DVT and its risks

Deep vein thrombosis (DVT) is a condition that could have various complications for people with disabilities and even cause death.

DVT is a condition whereby a thrombosis (a blood clot) forms within the venous (vein) system of the body – normally, but not exclusively, in the lower limb. These blood clots develop for a number of reasons, including the use of certain medications (the oral contraceptive pill); certain medical conditions, which predispose an individual to DVT (abnormalities of blood clotting, for example); and immobility in patients who have some form of functional loss in the limbs due to a stroke or spinal cord injury (SCI).

During the acute rehabilitation phase in hospital following a stroke, SCI or any condition that requires a patient to lie in bed for a prolonged period, patients are routinely required to wear elasticated stockings. These help to enable the return of blood from the venous system and prevent pooling of blood.

In addition, medications are given to prevent thrombosis and may include oral anticoagulants or injectable medications. One of the challenges in acute rehabilitation is to gain consensus about how long patients should receive thrombosis-preventing medications.

The prevention of thrombosis is critical, as complications following an acute thrombosis may result in fatality, especially when a clot from the deep vein of the leg travels to the lungs, which causes a sudden collapse and respiratory arrest. This is known as pulmonary embolism.

Thrombosis presents in several important clinical ways.

Normally, in a person in whom normal sensation has been preserved, pain is a common complaint. Clinically, pain can be exacerbated by certain manoeuvres of the limb – for example, the forced upward movement of the foot at the ankle joint. Swelling, redness and oedema (the collecting of watery fluids in the tissue) are other common symptoms.

These symptoms could, of course, be caused by something else, but it is important to determine whether it is thrombosis in order to ensure correct treatment and, hopefully, prevent complications. Traditionally, following the acute rehabilitation phase, the use of long-term medical treatment with either injections or oral medications is not encouraged.

Long-term treatment is expensive and the risks outweighs the benefits. Therefore, after discharge from a rehab unit, the use of blood thinners (usually an injectable form such as Clexane) is often stopped. What about the risk of clots for people with chronic disabilities?

The person with an SCI or dense hemiparesis caused by stroke is certainly at higher risk of DVT than a neurologically intact person. As mentioned, routine anticoagulation in the long term is not recommended. However, creating awareness of the signs and symptoms is important and any unilateral swelling of a limb with redness and oedema should be brought to the attention of your healthcare professional.

Preventive measures, such as the wearing of elasticated stockings after discharge from rehab, can help. Normally the chronic and ongoing use of elasticated stockings is not practised due to the inconvenience factor. However, if long-haul air travel is anticipated, the use of these stockings is advised.

Much has been said about DVT in recent years, with the topic being highlighted due to the increasing numbers of people on long-haul flights. Even among neurologically intact persons, the risk of developing DVT during a long flight is present. Certainly, among SCI individuals and those suffering from stroke with hemiparesis, the risk of developing DVT is higher than those without impairment.

In addition to the stockings, healthcare professionals would also recommend the use of an injectable anticoagulant commencing the day before an anticipated long-haul flight, the day of the flight and again a day after arriving at your destination. This should be repeated on return.

If there are no other risk factors, doctors wouldn’t normally recommend the chronic use of anticoagulants, such as Clexane or warfarin. Aspirin, unfortunately, doesn’t help significantly in the prevention of DVT. Awareness of the signs and symptoms is important.

Should a DVT have developed, the treatment would be to remain suitably anticoagulated for three to six months. This would require the use of a suitable oral anticoagulant. Once treated, patients normally discontinue oral anticoagulants, but if there is a repeat episode of DVT, lifelong anticoagulation should be considered.

 


Dr Ed Baalbergen is the medical officer at the Vincent Pallotti Rehabilitation Centre (Cape Town) and is a member of the International Spinal Cord Society and the Southern African Neurological Rehabilitation Association. email: ed.baalbergen@lifehealthcare.co.za

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