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Completed

NCT Number: NCT02829255

Effect of High Altitude Exposure, Acclimatization and Re-exposure on Cerebral Autoregulation in Lowlanders

Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure to high altitude on cerebral autoregulation

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Key information

Conditions

Effect of High Altitude Altitude Sickness Respiration Disorders Respiratory Tract Diseases

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Zurich

Zurich, 8091, Switzerland

About this study

Baseline measurements will be performed in Santiago de Chile, 520 m, over the course of 3 days. Participants will then travel by commercial airline (5 h flight) and by bus (3 h ride) to the ALMA base camp located at 2900 m near San Pedro de Atacama, northern Chile. Participants will stay there for the next 8 nights and they will be spend the days (6-8 h daily) at the telescope station at 5050 m while undergoing testing as described above at the first and the last day at 5050m. Daily transports from 2900 to 5050 m will be by car (1 h ride, one way). After the first 8 day altitude sojourn participants will return to the Santiago area (520 m) for a 6 day recovery period.

A second altitude sojourn with an identical schedule as the one described above and a final low altitude stay of 3 days will follow.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Born, raised and currently living <800m
  • No overnight stay at altitudes >1500 m 4 weeks before the study

Exclusion criteria

  • Previous altitude intolerance to altitude <3000 m
  • Pregnancy
  • Health impairment, which requires regular treatment

Treatment and study plan

Altitude exposure

Other

altitude exposure

Primary outcomes

  1. Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation.

    Time frame: day 1; day 2 first cycle

    Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 2 (5050 m) vs. day 1 (520 m) of the first cycle

Secondary outcomes

  1. Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation.

    Time frame: day 1; day 7 first cycle

    Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 7 (5050 m) vs. day 1 (520 m) of the first cycle.

  2. Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation.

    Time frame: day 2; day 7 second cycle

    Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 7 (5050 m) vs. day 2 (5050 m) of the second cycle.

  3. Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation.

    Time frame: day 2 first cycle; day 2 second cycle

    Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 2 (5050 m) second cycle vs. day 2 (5050 m) of the first cycle.

  4. Coherence between middle cerebral artery blood flow velocity and systemic blood pressure as measure of cerebral autoregulation.

    Time frame: day 7 first cycle; day 7 second cycle

    Change in magnitude of the coefficient of coherence between blood flow velocity in the middle cerebral artery measured by transcranial ultrasound Doppler and systemic blood pressure at day 7 (5050 m) second cycle vs. day 7 (5050 m) of the first cycle.

Sponsors and collaborators

Lead sponsor

University of Zurich

Other

Collaborators

  • University of Calgary

Registry information

Important dates

Study start
2016
Primary completion
2016
Study completion
2016
First posted
Jul 12, 2016
Registry last updated
Jan 17, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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