Deep Vein Thrombosis
Updated: Aug 30, 2019
In this week’s blog we are going to discuss Deep Vein Thrombosis (DVT). This topic is very relevant in today’s world, where accessibility to air travel, particularly long haul flights, is very easy.
Most people have heard about DVT affecting elite athletes as they fly around the world competing, or you may have heard about DVT being caused by flying following damage to the leg, specifically with knee or calf injuries.
So what is a DVT? As the name suggests Deep Vein Thrombosis is a clot in one or more of the deep veins of the body. It is most commonly seen in the lower limbs and especially the calf vein’s. Although there is a possibility of occurrence in the upper extremities, this usually only affects between 4-10% of the population. Specific veins that can be affected include:
- Upper arm veins
- Forearm veins
- Thigh veins
o External Iliac
o Deep vein of the thigh
- Calf veins (most common)
How does it occur? Thrombi form in the blood due to a process called hyper-coagulation. When our blood vessels are damaged the mechanism for repair initially starts with stopping the bleeding (coagulation). This coagulation of red blood cells and fibrin (connective tissue) is meant to break down after bleeding stops, but sometimes the blood clots form too easily or are not broken down properly and travel through the body limiting blood flow – this excessive blood clotting is known as hypercoagulation.
Hypercoagulation is dangerous due to its ability to allow thrombi to be dislodged, travel through the body and block areas where blood supply is vital. Veins function to push deoxygenated blood back to the heart and then onto the lungs where it expels carbon dioxide and picks up fresh oxygen for reoxygenation. A DVT can potentially cause a blockage in either of these vital organs, restricting the supply of reoxygenated blood cells.
There are other factors that can increase you risk of DVT and they are split up into acquired and genetic factors. Acquired factors are those that are triggered due to another disease or condition including:
- Overweight and obesity
- Prolonged bed rest
- Car and plane travel
Genetic or inherited factors are those we are born with, they are less common than acquired factors and can include:
- Genetic defects that affect the protein needed for the clotting
- Genetic defects that affect the substances that delay or dissolve blood clots
The signs and symptoms of a DVT vary with many individuals not experiencing any symptoms. Those who do have symptoms may notice pain and discomfort, swelling, warmth, tenderness on palpation and discoloration with a slight red/purple look. These symptoms are very similar to those experienced with musculoskeletal injuries, so if DVT is suspected, it should always be excluded prior to any examination and treatment.
The diagnostic testing used for DVT, in stages from most practical to gold standard, are:
- Observation and palpation – looking for the presence of the above signs and symptoms
- D-Dimer testing – simple blood test for D-dimer levels that would be increased in the presence of increased fibrin in the blood
- Venous Ultrasound – non-invasive ultrasound imaging to confirm the presence of DVT
- Venography – Gold standard test for DVT but is rarely used due to its invasive nature along with the availability of the above non-invasive testing
Movement of a limb with a DVT has the inherent risk of dislodging part of the clot and sending the thrombi toward vital organs. As such Physiotherapy, Chiropractic and Massage Therapy treatment is contraindicated in the early stages, and immediate referral to a medical practitioner is essential.
However, being first contact health professionals, these practitioners are in a crucial position to diagnosis a DVT, especially in the presence of a knee, ankle or calf injury. Medical treatment may include:
- Anti-coagulation medicine is the most common treatment and will generally be followed by a 3-6month period of blood thinning medication.
- Thombolysis – not so common but used for more extensive blood clots and current literature indicates the increased risk of serious bleeding as a complication.
- Inferior Vena Cava Filter – may help to prevent a pulmonary embolism however again complications for displacement, obstructions and erosion.
As with most injuries, Prevention is always better than cure, and the tips below are very important for DVT.
1. Early mobilisation following muscle injuries– maintain mobility to all of the muscles around the area of damage to help massage the flow of blood and not allow the slowing down and formation of the thrombosis.
2. Compression – applying external pressure to the leg in turn helps to maintain blood pressure and increased flow of blood to decrease the probability of hypercoagulation.
3. Avoiding flying, especially long haul, immediately after injury to the lower extremity.
4. Act quickly, if you experience the above symptoms report to your health care professional immediately for assessment and advice.
So that’s an overview of how DVT’s occur. It’s important to remember that they are very serious, constitute a medical emergency and need to be referred immediately for medical intervention.
If you have any questions or comments regarding DVT please e-mail us at firstname.lastname@example.org and we will be happy to answer them for you.