Study of the Effects of Commercial Air Travel on the Lungs

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01420224
Recruitment Status : Completed
First Posted : August 19, 2011
Last Update Posted : August 19, 2011
Information provided by:
University of Oxford

Brief Summary:
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 or disease Intervention/treatment
Healthy Volunteers Chuvash Polycythaemia Other: Commercial airline 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.

Study Type : Observational
Actual Enrollment : 9 participants
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
Study Start Date : May 2011
Actual Primary Completion Date : June 2011
Actual Study Completion Date : June 2011

Resource links provided by the National Library of Medicine

Group/Cohort Intervention/treatment
Healthy volunteers Other: Commercial airline flight
Normal scheduled passenger flight

Chuvash polycythaemia Other: Commercial airline flight
Normal scheduled passenger flight

Primary Outcome Measures :
  1. 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.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): 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

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
First Posted: August 19, 2011    Key Record Dates
Last Update Posted: August 19, 2011
Last Verified: August 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