Rédaction Africa Links 24 with Sarah Jane Lebrasse
Published on 2024-03-04 17:00:16
Venous thrombosis, that is the formation of a blood clot in a vein, is a fairly common but poorly understood health problem. However, it is a formidable condition that can have serious consequences if not detected and treated in time. Let’s take a look.
Also known as phlebitis, venous thrombosis occurs when blood clots form in the veins, mainly in the lower limbs. In 90% of cases, it affects the calf and thigh. These clots can partially or totally block blood vessels, compromising normal blood circulation. Hence the need to understand this potentially deadly condition that requires prompt and effective management.
Understanding the blood clotting process
To grasp the extent of the danger, it is essential to understand the mechanisms of blood coagulation. When an injury occurs, blood platelets interact with coagulation proteins to form a clot, thus preventing excessive bleeding. However, when this process occurs inappropriately inside a vein, it can lead to the formation of potentially deadly clots.
Recognizing warning signs
Venous thrombosis can manifest in various ways, depending on its depth and location. Symptoms can include intense pain, swelling, redness, and a sensation of warmth in the affected area. It is crucial to recognize these warning signs and promptly consult a healthcare professional for an accurate diagnosis.
Venous thrombosis can present in two main forms: superficial and deep. Superficial phlebitis affects veins near the skin surface and is often considered benign but painful. Nonetheless, it serves as a warning sign of a predisposition and therefore a higher risk of developing deep vein thrombosis, in which case, clots form in deeper, larger veins in the legs, arms, abdomen, etc. Often associated with intense pain, swelling, and abnormal skin discoloration (thus increasing the risk of potentially deadly pulmonary embolism), deep vein thrombosis can occur spontaneously in a person with risk factors (see below), or be a consequence of prolonged immobilization, vein wall injuries, or decreased blood fluidity.
Risk factors
Certain risk factors increase the likelihood of developing venous thrombosis. Prolonged immobility, personal or family history of phlebitis, blood clotting disorders, obesity, and hormonal contraceptive use are factors to consider. The elderly, obese individuals, women taking hormonal contraceptives, and those with a history of phlebitis are particularly at risk.
Symptoms
Phlebitis near the skin causes redness above the affected vein, which is warm and painful, sometimes swollen. Upon palpation, a hard cord where the vein is blocked can be felt. Superficial phlebitis (close to the skin) tends to appear in people with varicose veins. Phlebitis in a large vein leads to sharp pain in the calf or thigh, sometimes in the arm. Cramps, numbness, or a sensation of warmth in the affected limb may also be felt. However, in half of the cases, deep vein thrombosis causes few symptoms or goes unnoticed. When the blood clot significantly blocks blood flow, the limb becomes swollen, with tight, shiny skin in a whitish or bluish tone. If deep vein thrombosis affects the calf, the person may sometimes feel sharp pain when pointing the toes towards the knee (Homans sign). A mild fever (38°C) may also be present. The onset of these symptoms warrants urgent medical consultation. Under no circumstances should the painful area be massaged to avoid detaching the clot from the vein wall.
Complications
The complications of deep vein thrombosis can be severe, which is why prevention of this problem is crucial when risk factors are present. The main complication is an embolism, potentially fatal if left untreated. In this case, all or part of the blood clot detaches from the vein wall and is carried into the bloodstream. It ascends to the heart, then passes into the pulmonary artery (which carries non-oxygenated blood to the lung cells) where it obstructs, leading to what is known as a pulmonary embolism. Symptoms of pulmonary embolism include shortness of breath, chest pain, and sometimes loss of consciousness. In case of suspicion of a pulmonary embolism, emergency hospitalization is necessary.
Post-thrombotic syndrome
The post-thrombotic syndrome occurs when the deep vein is severely obstructed by the clot. Due to this obstruction, blood from the affected limb flows back to the heart through superficial veins located under the skin. These smaller diameter veins have trouble replacing the blocked vein, leading to the formation of varicose veins, local swelling, and potentially skin ulcers. The post-thrombotic syndrome occurs in 20 to 50% of cases of deep vein thrombosis.
Diagnosis
It is crucial to rapidly recognize the signs of venous thrombosis and seek medical help at their onset. The diagnosis is usually confirmed by venous echo-doppler (which visualizes blood flow blockage by passing an ultrasound probe over the affected limb) or, rarely, by a phlebography (a radiological examination of the veins), thus enabling the initiation of prompt anticoagulant treatment to prevent serious complications.
Causes
Venous thrombosis occurs when three conditions are met: local blood flow slowdown (stasis); injuries to the inner vein wall; an increased tendency for blood to coagulate. These conditions particularly occur in the case of prolonged bed rest (walking promotes blood circulation in veins and prevents stasis), chronic inflammatory disease, recent surgery (these factors damage blood vessel walls), blood clotting disorders, or cancer (two health problems that increase blood’s tendency to clot and form a clot).
Acting promptly
In case of a diagnosis of venous thrombosis, rapid treatment is essential to prevent serious complications such as pulmonary embolism. The duration of preventive deep vein thrombosis treatment varies depending on the nature of the risk factors. For example, after surgery, a one or two-week treatment is generally sufficient, including possibly wearing compression stockings or being prescribed an anticoagulant. For a person immobilized by a cast, preventive treatment is maintained until the cast is removed. People receiving preventive deep vein thrombosis treatment must take certain precautions: avoid high-dose aspirin or NSAIDs (ibuprofen, for example) unless expressly authorized by the doctor; possibly undergo regular blood tests to monitor platelet count. In people at risk of bleeding (such as those with digestive ulcers, chronic alcoholism, or anemia), preventive deep vein thrombosis treatment relies solely on the prescription of compression stockings.
Prevention of Travel Thrombosis
During travel by plane, train, or car for more than 6 consecutive hours, people at risk of venous thrombosis should take certain precautions: wear Class II compression stockings; perform foot flexion/extension exercises and move during the journey; drink sufficient water throughout the journey; wear loose clothing. Additionally, people at risk (with a history of phlebitis, recent trauma or surgery, cancer) may receive an injection of an anticoagulant medication in the days preceding the trip (low molecular weight heparins or fondaparinux). Increased awareness of symptoms and risk factors, as well as early medical intervention, are essential to prevent serious complications associated with this condition. By staying informed and proactive, we can all play a role in combating this silent threat to vascular health.
Box 1
All individuals whose mobility is greatly reduced for any reason are at risk of venous thrombosis: illnesses or accidents leading to immobilization or paralysis, plaster casts, bedridden individuals for several days without being able to stand up, etc. Moreover, certain categories of people are at higher risk of venous thrombosis: individuals over 75 years old; those who have experienced…
Read the original article(French) on Le Mauricien
