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Effect of Oxygen Therapy for Patients With Precapillary Pulmonary Hypertension Who Experience an Altitude Related Adverse Health Effect (ARAHE) During 30h Exposure to 2500m

Not Applicable
Completed
Conditions
Oxygen Therapy
High Altitude Pulmonary Hypertension
Interventions
Other: Oxygen Therapy
Registration Number
NCT05112172
Lead Sponsor
University of Zurich
Brief Summary

To study whether oxygen therapy titrated to maintain oxygenation (SpO2) \> 90% at 2500m would resolve altitude-related adverse health effects, symptoms and impaired exercise during 30h exposure to high altitude.

Detailed Description

Patients with pulmonary hypertension who reveal an altitude-related adverse health effects at 2500m will be given oxygen therapy by nasal cannula titrated to maintain the oxygen saturation above 90%. The study will investigate, whether this measure will restore altitude-induced impairment to baseline levels at low altitude.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
9
Inclusion Criteria
  • Informed consent as documented by signature
  • 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)

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Oxygen TherapyOxygen TherapyOxygen Therapy in patients developing an altitude related adverse health effect (ARAHE) during 30h exposure to 2500m of high altitude
Primary Outcome Measures
NameTimeMethod
Recovery from ARAHE30 hours

Proportion of patients with precapillary pulmonary hypertension experiencing an ARAHE at 2500 m of high altitude and receiving oxygen therapy titrated to achieve SpO2 ≥ 90% who recover from ARAHE, have improved symptoms and achieve constant work-rate exercise time within a minimal important difference as defined for patients with respiratory disease within 1.75 min of baseline value at 490 m; time frame within 6 h after initiation of oxygen therapy.

Secondary Outcome Measures
NameTimeMethod
Maximum work-rate in incremental ramp cycle exercise tests30 hours

Difference with oxygen therapy at high altitude vs. low altitude in maximal exercise capacity during a incremental ramp cycle exercise test

Hemodynamics30 hours

Difference with oxygen therapy at high altitude vs. low altitude in hemodynamics assessed by echocardiography at rest including pulmonary artery pressure, cardiac output, pulmonary vascular resistance and right heart function assessed as tricuspid plane systolic excursion and fractional area change.

Acute Mountain Sickness Score30 hours

Difference with oxygen therapy at high altitude vs. low altitude baseline in symptoms assessed by the Lake Louise acute mountain sickness score going from 0-12 points with mild AMS as 3-5 points, moderate AMS as 6-9 points, and severe AMS as 10-12 points.

Constant work-rate exercise time30 hours

Difference with oxygen therapy at high altitude vs. low altitude in constant work-rate exercise time cycle exercise test at 75% Wmax at low altitude

Sleep disordered breathing30 hours

Difference with oxygen therapy at high altitude vs. low altitude in sleep disordered breathing

Visual Analogue Scale30 hours

Difference with oxygen therapy at high altitude vs. low altitude baseline in symptoms assessed by the Visual Analogue Scale for dyspnoea, a 10cm line from left to right where patients have to add a cross-line with higher values meaning better feeling.

sit-to-stand test30 hours

Difference with oxygen therapy at high altitude vs. low altitude baseline in sit-to-stand test

Borg dyspnoea scale30 hours

Difference with oxygen therapy at high altitude vs. low altitude baseline in post-exercise Borg dyspnoea scale going from 1-10 scores with higher values meaning worse dyspnea

Cognitive testing30 hours

Difference with oxygen therapy at high altitude vs. low altitude baseline in cognitive function tests

6 minute walk test30 hours

Difference with oxygen therapy at high altitude vs. low altitude in 6 minute walk test

Trial Locations

Locations (1)

Respiratory Clinic, University Hospital of Zurich

🇨🇭

Zurich, Switzerland

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