Acute Exposure of Simulated Hypoxia on Blood and Tissue Oxygenation (aBGA, NIRS)

Sponsor

University of Zurich (Other)

Overall Status

Completed

CT.gov ID

NCT03637114

Collaborator

(none)

Enrollment

Location

Arms

Actual Duration (Months)

3.5

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Randomized crossover trial in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary Hypertension (CTEPH) to assess the acute response to simulated altitude (FiO2:15.1, equivalent to 2500m above sea level) on blood and tissue oxygenation (ABGA, near infrared spectroscopy)

Condition or Disease	Intervention/Treatment	Phase
Pulmonary Hypertension	Device: Simulated Altitude (FiO2: 15.1%) Device: Shamed Hypoxia (FiO2: 20.9)	N/A

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.

At rest and under exercise data from ABGA and near infrared spectroscopy will be compared under simulated altitude and shamed altitude.

Study Design

Study Type:

Interventional

Actual Enrollment :

28 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Intervention Model Description:

Including a baseline assessment and assessments under simulated altitude and normoxia.Including a baseline assessment and assessments under simulated altitude and normoxia.

Masking:

Single (Participant)

Masking Description:

The allocated gas mixture will not be disclosed to the patient since he will breath through a facemask during both interventions.

Primary Purpose:

Prevention

Official Title:

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

Actual Study Start Date :

Aug 1, 2018

Actual Primary Completion Date :

Apr 1, 2019

Actual Study Completion Date :

Apr 1, 2019

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Order air-hypoxia 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 hypoxia-air 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

Arm

Intervention/Treatment

Experimental: Order air-hypoxia

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 hypoxia-air

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

Outcome Measures

Primary Outcome Measures

arterial blood oxygenation under simulated altitude at rest (FiO2: 15.1) [2 hours]
Difference in arterial blood oxygenation under simulated altitude (FiO2: 15.1%) and shamed hypoxia (FiO2: 20.9%) at rest.
arterial blood oxygenation under simulated altitude at the time of exhaustion (FiO2: 15.1) [2 hours]
Difference in arterial blood oxygenation under simulated altitude (FiO2: 15.1%) and shamed hypoxia (FiO2: 20.9%) at the time of exhaustion

Secondary Outcome Measures

Near infrared spectroscopy under simulated altitude at rest (FiO2: 15.1) [2 hours]
Difference in cerebral tissue oxygenation and muscle tissue oxygenation under simulated altitude (FiO2: 15.1%) and shamed hypoxia (FiO2: 20.9%) at rest
Near infrared spectroscopy under simulated altitude at rest (FiO2: 15.1) [2 hours]
Difference in cerebral tissue oxygenation and muscle tissue oxygenation under simulated altitude (FiO2: 15.1%) and shamed hypoxia (FiO2: 20.9%)

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Informed consent
PH diagnosed according to internation Guidelines: mean pulmonary artery pressure (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