Efficacy of Positive Expiratory Pressure on Acute Mountain Sickness

N/ANot Yet RecruitingNCT07148674

BiALP - Alpine, Disaster and Wilderness Medicine3 enrolled

Overview

This pilot study aims to evaluate the efficacy of positive expiratory pressure (PEP) therapy at 10 cmH₂O in improving peripheral oxygen saturation (SpO₂) and mitigating symptoms of acute mountain sickness (AMS) in healthy individuals exposed to extreme altitude conditions. Three male participants will be monitored during an ascent of Mount Aconcagua, Argentina, at elevations of 4,300 m, 5,560 m, and 6,000 m above sea level. The study involves three sequential phases of 10 minutes each: baseline breathing without PEP, breathing with PEP applied via a mechanical face mask, and post-PEP breathing. Primary outcomes include changes in SpO₂ and Lake Louise Score (LLS) to assess AMS severity. Findings will provide preliminary data on the potential role of PEP as a non-pharmacological intervention in high-altitude medicine.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Acute Mountain Sickness (AMS)

Interventions

The intervention under investigation will be the application of positive expiratory pressure (PEP) at 10 cmH₂O using an Ambu mask. The mask will allow participants to inspire freely while generating a controlled expiratory pressure. The PEP device is a non-pharmacological medical device whose uses in both hospital and pre-hospital settings are part of everyday medical practice.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 99 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Healthy volunteers without ongoing medical conditions * Over 18 years of age * Volunteers with the physical and technical skills necessary to undertake a mountaineering expedition on Mount Aconcagua, Argentina, and with previous experience at extreme altitudes Exclusion Criteria: * Subjects with any ongoing medical conditions * Under 18 years of age * Subjects without previous mountaineering experience at extreme altitudes and without adequate physical and technical preparation necessary to undertake a mountaineering expedition on Mount Aconcagua, Argentina

Outcomes

Primary Outcomes

Peripheral Oxygen Saturation (SpO2)

Time frame: During the 3 weeks of expedition on Mount Aconcagua, after arrival of participants at 4300masl, 5560masl and 6000 masl.

Secondary Outcomes

Lake Louise Score

The Lake Louise Score (LLS) is a standardized tool to diagnose Acute Mountain Sickness (AMS). It combines self-reported symptoms (headache, gastrointestinal upset, fatigue/weakness, dizziness/lightheadedness) rated from 0 (none) to 3 (severe). AMS is diagnosed when headache is present plus at least one other symptom, with a total score ≥3. Higher scores reflect greater symptom severity: 3-5 mild AMS, 6-9 moderate, ≥10 severe. The LLS is used in research and expeditions to quantify altitude illness and monitor response to acclimatization or treatment.