Preventing blood clots for legs in plaster casts, splints, and boots
The purpose of this information is to make patients aware of the risk of blood clots associated with limb immobilisation and how to reduce the risk of this happening.
Blood clots or Venous Thromboembolism (VTE) can be a complication of having a limb immobilised following a fracture or injury. You may have had the whole leg or some of your leg placed in a plaster cast, a splint, or a protective boot. As you will no longer be able to move the limb as freely as you were able to before the injury, there is risk that a blood clot could form. This is usually in the deeper veins of the legs, which is commonly known as a Deep Vein Thrombosis or DVT.
These can be very painful, resulting in swollen and sometimes discoloured calves.
There is a risk that bits of the clot can break up and lodge in the lungs causing a Pulmonary Embolism (PE) causing chest pain, difficulties with breathing and sometimes coughing up blood streaked sputum. This is rare but life threatening and can usually be avoided with appropriate management. However, sometimes it will occur despite best management.
Am I at risk?
All patients with lower limb immobilisation are unfortunately at risk. Blood normally flows quickly through veins, and does not clot. Blood flowing in the leg veins is helped along by movement of the legs, because muscle action squeezes the veins. While your leg is immobilised, blood flow becomes sluggish and can form clots.
Your doctor or nurse will ensure that you have been properly risk assessed while in the Emergency Department and a decision will be made as to whether or not you will require medication to prevent you from developing a blood clot.
What medication will I need?
If you are assessed as high risk of developing a DVT you may need to take some medication to prevent this from occurring.
Anticoagulants (drugs that prevent clotting) may be used, in the form of a daily tablet or injection. The doctor or nurse will make the decision to commence you on medications and advise you on when to stop taking them.
If you need help with administering injections at home, please ask the nurse attending to you.
What happens if I don’t need medication?
If your doctor or nurse has decided that you don’t need any anticoagulation medication, this is because you are at low risk of developing a blood clot.
If your leg is immobilised in a cast, you may receive a follow up appointment to an outpatient fracture clinic within 7-14 days. Alternatively, if your injury is stable, your x-rays may be discussed in the virtual fracture clinic and you may be discharged with advice instead.
How can I reduce the risk of developing a DVT?
It is difficult to predict who will get a blood clot, and there are steps you can be take to try and reduce this risk:
- Drink plenty of fluids.
- Stop smoking (if you smoke) - this will help your bone to heal.
- Mobilise as possible, as advised by your doctor or nurse.
How will I know if I have a DVT?
Physical signs may include swelling, pain or tenderness with discolouration or redness of the leg. The leg may feel hot to touch. These symptoms usually affect one leg, although clots can occur in both legs. If the clot is somewhere other than in your leg, there may be no physical signs of DVT.
Sometimes bits of the clot can break up and lodge in the lungs causing a Pulmonary Embolism (PE). This will cause symptoms such as chest pain, difficulties with breathing and coughing up blood streaked sputum, palpitations, and possible collapse.
If you develop any of the signs or symptoms mentioned in this leaflet please seek medical attention immediately.
Where can I find out more?
Please ask your doctor or nurse for more information.
Alternatively, the NHS website provides patient information on blood clots: www.nhs.uk