By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic Medicine

YOUNGER AGE AND ATHELETIC TRAINING RISK FACTORS FOR AIR TRAVELER’S THROMBOSIS

Question: A friend of mine got a blood clot in her leg after flying home from Europe. She said it was “Economy Class Syndrome.” Exactly what is this, and do I need to worry about it since I am flying business class? My friend is overweight, but I run daily and do 10K marathons. I have never heard of this before. Is it a new condition?

Answer: Economy Class Syndrome is the development of blood clots in the legs during long flights. These blood clots are referred to as deep vein thrombosis (DVT) in medical jargon. After a person develops DVT, a piece of a blood clot can break off and travel to the pulmonary blood vessels in the lungs. This is called a pulmonary embolism and can cause sudden death.

DVT leading to pulmonary embolism is not a new problem. During World War II, a dramatic increase in pulmonary emboli was noted in London air raid shelters, and this was traced to people sitting all night in deck chairs. In the early 1950s, a similar association was noted in air travelers as well as car travelers.

It was in 1977 that the term “economy class syndrome” was first used to describe this problem, probably because of the especially cramped nature of economy class seats and the greater difficulty one has in doing leg exercises in flight. Let me assure you, though, that this syndrome is not limited to “the cheap seats” and can happen to anyone -- even a first-class passenger -- on a long flight. In fact, a recent study of more than 800 passengers on flights of at least four hours’ duration found that nine people developed what’s now being called “air traveler’s thrombosis” -- and two of these were in business class.

There are many known risk factors for the development of DVT in the general population. These include previous history of DVT, cancer, diabetes, obesity and heart trouble. Pregnancy or use of oral contraceptives also are risk factors. One additional risk factor for air traveler’s thrombosis may surprise you -- superb athletic training, especially long distance runners. This is because athletes who are in excellent condition have a very slow resting heart rate, which makes them prone to blood pooling in the legs during long flights.

Other known risk factors include recent surgery or injury. Such events in your life should be a reason to postpone long air flights -- or car trips, for that matter -- for at least 30 days. Finally, age is a risk factor as well. While older people are more prone to blood clots in the general population, surprisingly it’s younger people who seem to have more DVT from prolonged travel.

Here are some things to do when you travel by air, especially if your flight is more than four continuous hours. Exercise your legs every fifteen minutes. This helps to prevent blood pooling in the lower legs -- the most common site for blood clots. Don’t cross your legs. Avoid sleeping. This is very hard for many people, but if you are asleep sitting up, you are not moving your legs. Drink plenty of fluids, but electrolyte solution is preferable to water. Avoid drinking alcohol. Finally, if possible, get up and walk around frequently.

If you are at risk, talk with your physician several weeks prior to travel about the use of compression stockings and/or medications to decrease blood clotting.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.