Is There a Doctor Onboard?

By Sanjay Gupta, M.D.

As a physician who travels quite a bit, I spend a lot of time on planes listening for that dreaded "Is there a doctor onboard?" announcement. I've been called only once--for a woman who had merely fainted. But the incident made me curious about how often this kind of thing happens. I wondered what I would do if confronted with a real midair medical emergency--without access to a hospital staff and the usual emergency equipment. So when the New England Journal of Medicine last week published a study about in-flight medical events, I read it with interest. The study estimated that there are an average of 30 in-flight medical emergencies on U.S. flights every day. Most of them are not grave; fainting, dizziness and hyperventilation are the most frequent complaints. But 13% of them--roughly four a day--are serious enough to require a pilot to change course. The most common of the serious emergencies include heart trouble (46%), strokes and other neurological problems (18%), and difficulty breathing (6%).

Let's face it: plane rides are stressful. For starters, cabin pressures at high altitudes are set at roughly what they would be if you lived at 5,000 to 8,000 feet above sea level. Most people can tolerate these pressures pretty easily, but passengers with heart disease may experience chest pains as a result of the reduced amount of oxygen flowing through their blood. Low pressure can also cause the air in body cavities to expand--as much as 30%. Again, most people won't notice anything beyond mild stomach cramping. But if you've recently had an operation, your wound could open. And if a medical device has been implanted in your body--a splint, a tracheotomy tube or a catheter--it could expand and cause injury.

Another common in-flight problem is deep venous thrombosis--the so-called economy-class syndrome. When you sit too long in a cramped position, the blood in your legs tends to clot. Most people just get sore calves. But blood clots, left untreated, could travel to the lungs, causing breathing difficulties and even death. Such clots are readily pre-vented by keeping blood flowing; walk and stretch your legs when possible.

Whatever you do, don't panic. Things are looking up on the in-flight-emergency front. Doctors who come to passengers' aid used to worry about getting sued; their fears have lifted somewhat since the 1998 Aviation Medical Assistance Act gave them "good Samaritan" protection. And thanks to more recent legislation, flights with at least one attendant are starting to install emergency medical kits with automated defibrillators to treat heart attacks.

Are you still wondering if you are healthy enough to fly? If you can walk 150 ft. or climb a flight of stairs without getting winded, you'll probably do just fine. Having a doctor close by doesn't hurt, either.

Dr. Gupta is a neurosurgeon and CNN medical correspondent