Controlled Hyperventilation as Prophylaxis for Acute Mountain Sickness
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ClinicalTrials.gov Identifier: NCT02972411 |
Recruitment Status : Unknown
Verified November 2016 by Sebastián Drago Pérez, Hospital del Trabajador de Santiago.
Recruitment status was: Recruiting
First Posted : November 23, 2016
Last Update Posted : November 23, 2016
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Altitude Sickness | Behavioral: Voluntary ventilatory response Drug: Acetazolamide | Not Applicable |
Rationale: Acute mountain sickness (AMS) is a common condition among people who go to altitude and stay at altitude. Acclimatization is the most important mechanism in order to reduce the risk of AMS, however, this is not possible or adequate in a large part of the cases. Recently, there are indications that adjustment of respiration by means of a voluntary increase in the respiratory minute volume can have a similar prophylactic effect. The purpose of this study is to measure the effect of the voluntary increase of the minute volume by means of controlled hyperventilation as prophylaxis for acute mountain sickness without prior acclimatization, with AMS being expressed in the Lake Louise Self-Report Score (LLSRS).
Objective: To investigate the safety and efficacy of the voluntary increase in minute ventilation by means of controlled hyperventilation as prophylaxis for AMS, measured by the LLSRS in a randomized controlled trial ascending to 4954m altitude.
Study design: Prospective randomized controlled trial, safety and efficacy.
Study population: 30 healthy subjects
Intervention: The investigational prophylaxis is controlled hyperventilation. Participants in the interventional group will be trained to hyperventilate in a controlled fashion doing a series of exercises during the 4 days prior to the ascent. They will also be taught in a practical way to recognize early clinical signs and symptoms of hypocapnia.
Main study parameters/endpoints: Safety and efficacy measured by comparing the LLSRS between the two groups. Target end-tidal CO2 ( PETCO2) will be measured to objectify adequate hyperventilation. Symptoms of hypocapnia due to the (pre-)intervention as well as any adverse events will be reported and analysed.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 30 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Single (Participant) |
Primary Purpose: | Prevention |
Official Title: | Controlled Hyperventilation as Prophylaxis for Acute Mountain Sickness: A Randomized Controlled Trial |
Study Start Date : | October 2016 |
Estimated Primary Completion Date : | May 2017 |
Estimated Study Completion Date : | May 2017 |

Arm | Intervention/treatment |
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Experimental: Intervention
Voluntary increase in respiration
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Behavioral: Voluntary ventilatory response
Training of the subjects for voluntary increase in the respiratory minute ventilation |
Active Comparator: Acetazolamide
Administration of Acetazolamide 125mg. since 24 hours before ascent and until 48 hours post altitude exposure, and absence of altitude sickness symptoms
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Drug: Acetazolamide
Acetazolamide 125mg. PO every 12 hours since 24 hours before ascent, until 48 hours at high altitude |
- Lake Louise Score [ Time Frame: Up to 5 months ]Intensity and prevalence of Acute Mountain Sickness. During Ascent.
- PETCO2 [ Time Frame: Up to 5 months ]Pressure of expired CO2, measured with a monitor in the moutain. During ascent.
- Pulse oxygen saturation [ Time Frame: Up to 5 months ]During ascent.
- Respiratory rate [ Time Frame: Up to 5 months ]During ascent
- Heart rate [ Time Frame: Up to 5 months ]During ascent
- Borg Scale [ Time Frame: Up to 5 months ]During ascent
- Training satisfactory. PETCO2 below 20 mmHg [ Time Frame: Up to 6 months ]After ascent.
- Training satisfactory after Ascent. PETCO2 below 20mmHg [ Time Frame: Up to 6 months ]After ascent.
- hypoxic ventilatory response [ Time Frame: Up to 6 months ]Before ascent

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Ages Eligible for Study: | 18 Years to 40 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Living at lower altitude than 900 meters
Exclusion Criteria:
- Cardiac or pulmonary comorbidity
- Smoking
- Infectious disease during the last 30 days
- BMI> 30
- Pharmaceutical use as diuretics, corticosteroids, acetazolamide, or anti -inflammatory drugs during the 2 weeks prior to the study
- A history of high altitude cerebral edema or high altitude pulmonary edema
- Cardiovascular risk factors such as a personal history of cardiovascular disease, familial history of major adverse cardiovascular events (MACE) at age younger than 45 yrs, hypercholesterolemia and stroke.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02972411
Contact: Sebastián Drago, MD | +56992191310 | sebadrago@gmail.com | |
Contact: Juan Campodónico, MD | +56981379351 | campodonicouc@gmail.com |
Chile | |
110 Sports and health center | Recruiting |
Santiago, Chile, 8320000 | |
Contact: Mario Sandoval, MD +56993593944 mariosandoval@110.cl |
Principal Investigator: | Sebastián Drago, MD | Hospital del Trabajador Santiago |
Responsible Party: | Sebastián Drago Pérez, Orthopaedic Surgeon, Hospital del Trabajador de Santiago |
ClinicalTrials.gov Identifier: | NCT02972411 |
Other Study ID Numbers: |
HospitalTS |
First Posted: | November 23, 2016 Key Record Dates |
Last Update Posted: | November 23, 2016 |
Last Verified: | November 2016 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Hyperventilation Altitude Sickness Respiration Disorders Respiratory Tract Diseases Signs and Symptoms, Respiratory Acetazolamide Anticonvulsants |
Carbonic Anhydrase Inhibitors Enzyme Inhibitors Molecular Mechanisms of Pharmacological Action Diuretics Natriuretic Agents Physiological Effects of Drugs |