This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Study of the Effects of Commercial Air Travel on the Lungs

This study has been completed.
Information provided by:
University of Oxford Identifier:
First received: August 18, 2011
Last updated: NA
Last verified: August 2011
History: No changes posted
The study hypothesis is that commercial air travel causes an increase in the blood pressure in the lungs (pulmonary artery pressure) that can be clinically relevant. Portable echocardiography (heart ultrasound) now offers a non-invasive means of studying this in-flight.

Condition Intervention
Healthy Volunteers Chuvash Polycythaemia Other: Commercial airline flight

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Study of the Effects of Commercial Air Travel on Pulmonary Artery Pressure in Healthy Passengers and in a Patient With Chuvash Polycythaemia

Resource links provided by NLM:

Further study details as provided by University of Oxford:

Primary Outcome Measures:
  • Systolic pulmonary artery pressure [ Time Frame: In-flight ]
    The primary outcome measure is the effect of commercial air travel on systolic pulmonary artery pressure assessed by in-flight portable Doppler echocardiography.

Enrollment: 9
Study Start Date: May 2011
Study Completion Date: June 2011
Primary Completion Date: June 2011 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Healthy volunteers Other: Commercial airline flight
Normal scheduled passenger flight
Chuvash polycythaemia Other: Commercial airline flight
Normal scheduled passenger flight

Detailed Description:

In a commercial airliner flying at high altitude, the reduced cabin air pressure means that all passengers are exposed to slightly lowered oxygen levels ('hypoxia') equivalent to an altitude of approximately 5,000 to 8,000 ft. Although mild, this hypoxia is sufficient to stimulate some of the body's protective responses (eg changes in breathing and in hormonal secretion) and can be dangerous for passengers with heart or lung disease, who must breathe supplementary oxygen in-flight or may even be prohibited from flying because of the risks of hypoxia.

It is well known that severe hypoxia results in constriction of blood vessels in the lungs (a phenomenon called hypoxic pulmonary vasoconstriction), which in turn causes an increase in the blood pressure in the lungs ('pulmonary arterial pressure'). Unlike other physiological responses to hypoxia, this is often harmful and frequently leads to pulmonary hypertension and right heart failure (eg in some lung diseases and at high altitude). Even a modest increase in pulmonary arterial pressure could be clinically important in some airline passengers with heart/lung disease, as it may exacerbate their condition. However, it is not known whether the mild hypoxia experienced in an aircraft cabin is able to cause an increase in pulmonary artery pressure. Limited evidence suggests that it might - for example, there have been reports of passengers acutely developing new right heart failure in-flight, and data from animal studies also support this possibility.

This study aims to establish the effect of mild aircraft cabin hypoxia on pulmonary arterial pressure in healthy passengers and also in a patient with Chuvash polycythaemia. In this rare genetic disease, cellular responses to hypoxia are 'switched on' to some extent even during normoxia, causing increased red blood cell production. Affected individuals usually present with symptoms of polycythaemia in early adulthood and are typically asymptomatic following treatment with therapeutic venesection. Importantly, affected individuals have exaggerated acute hypoxic pulmonary vasoconstriction which may place them at risk of pulmonary hypertensive responses during air travel.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Patient with Chuvash polycythaemia recruited from previous study participants with the disease.

For healthy volunteers:

Inclusion Criteria:

  • suitable for echocardiographic measurements
  • in good health

Exclusion Criteria:

  • any significant medical condition

For patient with Chuvash polycythaemia:

Inclusion Criteria:

  • diagnosis of Chuvash polycythaemia
  • suitable for echocardiographic measurements

Exclusion Criteria:

  • any other significant medical condition
  • pulmonary hypertension
  • uncontrolled erythrocytosis
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01420224

United Kingdom
University of Oxford
Oxford, United Kingdom, OX13PT
Sponsors and Collaborators
University of Oxford
Principal Investigator: Thomas Smith, MBBS DPhil FRCA University of Oxford
  More Information

Responsible Party: Ms Heather House, Head of Clinical Trials and Research Governance, University of Oxford Identifier: NCT01420224     History of Changes
Other Study ID Numbers: Oxford in-flight 2011
Study First Received: August 18, 2011
Last Updated: August 18, 2011

Keywords provided by University of Oxford:
Air travel
Aircraft cabin hypoxia
Pulmonary artery pressure
Hypoxic pulmonary vasoconstriction
Pulmonary hypertension

Additional relevant MeSH terms:
Hematologic Diseases processed this record on September 21, 2017