Approximately 2.8 million passengers flew in and out of U.S. airports per day in 2018.¹ An overhead announcement requesting medical assistance at cruising altitude presents a unique situation for any health care professional given the physically constrained, resource-limited environment. The term “in-flight medical event” is often used interchangeably with “in-flight medical emergency” and includes a spectrum of conditions, ranging from minor to serious.² There is no internationally agreed-upon recording and classification system for in-flight medical emergencies, and prevalence estimates vary between 24 and 130 emergencies per 1 million passengers.^3–5

In-flight Medical Emergency Basics

Up to 65% to 70% of in-flight medical emergencies are managed by a cabin crew without the assistance of a health care professional.^3,6 Crewmembers are trained in individual airline operating protocols, cardiopulmonary resuscitation (CPR), and the use of emergency and lifesaving equipment (e.g., automated external defibrillators [AEDs]) carried onboard.² If a crewmember requests assistance from a volunteer medical professional, the volunteer should first consider if he or she is in a suitable condition to render aid (e.g., no recent use of alcohol or sleep aids, not fatigued).² Table 1 summarizes a general approach to in-flight emergencies for volunteer medical professionals.^2,7,8 Volunteers should understand that an aircraft in flight is a medically austere environment. For example, aircraft noise may render a stethoscope ineffective for auscultating a manual blood pressure; alternative systolic blood pressure can be measured by the first palpable radial pulse when slowly releasing the pressure in the sphygmomanometer.⁷

Physicians assist in 46% to 48% of in-flight medical emergency requests^6,7; other skilled medical professionals who respond include nurses (20.1%) and emergency medical services personnel (4.4%).⁷ Medical volunteers are generally protected when providing medical care during an in-flight medical emergency on U.S. commercial aircraft by the Aviation Medical Assistance Act of 1998, which releases volunteers from liability unless there is gross negligence or willful misconduct.⁹ There is no equivalent law governing international travel; legal jurisdiction depends on the patient's and volunteer's countries of citizenship and the country in which the aircraft is registered.^8,10–13 The United States, England, and Canada do not mandate physicians to render emergency medical services in flight,^13–15 but a legal obligation to assist exists in Australia and many other European countries.^10,14 Experts in aviation medicine support the use of medical volunteers for in-flight medical emergencies because the overall personal legal risk is small.^16,17 There has yet to be a U.S. case heard in court against a physician-passenger providing medical care during an in-flight medical emergency.^10,14

Onboard Medical Equipment

The Federal Aviation Administration (FAA) has mandated that certain medical supplies be available on U.S. commercial aircraft (Table 2)¹⁸; similarly, the European Union Aviation Safety Agency and International Civil Aviation Organization have established minimum recommendations for emergency medical kit contents.^18–20 The FAA requires an AED on aircraft with at least one flight attendant and a capacity for 30 or more passengers.¹⁸ No such mandate exists for European airlines; however, many carry an AED onboard.²¹ Non-U.S. airlines may carry additional controlled substances for analgesia and sedation.^19,21 Some U.S. and international airlines have opted to expand their emergency medical kits with additional medications or equipment (Table 3).^19,22 If the desired item is not available in the kit, the flight crew can make an overhead announcement requesting the item from other passengers.