In-flight medical emergencies (IMEs) are common and occur in a complex environment with limited medical resources.
Estimated prevalence is one in 604 flights.
Estimates range from 24-130 in-flight emergencies per 1 million passengers.
This estimate is likely low because many minor incidents do not result in consultations.
Approximately 4 billion commercial airline passengers travel worldwide annually, and it is possible that 260-1420 in-flight emergencies occur daily worldwide.
Syncope or near syncope is the most common in-flight emergency at almost 33%.
The most common IMEs involve syncope or near-syncope (32.7%) and gastrointestinal (14.8%), respiratory (10.1%), and cardiovascular (7.0%) symptoms.
The most common IMEs involve syncope or near-syncope (32.7%) and gastrointestinal (14.8%), respiratory (10.1%), and cardiovascular (7.0%) symptoms.
Other common conditions include gastrointestinal, respiratory, and cardiovascular symptoms.
In-flight cardiac arrest is rare accounting for 0.2% of in-flight emergencies.
Flight diversion occurs in about 4.4% of in-flight emergencies.
Commercial aircraft flying at an altitude of 30,000-40,000 feet and passenger cabin is pressurized to12 psi-11 psi, which is equivalent to being at an altitude of 5000-8000 feet.
Pressurization leads to the expansion of closed gas containing spaces in the body such as sinuses and middle ear and nonphysiological gas collections such as pneumothorax or following gastrointestinal, ocular, or intracranial surgery.
At 8000 feet of altitude the volume of gas in an enclosed space increases by approximately 30%, and may trigger discomfort in patients especially in those with upper respiratory tract inflammation or infection, including sinusitis or otitis media.
Aircraft cabin has a lower partial pressure of oxygen at altitude with resulting in mild hypoxia decreasing mean arterial oxygen saturation from 97% to 93% in healthy passengers.
Passages with hypoxemia or respiratory insufficiency and baseline may benefit from supplemental oxygen at cruising altitude.
The use of portable oxygen concentrator during a flight requires approval by the airline, physician certification, and sufficient battery life, all coordinated at least 48 hours prior to the flight.
Air travel and venous thromboembolism occur due to prolonged sitting and hypoxia triggering decreased venous flow, systemic inflammation, and platelet activation.
The risk of lower limb venous thrombosis in high-risk patients maybe up to 5% per flight, and symptom of venous thromboembolism may occur in up to 10% of passages on flights of long duration.
Cabin air drawing from an outside dry environment at altitude and pressurized and dehumidified by cycling through the engine compartment may contribute to dehydration of passengers.
Recycling away or may expose passengers to allergens.
The enclosed and limited space environment of aircraft raises concerns of transmission of communicable diseases, although pre-existing exposure is a more common source of infection.
The Federal Aviation Administration requires an automated external defibrillator in all airplanes with a maximum payload capacity of more than 7500 pounds and at least one flight attendant.
The FAA requires a medical kit to include medications for mild pain, allergic reactions, bronchoconstriction, hypoglycemia, dehydration, and some cardiac conditions.
Commonly medical kits include a glucometer, urinary catheter, medications for nausea, medications for moderate to severe pain, seizures, and additional cardiac indications.
Controlled substances are not commonly available in US airline medical kits.
Aircraft carry oxygen bottles for short term use during certain depressurization.
Ground based medical support is available through radio or satellite telephone communications.
Medical volunteers are frequently sought by airline personnel, and they are protected by Good Samaritan laws.
Health care personnel are often asked to assist affected passengers and the flight team, and many have limited experience in this environment.