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

• ClinicalTrials.gov Identifier: NCT03600415
• Recruitment Status: Completed
• First Posted: July 26, 2018
• Last Update Posted: January 7, 2020
• Sponsor: University of Zurich
• Information provided by (Responsible Party): University of Zurich

Study Description

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).

Condition or disease	Intervention/treatment	Phase
Pulmonary Hypertension	Other: Low altitude: 470m above sea level; Other: Säntis; 2500m above sea level	Not Applicable

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 Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 28 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Intervention Model Description: Including a baseline assessment and assessments at Low altitude and High altitude
• Masking: None (Open Label)
• Primary Purpose: Prevention
• Official Title: Acute Exposure to Hypoxia in Precapillary Pulmonary Hypertension: Physiological and Clinical Effects at Rest and During Exercise
• Actual Study Start Date: July 1, 2018
• Actual Primary Completion Date: January 1, 2019
• Actual Study Completion Date: January 1, 2019

Arms and Interventions

Arm	Intervention/treatment
Experimental: Order A; The participants will be tested in Zurich (Low altitude: 470m above sea level) and consecutively at High Altitude(Säntis; 2500m above sea Level)	Other: Low altitude: 470m above sea level; Assessment at Low Altitude (in Zurich; 470m above sea level) in order to compare this data with High altitude exposure; Other: Säntis; 2500m above sea level; Exposure to High Altitude (Säntis; 2500m above sea level) for approximately 5 hours
Experimental: Order B; The participants will be tested at High Altitude (Säntis; 2500m above sea level) and consecutively in Zurich (Low altitude; 470m above sea level).	Other: Low altitude: 470m above sea level; Assessment at Low Altitude (in Zurich; 470m above sea level) in order to compare this data with High altitude exposure; Other: Säntis; 2500m above sea level; Exposure to High Altitude (Säntis; 2500m above sea level) for approximately 5 hours

Outcome Measures

Primary Outcome Measures :

1. Arterial blood oxygenation at High Altitude (2500m above sea level) [ Time Frame: 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 :

1. Near infrared spectroscopy at High Altitude (2500m) [ Time Frame: 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)

Eligibility Criteria

• Ages Eligible for Study: 18 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Criteria

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

Contacts and Locations

Locations

Switzerland

Respiratory Clinic, University Hospital of Zurich

Zurich, Switzerland, 8091

Sponsors and Collaborators

University of Zurich

Investigators

• Principal Investigator: Silvia Ulrich, Prof.; University of Zurich

More Information

• Responsible Party: University of Zurich
• ClinicalTrials.gov Identifier: NCT03600415
• Other Study ID Numbers: 2018-00455_B5
• First Posted: July 26, 2018
• Last Update Posted: January 7, 2020
• Last Verified: January 2020

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

Keywords provided by University of Zurich:

High Altitude; arterial blood gas analysis; near infrared spectroscopy

Additional relevant MeSH terms:

Hypertension, Pulmonary; Hypertension; Vascular Diseases; Cardiovascular Diseases; Lung Diseases; Respiratory Tract Diseases