April 01, 1998
Meetings & Conventions: Planner's Portfolio April 1998 Current Issue
April 1998 On TravelPLANNER'S PORTFOLIO:

On Travel


Don't Just Sit There

Flying can trigger life-threatening blood clots; are you at risk?

If you're the traveling equivalent of a couch potato hunkered down in an airplane or car for hours on end the consequences can be far more serious than a crick in your neck, swollen ankles or an aching back. They can be life threatening.

A number of medical studies have found that those who sit for extended periods of time, whether in an airplane seat or at a desk, may develop blood clots in the lower leg. A study released last October, conducted by doctors at the Pasteur Hospital in Nice, France, looked at 160 patients with documented clotting, known as deep venous thrombosis (DVT), and compared their recent travel histories with those of a control group. Of those with DVT, 48 had flown recently; only 16 of 160 people in the control group had traveled.

The study concluded that extended travel is a real risk factor for DVT. And it doesn't take a flight from L.A. to Africa to cause the condition. Stanley R. Mohler, M.D., director of aerospace medicine at Wright State University in Dayton, Ohio, says DVT can develop during flights as short as three hours.

The condition results when sitting causes blood to pool in the deep leg veins, where clots can form and break off. The clots enter the bloodstream and can travel to the lungs. The longer you sit without moving, the larger the clots may be, and the more serious the results stroke, coronary artery blockage, circulation problems, even death.

Should you be worried? A 1996 clinical study puts the incidence of DVT at one per 1,000 people per year. Another found that 18 percent of sudden deaths among long-distance travelers involved blood clots, but Mohler notes that the number may be even higher because people may have died from unrecognized DVT.

Those with a history of blood clotting or poor circulation are at the top of the risk chart. Other high-risk factors are smoking, varicose veins, family history of DVT and recent surgery. Diabetics should be wary, as should those over 40, the obese, pregnant women and people with cancers that increase blood coagulation. But just because you're young, in good health and athletic doesn't mean you're immune to DVT. It can strike a physically fit non-smoker with no history of cardiovascular disease.

Mohler cites two other groups who might be at risk: the very tall and the very short. "The seat cushions hit them at points where there can be pressure on the leg that can stop or limit circulation and constrict blood flow," he says.

Since blood clots form slowly, symptoms may not appear until hours or days after deplaning. Watch for pain in your calf or other parts of your leg; leg swelling, redness, tenderness or cramping; chest discomfort, and coughing. In some cases, there will be vein swelling. More serious symptoms include coughing up blood, chest pain, shortness of breath, rapid heartbeat or feeling faint. These may indicate bigger clots, so seek immediate medical attention, and don't forget to mention your recent flight.

Although some elements that affect your ability to move around easily may be out of your control (seat selection, load factor and your seatmates), you can reduce the odds of getting DVT.

  • Don't: Cross your legs at the knee or wear constricting clothing. Avoid alcohol, smoking, dehydrating medications (like antihistamines), medications that impair circulation and sleeping pills. Don't sleep for a long time in the same position. Don't wear tight socks or knee highs that stop below the knee.
  • Do: Opt for an aisle seat and the widest possible seat you can afford. Sit straight and avoid putting undue pressure on your lower back and legs, which can cut off circulation. If you're short, prop your feet up on a bag on the floor to keep your knees higher than your hips, which reduces pressure on the leg veins. Drink lots of water. Wear loose clothing and roomy shoes. And, take one aspirin a day for a few days before the flight and on the day you leave, to reduce blood coagulation.
  • Of course, blood that is circulating freely is less likely to clot, so flex your feet, contract and relax the thigh and calf muscles, stretch your legs, practice yoga, do stationary exercises and walk up and down the aisles. You should move at least once every 30 minutes.

    Many passengers avoid getting up and down out of respect for fellow passengers. Dr. Mohler's prescription: Get over it.

    Marlene R. Fedin is a contributing editor to Frequent Flyer magazine, a sister publication of M&C. This article was adapted from Frequent Flyer.

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