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

Not Applicable

Completed

• Conditions: Pulmonary Hypertension

• Registration Number: NCT03637114
• Lead Sponsor: University of Zurich

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.

Study Timeline

• Study First Submitted: 2018-07-09
• Study Start: 2018-08-01
• Study First Submitted QC: 2018-08-16
• Study First Posted: 2018-08-17
• Primary Completion: 2019-04-01
• Study Completion: 2019-04-01
• Status Verified: 2020-01
• Last Update Submitted: 2020-01-06
• Last Update Posted: 2020-01-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 28

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
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

Name	Time	Method
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%)

Trial Locations

Locations (1)

Respiratory Clinic, University Hospital of Zurich; 🇨🇭 Zurich, Switzerland