Deep Venous Thrombosis
Deep venous thrombosis is a disease characterized by thrombi formation in the deep veins, especially veins in the legs. Because deep venous thrombosis can lead to occurrence of pulmonary embolism, prophylaxis and treatment of this condition should be done as accurately as possible.
Treatment of deep venous thrombosis:
The main aims of treatment for deep venous thrombosis are to prevent:
- Increasing in size of the thrombus;
- Detachment of thrombus and appearance of pulmonary embolism;
- Development of post-thrombotic syndrome, a condition that causes pain, swelling and sores in the affected limb
- Recurrence of the thrombi.
Once the diagnosis of deep venous thrombosis is made, the treatment should be started immediately, to prevent the increasing in size and embolization of thrombus or its detachment. Early therapy also decreases the risk of post-trombotic syndrome.
Deep venous thrombosis is usually treated with anticoagulants like heparin or warfarin. Heparin is administered by intravenous injection and warfarin is administered orally. Heparin acts immediately, while warfarin is effective in a few days after the administration. Treatment begins with both drugs, but the administration of heparin will be discontinued after warfarin becomes effective.
Patients with deep venous thrombosis in the thigh veins will continue treatment with warfarin for 3-6 months, sometimes more. After 3-6 months, depending on the risk factors, the doctor may recommend that the treatment with warfarin should be continued, but in low doses, as a maintenance therapy to prevent recurrence of the thrombi.
For the treatment of deep venous thrombosis are available two types of heparin: unfractionated heparin, which is administered in the hospital and fractionated heparin (low molecular weight heparin), which can be administered at home, is easier to use and is cheaper. Also, low molecular weight heparin does not require periodic tests to monitor its effects. Both types of heparin are equally effective.
Patients with deep venous thrombosis in the leg veins require anticoagulant therapy for 6 to 12 weeks. If anticoagulation is contraindicated, can be administered NSAIDs, like aspirin or naproxen and should be performed periodic ultrasound monitoring of the thrombus. Other measures, such as raising the legs, when is possible, the using of warm compresses and the using elastic stockings, are helpful to alleviate pain that appear in deep venous thrombosis.
If anticoagulation therapy is contraindicated, can be installed filters in the inferior vena cava or other drug therapy may be given.
Patients with deep venous thrombosis in the thigh veins, will continue the treatment with warfarin for 3 to 6 months, sometimes more. After 3-6 months, depending on risk factors, the doctor may recommend that warfarin to be used in a lower dose as a maintenance therapy to prevent recurrence of the thrombi.
During anticoagulant therapy must be done regular tests to monitor the action of anticoagulant drugs. Test that measures the time of forming a blood clot is called the prothrombin time.
Certain medications (especially antibiotics), diet and some habits may influence anticoagulant drugs. Is indicated that blood tests to be done periodic for accordingly adjust of the drug doses.
In pregnant women, oral anticoagulants, like warfarin, are contraindicated, because can cause birth defects. It can still be given, if necessary, intravenous anticoagulants. Oral anticoagulant therapy can be started immediately after birth.
Although not proven, the use of elastic stockings is recommended in the case of deep venous thrombosis accompanied by symptoms. Elastic stockings can relieve pain and leg swelling, in some people. Certain types of compressive stockings (elastic) can help prevent deep venous thrombosis in individuals with high risk of developing this disease. The use of elastic stockings can also prevent post-trombotic syndrome.
Home treatment of deep venous thrombosis:
Home treatment refers to the realization of a safe anticoagulant therapy, because it increases the risk of bleeding.
Anticoagulant therapy, in a first episode of deep venous thrombosis lasts 3 to 6 months. During this treatment is indicated:
- Administration of anticoagulants after doctor’s indications.
- Monitoring the response to treatment, this may require blood tests once or twice a week in the first 2-4 weeks of treatment.
- Avoid activities that have an increased risk of injury.
- Following a indicated diet. Certain foods can interfere with the action of anticoagulants.
- The patient should consult his physician before taking other drugs or before stop or change the dose of some drugs that are administered simultaneously with anticoagulant therapy.
- Moderate alcohol consumption.
It is recommended the use of warm compresses for 20-30 minutes for 3-4 times a day and to walk 5-6 times per day is possible, because these measures can help to reduce pain and swelling.
Options of medication:
Anticoagulant drugs prevent the formation of new clots and prevent the increasing of a existing clot, but do not break and dissolve thrombi which are already formed.
Anticoagulants are used for:
- Treatment of installed deep venous thrombosis
- Prevention of thrombus formation after some surgical interventions
- Prevention of thrombus formation in people with high risk.
The types of anticoagulant used to treat deep venous thrombosis are:
- Heparin – there are two types of heparin: low molecular weight heparin that can be given by injection at home and unfractionated heparin that is administered intravenously and requires hospitalization.
- Warfarin – oral anticoagulation.
Is preferred low molecular weight heparin because is effective and does not require hospitalization and the monitoring of blood tests.
The ideal time to perform oral anticoagulant therapy varies and is still considered to be in study. In general, the therapy is continued for 3 to 6 months. Studies have shown that anticoagulant therapy reduced the risk of recurrent of the thrombosis from 25% to 5% and the pulmonary thromboembolic risk by 60-70%, in the first 3 months of treatment.
After the initial treatment with warfarin, it may be indicated a continuous administration of warfarin, but in a lower dose, to prevent relapses.
The administration of a new anticoagulant agent, called ximelagastan have demonstrated that is reducing the risk of recurrence of deep venous thrombosis in people who received conventional therapy with warfarin, for 6 months. Unlike warfarin, ximelagastan dose not require frequent blood tests to adjust the dose.
This are drugs that are rapidly dissolving the clots and for this reason, are sometimes used to treat deep venous thrombosis with large thrombi, that are recently formed and produce severe symptoms. These drugs increase rapidly the risk of bleeding, so are given only in certain situations where the risk of bleeding is less higher than the risk of allowing the thrombus to be undissolved. Generally, thrombolytics are given only when symptoms are severe or potentially life-threatening or the patient can lose his foot.
Thrombolytics can reduce the risk of developing the post-thrombotic syndrome.
Thrombin inhibitors (hirudin and hirulog) are introduced as new agents with a mechanism of action that interfere with the action of thrombin, a component used in thrombus formation.
Aspirin may prevent thrombus formation and reduce the risk of pulmonary embolism. A study showed that aspirin reduce the risk of pulmonary embolism after surgical procedures by 33%. This study showed that aspirin can be administered with great benefits in patients with risk of thrombosis.
Surgical treatment consist in thrombus removal and represents a alternative only in rare cases, like deep venous thrombosis with large thrombus, that is causing symptoms and is blocking a major vessel. Surgery increases the risk of the development of a new thrombus.
Installation of the filters at the level of vena cava, represents a alternative in patients with bleeding disorders, malignancy or bleeding from a gastric ulcer and can not take anticoagulation therapy. These filters prevent transporting of blood clots from the veins into pulmonary vessels.
Filters in the vena cava can be used in cases where:
- The thrombi appear, even during a anticoagulant therapy;
- Recurrent thrombi and pulmonary hypertension.
Prophylactic measures can be done before and after some procedures or events that are increasing the risk of deep venous thrombosis. These measures may include:
- Administration of anticoagulants to prevent blood clots after certain types of surgical interventions. It is also used in people who have an increased risk of thrombus formation or those who had deep venous thrombosis in the past.
- Exercises which are involving the lower limb and improve the circulation at this level. The toes are moved to stretch the lower leg muscles and then to relax them (the toes are pulled toward the head, in lying position). These exercises are especially important when the person is obliged to maintain a certain position for a longer period of time.
- Getting up from the bed as soon as possible after a surgery or a illness.
- Use of elastic stockings to prevent thrombosis in individuals at high risk.
Long plane flights are increasing the risk of developing deep venous thrombosis, even in people without risk factors. Many doctors recommend the use of elastic stockings for flights longer than 8 hours. During long flights is indicated to get up from a chair to make some movement every hour, leg movements every 20 minutes, drinking large amounts of liquid in a large glass every 2 hours and avoidance of alcohol or caffeine consumption, because it produce dehydration and increase the risk of developing blood clots.
People who have an increased risk of developing deep venous thrombosis should go to a medical consultation, before taking a long plane flight.
For prophylaxis of deep venous thrombosis can be used pneumatic compression devices. These devices allow rhythmic inflation and deflation of some boots that are covering the leg up to the knee, in this way the blood circulation of the leg is stimulated. These pumps are commonly used in hospital after surgical procedures.