Evaluation of Air Pocket Factors That Contribute to the Development of Hypoxia and Hypercapnia
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 12
- 试验地点
- 2
- 主要终点
- SpO2 (%)
研究概览
简要总结
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).
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy volunteers with an age above 18yr-old, physically active.
- •Volunteers have been informed and have signed consent.
排除标准
- •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.
结局指标
主要结局
SpO2 (%)
时间窗: Changes from baseline (measurement at 0min) -> snow-breathing phase (5min, 15min, and timepoint immediately before interruption of snow-breathing phase [max 30min]) -> 2.5min and 5min after snow-breathing phase
Continuous monitoring
次要结局
- VE (L/min)(Changes from baseline (measurement at 0min) -> snow-breathing phase (5min, 15min, and timepoint immediately before interruption of snow-breathing phase [max 30min]) -> 2.5min and 5min after snow-breathing phase)
- EtCO2 (mmHg)(Changes from baseline (measurement at 0min) -> snow-breathing phase (5min, 15min, and timepoint immediately before interruption of snow-breathing phase [max 30min]) -> 2.5min and 5min after snow-breathing phase)
- Cause of interruption(Timepoint immediately before interruption of snow-breathing phase (max 30min))
- rSO2 (%)(Changes from baseline (measurement at 0min) -> snow-breathing phase (5min, 15min, and timepoint immediately before interruption of snow-breathing phase [max 30min]) -> 2.5min and 5min after snow-breathing phase)