The Effects of Hypobaria vs Hypoxia on Cerebral Functions. (Hypoxia)

The Effects of Hypobaria vs Hypoxia on Cerebral Vasoreactivity, Brain's Electrical Activity and Concentration Performance on Pilots.

The investigators will investigate the effect of hypobaria and hypoxia on physiological responses such as: oxygen saturation, heart rate, cerebral blood flow, cerebral oxygenation, brain's activity and concentration performance.

Study Overview

• Status: Completed
• Conditions: Cerebral Hypoxia
• Intervention / Treatment: Other: Hypoxia

Detailed Description

The main goal of this project is to investigate how hypoxia affects cognitive functions. The KLT-R test asses the concentration level of a person. Subjects will do this test at different simulated altitude level in the hypobaric chamber at the FAI in Dübendorf. Investigators' first hypothesis is that concentration level will be altered by hypoxia. The higher altitude the subjects are, the more the concentration would be altered. KLT-R performance would be impaired by hypoxia compare to sea level performance.

The primary endpoint of this project is to investigate how KLT-R performance is affected by the different hypoxic conditions. KLT-R test will be passed nine times in total during the test visit. There will be a pre-test; a test at each of the conditions (3000m HH, 5500m HH, 5500m NH and 5500m HN); between each condition at sea level (to have a new baseline before each condition) and a post-test at the end of the protocol. To avoid influence of fatigue, all conditions will be randomized.

The second endpoint of this study is how the brain electrical activity is modulated by hypoxia. Micro-states also will be measure during hypobaric hypoxia conditions (3000m HH and 5500m HH).

• Study Type: Interventional
• Enrollment (Actual): 17
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Zürich
    • Dübendorf, Zürich, Switzerland, 8600
      • Mathias Aebi

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 36 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• No history of flight sickness
• No relevant medical diseases
• Age 18 - 40 years
• Written consent acceptance

Exclusion Criteria:

• Known pathologies
• Relevant medical disorders
• Drug addiction
• Anemia or poor health
• People who have already had problems with elevation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Left; No product administration will be done in this study.	Other: Hypoxia; No drug or product will be used in this study. No medication will be give to the participants. No arm will be used for product administration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentration performance	Performance of concentration at different altitude levels.	4 minutes per test

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
EEG micro-states	5 minutes recording in each conditions, eyes closed, at rest.	5 minutes per record

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cerebral vaso-reactivity	Cerebral vasoreactivity after 1 minute hyperventilation and 3 minutes breathing of 5% CO2 mixture.	8 Minutes per test

Collaborators and Investigators

• Sponsor: Fliegerärztliches Institut

Publications and helpful links

General Publications

• Aebi MR, Bourdillon N, Kunz A, Bron D, Millet GP. Specific effect of hypobaria on cerebrovascular hypercapnic responses in hypoxia. Physiol Rep. 2020 Feb;8(4):e14372. doi: 10.14814/phy2.14372.

Study record dates

Study Major Dates

• Study Start (Actual): November 16, 2017
• Primary Completion (Actual): March 5, 2018
• Study Completion (Actual): March 5, 2018

Study Registration Dates

• First Submitted: October 2, 2017
• First Submitted That Met QC Criteria: October 2, 2017
• First Posted (Actual): October 5, 2017

Study Record Updates

• Last Update Posted (Actual): August 18, 2021
• Last Update Submitted That Met QC Criteria: August 17, 2021
• Last Verified: August 1, 2021

More Information

Terms related to this study

• Keywords: Hypoxia; Brain; EEG; Cerebral oxygenation; Heart rate variability; Cerebral vaso-reactivity; Concentration performance; Cerebral blood-flow
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Signs and Symptoms, Respiratory; Hypoxia; Hypoxia, Brain
• Other Study ID Numbers: 2017-00752

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No
• IPD Plan Description: Results will be shared in scientific publications by the end of this year and in 2018.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No