Last updated: 11/24/2009

There are several methods physicians use to prevent blood clots. Some use medications, others use mechanical means, and still others require behavioral changes, or a combination of all of these.

Heparin and other blood thinners

Anticoagulants (blood thinners) such as heparin are often prescribed as prophylactics for venous thrombosis. These drugs decrease the clotting ability of the blood. There has been very good success combining heparin and pneumatic compressions stockings, especially for colorectal and cardiac surgery patients.

There are some precautions, however, for using this drug. People who have had an unusual reaction to the drug should not take it, as well as those with allergies to beef and pork. Women who are pregnant and nursing should only use with caution. In addition, certain medications should not be used with heparin. They include aspirin, hyperthyroid medication, and drugs for pain or inflammation.

Mechanical leg pumps (pneumatic compression stockings)

Mechanical stimulation of the calf muscles of the leg can help stimulate blood flow. Many hospitals require all surgery patients, especially those who have abdominal or cardiac surgery, to wear pneumatic compression stockings. These devices wrap around the lower leg from ankle to the knee, some reach as high as the thigh. When plugged in and turned on, a pneumatic device pumps air into chambers within the stocking, which gently tighten around the legs for a few seconds and then are released. This pulsing massage keeps the blood flowing and discourages venous thrombosis.

Compression stockings

Often physicians recommend compression stockings for patients to prevent DVT and edema, and to treat varicose veins and phlebitis. Graduated compression stockings apply more pressure at the ankle and less up the leg and closer to the knee. This pressure prevents backflow of blood and clot formation.

Exercise

Sitting for long periods or being confined to bed after surgery or during a long illness can slow blood flow, allowing clots to form. As soon as possible after surgery, the patient should move the legs, stand, and begin taking short walks. Travelers or people who work sitting at a desk or computer for several hours at a time should take breaks every hour to get up and move around. While sitting in the confines of an airplane or lying in bed, specific exercises, such as ankle circles or leg lifts, can be done also.

Fluids

It is important not to restrict fluids when recovering from surgery, traveling, or working for long periods in a seated position. Not only will the body be kept hydrated but drinking fluids will help prevent venous thrombosis. Drinking fluids keeps the blood liquid and moving, discouraging clot formation. Travelers should drink something every hour. This may be difficult since some air carriers may not have frequent beverage service.