Chronic obstructive pulmonary disease • 11: Fitness to fly with COPD

• Published in: Thorax Vol. 58; no. 8; pp. 729 - 732
• Main Author: Johnson, A O C
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd and British Thoracic Society 01.08.2003; BMJ Publishing Group LTD; BMJ Group
• Subjects: Aerospace Medicine; Air travel; Aircraft; Airlines; Altitude Sickness - etiology; Chronic obstructive pulmonary disease; Emergencies; Humans; Hypoxia - etiology; Oxygen; Oxygen - therapeutic use; Physical Examination; Pulmonary Disease, Chronic Obstructive - complications; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - therapy; Review Series; Risk Factors
• ISSN: 0040-6376; 1468-3296
• DOI: 10.1136/thorax.58.8.729

For reasons of aircraft weight and fuel economy, it is impractical to maintain cabin pressure at sea level pressure but international regulations do not allow cabin pressure to fall below 74 kPa (the equivalent of atmospheric pressure at 2450 m (8000 ft)) except in emergencies. 4 In practice, cabin altitude is normally maintained at about 1850 m but, according to one study, flight profiles in newer aircraft may produce cabin altitudes that are near or possibly exceed the stipulated maximum. 5 The concentration of oxygen in air is constant at 20.9% to very high altitudes (up to 90 km), so the lowest inspired oxygen pressure to which passengers should be exposed under normal flight circumstances is about 15 kPa (20.9% of the cabin pressure of 74 kPa). While the effects of acute hypoxaemia during air travel have not been fully explored, most authors consider it reasonable to choose an arbitrary level of hypoxaemia (usually Pa o 2 of 6.6 kPa) below which it is considered unsafe to fly without supplemental oxygen therapy. 8 This approach seems to work in practice to ensure safe and comfortable air travel. 11 By far the most common effect of altitude induced gas expansion is ear pain associated with poor ventilation of the middle ear.