Confirmed Deep Vein Thrombosis (DVT)

Transcription

1 Confirmed Deep Vein Thrombosis (DVT) Information for patients

2 What is deep vein thrombosis? Blood clotting provides us with essential protection against severe loss of blood from an injury to a vein or artery. However, blood is only supposed to clot when it is outside a blood vessel. Clotting within an artery or vein can be dangerous. A deep vein thrombosis (DVT) occurs when a blood clot forms in a vein. The DVT usually forms in a deep leg vein and can cause immobility (lack of movement). A DVT can form across all or part of the width of your vein, which can block your blood flow either completely or partially. DVT and pulmonary embolisms (clots in the lungs) are conditions known as venous thromboembolisms. Fortunately, venous thromboembolisms are rare conditions. DVT is less common in people under the age of 40 and more common in people over the age of 80. A DVT usually develops in the calf, but it sometimes also occurs in the thigh. Occasionally, other deep veins in the body are affected. Inflammation of surface veins (superficial phlebitis) is much less serious. 2

3 What are the causes? Deep vein thrombosis (DVT) sometimes occurs in normal veins for no apparent reason. However, the risk of developing DVT is increased in certain circumstances. These include immobility (lack of movement), history of previous DVT or vein damage, some medication i.e. chemotherapy, contraceptive pill and hormone replacement therapy (HRT), medical and genetic conditions such as cancer and heart failure and also pregnancy. Your risk of developing DVT is also increased if you are: obese, a smoker, or over 40 years of age (particularly if you have a condition that restricts your mobility). How is it diagnosed? As there are many different causes of a swollen, painful calf, it can be difficult to diagnose deep vein thrombosis (DVT) from the symptoms alone. If your Doctor suspects that you have DVT, they will usually recommend that you have some tests done as quickly as possible. There are a number of tests that can be used to diagnose DVT. 3

4 D-dimer test A specialised blood test, known as the D-dimer test, is sometimes used to detect pieces of a blood clot that have been broken down and are loose in your blood stream. The larger the number of fragments found, the more likely it is that you have a blood clot in your vein. Ultrasound scan An ultrasound scan can be used to detect a clot in the vein of your leg. A special type of ultrasound, known as Doppler ultrasound, is also sometimes used to find out how fast the blood is flowing through a blood vessel. Venogram If the results of a D-dimer test and an ultrasound scan cannot confirm a diagnosis of DVT, a venogram is occasionally required. This is a more detailed test that involves a contrast dye being injected into the vein in your leg. An X-ray is then used to see whether the dye is flowing through your vein, or if it is blocked by a blood clot. How is it treated? Treating deep vein thrombosis (DVT) will prevent the clot getting larger, breaking off (an embolism) and travelling up the vein to your lungs. It can also reduce the risk of post-thrombotic syndrome and prevent a further DVT from occurring in the future. 4

5 Anticoagulation (thinning of the blood) Anticoagulant medicines are used to prevent the DVT from getting larger. Although they are sometimes referred to as blood thinners, anticoagulants do not actually thin the blood, they alter chemicals within it which prevent clots from forming so easily. If anticoagulation treatment is started soon after a DVT develops, it significantly reduces the chances of you developing a serious embolism. The usual treatment for DVT involves using the anticoagulant medicines, heparin and warfarin. Heparins Heparins may be given either as unfractionated heparin (a continuous infusion into the vein) or by daily injections of low molecular weight heparin (LMWH). LMWH is given by subcutaneous (beneath the skin) injections once daily. The dose is based on your body weight. The LMWH used are enoxaparin, dalteparin and tinzaparin. Heparin will normally be started as soon as the tests show you have had a DVT, or sometimes before the test results are known. 5

6 Warfarin Warfarin is an anticoagulant that is taken as tablets once daily. The dose of warfarin has to be precise to ensure that the blood does not clot too easily, or that it does not cause excessive bleeding. While taking warfarin, you will need to have regular blood tests to check your International Normalised Ratio (INR) - which measures how long it takes your blood to clot. The INR result tells your GP whether you are on the correct dose of warfarin, or if it needs adjusting. In treating DVT, your GP will aim for an INR of 2.5 (between 2-3). Initially, you will be given heparin and warfarin together until your INR is in range. Warfarin usually takes a couple of days to reach the correct level, so you need the heparin to help treat the clot while the warfarin starts to act. Once the INR has been in the correct range for at least two days, the heparin can be stopped. You will usually need to take warfarin for at least three to six months, although this will be reviewed by your GP depending on your risk of getting another DVT in the future. For pregnant women, heparin injections are given for the full length of treatment instead of warfarin tablets. 6

7 Compression stockings Compression stockings help to prevent damage to the tissue of your calf, that may be caused by the increase in blood pressure that occurs due to the blood being diverted to the outer veins. They may also prevent, or reduce, calf pain, swelling and the risk of ulcers developing. Compression stockings can help stop post-thrombotic syndrome occurring. Stockings should be worn every day for at least two years because symptoms of post-thrombotic syndrome may develop several months, or even years, after having DVT. If you have had DVT and compression stockings are recommended, make sure that you have them fitted professionally. You should put your compression stockings on in the morning, wear them all day, and take them off before going to bed. However, you can take them off in the evening while you rest with your leg raised. Tips for travelling If you are at risk of getting a DVT, or have had a DVT previously, you should consult your GP before embarking on long distance travel. During long distance travel (journeys of six hours or more), particularly during longhaul flights. 7

8 Contact details If you have any further questions and would like to know anything else, please contact: Leanne Cook, Vascular Nurse Specialist on: We are committed to providing high quality care. If you have a suggestion, comment, complaint or appreciation about the care you have received, or if you need this leaflet in another format please contact the Patient Advice and Liaison Service on: or pals@midyorks.nhs.uk To contact any of our hospitals call: To book or change an appointment call: a Published Jan 2012 Review Date 2015 SMOKE FREE hospital Design: The Mid Yorkshire Hospitals NHS Trust - design and print dept