Nocturnal Oxygenation and Sleep-related Breathing Disorders During the First Night of a Stay at 2500m of High Altitude in Patients With Precapillary Pulmonary Hypertension

Study Overview
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Brief Summary
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The impact of hypoxia at 2500m of high altitude on sleep in patients with precapillary pulmonary hypertension

Official Title
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The Impact of Hypoxia on Patients With Precapillary Pulmonary Hypertension and Treatment of Adverse Effects

Conditions
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High Altitude Pulmonary Hypertension, Sleep

Intervention / Treatment
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* Procedure: Nocturnal rest (sleep study)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent as documented by signature (Appendix Informed Consent Form) PH class I (PAH) or IV (CTEPH) diagnosed according to guidelines: mean pulmonary artery pressure >20 mmHg, pulmonary vascular resistance ≥3 wood units, pulmonary arterial wedge pressure ≤15 mmHg during baseline measures at the diagnostic right-heart catheterization Exclusion Criteria: resting partial pressure of oxygen <8 kilopascal at Zurich at 490 m low altitude exposure to an altitude >1000 m for ≥3 nights during the last 2 weeks before the study inability to follow the procedures of the study other clinically significant concomitant end-stage disease (e.g., renal failure, hepatic dysfunction)

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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Design Details

Primary Purpose: Screening
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High altitude 2500 m above sea level<br> | Procedure: Nocturnal rest (sleep study)<br>* Proportion of patients free of severe hypoxemia without oxygen therapy during nocturnal rest .<br>|
| Active Comparator: Low altitude 470 m above sea level<br> | Procedure: Nocturnal rest (sleep study)<br>* Proportion of patients free of severe hypoxemia without oxygen therapy during nocturnal rest .<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of patients free of severe hypoxemia | Proportion of patients free of severe hypoxemia (defined as oxygenation (SpO2)<80% for >30 min) without oxygen therapy during nocturnal rest at 2500 m vs. 490 m | 30 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nocturnal oxygenation | Difference in mean nocturnal oxygenation (SpO2) 2500 m of high altitude vs 490 m low altitude | 30 hours | 
| Oxygen desaturation index | Difference in oxygen desaturation index sleeping at 2500 m high altitude vs 490 m low altitude | 30 hours | 
| Periodic breathing | Difference in time spent with periodic breathing in patients sleeping at 2500 m of high altitude vs 490 m low altitude | 30 hours | 
| Nocturnal transcutaneous carbon dioxide tension | Difference in nocturnal transcutaneous carbon dioxide tension in patients sleeping at 2500 m of high altitude vs 490 m low altitude | 30 hours | 
| Visual Analogue Scale | Subjective sleep quality Visual Analogue Scale score 2500 m high altitude vs 490 m low altitude | 30 hours | 
| Time spent awake during the night | Subjective time spent awake during the night high altitude vs 490 m low altitude | 30 hours | 
| Cerebral tissue deoxygenation | Proportion of patients free of severe cerebral tissue deoxygenation (drop in cerebral tissue oxygen saturation >5%) without oxygen therapy during a night at 2500 vs. 490 m | 30 hours | 
| Cerebral tissue oxygen saturation awake | Difference in cerebral tissue oxygen saturation awake in patients with precapillary pulmonary hypertension at 2500m of high altitude without supplemental oxygen vs. low altitude | 30 hours | 
| Cerebral tissue oxygen saturation during sleep without oxygen | Difference in cerebral tissue oxygen saturation during sleep in patients with precapillary pulmonary hypertension at 2500m of high altitude without supplemental oxygen | 30 hours | 
| Cerebral tissue oxygen saturation during sleep with oxygen | Difference in cerebral tissue oxygen saturation during sleep in patients with precapillary pulmonary hypertension at 2500m of high altitude with supplemental oxygen | 30 hours | 
| Cerebral oxygen desaturation index without oxygen | Difference in the cerebral oxygen desaturation index in patients with precapillary pulmonary hypertension at 2500m of high altitude without supplemental oxygen vs. low altitude | 30 hours | 
| Cerebral oxygen desaturation index with oxygen | Difference in the cerebral oxygen desaturation index in patients with precapillary pulmonary hypertension at 2500m of high altitude under supplemental oxygen. | 30 hours | 
| Cerebral tissue oxygen saturation between different sleep stages | Changes in the cerebral tissue oxygen saturation between different sleep stages at 2500 m compared to low altitude. | 30 hours |