Efficacy of Positive Expiratory Pressure on Acute Mountain Sickness

NCT07148674 | Not Yet Recruiting

• 1 other identifier: 6962
• Study Type: interventional
• Target: 3
• Locations: 0 countries
• Sites: N/A

Brief Summary

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.

Conditions

Acute Mountain Sickness (AMS)

Outcome Measures

Primary Outcomes (1)

• Peripheral Oxygen Saturation (SpO2)

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

Secondary Outcomes (1)

• Lake Louise Score

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

Study Arms (1)

Intervention

EXPERIMENTAL

Pilot trial of positive expiratory pressure for acute mountain sickness. 1 single arm with 3 phases: * 1: Baseline Breathing (No PEP) Participants breathe normally without any device for 10 minutes in supine position, serving as control. * 2: Positive Expiratory Pressure (PEP) Breathing Participants breathe through a face mask with a mechanical PEP device set at 10 cmH₂O expiratory pressure for 10 minutes supine. Inspiration is unrestricted; expiration occurs against resistance to improve oxygenation and reduce AMS symptoms. * 3: Post-PEP Breathing (No PEP) After PEP, participants breathe normally for 10 minutes supine. Each phase is consecutive at altitudes 4,300 m, 5,560 m, and 6,000 m

Device: Positive Expiratory Pressure (10cmH2O) in hypobaric hypoxia

Interventions

Positive Expiratory Pressure (10cmH2O) in hypobaric hypoxia DEVICE

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.

Intervention

Eligibility Criteria

• Age: 18 Years - 99 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• BiALP - Alpine, Disaster and Wilderness Medicine: lead
• Società Italiana Medicina degli Ambienti Estremi: collaborator

Related Publications (15)

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  PMID: 37847882 BACKGROUND

• Nespoulet H, Rupp T, Bachasson D, Tamisier R, Wuyam B, Levy P, Verges S. Positive expiratory pressure improves oxygenation in healthy subjects exposed to hypoxia. PLoS One. 2013 Dec 23;8(12):e85219. doi: 10.1371/journal.pone.0085219. eCollection 2013.

  PMID: 24376872 BACKGROUND

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  PMID: 24067184 BACKGROUND

• Rupp T, Saugy JJ, Bourdillon N, Verges S, Millet GP. Positive expiratory pressure improves arterial and cerebral oxygenation in acute normobaric and hypobaric hypoxia. Am J Physiol Regul Integr Comp Physiol. 2019 Nov 1;317(5):R754-R762. doi: 10.1152/ajpregu.00025.2019. Epub 2019 Sep 18.

  PMID: 31530174 BACKGROUND

• Rupp T, Maufrais C, Walther G, Esteve F, Macdonald JH, Bouzat P, Verges S. MEDEX 2015: Prophylactic Effects of Positive Expiratory Pressure in Trekkers at Very High Altitude. Front Physiol. 2021 Sep 21;12:710622. doi: 10.3389/fphys.2021.710622. eCollection 2021.

  PMID: 34621182 BACKGROUND

• Fagevik Olsen M, Lannefors L, Westerdahl E. Positive expiratory pressure - Common clinical applications and physiological effects. Respir Med. 2015 Mar;109(3):297-307. doi: 10.1016/j.rmed.2014.11.003. Epub 2014 Nov 12.

  PMID: 25573419 BACKGROUND

• Gabry AL, Ledoux X, Mozziconacci M, Martin C. High-altitude pulmonary edema at moderate altitude (< 2,400 m; 7,870 feet): a series of 52 patients. Chest. 2003 Jan;123(1):49-53. doi: 10.1378/chest.123.1.49.

  PMID: 12527602 BACKGROUND

• Agostoni P, Caldara G, Bussotti M, Revera M, Valentini M, Gregorini F, Faini A, Lombardi C, Bilo G, Giuliano A, Veglia F, Savia G, Modesti PA, Mancia G, Parati G; HIGHCARE Investigators. Continuous positive airway pressure increases haemoglobin O2 saturation after acute but not prolonged altitude exposure. Eur Heart J. 2010 Feb;31(4):457-63. doi: 10.1093/eurheartj/ehp472. Epub 2009 Nov 10.

  PMID: 19903683 BACKGROUND

• Wang C, Wang X, Chi C, Guo L, Guo L, Zhao N, Wang W, Pi X, Sun B, Lian A, Shi J, Li E. Lung ventilation strategies for acute respiratory distress syndrome: a systematic review and network meta-analysis. Sci Rep. 2016 Mar 9;6:22855. doi: 10.1038/srep22855.

  PMID: 26955891 BACKGROUND

• Roach RC, Hackett PH, Oelz O, Bartsch P, Luks AM, MacInnis MJ, Baillie JK; Lake Louise AMS Score Consensus Committee. The 2018 Lake Louise Acute Mountain Sickness Score. High Alt Med Biol. 2018 Mar;19(1):4-6. doi: 10.1089/ham.2017.0164. Epub 2018 Mar 13.

  PMID: 29583031 BACKGROUND

• Luks AM, Beidleman BA, Freer L, Grissom CK, Keyes LE, McIntosh SE, Rodway GW, Schoene RB, Zafren K, Hackett PH. Wilderness Medical Society Clinical Practice Guidelines for the Prevention, Diagnosis, and Treatment of Acute Altitude Illness: 2024 Update. Wilderness Environ Med. 2024 Mar;35(1_suppl):2S-19S. doi: 10.1016/j.wem.2023.05.013. Epub 2023 Dec 27.

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  PMID: 33732460 BACKGROUND

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  PMID: 62991 BACKGROUND

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  PMID: 23809076 BACKGROUND

Related Links

• Theoretical underpinning
• Theoretical underpinning

MeSH Terms

Conditions

Altitude Sickness

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases

Central Study Contacts

Paolo Rodi, MD

CONTACT

+41766992164; paolorodi95@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD, MScMD, principal investigator

Study Record Dates

• First Submitted: August 6, 2025
• First Posted: August 29, 2025
• Study Start: September 5, 2025
• Primary Completion: December 31, 2025
• Study Completion: December 31, 2025
• Last Updated: August 29, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share