- 5 minutes to read
- 30 July 2019
What is thrombosis and what causes it?
Thrombosis is a condition where a blood clot (thrombus) (A) forms inside a blood vessel and thus causes a restriction or blockage of the blood flow within the vessel (B).
Thromboses are dangerous as they might lead to a pulmonary embolism (see FAQs) in the event of the blood clot travelling to the lungs (C).
When is there an increased risk of thrombosis?
Common causes of thrombosis are confinement to bed, infections and injuries such as bone fractures, etc. There is also an increased risk in people who are overweight, smoke, take hormone treatment or who have already had thrombosis.
Thromboses in the case of spinal cord injuries
The risk of people with spinal cord injuries getting venous thromboses is about 250 times greater in the first few months; the risk drops to 20 times in the first few years, and then remains 3 – 10 times greater for the rest of their lives. The causes for the high risk of thromboses in people with spinal cord injuries are only partly known (lack of a muscle pump or paralysis of the autonomic nervous system are not sufficient explanation). It is unknown whether people with incomplete paralysis are at lower risk than those with complete paralysis, which is why we treat them all the same.
What are the signs and symptoms of thrombosis? Possible physical trouble:
- Sudden pain in the affected area (only with sustained sensitivity)
- pain in the sole of the foot
- dragging pain along the vein
- In case of no sensation of pain, symptoms may include:
- one leg is significantly thicker than the other (by at least 2 cm), and the whole leg swells below the site of the thrombosis. Isolated swelling of the knee or thigh, for instance, would suggest it is not a thrombosis.
- redness / blueness and overheating of the affected part of the body
- Increased frequency of spasms and spasticity
- Heavy legs / feeling of tension in the legs
- General feeling of discomfort
- Rapid pulse, slightly elevated body temperature
- Shortness of breath
What should I do if I suspect that I have a venous thrombosis?
Thromboses must be treated as quickly as possible as they may be life-threatening.
If you suspect that you have a thrombosis, consult a GP immediately and, if possible, avoid any further movement (stay still) – there is a risk of a pulmonary embolism as a result of the thrombus becoming loose. It is diagnosed through ultrasound or computerised tomography and laboratory tests.
How to prevent thrombosis:
Thromboses can be prevented through
- Sufficient fluid intake
- Injection of blood-thinning preparations in case mobilisation is restricted for a certain period of time (please consult your GP)
- Wearing of compression stockings in the case of extensive swelling of the legs
- Due to the very high risk among people who have recently become paralysed, blood thinners and compression stockings are used during the first 6 months. In the absence of any certainty as to whether incomplete paralyses pose a lower risk, we treat all patients the same way.
- After 6 months, blood thinning drugs only have to be administered in high-risk situations.
What are the high-risk situations for venous thromboses?
Particular caution is advised:
- During summer
- warmer temperatures: sufficient fluid intake
- When travelling
- hot climate: sufficient fluid intake
- on journeys shorter than four hours: possibly wear compression stockings (bus, plane)
- on journeys longer than four hours: injection of blood-thinning drugs (please consult your GP)
- In the case of leg injuries, e.g. fractures or heavy bruises as a result of a fall (please consult your GP)
- In the case of infections (please consult your GP)
Wearing compression stockings
Compression stockings lower venous pressure, prevent water retention in the legs and improve the blood supply to the legs. The risk of blood clots forming is reduced by the fact that there is an improvement in the return of blood to the heart. As a result of the pressure of the stockings, less fluid is retained in the tissue. Consequently, the stocking prevents the formation of oedemas1.
Given the very high risk of thrombosis following the occurrence of a spinal cord injury, class II compression stockings must be worn right from the start. They can generally be taken off again in the fullness of time. In the event of bad circulation problems or swelling of the legs during movement, it is rather difficult to dispense with the stockings.
If you wear compression stockings, it is important to put them on correctly, without any creases. If stockings are rolled down, this may lead to blockages; creases encourage the development of pressure sores. In addition, support stockings must be looked after correctly. The effectiveness of the stockings is preserved by washing them regularly (every day or every other day).
In the event of changes in the circumference of the legs or if the stockings become too loose with ageing, it is important to replace them.
What is a pulmonary embolism?
A pulmonary embolism is a life-threatening condition caused by a sudden blockage of a blood vessel in the lungs. Symptoms of a pulmonary embolism include shortness of breath, anxiety, irritation of the throat and a rapid pulse. Depending on the size of the pulmonary embolism, the symptoms are more or less pronounced. Small pulmonary embolisms generally go undetected, whereas larger ones may be fatal.
What does sufficient fluid intake mean?
It is recommended to drink at least 2.5 litres each day. On hot days correspondingly more. Suitable fluids are water and fluids that are rich in minerals (mineral water). It is better to avoid alcoholic drinks as they lead to a widening of the blood vessels. A good gauge is the colour of your urine: it should be light yellow (except urine in the morning).
What should I do if my compression stockings cause pressure sores?
Check that the stockings have been put on correctly and whether the pressure sores recover over night. If this is not the case, stop wearing the compression stockings. Contact the supplier who will check that the stockings are sitting correctly.
What is the correct way of caring for compression stockings?
Compression stockings can be washed in the machine at 40 °C. Use a detergent for delicates and do not use any fabric softener. If you wash the stockings by hand, rinse them thoroughly; do not wring them out, but rather roll them up in a towel and press them. Most stockings can be dried on the delicates cycle in the tumble dryer. It is not advisable to lay them out on a radiator or to dry them in the sun. Holes or tears should only be mended by experts. Do not cut off loose threads! Look for the reasons for these defects (rough skin, long toe nails, defective shoe insoles, incorrect handling, etc.).
How long should you hold on to compression stockings, and where can you obtain them?
Use medical compression stockings for half a year, until the fabric loses strength, and the medical effectiveness lessens. In general, health insurance schemes will pay for 2 pairs of stockings every year. A prescription is required. You can buy stockings from a medical supplies stockist. In order to ensure that the stockings fit correctly, your legs have to be measured again.
1 Deposits of water in the tissue