Change in Peripheral Oxygen Saturation by Using Different Breathing Procedures in High Altitude

Study Overview
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Brief Summary
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In this investigation the researchers explore whether different types of breathing procedures can improve the peripheral oxygen saturation to reduce the risk of becoming a acute mountain sickness or a high altitude pulmonary edema.

Detailed Description
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Acute mountain sickness (AMS) is a pathological effect of high altitude on humans caused by acute exposure to low partial pressure of oxygen at high altitude. It commonly occurs above 2500 meters of altitude. AMS appears as a collection of nonspecific symptoms acquired at high altitude or in low air pressure resembling a case of flu, carbon monoxide poisoning, or a hangover. It is caused by a drop in pressure and lowering partial pressure of oxygen during increasing altitude. The direct consequence of those changes is a hypoxic pulmonary vasoconstriction (Euler-Lijestrand-mechanism). In addition a rise in pulmonary blood pressure (Hypertonia) can occur so that there is a higher risk of developing a high altitude pulmonary edema (HAPE). In this investigation the investigators are exploring whether different types of breathing procedures can improve the peripheral oxygen saturation. We are comparing breathing with no regulation with two different procedures of hyperventilation during trekking in different altitudes. Procedure 1 (hyperventilation 1) describes inhalation during one step and exhalation during the next step. Procedure 2 (hyperventilation 2) describes inhalation and exhalation during one step. The effect of the different breathing procedures can be quantified measuring the peripheral oxygen saturation. In addition the investigators are comparing the breathing rate and the minute ventilation as well as the expiratory end-tidal CO2-partial pressure of the three different breathing procedures. Furthermore, the investigators are examining the ability to concentrate in order to quantify the effect of AMS on organ functions.

Conditions
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Acute Mountain Sickness

Intervention / Treatment
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* Other: Breathing procedure 1
* Other: Breathing procedure 2


Participation Criteria
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Eligibility Criteria
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Exclusion Criteria: acute clinically significant inter-current diseases

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Breathing procedure 1<br>Walking with breathing procedure 1. | Other: Breathing procedure 1<br>* inhalation during one step, exhalation during the next step<br>|
| Experimental: Breathing procedure 2<br>Walking with breathing procedure 2. | Other: Breathing procedure 2<br>* inhalation and exhalation during one step<br>|
| No Intervention: Control group<br>Walking without any reglementation of breathing | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change of peripheral oxygen saturation | change of peripheral oxygen saturation under different breathing procedures in different altitudes | immediate after intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change of breathing parameters | change of breathing parameters under different breathing procedures in different altitudes breathing rate minute ventilation expiratory end-tidal CO2-partial pressure | immediate after intervention | 
| change of cognition | change of ability of cognition (measured by d2-test) under different breathing procedures in different altitudes | immediate after intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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AMS, HAPE, high altitude, oxygen, saturation, mountain, climbing, breathing