Tuesday, May 06, 2008 Travelers beware of killer legs! By Henrylito D. Tacio Health 101
SIXTY-YEAR-OLD Steve was looking forward to see his grandchildren in Duluth, Minnesota. His wife, Marianne, died two years ago, and so he had to travel alone -- all the way from Manila to Nagoya, Japan and then to Minnesota.
Steve never made it. He apparently died of a deep vein thrombosis (DVT) that reached his lungs. He collapsed in St. Paul/Minneapolis airport after complaining of breathing difficulties due to what has been dubbed "economy class syndrome."
DVT is the formation of a blood clot (known in medical parlance as "thrombus") in one of the deep veins of the body, usually in the leg. This can have two serious consequences. If the thrombus partially or completely blocks the flow of blood through the vein, blood begins to pool and build-up below the site. Chronic swelling and pain may develop. The valves in the blood vessels may be damaged, leading to hypertension. A person's ability to live a full, active life may be impaired.
If the thrombus breaks free and travels through the veins, it can reach the lungs, where it is called a pulmonary embolism (PE), a potentially fatal condition that can kill within hours. This was what happened to Steve.
As expected, DVT is thought to affect passengers who sit for long spells in cramped conditions. "There is no conclusive evidence to link DVT with flying per se, however, we know that it is linked with long periods of immobility, and that can be on a train or any other form of transport," explains a British Airways spokesperson. "But we are keen to learn more about DVT and whether there is anything about the cabin environment which may be a factor and therefore we are committed to becoming involved in further research."
But flying is just one of the probable causes of DVT. You can suffer from it even just by sitting in front of the computer. In New Zealand, a 32-year-old man who spent up to 18 hours at his computer suffered a massive blood clot that caused him to black out.
"(The blood clot) broke off and traveled to his lung, which obstructed the blood flow into his lung, which made him very sick, obviously," said Richard Beasley, a professor at the Medical Research Institute of New Zealand, who co-authored a paper on the incident. "He collapsed unconscious, but came round."
The only cause of the clot the researchers could find was the man's habit of sitting in front of the computer without moving for long periods of time. This syndrome has appeared throughout history. It was first recognized during the London blitz in World War II. "People sleeping in deck chairs in air raid shelters had a very high incidence of blood clots that were fatal," Beasley said.
Medical experts claim there are various factors that make a DVT more likely to occur. Studies have shown that DVT is more common in people aged over 40 and in people who are obese, or who have already had a DVT. Several inherited conditions make the blood more likely to clot than usual, increasing the risk.
Three main factors can contribute to DVT: injury to the vein's lining, an increased tendency for blood to clot, and slowing of blood flow. "Veins may be injured during surgery, by injection of irritating substances, or by certain disorders," explains the second home edition of 'The Merck Manual of Medical Information.' "They may also be injured by a clot, making formation of a second clot more likely."
Some disorders cause blood to clot when it should not. Some cancers and, rarely, use of oral contraceptives, can cause blood to clot more readily. Sometimes, blood clots more readily after childbirth or surgery. Among older people, dehydration and smoking are common causes of this tendency and can therefore contribute to DVT.
"During prolonged bed rest, blood flow slows, because the muscles are not contracting and squeezing the blood toward the heart," the Merck manual states. For instance, DVT may develop in people who have had a heart attack and lie in hospital beds for several days without sufficiently moving their legs or in people whose legs and lower body are paralyzed.
