As air travel has become more common, travel opportunities have increased for people with serious medical conditions. This includes passengers with lung disease who require supplemental oxygen during air travel. Commercial air carriers' policies regarding in-flight oxygen vary considerably, potentially leading to a great deal of confusion for travelers.
This topic review provides an overview of the potential effects of air travel; measures to determine who may require in-flight oxygen; and steps to help patients plan ahead so that traveling with oxygen can be achieved safely, comfortably, and relatively easily.
EFFECTS OF AIRLINE TRAVEL
Traveling by airplane exposes people to decreased air pressure and lower than normal oxygen levels. For most people, these changes are not noticeable. However, for patients with certain underlying lung conditions, small atmospheric changes can have significant and potentially severe effects.
Cabin pressure — Air pressure drops as altitude increases. Thus, as an airplane ascends, the air pressure inside the plane is reduced. Inside commercial airplanes, pressurization of the cabin limits the fall of pressure. This allows the airplane to cruise at altitudes up to 40,000 feet without exposing travelers to dangerously low levels of air pressure.
Cabin pressurization levels vary by the type of airplane. The United States Federal Aviation Administration (FAA) requires that the cabin pressure on commercial airplanes be maintained at levels equivalent to the atmospheric pressure below 8,000 feet. The FAA allows for brief drops in air pressure for safety purposes only, such as to avoid bad weather conditions. The minimum air pressure to which travelers could be exposed for short periods of time is equal to that encountered 10,000 feet above sea level.
Risks of exposure to low air pressure — The effects of increased altitude and associated reductions in air pressure can result in expansion of the air or gas trapped within the body. Trapped air or gas can be located in many different places, including:
●Tubes within the ear
●Abnormal pockets within the lung (bullae)
●The space between the outer layer of the lung and the inner layer of the chest wall; air trapped in this region is referred to as a pneumothorax
●Internal organs in the abdominal cavity
As atmospheric pressure drops, trapped air expands. This explains the "ear-popping" with which most travelers are familiar. When air is trapped in the chest, gas expansion can be life-threatening.
Low air pressure during air travel also decreases the amount of oxygen in the air. This effect is modest and generally not noticeable for healthy travelers. For patients with significant lung disease, a small decrease in available oxygen can cause significant symptoms, especially with exercise. Although air travelers usually remain sitting and are relatively inactive during flight, even modest exertion (eg, walking to lavatory) under these conditions can cause low oxygen levels in up to 80 percent of people with lung disease.
Despite the theoretical risks associated with air travel, studies indicate that medical emergencies and deaths are uncommon in people with long-standing (chronic) lung disease or pulmonary hypertension who fly. Most studies suggest that medical emergencies occur in about one in every 19,000 to 40,000 travel episodes and that deaths occur in approximately one in every 3,200,000 travel episodes.
WILL I REQUIRE IN-FLIGHT SUPPLEMENTAL OXYGEN?
Patients with diseases that can cause low oxygen levels, particularly chronic obstructive pulmonary disease (COPD), may need oxygen supplementation in-flight. This is true even if the person does not use oxygen at home.