DVT: A clot by any other name
By Cortney Cleereman, ANPN
Ministry Medical Group/Ascension
If you have ever taken a flight over the Pacific Ocean, you know the meaning of fatigue–not the fatigue gained by climbing a mountain or running a marathon but the fatigue caused by being mostly immobile over a 12 to 16-hour period. Immobility is a major risk factor for deep vein thrombosis (DVT), a potentially severe medical condition.
As the name implies, deep vein thrombosis (DVT) is the formation of a clot in a deep vein, usually one in the legs. A clot in any blood vessel is risky because it hinders proper circulation. With DVT, there is an even greater risk: part of the clot could break off and travel to the lungs, causing a pulmonary embolism–a life-threatening emergency.
The link between air travel and DVT has been noted since the 1950s. And the LONFLIT studies published a decade and a half ago found an incidence of 4-6 percent for DVT among high-risk subjects after a flight longer than 10 hours.
More recent studies have concluded that the overall risk of DVT associated with air travel is relatively low even for frequent flyers–one case for every 4,500 flights, according to one study. For the really long flights, however, such as the one from Los Angeles to Sydney, Australia, the risk increases by as much as fourfold.
And immobility is clearly a major factor. Business class travelers are just as vulnerable as those in the more cramped economy class. But the highest incidence is with those sitting in seats not on the aisle.
Any extended travel–whether by car, train, bus or air–leads to immobility. So does bed rest as a result of a serious illness, injury or surgery.
Other factors than can increase the risk of DVT include an injury or surgery that affects veins, smoking (which affects both blood clotting and circulation), pregnancy (which increases the pressure on veins in the lower body), birth control pills or hormone replacement therapy (which alter the body’s blood clotting ability), obesity (which puts added pressure on veins in the leg and pelvis), an inherited blood clotting disorder, being age 60 or older and medical conditions such as heart failure, inflammatory bowel disease or cancer.
Symptoms of DVT include pain, swelling and warmth in one leg (rarely both) plus, in most cases, some redness or discoloration of the skin. The pain is most commonly in the calf and may be mistaken for a cramp or sore muscle.
The condition may not cause any symptoms. Or the symptoms can occur several days after your flight has landed.
If you experience these symptoms or have reason to believe you may have DVT, see a clinician right away.
Pulmonary embolism symptoms usually appear two to four days or longer after the initial clot. They include shortness of breath, rapid breathing, a cramp in your side, causing painful breathing, chest pain, fever, coughing up blood and fainting.
Because the clot prevents proper circulation of blood through the lungs, the body becomes deprived of the oxygen it needs. A medium-sized embolism can cause chest pain and breathing problems; a large one can cause the lung to collapse, resulting in sudden death.
It is estimated that half of individuals with a pulmonary embolism large enough to cause symptoms will eventually develop life-threatening complications.
Another serious complication of DVT is post-phlebitic syndrome, permanent damage to the vein that can occur as a result of deep vein thrombosis. Symptoms are similar to those of DVT–swelling, pain, discoloration and skin sores on the leg. With post-phlebitic syndrome, however, these symptoms are chronic.
Treatment for DVT aims at preventing the clot from getting bigger and preventing it from breaking off and moving to your lungs. It’s also important to prevent another clot.
Anticoagulants (blood thinners) such as Warfarin or Pradaxa are prescribed, usually for a three- to six-month period, unless there are other risk factors.
The leg swelling can be reduced through use of compression stockings, worn from the arch of the foot to just above or below the knee. The idea is to create gentle pressure to keep blood flowing up the leg.
When you are traveling, whether by air or otherwise, follow some common sense tips to protect yourself. Get up and move around at least once every hour. During other times, move your legs frequently and flex your feet and ankles. Wear loose and comfortable clothing. Drink fluids but not too much alcohol or caffeine, both of which can have a dehydrating effect.
Cortney Cleereman, APNP, is a Nurse Practitioner with Ministry Medical Group, part of Ascension. For more information, visit ministryhealth.org or call 715-361-4060.