

Norway

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026