Acute Exposure to High Altitude on Blood and Tissue Oxygenation (ABGA, NIRS)

Not Applicable

Completed

• Conditions: Pulmonary Hypertension
• Interventions: Other: Säntis; 2500m above sea level

• Registration Number: NCT03600415
• Lead Sponsor: University of Zurich

Brief Summary

Randomized crossover Trial in patients with Pulmonary Hypertension (PAH, CTEPH) to assess the acute response to High Altitude (2500m above sea level) on blood and tissue oxygenation (ABGA, NIRS).

Detailed Description

Low altitude baseline measurements will be performed in Zurich (460m asl) including Echocardiography, Right heart catheterization, 6MWT, pulmonary function test, clinical assessment and blood gas Analysis.

Randomly assigned to the order of testing, the participants will be tested in Low Altitude (Zurich, 470m) and at High Altitude (2500m).

At rest and under exercise data from ABGA and NIRS will be compared at low altitude and High Altitude.

Study Timeline

• Study Start: 2018-07-01
• Study First Submitted: 2018-07-09
• Study First Submitted QC: 2018-07-24
• Study First Posted: 2018-07-26
• Primary Completion: 2019-01-01
• Study Completion: 2019-01-01
• 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: mPAP ≥ 25 mmHg along with a 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 PaO2 ≤7.3 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, 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

Arm && Interventions

Group	Intervention	Description
Order A	Säntis; 2500m above sea level	The participants will be tested in Zurich (Low altitude: 470m above sea level) and consecutively at High Altitude(Säntis; 2500m above sea Level)
Order B	Säntis; 2500m above sea level	The participants will be tested at High Altitude (Säntis; 2500m above sea level) and consecutively in Zurich (Low altitude; 470m above sea level).

Primary Outcome Measures

Name	Time	Method
Arterial blood oxygenation at High Altitude (2500m above sea level)	within 5 hours	Difference in arterial blood oxygenation at Low Altitude (Zurich, 470m above sea level) and High Altitude (Säntis; 2500m above sea level)

Secondary Outcome Measures

Name	Time	Method
Near infrared spectroscopy at High Altitude (2500m)	within 5 hours	Difference in cerebral tissue oxygenation and muscle tissue oxygenation measured by near infrared spectroscopy at low Altitude (Zurich) and High Altitude (Säntis, 2500m)

Trial Locations

Locations (1)

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