Advice after your nerve block for surgery
On this page…
Am I at risk of developing a Deep Vein Thrombosis (DVT) or a Pulmonary Embolism (PE)?
This information explains the risks of developing blood clots following the application of a plaster cast.
What is a Deep Vein Thrombosis (DVT)?
Blood clotting is an important process that prevents excessive bleeding when a blood vessel is injured; this stops the bleeding by forming a clot over the injury. Typically, your body will naturally dissolve the blood clot after the injury has healed. Sometimes, however, clots form on the inside of the blood vessels following an injury or a period of immobilisation and these do not dissolve naturally. These situations can be dangerous and require accurate diagnosis and appropriate treatment.
Veins carry deoxygenated blood away from the body’s organs and limbs back to the heart. An abnormal clot that forms in a vein may restrict the return of blood to the heart and can result in pain and swelling as the blood collects behind the clot. Deep-vein thrombosis (DVT) is a type of clot that forms in a major vein of the leg.
In some cases, a clot in a vein may break off and travel through the heart to the lungs where it becomes wedged, preventing adequate blood flow. This condition is called a Pulmonary Embolism (PE) and can be extremely dangerous.
Am I at Risk?
You have been given this leaflet because your leg is in a cast and this does increase your risk of getting a DVT or PE, but there are other factors involved in this condition.
Different risk factors or events can cause unnatural clotting; however, each factor may initiate clotting in a different way. Your body has a system to let it know when, where, and how quickly to form a clot, and genetics play a role in how quickly your body reacts to these signals. Certain risk factors, such as obesity, slow down the flow of blood in the veins, while others, such as age, can increase the body’s natural ability to clot.
The following factors increase your risk of developing a venous blood clot:
• Previous DVT or PE
• Obesity
• Pregnancy
• Immobility (including prolonged inactivity, long trips by plane or car)
• Smoking
• Oral contraceptives
• Certain cancers
• Trauma
• Previous surgeries or serious illnesses
• Age (increased risk for people over age 60)
• Inherited clotting disorders (family members who have had clots)
• Chronic inflammatory diseases
If you have any of the above risk factors please inform the doctor who can fully assess your risk factors and advise you regarding preventative treatment for a DVT.
What are the symptoms of a DVT?
Symptoms range from barely noticeable to severe. They may be in the foot, ankle or calf, or involve the whole leg. They occur not just for a few seconds or minutes, but for hours or days. The classic symptoms of an acute DVT are:
- Pain in the leg that is different from the pain of the injury.
- Calf tenderness
- Swelling of the affected leg
- Calf may be warm and red
- Discolouration (bluish, slightly purplish or reddish)
- If the clot has developed higher up the leg, there may be pain in the lower back.
What are the symptoms of a superficial clot (superficial thrombophlebitis)?
A clot can develop in the superficial veins of the leg - veins that are near the surface of the skin. There is tenderness, pain, swelling, redness, or warmth in just one clearly defined, focal area. The skin is extremely tender and the pain feels like it is right in the skin - sometimes a firm cord or small lump can be felt in the calf. These symptoms suggest superficial thrombophlebitis.
What are the symptoms of a Pulmonary Embolism?
Symptoms of a PE range from minor to severe, depending on how big the clot is. In the most severe case, a massive PE can be life threatening. Very small PEs occur fairly commonly in patients with a DVT and lead to no symptoms whatsoever. The classic symptoms of an acute PE are listed below. They occur not just for a few seconds or minutes, but for hours or days.
• Chest pain, particularly when taking in a deep breath
• Shortness of breath
• Unexplained cough (sometimes coughing up of blood)
• Unexplained heart racing or pounding
• Passing out / losing consciousness
If you have developed any of these symptoms, you must seek medical attention.
If your doctor felt at the beginning of your treatment that you were at risk of developing a DVT or a PE, he/she would have prescribed daily injections of Fragmin. If you develop symptoms later or your risk factors increase (e.g., going on an airplane journey), then you may be prescribed medication.
Can I reduce the risk of a DVT or PE?
There are some ways to help reduce the risk.
- If you smoke, then stop or reduce the amount as much as possible.
- Drink plenty of fluid to keep hydrated – avoid alcohol as this has the opposite effect.
- Do regular exercise, moving the hip in a circular motion, bending the knee and straightening it - if the cast allows - and moving your toes.
- Elevate the leg, preferably to heart level. This helps the flow of blood back to the heart and also reduces swelling.
What should I do if my calf is painful / swollen in the cast or after the cast is removed?
Some amount of swelling is expected over the initial period following an injury to your leg. If you feel that the swelling is increasing within the plaster cast rather than settling down or you are experiencing any of the symptoms mentioned in this leaflet, you will need to be seen. Please feel free to phone for advice if you are worried.
During the week you can contact the Plaster Room at Wexham Park 0300 615 4058 or Frimley Park 0300 613 4339
Alternately NHS 111 offers health information and advice from specially trained nurses over the phone 24 hours a day.
Contact us
If you have any queries relating to this information, please contact the Plaster room service.
About this information
Service:
Plaster room
Reference:
N/030
Approval date:
27 February 2024
Review date:
1 February 2027
Click ‘show accessibility tools’ at the bottom of the page
Then click ‘select language’
Alternative formats
You can use the accessibility toolbar at the bottom of your screen to:
-
Change the text size
-
Adjust the font
-
Modify the colour contrast
-
Use the translate function
If you would like this information in another format, such as Braille, audio, or easy read, please speak to a member of staff.
You can also print as well as download as PDF using the “Print this page” button at the end of the page.
Staff will print a copy for you on request
Important note
This page provides general information only. It is developed by clinical staff and is reviewed regularly every 3 years for accuracy. For personal advice about your health, or if you have any concerns, please speak to your doctor.