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PATIENT INFO - DEEP VEIN THROMBOSIS
Deep vein thrombosis, also known as DVT refers to the formation of a thrombus in a deep vein in the leg. A thrombus is a blood clot. Deep vein thrombosis tends to occur in leg veins, such as the popliteal or femoral veins, as well as deep veins within the pelvis. If the thrombus breaks off, it is known as an embolus - a piece of blood clot - and can make its way to the lung, resulting in a pulmonary embolism. In other contexts, an embolus may also refer to a piece of fat or an air bubble.
When blood clots form in the superficial veins, which lie just under your skin, the condition is known as superficial thrombophlebitis. These superficial blood clots are different to DVT and are much less serious, although they can occasionally spread to deep veins.
Symptoms of DVT
In about half of all cases, deep vein thrombosis occurs without any noticeable symptoms
When deep vein thrombosis symptoms occur, they can include:
- Swelling in one or both legs
- Pain or tenderness in one or both legs, which may occur only while standing or walking
- Warmth in the skin of the affected leg
- Red or discoloured skin in the affected leg
- Visible surface veins
- Leg fatigue
If the clot becomes dislodged and finds it way to the lung, the following signs and symptoms may indicate pulmonary embolism
- Breathlessness - this may develop slowly, or come on suddenly
- Chest pain, pain is usually more severe during inhalation, eating, coughing, stooping or bending over. During exertion the pain will get worse, and will not go away when the patient rests.
- Coughing may produce bloody or bloodstained sputum
- Wheezing
- Lightheadedness, and sometimes even fainting (collapse)
- Unexplained anxiety
- Accelerated heartbeat
- Rapid pulse
- Sweating
Causes
DVT occurs in between one and three people in every 1000 people in the general population every year.
DVT is more likely to occur in:
- People aged over the age of 40
- People with a family history of blood clots
- People suffering from, or who have had treatment for cancer
- People with certain blood diseases (sickle cell anaemia)
- People being treated for heart failure and circulation problems (often caused by smoking)
- People who have had recent surgery especially on the hips or knees
- People who have an inherited clotting disorder
- People who are very tall
DVT is also more common in women
- who are pregnant
- who have recently had a baby
- who are taking the contraceptive pill
- who are on hormone replacement therapy (HRT)
Diagnosis of DVT
DVT is normally diagnosed by examination and assessment of the leg and the following tests:
D-dimer test – D-dimer is a protein fragment which is present in blood after a blood clot is degraded by firbinolysis, if more than a certain amount is found in a blood test, it is likely that the patient has a blood clot in a vein.
Ultrasound – this type of scan can detect clots in veins, and also determine bloodflow speed within a vein. If a doctor knows blood flow has slowed down, he/she may be able to locate a clot if there is one. A Doppler ultrasound (Doppler sonography) can tell how fast blood is flowing.
Venogram – this diagnostic test may be used if the ultrasound scan and D-dimer tests are inconclusive. The doctor injects a dye into a vein in the patient's foot or groin. X-ray images can see the dye as it moves and will reveal the location of a blood clot, because the dye will not be able to flow around it - it will appear as a gap in the blood vessel.
CT or MRI scans – Both computerized tomography (CT) and magnetic resonance imaging (MRI) can provide visual images of your veins and may show if you have a clot. Sometimes a clot is found when these scans are performed for other reasons.
Blood tests include:
- Activated partial thromboplastin time (APTT) to monitor treatment with heparin.
- Prothrombin time (PT), also referred to as INR, to monitor treatment with warfarin (Coumadin).
Treatment for DVT
Deep vein thrombosis treatment options include:
Anticoagulants - these are drugs that prevent the clot from getting bigger, as well as stopping it from breaking off and causing a pulmonary embolism. There are two types of anticoagulants used in the treatment of DVT - heparin and warfarin.
- Heparin - Two types of heparin are available for treatment of deep vein thrombosis. Unfractionated heparin (UH) is given in the hospital, whereas low-molecular-weight heparin (LMWH) can be self-injected at home, which usually is more convenient. Low-molecular-weight heparin usually does not require periodic blood tests to monitor its effects.
- Warfarin - If you have a blood clot in your upper (proximal) leg vein, you will likely need to take warfarin for at least 3 months. After 3 months and depending on your risk factors, your doctor may recommend that you continue on lower doses of warfarin on an ongoing basis to prevent deep vein clots from recurring.
Clotbusters - If you have a more serious type of deep vein thrombosis or pulmonary embolism, or if other medications aren't working, your doctor may try other medications. One group of medications is known as thrombolytics. These drugs, such as tissue plasminogen activator (TPA), are given through an intravenous (IV) line to break up blood clots. These drugs can cause serious bleeding and are typically used only in life-threatening situations.
Filters - If you can't take medicines to thin your blood, a filter may be inserted into a large vein — the vena cava — in your abdomen. This filter prevents clots that break loose from lodging in your lungs. The filters are sometimes referred to as umbrellas because they look like the wire spokes of an umbrella.
Compression stockings - These help prevent swelling associated with deep vein thrombosis. These stockings are worn on the leg from your foot to about the level of your knee. This pressure helps reduce the chances that your blood will pool and clot. You should wear these stockings for at least a year if possible.
Prevention for DVT
Although DVT blood clots can occur with little or no warning, your risk of DVT can be reduced by recognizing the signs and symptoms and taking the appropriate preventative care.
Maintaining a healthy lifestyle:
- Maintain an active lifestyle and exercise regularly -- daily, if possible. Walking, swimming, and bicycling are all great activities.
- Manage your weight with exercise as well as by eating a healthy diet.
- If you smoke, quit!! Nicotine therapy (in patches, gums, or sprays) and support groups can make this much easier to do.
Remaining active, even when mobility is restricted
- Get up and walk around as much as possible
- If you are driving, stop every hour or so to walk around
- Move your legs and stretch to promote blood flow in your calves raise and lower your heels while keeping your toes on the floor raise and lower your toes while keeping you heels on the floor tighten and release your calf and thigh muscles
- Wear loose, comfortable clothing
- Stay hydrated. Drink plenty of water (to avoid dehydration).
- Do not drink too much alcohol. (Alcohol can cause dehydration and immobility.)
- Do not take sleeping tablets, which cause immobility.