Why might air travel be a concern for patients with respiratory illnesses?
Air travel poses three main challenges for patients with respiratory illnesses. The first is the hypobaric environment, commercial aircraft are routinely pressurised to 8000 ft (2438m). At this altitude, the partial pressure of oxygen equates to 15.1% oxygen at sea level. In healthy seated passengers, PaO2 falls to 8.0-10.0 kPa and may fall further if exercising or asleep. The normal response to this is mild to moderate hyperventilation, a fall in PaCO2, and moderate tachycardia. Exposure to cabin altitude worsens pre-existing hypoxemia and is a particular challenge for those requiring oxygen at sea level.
The second is immobility from overcrowding, which can confer a risk of venous thromboembolism (VTE) and exposure to respiratory infections.
The third challenge is reduced cabin pressure causing expansion (by 38%) of saturated air within cavities. This is a particular concern for patients with a closed pneumothorax or non-communicating bulla.
What practical advice can clinicians give to a respiratory patient who wishes to travel by plane?
Most patients with well-controlled, stable conditions and no other illnesses should be able to travel safely on commercial flights.
Patients with more severe or unstable conditions, including those recently in hospital for a respiratory illness and/or exacerbation, should consult their respiratory specialist well beforehand to allow time for any specialist assessments required, and discussion with the airline.
Patients with highly contagious infections including tuberculosis (TB) should not travel until they are considered non-infectious.
Additional risk factors for VTE include malignancy and previous VTE, these patients should consult their primary care practitioner or hospital specialist for advice before travelling.
Patients should carry all medications including spacer devices in hand luggage to lessen the impact of lost hold baggage. Emergency medications, including inhalers, spacers and epinephrine auto-injectors must be readily available. Patients with severe or complex respiratory conditions should take copies (digital or paper) of their management plan, medications, and/or relevant clinic letters.
What are the recommendations around air travel and portable oxygen concentrators? Do all airlines permit their use?
Airlines will have their own regulations regarding medical oxygen so it is vital to check with the airline before flying. Many but not all permit the use of portable oxygen concentrators (POCs) and publish a list of approved devices. Patients requiring oxygen for overseas travel usually need to lease a POC privately this is because UK companies generally do not allow equipment provided through the NHS to be taken abroad. Some airlines supply medical oxygen for a fee, which can vary widely.
Patients need to inform the airline beforehand that they will bring a POC and ensure they have enough battery power for the flight, including any delays. Spare batteries must be correctly packaged and carried in cabin baggage. Patients and their respiratory healthcare professional need to complete an airline Medical Information Form (MEDIF) beforehand.
Where can clinicians and patients go to find further advice or information?
The following documents and websites provide advice, information and support:
BTS Clinical Statement on air travel for passengers with respiratory disease