A physician passenger responds to nearly one in two in-flight medical crises, which most commonly involve fainting, respiratory problems, or nausea, according to research published this week in NEJM.

The study is one of the largest to track in-flight medical emergencies, which occur on one in every 604 flights and affect an estimated 44,000 of the 2.75 billion airline passengers each year.

• 'Is there a doctor on board?' How airlines handle medical emergencies

For the study, University of Pittsburgh Medical Center researchers examined calls made between January 2008 and October 2010 to the school's STAT-MD Communications Center, which provided remote medical assistance to five major airlines during the study period. Those airlines operated 7,198,118 flights during that time, accounting for about 10% of all airline traffic.  

What kind of emergencies happen mid-air?

Overall, there were 11,920 medical emergencies, or one for every 604 flights, the researchers found. The most common emergencies involved:

• Lightheadedness or fainting (37.4% of emergencies);
• Respiratory problems (12.1%);
• Nausea or vomiting (9.5%);
• Cardiac symptoms (7.7%); and
• Seizures (5.8%).

The least common emergencies involved:

• Laceration (0.3%);
• Cardiac arrest (0.3%);
• Ear pain (0.4%);
• Obstetrical or gynecological symptoms (0.5%); and
• Headache (1%).

Although cardiac arrest, obstetric and gynecologic problems, and strokes were among the least common emergencies, they were more likely to result in the plane's diversion and a subsequent hospitalization.

Pilots made an unscheduled landing in about 7% of cases, most often because of cardiac arrest. About 26% of passengers with in-flight emergencies were transported to the hospital upon landing, 9% were admitted, and just 0.3%—or 36 patients—died, including 31 from cardiac arrest.

Who responds to the crises?

About one in three medical emergencies is resolved while still in flight, the study found. This is likely due to the fact that in the vast majority of cases, health care providers are often on board to aid sick fliers, the researchers suggest. According to the study:

• A physician passenger responded in 48.1% of crises;
• A nurse passenger responded in 20.1% of crises; and
• An EMT passenger responded in 4.4% of crises.

Researchers: Doctors should be ready for in-flight problems

In a telephone interview with Reuters, lead author Christian Martin-Gill said that the study was designed to help health care providers who are called upon during in-flight emergencies and "rais[e] awareness to what they might encounter when flying." He urges providers to familiarize themselves with the contents of an onboard medical kit.

Martin-Gill also emphasized that doctors and nurses who aid fellow airplane passengers are protected from medical liability under a "Good Samaritan" law. He wrote in the study, "Although there is no legal obligation to intervene, we believe that physicians and other health care providers have a moral and professional obligation to act as Good Samaritans" (Beck, Wall Street Journal, 5/29; Emery, Reuters, 5/29; Marchione, AP/Miami Herald, 5/29; Szabo, USA Today, 5/29; Walsh, MedPage Today, 5/29; Martin-Gill et al., NEJM, 5/30 [subscription required]).