How is thrombosis/embolism diagnosed?
There are several ways of diagnosing these conditions. Firstly, the symptoms described by the person presenting with the condition are checked, and also where appropriate the risk situation and hence the probability of thrombosis occurring are assessed.
If there is good reason to suspect thrombosis, the first line of action is generally to prescribe an ultrasound scan of the vessels (Doppler). This gives an image of the blood flow. Modern instruments and experienced operators are nowadays able to make a definitive statement.
Occasionally an additional x-ray examination is necessary (so-called phlebography). A contrast medium is injected into a vein in the foot and the return flow can be traced through x-ray imaging.
In the case of pulmonary embolism, an attempt is made to create an image of blood circulation in the lung, or of ventilation…
There is often increased clotting activity in the blood, which can be measured based on the so-called D-dimer value. In patients with thrombosis/embolism the D-dimer values are often significantly increased. However, a high D-dimer value is not conclusive proof of thrombosis, though an unremarkable value can rule it out.
What treatment is given?
1. Acute therapy:
The primary aim of acute therapy is to prevent pulmonary embolism where it has not yet occurred, and also to prevent the formation of thrombi.
This is achieved by diluting the blood as rapidly as possible. As soon as thrombosis/embolism has been diagnosed, the patient generally receives intravenous or subcutaneous heparin. The advantage of heparin is that it is fast-acting. The faster the blood can be diluted, the less chance there is of complications.
Additionally, in the case of deep vein thrombosis, so-called compression therapy is instituted, with tight-fitting stockings or bandages. This promotes the return flow of blood and eases the congestive symptoms.
2. Long-term therapy:
During treatment the patient is then normally put on long-term oral anticoagulation (vitamin K antagonists: Marcumar®, Sintrom®, Coumadin®). This long-term anticoagulation is very important as, in the first three months especially after thrombosis, new thrombi may form.
Compression therapy on the leg should be continued for a long time, preferably for one to two years following thrombosis depending on its severity. This is important, as compression therapy can help avoid a common complication of thrombosis: so-called post-thrombotic syndrome.
In post-thrombotic syndromes, changes occur to the skin with pigmentation and a general thinning of the skin, especially around the ankles. Ulceration of the legs may occur. Compression therapy is a very effective preventive measure and is thus also extremely important.
The duration of anticoagulation (blood dilution) depends on the localization of the thrombosis, on the patient’s history (risk profile) and also on possible thrombophilia, or tendency for thrombosis to occur. There will be a report on this in the next editions of “Coagulation”.)
Long-term or life-long therapy with vitamin K antagonists (Marcumar®, Sintrom®, Coumadin®) is generally necessary:
- In the case of severe congenital coagulation defects. Thrombophilia does not always require life-long therapy.
- In the condition following thrombosis or thromboembolism.
- Following particularly severe life-threatening illness, e.g. sinus vein thrombosis, mesenteric vein thrombosis, and many other conditions.
- Where there are additional risk factors such as cardiac arrhythmia (atrial fibrillation), foramen ovale apertus, and many others.
Patients needing long-term anticoagulation may be eligible to receive a Coagu-Check® monitor for INR self-testing. Please consult your health scheme for details.
The INR target range for long-term anticoagulation where there is a thrombotic risk: INR 2.0 – 3.0.
Dr. med. Hannelore Rott, Specialist in Transfusion Medicine, Königstr. 53, 47051 Duisburg/Germany (2005)