Pulmonary Hypertension
Conditions
Keywords
Simulated altitude, arterial blood gas analysis, near infrared spectroscopy
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)
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.
Interventions
Inhalation of deoxygenated air through a altitude simulator (Altitrainer), for approx. 1 hour. given by a facemask.
Inhalation of unmodified air through an altitude Simulator (Altitrainer) for approximately 1 hour given by a facemask
Sponsors
University of Zurich
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
SINGLE (Subject)
Masking description
The allocated gas mixture will not be disclosed to the patient since he will breath through a facemask during both interventions.
Intervention model description
Including a baseline assessment and assessments under simulated altitude and normoxia.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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 |
Countries
Switzerland
Outcome results
None listed