Patients With Pulmonary Hypertension or Interstitial Lung Disease at Altitude - Effect of Oxygen on Breathing and Sleep

Phase 4

• Conditions: Precapillary Pulmonary Hypertension; Interstitial Lung Disease
• Interventions: Behavioral: Moderate altitude sojourn; Behavioral: Low altitude sojourn; Drug: Oxygen; Drug: Sham oxygen (room air)

• Registration Number: NCT02150616
• Lead Sponsor: University of Zurich

Brief Summary

The purpose of this study is to investigate the effect of travelling to moderate altitude and of nocturnal oxygen therapy during a stay at moderate altitude on breathing and sleep of patients with pulmonary hypertension or with interstitial lung disease.

Detailed Description

Patients with pulmonary hypertension or with interstitial lung disease living below 800 m will be invited to participate in a randomized, cross-over field trial evaluating the hypotheses that: a), breathing and sleep during a 2 day sojourn at moderate altitude are impaired in comparison to low altitude; b), breathing and sleep during a 2 day sojourn at moderate altitude are improved by nocturnal oxygen therapy compared to room air (sham oxygen) administered during nights at altitude. Outcomes will be assessed at low altitude (Zurich, 490 m, baseline), and during 2 study periods of 2 days each spent at moderate altitude (St. Moritz Salastrains, 2048 m), separated by a wash-out period of at least 2 weeks spent at low altitude (\<800 m). The order of stays at the different altitudes and of the treatments will be randomized.

Study Timeline

• Study Start: 2014-05
• Study First Submitted: 2014-05-18
• Study First Submitted QC: 2014-05-27
• Study First Posted: 2014-05-30
• Status Verified: 2020-01
• Last Update Submitted: 2020-02-05
• Last Update Posted: 2020-02-06
• Primary Completion: 2020-12
• Study Completion: 2020-12

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

• Precapillary pulmonary hypertension, or interstitial lung disease.
• New York Heart Association class 2-3.
• Residence at low altitude (<800m).

Exclusion Criteria

• Unstable or exacerbated condition
• Very severe pulmonary hypertension or interstitial lung disease, New York Heart Association class 4
• requirement for oxygen therapy at low altitude residence
• hypoventilation
• more than mild or unstable cardiovascular disease
• use of drugs that affect respiratory center drive
• internal, neurologic or psychiatric disease that interfere with protocol compliance including current heavy smoking (>20 cigarettes per day), inability to perform 6 min walk test.
• previous intolerance to moderate altitude (<2600m).
• Exposure to altitudes >1500m for >2 days within the last 4 weeks before the study.
• Pregnant or nursing patients

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Moderate altitude sojourn	Moderate altitude sojourn	Sojourn at moderate altitude (2048 m)
Moderate altitude sojourn	Low altitude sojourn	Sojourn at moderate altitude (2048 m)
Moderate altitude sojourn	Sham oxygen (room air)	Sojourn at moderate altitude (2048 m)
Low altitude sojourn	Sham oxygen (room air)	Sojourn at low altitude (490 m, baseline)
Sham oxygen (room air)	Moderate altitude sojourn	Sham oxygen (room air) administration via a nasal cannula at a rate of 3 L/min during nights
Low altitude sojourn	Moderate altitude sojourn	Sojourn at low altitude (490 m, baseline)
Low altitude sojourn	Low altitude sojourn	Sojourn at low altitude (490 m, baseline)
Oxygen	Sham oxygen (room air)	Oxygen administration via a nasal cannula at a rate of 3 L/min during nights spent at 2048 m
Sham oxygen (room air)	Low altitude sojourn	Sham oxygen (room air) administration via a nasal cannula at a rate of 3 L/min during nights
Sham oxygen (room air)	Sham oxygen (room air)	Sham oxygen (room air) administration via a nasal cannula at a rate of 3 L/min during nights
Low altitude sojourn	Oxygen	Sojourn at low altitude (490 m, baseline)
Oxygen	Moderate altitude sojourn	Oxygen administration via a nasal cannula at a rate of 3 L/min during nights spent at 2048 m
Oxygen	Low altitude sojourn	Oxygen administration via a nasal cannula at a rate of 3 L/min during nights spent at 2048 m
Moderate altitude sojourn	Oxygen	Sojourn at moderate altitude (2048 m)
Oxygen	Oxygen	Oxygen administration via a nasal cannula at a rate of 3 L/min during nights spent at 2048 m
Sham oxygen (room air)	Oxygen	Sham oxygen (room air) administration via a nasal cannula at a rate of 3 L/min during nights

Primary Outcome Measures

Name	Time	Method
Apnea/hypopnea index measured by polysomnography	Approximately 8 hours (during the first night at 2048 m)	Difference in apnea/hypopnea index between measurements at 2048 m (altitude) and 490 m (baseline); and between the oxygen and sham oxygen treatment periods at 2048 m.
Mean nocturnal oxygen saturation measured by pulse oximetry	Approximately 8 hours (during the first night at 2048 m)	Difference in mean nocturnal oxygen saturation between measurements at 2048 m (altitude) and 490 m (baseline); and between the oxygen and sham oxygen treatment periods at 2048 m.

Secondary Outcome Measures

Name	Time	Method
Severe hypoxemia	Approximately 72 hours, Day 1 to 3 at 2048 m	Number of participants in whom arterial oxygen saturation measured by pulse oximetry is less than 75% for more than 30 min during the sojourn at 2048 m (altitude) and 490 m (baseline); and during the oxygen and sham oxygen treatment periods at 2048 m.
Subjective sleep quality visual analog scale score	Approximately 8 hours (during the second night at 2048 m)	Difference in subjective sleep quality between visual analog scale measurements at 2048 m (altitude) and 490 m (baseline); and between the oxygen and sham oxygen treatment periods at 2048 m.
Apnea/hypopnea index measured by polygraphy	Approximately 8 hours (during the second night at 2048 m)	Difference in apnea/hypopnea index between measurements at 2048 m (altitude) and 490 m (baseline); and between the oxygen and sham oxygen treatment periods at 2048 m.
Mean nocturnal oxygen saturation measured by pulse oximetry	Approximately 8 hours (during the second night at 2048 m)	Difference in mean nocturnal oxygen saturation between measurements at 2048 m (altitude) and 490 m (baseline); and between the oxygen and sham oxygen treatment periods at 2048 m.
Sleep quality visual analog scale score	Approximately 8 hours (during the first night at 2048 m)	Difference in subjective sleep quality between visual analog scale measurements at 2048 m (altitude) and 490 m (baseline); and between the oxygen and sham oxygen treatment periods at 2048 m.
Psychomotor vigilance test reaction time	Approximately at 10 a.m. on the second day at 2048 m	Difference in reaction time between measurements at 2048 m (altitude) and 490 m (baseline); and between the oxygen and sham oxygen treatment periods at 2048 m.

Trial Locations

Locations (1)

University Hospital Zurich, Pulmonary Division; 🇨🇭 Zurich, Switzerland