Acute Exposure to Simulated Hypoxia on Exercise Capacity

Acute Exposure to Hypoxia in Precapillary Pulmonary Hypertension: Physiological and Clinical Effects at Rest and During Exercise

Randomized crossover trial in patients with Pulmonary Hypertension (PAH, CTEPH) to assess the acute response to simulated altitude (FiO2:15.1, equivalent to 2500m above sea level) in constant loaded exercise capacity.

Study Overview

• Status: Completed
• Conditions: Pulmonary Hypertension
• Intervention / Treatment: Device: Simulated Altitude (FiO2: 15.1%); Device: Shamed Hypoxia (FiO2: 20.9)

Detailed Description

Low altitude baseline measurements will be performed in Zurich (460m asl) including Echocardiography, Right heart catheterization, six-minute walk test (6MWT), pulmonary function test, clinical assessment and blood gas Analysis.

Randomly assigned to the order of testing, the participants will be tested under simulated altitude (FiO2: 15.1% with the "AMC Altitrainer") and shamed altitude with the same device.

Towards the end of the exposure after approximately 1h, the participants will perform a constant loaded exercise test on an Ergometer with a calculated resistance of their 60% max. workload.

The patients will be encouraged to perform this test up to their physical exhaustion.

• Study Type: Interventional
• Enrollment (Actual): 28
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Zurich, Switzerland, 8091
    • Respiratory Clinic, University Hospital of Zurich

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Informed consent
• PH diagnosed according to internation Guidelines: mean pulmonary artery presssure (mPAP) ≥ 25 mmHg along with a pulmonary artery wedge pressure (PAWP) ≤15 mmHg during right heart catheterization at the time of initial diagnosis
• PH class 1 (PAH) or 4 (CTEPH)
• Stable condition, on the same medication for > 4 weeks
• Patient live permanently at an altitude < 1000m asl.

Exclusion Criteria:

• Resting partial Oxygen pressure (PaO2) ≤7.3 kiloPascal (kPA) corresponding to the requirement of long-term oxygen therapy > 16hour daily (nocturnal oxygen therapy alone is allowed)
• Severe daytime hypercapnia (pCO2 > 6.5 kPa)
• Susceptibility to high altitude related diseases (AMS, High Altitude Pulmonary edema (HAPE), etc.) based on previous experienced discomfort at altitudes.
• Exposure to an altitude >1500m for ≥3 nights during the last 4 weeks before the study participation
• Residence > 1000m above sea level
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, neurological or orthopedic problems with walking disability
• Women who are pregnant or breast feeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Order A; The participants will be exposed to shamed hypoxia (FiO2: 20.9% equivalent to sea level and consecutively to simulated altitude (FiO2: 15.1% equivalent to 2500m above sea level) administered by an altitude Simulator ("Altitrainer", SMTEC), simulated altitude (FiO2: 15.1%), with a facemask.	Device: Simulated Altitude (FiO2: 15.1%); Inhalation of deoxygenated air through a altitude simulator ("Altitrainer"), for approx. 1 hour. given by a facemask.; Device: Shamed Hypoxia (FiO2: 20.9); Inhalation of unmodified air through an altitude Simulator ("Altitrainer") for approximately 1 hour given by a facemask
Experimental: Order B; The participant will be exposed to hypoxia (FiO2, 15.1% equivalent to 2500m above sea level), simulated altitude (FiO2: 15.1%), and consecutively to shamed hypoxia (FiO2, 20.9%) administered by an altitude simulator ("Altitrainer", SMTEC) with a facemask.	Device: Simulated Altitude (FiO2: 15.1%); Inhalation of deoxygenated air through a altitude simulator ("Altitrainer"), for approx. 1 hour. given by a facemask.; Device: Shamed Hypoxia (FiO2: 20.9); Inhalation of unmodified air through an altitude Simulator ("Altitrainer") for approximately 1 hour given by a facemask

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Endurance time under hypoxia (FiO2: 15.1%)	Constant loaded exercise test	Towards the end of a one hour exposure

Collaborators and Investigators

• Sponsor: University of Zurich

Publications and helpful links

General Publications

• Schneider SR, Lichtblau M, Furian M, Mayer LC, Berlier C, Müller J, Saxer S, Schwarz EI, Bloch KE, Ulrich S. Cardiorespiratory Adaptation to Short-Term Exposure to Altitude vs. Normobaric Hypoxia in Patients with Pulmonary Hypertension. J Clin Med. 2022 May 14;11(10). pii: 2769. doi: 10.3390/jcm11102769.
• Schneider SR, Mayer LC, Lichtblau M, Berlier C, Schwarz EI, Saxer S, Furian M, Bloch KE, Ulrich S. Effect of Normobaric Hypoxia on Exercise Performance in Pulmonary Hypertension: Randomized Trial. Chest. 2021 Feb;159(2):757-771. doi: 10.1016/j.chest.2020.09.004. Epub 2020 Sep 9.

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2018
• Primary Completion (Actual): April 1, 2019
• Study Completion (Actual): April 1, 2019

Study Registration Dates

• First Submitted: July 9, 2018
• First Submitted That Met QC Criteria: July 18, 2018
• First Posted (Actual): July 19, 2018

Study Record Updates

• Last Update Posted (Actual): August 16, 2019
• Last Update Submitted That Met QC Criteria: August 15, 2019
• Last Verified: August 1, 2019

More Information

Terms related to this study

• Keywords: exercise capacity; simulated altitude
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Respiratory Tract Diseases; Lung Diseases; Signs and Symptoms, Respiratory; Hypertension; Hypertension, Pulmonary; Hypoxia
• Other Study ID Numbers: 2018-00455_A1

Drug and device information, study documents

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