Veins On Planes - What You Need To Know About Deep Vein Thrombosis (DVT)
(Updated July 11, 2003)
Last week, a California U.S. District Court judge ruled that airlines who fail to warn travelers that cramped legroom could be dangerous to their health may face lawsuits. The court ruling will allow a California woman and an Arizona man to seek damages in separate lawsuits against three airlines that did not warn them of dangers from deep vein thrombosis (DVT) -- a blood clot condition also called "economy class syndrome."
With seemingly healthy individuals collapsing and dying after long flights, worldwide
attention has been focused on this life-threatening condition. Mounting medical
evidence shows that airline passengers who take long flights are at
high risk. A recent study by British doctors concluded that every month
at least one long-haul passenger dies from a blood clot within
minutes of landing at Heathrow Airport. Globally, it is estimated
that as many as 2,000 people die from travel-related DVT each year.
"Economy Class Syndrome"
British doctors, who
attribute the clots to long flights in cramped airplane seats, have
dubiously dubbed DVT as "Economy Class Syndrome." This might be an
unfair distinction, however, since DVT can be caused by any
situation of immobility for long periods, including those during
long-haul car, bus, and train rides. Plus, people in coach aren't
the only ones affected. In fact, some of the most famous DVT
sufferers include U.S. President Richard Nixon and Vice President
Dan Quayle—and they weren't flying economy!
Research &
Education
The growing evidence that air travel and DVT
are inextricably linked has led to an international outcry for more
research into the problem. Recently in Geneva, The World Health
Organization (WHO) held a symposium of medical experts and 16
airline officials. In a statement
issued by WHO, the airline industry representatives conceded
that there "probably exists an association between venous thrombosis
and travel in general," and that more research is needed into DVT
triggered by travel.
Airlines are rejecting the idea of any
link between airline seating and DVT. Still, major airlines are
warning passengers that it is their responsibility to take basic
precautions against DVT on long-distance flights. They have begun
educating passengers of the problem through their websites and
in-flight videos and magazines. Airlines are also recommending mild
exercise to help prevent blood clots, along with drinking water,
avoiding alcohol, and avoiding drugs such as sleeping
pills.
The advice doesn't stop with airline passengers;
crewmembers are also being advised. Qantas Airlines issued a
detailed warning regarding DVT to its crewmembers following the
collapse of a flight attendant from a potentially fatal blood clot
after a 15-hour flight from Sydney to Los Angeles in
February.
How to Manage DVT and Who's at
Risk
The big question is how to manage this important
travel health issue. To find out what air travelers need to know, I
recently spoke with Dr. Geno Merli, MD, professor and acting
chairman of medicine at Jefferson Medical College of Thomas
Jefferson University, who is a medical expert on blood clots.
"Anyone being confined in a position for extended periods is
at risk for DVT since the blood doesn't circulate as rapidly; stasis
is the term we use," Dr. Merli explains. He goes on to say, "We've
known for years that in surgery, where the patient is immobilized
for three, four, or five hours, there is a significant risk of
stasis."
Dr. Merli explains that, given the immobility of a
traveler, some bodily habits and conditions compound the risk of
DVT. "Anyone 30 percent above their ideal body weight is considered
obese, and obesity is a big risk factor being put in the right
circumstances," he says. "There are numerous medications that can
increase the chances for DVT," Merli says. They include:
- Birth control pills
- Estrogen replacement therapy
- Cancer chemo treatments utilizing tomoxifin
- Lupron injections for prostate cancer
In addition, Dr.
Merli states that special groups of patients are at risk,
including:
- Cancer patients
- People with varicose veins
- Pregnant women
- People with personal or family history of hereditary clotting
disorders
- People who have recently had major surgery
High-risk
patients that plan to travel do have several options. Dr. Merli
treats his patients, who have a history of blood clots, with new
antithrombotic medications such as heparin and enoxaparin.
These medications do not require blood monitoring and are easily
self-injectable, providing more convenience for patients. "I teach
my patients how to inject themselves with the required dosages, at
the appropriate times," he says.
Preventing
DVT
If you have risk factors, and even if you don't,
there are certain things you can do to lessen the odds of getting
DVT. Dr. Merli recommends the following to reduce the amount of
blood stasis in your legs:
- Get an aisle seat.
- Get up every hour.
- Flex your feet and pump the calf muscle to help drain blood
from the legs.
- Wear support stockings. (Men need to wear the full-length
stocking.)
- Drink plenty of water and avoid alcohol.
There has been
some discussion on whether taking aspirin will lower the risk of
DVT. Dr. Merli says, "Studies have shown aspirin has never been good
for DVT. Aspirin has been very effective for arterial thrombosis,
not DVT."
Be Alert for Signs of DVT
There are
certain signs of DVT people need to be aware of. Dr. Merli states,
"If you have a dull, aching pain in your leg that is made worse by
standing or walking, or shows signs of swelling, see a doctor
immediately." He goes on to say, "people need to remember symptoms
of DVT may not show up two or three days after a flight. If your
legs start bothering you, and you start developing swelling, again
see a doctor."
Being aware of the signs of DVT can save your
life. DVT is treatable with hospitalization and medication. If you
ignore the symptoms of DVT, and the clot is later dislodged, it can
travel to the lungs, causing a pulmonary embolism, which can be
fatal.
More Links on DVT:
Sol Sherry Thrombosis
Research Center, Temple University
American
Heart Association Management of Deep Vein Thrombosis and Pulmonary
Embolism
Air
Travel and Health—A House of Lords Report
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