Controlled Hyperventilation as Prophylaxis for Acute Mountain Sickness

Altitude Sickness Clinical Trial

Official title:

Controlled Hyperventilation as Prophylaxis for Acute Mountain Sickness: A Randomized Controlled Trial

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT02972411
• Other study ID #: HospitalTS
• Status: Recruiting
• Phase: N/A
• First received: October 25, 2016
• Last updated: November 21, 2016
• Start date: October 2016
• Est. completion date: May 2017

Study information

• Verified date: November 2016
• Source: Hospital del Trabajador de Santiago
• Contact: Sebastián Drago, MD
• Phone: +56992191310
• Email: sebadrago[@]gmail.com
• Is FDA regulated: No
• Health authority: Chile: Comité de Ética de Hospital del Trabajador de Santiago
• Study type: Interventional

Clinical Trial Summary

This study evaluates the safety and efficacy of the voluntary ventilatory response as prophylaxis for acute mountain sickness, measured by the Lake Louise Self-Report Score, comparing to a group using acetazolamide.

Description:

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 30
• Est. completion date: May 2017
• Est. primary completion date: May 2017
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 40 Years

Eligibility

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.

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Altitude Sickness
• Hyperventilation

Intervention

Behavioral:
• Voluntary ventilatory response
Training of the subjects for voluntary increase in the respiratory minute ventilation

Drug:
• Acetazolamide
Acetazolamide 125mg. PO every 12 hours since 24 hours before ascent, until 48 hours at high altitude

Locations

Country	Name	City	State
Chile	110 Sports and health center	Santiago

Sponsors (1)

Lead Sponsor	Collaborator
Hospital del Trabajador de Santiago

Country where clinical trial is conducted

Chile, 

References & Publications (10)

Acetazolamide in control of acute mountain sickness. Lancet. 1981 Jan 24;1(8213):180-3. — View Citation

Bärtsch P, Swenson ER. Clinical practice: Acute high-altitude illnesses. N Engl J Med. 2013 Jun 13;368(24):2294-302. doi: 10.1056/NEJMcp1214870. Review. — View Citation

Bernardi L, Passino C, Spadacini G, Bonfichi M, Arcaini L, Malcovati L, Bandinelli G, Schneider A, Keyl C, Feil P, Greene RE, Bernasconi C. Reduced hypoxic ventilatory response with preserved blood oxygenation in yoga trainees and Himalayan Buddhist monks at altitude: evidence of a different adaptive strategy? Eur J Appl Physiol. 2007 Mar;99(5):511-8. — View Citation

Bernardi L, Schneider A, Pomidori L, Paolucci E, Cogo A. Hypoxic ventilatory response in successful extreme altitude climbers. Eur Respir J. 2006 Jan;27(1):165-71. — View Citation

Buijze GA, Hopman MT. Controlled hyperventilation after training may accelerate altitude acclimatization. Wilderness Environ Med. 2014 Dec;25(4):484-6. doi: 10.1016/j.wem.2014.04.009. — View Citation

Luks AM, McIntosh SE, Grissom CK, Auerbach PS, Rodway GW, Schoene RB, Zafren K, Hackett PH; Wilderness Medical Society.. Wilderness Medical Society consensus guidelines for the prevention and treatment of acute altitude illness. Wilderness Environ Med. 2010 Jun;21(2):146-55. doi: 10.1016/j.wem.2010.03.002. Erratum in: Wilderness Environ Med. 2010 Dec;21(4):386. — View Citation

Moore LG, Harrison GL, McCullough RE, McCullough RG, Micco AJ, Tucker A, Weil JV, Reeves JT. Low acute hypoxic ventilatory response and hypoxic depression in acute altitude sickness. J Appl Physiol (1985). 1986 Apr;60(4):1407-12. — View Citation

Richalet JP, Larmignat P, Poitrine E, Letournel M, Canouï-Poitrine F. Physiological risk factors for severe high-altitude illness: a prospective cohort study. Am J Respir Crit Care Med. 2012 Jan 15;185(2):192-8. doi: 10.1164/rccm.201108-1396OC. — View Citation

Schulz KF, Altman DG, Moher D; CONSORT Group.. CONSORT 2010 statement: updated guidelines for reporting parallel group randomized trials. Ann Intern Med. 2010 Jun 1;152(11):726-32. doi: 10.7326/0003-4819-152-11-201006010-00232. — View Citation

Vargas M, Osorio J, Jiménez D, Moraga F, Sepúlveda M, Del Solar J, Hudson C, Cortés G, León A. [Acute mountain sickness at 3500 and 4250 m. A study of symptom, incidence and severity]. Rev Med Chil. 2001 Feb;129(2):166-72. Spanish. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Training satisfactory. PETCO2 below 20 mmHg	After ascent.	Up to 6 months	No
Other	Training satisfactory after Ascent. PETCO2 below 20mmHg	After ascent.	Up to 6 months	No
Other	hypoxic ventilatory response	Before ascent	Up to 6 months	No
Primary	Lake Louise Score	Intensity and prevalence of Acute Mountain Sickness. During Ascent.	Up to 5 months	No
Secondary	PETCO2	Pressure of expired CO2, measured with a monitor in the moutain. During ascent.	Up to 5 months	No
Secondary	Pulse oxygen saturation	During ascent.	Up to 5 months	No
Secondary	Respiratory rate	During ascent	Up to 5 months	No
Secondary	Heart rate	During ascent	Up to 5 months	No
Secondary	Borg Scale	During ascent	Up to 5 months	No