Commercial aircraft have a hypoxic environment, equivalent to an altitude of 2,438 m (8,000 ft) above sea level.
Normal subjects and the majority of respiratory patients can tolerate this without symptoms. In practice, medical diversions for respiratory problems are very rare.
The tendency of individual patients to become hypoxic in these conditions cannot be predicted with accuracy from sea-level oxygen saturation or spirometry.
Hypoxic challenge may be used to simulate the inflight environment, to predict hypoxaemia and to assess the effectiveness of inflight oxygen.
Most airlines, with adequate warning, can provide oxygen at 2 or 4 litres per minute for respiratory patients.
While it may be possible to predict hypoxia during flight, there are no means of predicting symptoms or actual risk of harm during air travel.
To identify the potential problems that patients with chronic respiratory conditions may encounter during air travel.
To recognise that guidelines have been developed from a number of sources to assist doctors involved in assessing a patient who is considering air travel.
To make clinicians aware of the different methods of hypoxic challenge that have been developed to help with the clinical assessment of patients.
To highlight that many patients with chronic lung disease are capable of air travel without developing significant hypoxia, but to raise awareness about which patients are likely to be at risk.
To discuss the potential difficulties that may arise for the patient when they are arranging inflight oxygen.
Summary Doctors are frequently asked by patients with chronic lung disease if they are fit to fly. As commercial flights are not pressurised to sea level, there is a reduction in partial pressure of oxygen (PO2), which may result in significant hypoxia in otherwise asymptomatic patients.
A number of different assessment methods have been developed to assess flight fitness and several professional organisations have developed guidelines to help doctors give informed advice.
Patients who become significantly hypoxic during a flight assessment may still be able to travel with supplemental oxygen. However, the provision of supplemental oxygen is dependent on individual airline policy and considerable variations in policy have been recorded.
This review aims to give a brief overview of air travel for patients with lung disease, including physiology, guidelines, assessing fitness to fly and oxygen supplementation.
- ©ERS 2006
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