Effect of Normobaric Hypoxia and Hyperoxia in Patients With Pulmonary Hypertension

Study Overview
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Brief Summary
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Pulmonary Hypertension (PH) is a severe disease with a bad prognosis. However, thanks to extensive research in this field, there are more and better treatment options that allow patients to participate in recreational activities at moderate altitude or bring up the question of air-travel. Still very few is known about the effects hypoxic conditions have on PH patients. The aim of this study is to investigate the effects of hypoxia in comparison to normoxia and hyperoxia on pulmonary hemodynamics in patients with pulmonary hypertension during routine right heart catheterisation. We aim to get insight into the pathophysiology of pulmonary hemodynamics under hypoxic conditions in comparison to normoxia and hyperoxia in patients with pulmonary arterial and chronic thromboembolic pulmonary hypertension compared with control patients, that are scheduled for right heart catheterisation due to dyspnea but have no PH.

Official Title
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Effect of Normobaric Hypoxia and Hyperoxia on Pulmonary Hemodynamics in Patients With Pulmonary Hypertension

Conditions
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Pulmonary Hypertension

Intervention / Treatment
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* Other: Hypoxia and Hyperoxia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: clinically indicated right heart catheterisation diagnosis of pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension or control without pulmonary hypertension Exclusion Criteria: hemodynamically unstable partial pressure of Oxygen < 7.3kPa no informed consent pulmonary hypertension due to left heart disease, chronic lung disease or miscellaneous (Groups II, III and V) according to Galié ERJ 2015

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| PH-Patients<br>Patients with mean pulmonary artery pressure >25mmHg and a pulmonary arterial wedge pressure <15mmHg during right heart catheterisation, which are diagnosed as having pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension. | Other: Hypoxia and Hyperoxia<br>* 10 minutes of breathing a gas mixture with FiO2 0.16 via a tight fitting mask. After 10 minutes of breathing ambient air (normoxia), patients were exposed to hyperoxia (FiO2 1.0) for 10 minutes.<br>|
| Control group<br>Patients with clinically indicated right heart catheterisation (because of dyspnea or other signs of PH), but had no PH (no elevated mean pulmonary artery pressure (mPAP <20mmHg)). | Other: Hypoxia and Hyperoxia<br>* 10 minutes of breathing a gas mixture with FiO2 0.16 via a tight fitting mask. After 10 minutes of breathing ambient air (normoxia), patients were exposed to hyperoxia (FiO2 1.0) for 10 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of pulmonary vascular resistance during hypoxia in comparison to normoxia and hyperoxia |  | Day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change of mean pulmonary artery pressure under hyperoxia in comparison to normoxia and hyperoxia |  | Day 1 | 
| change of the cardiac output under hyperoxia in comparison to normoxia and hyperoxia |  | Day 1 | 
| change of the partial pressure of carbon dioxide under hyperoxia in comparison to normoxia and hyperoxia |  | Day 1 | 
| change of the partial pressure of oxygen under hyperoxia in comparison to normoxia and hyperoxia |  | Day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pulmonary arterial hypertension, Chronic thromboembolic pulmonary hypertension, Hypoxia, Hyperoxia