Jan. 12, 2001 -- Joining a growing list of airlines, Singapore Airlines announced plans Friday to warn travelers about the risk of developing potentially fatal blood clots during long-haul flights.
Singapore's national carrier joins British Airways and Australia's two biggest airlines in issuing brochures on travel health tips to counter deep vein thrombosis (DVT), also known as "economy class syndrome." The condition may occur when people develop blood clots in the deep veins of their legs after sitting through long flights, presumably in cramped airplane seats.
According to the Singapore airlines web site, health tips will be displayed at check-in counters and on board the aircraft, where they will be printed on laminated cards placed in each seat pocket. These tips will advise passengers how to relieve stress, minimize jet lag, and reduce the risk of motion sickness, heart conditions, and DVT.
Affecting millions of people each year, these blood clots can travel to the lungs or other areas, causing severe organ damage or death. Such clots have been reported after automobile trips and even after evenings at the theater, but long airplane flights pose a greater risk.
Still, most medical experts here and abroad contend this condition has more to do with passengers sitting still for too long than with cramped seating conditions on airplanes.
"It's fair to say that common sense goes a long way, and airlines are doing what they can to provide recommendations for their passengers that will promote and insure a comfortable travel experience," says Michael Wascom, a spokesman for the Air Transport Association in Washington, D.C, a trade group that represents major U.S. passenger and cargo airlines.
"This particular medical ailment has not been widely reported among U.S. travelers," he tells WebMD. "It's not an epidemic."
Wascom, along with medical experts, says that DVT actually is caused by remaining in the same position without moving, not by too-small airplane seats.
"When you sleep at night, if you sleep on one of your arms, at some point you will lose feeling in your arm," he says. "It's the same concept."
A famous recent episode occurred in 1994 when former Vice President Dan Quayle developed a leg clot that traveled to his lung soon after a series of airplane trips. And researchers from the Hospital Pasteur in Nice, France, have reported that travelers who sit for more than five hours on planes are more than four times as likely to develop blood clots in their leg than nontravelers
In London, at least 30 people have died of blood clots in the past three years after arriving from lengthy flights at London's Heathrow Airport, according to a study conducted at Ashford Hospital in southeast England. Just this past October, newspapers reported that a 28-year-old women flying from Sydney to London developed DVT and collapsed and died after reaching Heathrow.
"In patients prone to circulatory problems, when they lie still for extended periods of time, [long-haul flights] don't help, but there is no reason for the average person to be concerned about this," says Louis D. Fiore, MD, an assistant professor at Boston University School of Medicine and School of Public Health and the chief of oncology at the VA Boston Health Care System.
People at high risk for DVT include people with varicose veins or cancer, smokers, individuals with history of leg clots, leg or pelvic surgery or a leg injury, pregnant women, women taking birth control pills and hormone-replacement therapy, overweight individuals, elderly people, and very tall people.
Warning signs include a warm or hardened area in the lower extremity, aching legs, pins-and-needles sensations, and problems bearing weight on the legs. If the clot moves to the lungs, chest pain is often a sign, as is shortness of breath.
Ways to prevent DVT while flying include:
- Your blood becomes thicker when you are dehydrated, increasing risk of clots. So try to drink an 8-ounce glass of water every two hours when flying and avoid alcohol and coffee, as they are dehydrating.
- Try compression hose. They are available over the counter at surgical supply stores and cost about $15 per pair. Even better are tailor-made support hose, made based on a person's leg measurements. Such support hose work by keeping blood flowing and preventing pooling of stagnant blood.
- Book a seat in an exit row, a bulkhead seat, or an aisle seat.
- Walk up and down the aisle about once an hour.
- Wear loose-fitting clothing.
- Don't smoke.
- While in your seat, contract your calf muscles from time to time by clenching your toes. Another exercise, suggested by British Airways: Bend your foot upward, spread your toes, and hold for three seconds -- then point your foot down, clench your toes, and hold for three seconds.
- People at high risk of blood clots should ask their doctors whether to take aspirin before flying to inhibit blood clotting.
- Don't cross your legs or sit on the edge of your seat, since these positions can reduce blood flow in your legs.
Above all, if you think you have a DVT, head immediately to your doctor or an emergency department, because immediate evaluation and treatment can be lifesaving.