MONDAY, Sept. 13, 2004 (HealthDayNews) -- Stretch your calves, avoid alcohol and coffee, and don't depend on aspirin.
Those are some of the ways to reduce the risk of dangerous blood clots while traveling on airplanes, according to new recommendations from a leading organization of doctors.
The group, the American College of Chest Physicians, has also issued new guidelines about an alternative to the popular blood thinner heparin.
While the group has issued more than 500 new recommendations about the treatment of blood clots, only the ones about the risks facing airline passengers are likely to make their way to the attention of ordinary people. Over the past few years, the risk of blood clots -- deep vein thrombosis -- while flying has received significant media attention, especially after several high-profile cases of people who died after long flights.
In airplanes, the combination of cramped seating conditions and dry air appear to boost the chances of blood clots forming in the legs, said Dr. Jack Hirsh, professor emeritus at McMaster University in Canada and a member of the panel that drafted the recommendations. People usually dispose of leg blood clots with no apparent symptoms, although they can cause pain and swelling. But if they break off and head to the lungs, they can cause shortness of breath or even death if they manage to become a pulmonary embolism and block an artery, he said.
Overall, the risks of leg blood clots on airplanes are fairly small; it's about 2,000 times riskier to undergo a hip operation, Hirsh said. But the risk still exists, especially among those prone to blood clots, such as people who have already suffered them. An estimated one in 20 North Americans will develop a leg blood clot that causes symptoms, he said.
In the new recommendations, issued in a supplement to the September issue of Chest, the physicians advise airline travelers to move about the plane, avoid constrictive clothing around the legs and waist, and drink lots of fluids, although Hirsh warned that coffee and alcoholic drinks will boost dehydration.
The organization also recommends that travelers stretch their calves as they sit in their seats. Hirsh said he teaches his patients how to do it: "They just twitch their calf muscles periodically, five minutes every hour. That muscle contraction stimulates and pumps up blood to the heart and prevents it from pooling in the legs."
The chest physicians also advise high-risk patients to take doses of heparin or fondaparinux before their flights. While patients often take aspirin to keep their blood thin, it's not recommended for airline passengers because research suggests it doesn't prevent leg blood clots, Hirsh said.
Dr. Victor Tapson, an associate professor of medicine at Duke University who studies blood clots and pulmonary embolisms, said the new recommendations make sense. But he added that travelers at high risk should contact their physician and get referred to a specialist, if necessary. He said other risk factors include active cancer, pregnancy, significant obesity, recent surgery and illnesses that affect mobility, such as congestive heart failure.
In another development, the American College of Chest Physicians recommended that doctors consider the new blood thinner fondaparinux to be a "practical alternative" to heparin. The doctors said fondaparinux lasts longer, acts more predictably and has fewer side effects than heparin.
The organization said it especially recommends the use of fondaparinux by patients who are undergoing orthopedic operations of the hip and knee.
More information
To learn more about deep vein thrombosis, visit the National Library of Medicine.
