Study of the Effects of Commercial Air Travel on the Lungs

Healthy Volunteers Clinical Trial

Official title:

Study of the Effects of Commercial Air Travel on Pulmonary Artery Pressure in Healthy Passengers and in a Patient With Chuvash Polycythaemia

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01420224
• Other study ID #: Oxford in-flight 2011
• Status: Completed
• Phase: N/A
• First received: August 18, 2011
• Last updated: August 18, 2011
• Start date: May 2011
• Est. completion date: June 2011

Study information

• Verified date: August 2011
• Source: University of Oxford
• Contact: n/a
• Is FDA regulated: No
• Health authority: United Kingdom: Research Ethics Committee
• Study type: Observational

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 9
• Est. completion date: June 2011
• Est. primary completion date: June 2011
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years and older

Eligibility

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

Study Design

Time Perspective: Prospective

Related Conditions & MeSH terms

• Chuvash Polycythaemia
• Healthy Volunteers
• Polycythemia

Intervention

Other:
• Commercial airline flight
Normal scheduled passenger flight

Locations

Country	Name	City	State
United Kingdom	University of Oxford	Oxford

Sponsors (1)

Lead Sponsor	Collaborator
University of Oxford

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Systolic pulmonary artery pressure	The primary outcome measure is the effect of commercial air travel on systolic pulmonary artery pressure assessed by in-flight portable Doppler echocardiography.	In-flight	Yes