Deep vein thrombosis

03 Jun 2013

Deep vein thrombosis (DVT) can happen to anyone, but the risk increases as you age. Each year in Australia, there are almost 400 deaths from pulmonary embolism, caused by blood clotting.

What is deep vein thrombosis?

DVT occurs when a blood clot forms in the vein and most often than not, occurs in the leg. A blood clot causes the blood flow to be partially or completely blocked within the particular vein.

Blood flows in an upwards direction in the legs so it generally requires some mechanical help. This is aided by valves and the calf muscle, which acts as a pump.

Sitting for long periods of time or immobility allows blood to pool in the veins rather than pump through the legs. As a result, DVT is often associated with surgery, and long periods of sitting or lying.

Of course, it can be caused by other factors including blood clotting disorders, pregnancy and hormone therapy.

Symptoms commonly include swelling, tenderness and pain when moving, although many people with the condition have no symptoms.

Risk factors

According to research, age is a fact considered to increase the risk of DVT. While many people associated long-haul flying with DVT, there have been reports that have thwarted that claim. Also, it’s not just long-haul flying that may trigger blood clotting, it’s long-haul anything. This is why surgery patients are at risk, as generally, rest is enforced upon them.

However, best practice in some hospitals currently is to get the patient up and moving soon after surgery to avoid risk factors such as clotting and DVT.

Other risk factors include smoking, coronary heart disease, family history of blood clotting and some types of cancer.

Pulmonary embolism

DVT remaining in the leg vein can cause a number of complications including leg ulcers.

However, what’s more dangerous is if the clot travels through the circulatory system causing a pulmonary embolism. When the clot breaks free from the veins and travels through the heart into the arteries of the lungs. This may cause sharp chest pains and breathlessness, and may be life threatening.

Economy class syndrome

When you hear of deep vein thrombosis, many people think international air travel. Research is currently divided when it comes to whether air travel is a cause of DVT in everyone, or just those susceptible to it.

An ongoing investigation by the World Health Organisation (WHO) has found that the risk of DVT almost doubles not just after a long-haul flight but also after long-haul travel in cars, buses or trains.

However, the risk is increased when other factors are present, such as age, obesity and pre-existing clotting abnormalities.

Precautions to take

If you know you’re going to be immobile for quite a while, either on a plane, in a car or after surgery, there are some precautions you can take. Firstly, stay hydrated, and avoid alcohol and caffeine. Also, avoid constricting clothing. If you’re in a hospital, chances are the doctors will take care of your movement during your recovery. If you’re travelling, make sure you move around a lot. This means standing up and going for a walk up and down the aisles of a plane, train or bus and if you’re in a car, stopping regularly and having a stretch.

Treatment and management

Treatment for DVT includes medication that works to stop the blood from clotting more, while your body works to break down the original blood clot. These are usually blood-thinning medicines. Treatment will also usually involve numerous blood tests to check that the medication is working and to monitor any side effects, if any.

If the clot escalates to a pulmonary embolism, emergency treatment in hospital will be required.