The Pre-acclimatization Augmented Extreme Altitude Expedition

NCT05517044 | Unknown DMC

• 1 other identifier: BASEC 2022-00679
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of this study is to investigate the effect of pre-acclimatization in a nitrogen tent at home, ventilated with a slightly increased nitrogen percentage, in preparation for an expedition at extreme altitude. Specifically, the current study aims to gather knowledge, whether pre-acclimatization, first, leads to improved capillary function during an expedition to extreme altitude, and second, affects incidence of altitude sickness and the likelihood of reaching the expedition destination without oxygen supplementation. The project will be carried out in two phases corresponding to two randomized controlled trials in healthy volunteers, who are participating in an expedition at extreme altitudes with or without pre-acclimatization.

Conditions

Altitude Hypoxia; Perfusion; Complications

Keywords

Microcirculation; Oxygen delivery capacity; Preacclimatization; nitrogen concentration tent

Outcome Measures

Primary Outcomes (5)

• Difference in sublingual total capillary vessel density (TVD) induced by preacclimatization and high-altitude exposure (change from baseline)

  Sublingual microcirculatory functional hemodynamic variable measured using a handheld vital microscopy. (ref: Communications Biology 2019; 2: 217 UND ref. Curr Opin Crit Care 2020; 26: 273-280.)

  Microcirculation assessment taken: 4 and 1 week prior to the expedition start (preacclimatization), Day 5 to 10 of the expedition in Nepal, Day 2 after the return from Nepa

• Difference in sublingual functional capillary density (FCD) induced by preacclimatization and high-altitude exposure (change from baseline)

  Sublingual microcirculatory functional hemodynamic variable measured using a handheld vital microscopy. (ref: Communications Biology 2019; 2: 217 UND ref. Curr Opin Crit Care 2020; 26: 273-280.)

  Microcirculation assessment taken: 4 and 1 week prior to the expedition start (preacclimatization), Day 5 to 10 of the expedition in Nepal, Day 2 after the return from Nepa

• Difference in sublingual red blood cell velocity (RBCv) induced by preacclimatization and high-altitude exposure (change from baseline)

  Sublingual microcirculatory functional hemodynamic variable measured using a handheld vital microscopy. (ref: Communications Biology 2019; 2: 217 UND ref. Curr Opin Crit Care 2020; 26: 273-280.)

  Microcirculation assessment taken: 4 and 1 week prior to the expedition start (preacclimatization), Day 5 to 10 of the expedition in Nepal, Day 2 after the return from Nepa

• Difference in sublingual capillary hematocrits (cHct) induced by preacclimatization and high-altitude exposure (change from baseline)

  Sublingual microcirculatory functional hemodynamic variable measured using a handheld vital microscopy. (ref: Communications Biology 2019; 2: 217 UND ref. Curr Opin Crit Care 2020; 26: 273-280.)

  Microcirculation assessment taken: 4 and 1 week prior to the expedition start (preacclimatization), Day 5 to 10 of the expedition in Nepal, Day 2 after the return from Nepa

• Difference in sublingual Tissue red blood cell perfusion (tRBCp) induced by preacclimatization and high-altitude exposure (change from baseline)

  Sublingual microcirculatory functional hemodynamic variable measured using a handheld vital microscopy. (ref: Communications Biology 2019; 2: 217 UND ref. Curr Opin Crit Care 2020; 26: 273-280.)

  Microcirculation assessment taken: 4 and 1 week prior to the expedition start (preacclimatization), Day 5 to 10 of the expedition in Nepal, Day 2 after the return from Nepa

Secondary Outcomes (5)

• Change in acute mountain sickness (Lake Louise score)

  LLS_AMS score reported: 4 and 1 week prior to the expedition start (preacclimatization), Day 5 to 10 of the expedition in Nepal, Day 2 after the return from Nepal

• Summit success

  Day 9 of the expedition in Nepal (Summit attempt)

• Nitrogen tent

  4 weeks (prior to the expedition start (preacclimatization))

• Low hemoglobin oxygen saturation

  4 weeks (prior to the expedition start (preacclimatization))

• Hemoglobin oxgen saturation dips

  4 weeks (prior to the expedition start (preacclimatization))

Study Arms (2)

Preacclimatization group

EXPERIMENTAL

The participants assigned to the preacclimatization group will undergo a defined preacclimatization program by sleeping in a nitrogen concentration tent prior to an expedition to high altitude.

Other: Nitrogen tent preacclimatization to high altitude

Control group

NO INTERVENTION

The participants assigned to the control group sleep in their regular environment without use of a nitrogen concentration tent prior to an expedition to a high altitude expedition.

Interventions

Nitrogen tent preacclimatization to high altitude OTHER

The participants assigned to the preacclimatization group spend a minimum of six hours during sleep, throughout the acclimatization period (four weeks preceding the expedition) in a nitrogen concentration tent (Hypoxico OHG, Traunstein, Germany) set to an environmental PO2 corresponding to an altitude of 2500 masl, with a progression to 5500 masl within 28 days in steps of 1000 m every seven days. Respiratory Polygraphy is used to detect periodic breathing, SpO2, and heart rate continuously during sleep and is performed before and after the designated preacclimatization period, and repetitively when increasing normobaric hypoxia in the group with nitrogen concentration tent preacclimatization.

Preacclimatization group

Eligibility Criteria

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

You may qualify if:

• Healthy
• Active alpinists (active alpinists denotes individuals with regular experience in alpine high mountain climbing in rock, ice and snow terrain of difficulty WS - ZS according to the Swiss Alpine Club (SAC-CAS) grading scale assessed in a self-reporting questionnaire
• age \> 18 years

You may not qualify if:

• history of high-altitude pulmonary edema or cerebral edema
• pregnancy or lactation
• heart failure (AHA Stage B and above)
• pulmonary hypertension
• pulmonary disease excluding mild bronchial asthma
• chronic kidney failure (KDIGO Stage 1 and above)
• chronic liver disease
• subjects with a history of smoking (\> 5 PY), and high familiar predisposition for cardiovascular disease, when combined with smoking

Sponsors & Collaborators

• University of Zurich: lead
• Swiss Sportclinic Bern: collaborator

Study Sites (1)

University Hospital of Zurich

Zurich, 8091, Switzerland

Location

MeSH Terms

Conditions

Altitude Sickness

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases

Study Officials

• Matthias P Hilty, PD Dr. med.

  University of Zurich

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Two independent randomized-controlled trials with each an intervention and a control group.

Study Record Dates

• First Submitted: August 3, 2022
• First Posted: August 26, 2022
• Study Start: August 4, 2022
• Primary Completion: November 22, 2023
• Study Completion: December 1, 2024
• Last Updated: December 22, 2023

Record last verified: 2023-12

Data Sharing

• IPD Sharing: Will not share

Locations

CH (1)