Introduction

Thrombophlebitis is an inflammation of the veins that causes blood clots, specifically in the legs, which leads to the blockage of the veins. There are two types of thrombophlebitis: superficial vein thrombophlebitis (SVT), which causes blockages of the veins close to the surface of the skin, and deep vein thrombosis (DVT) affecting the veins deeper in the body. 

SVT must be treated with medication to prevent it from progressing into DVT, as it can lead to serious health complications such as thrombosis. 

The main treatment option for thrombophlebitis is anticoagulation therapy. Heparin is mainly used to manage the formation of blood clots. Other management options include taking particular non-steroidal anti-inflammatory drugs (NSAIDs) and wearing elastic compression stockings. The use of anticoagulants in thrombophlebitis depends on the patient and the stage of the condition.^1,2

Pathophysiology of thrombophlebitis

Thrombophlebitis occurs from a combination of factors, including injury to the vein, blood stasis, and hypercoagulability, which leads to thrombus (blood clot) formation and inflammation. These factors are a part of what is called Virchow’s triad, named after physician Rudolf Virchow, which is used to investigate the formation of blood clots. This can help healthcare workers assess the condition of patients and identify the risk factors associated with the formation of thrombophlebitis.^3,4

• Vein damage: damage in the vessel wall of the vein can occur due to trauma, surgery, infection and inflammation. Vascular injuries from catheters are also considered damage to the vessel wall
• Blood stasis: inactivity and immobility for a long period can slow blood flow in the veins, which in turn increases the risk of clot formation. An example of immobility includes taking long-haul flights or people who are hospitalised for a long time
• Hypercoagulability: there are specific conditions that increase the chances of blood clots, such as a family history of blood clotting disorders. Other conditions like pregnancy and obesity are known to contribute to thrombophlebitis

Difference between superficial and deep thrombophlebitis

Superficial thrombophlebitis refers to blood clots in the veins closer to the surface of the skin, and the symptoms are usually redness and warm skin in the affected area. Superficial veins are affected, and these are the veins in the legs and arms that can be seen by the naked eye.⁵ 

Deep thrombophlebitis shows signs of swelling and pain because the blood clots are present further away from the skin's surface in deeper veins. A clinical examination is not always enough to differentiate and diagnose between SVT and DVT, therefore, an ultrasonography is a technique used to visually inspect the venous conditions in SVT. 

On the other hand, ultrasonography and clinical examination do not provide sufficient information for DVT diagnosis. A diagnostic blood test, like the D-dimer test, is used to diagnose DVT. Also, the treatment and management options between superficial and deep thrombophlebitis differ, as deep thrombophlebitis can lead to further health complications. 

Managing SVT is more accessible as over-the-counter painkillers could be taken for pain relief, and compression socks could be worn day to day to relieve symptoms, however, if the condition worsens, surgery could be an option. For DVT, blood-thinning medication or anticoagulants are mainly used to prevent blood clotting. Specifically, heparin and fondaparinux are used.^2,6,7

When and how anticoagulants are used in thrombophlebitis

Low molecular weight heparin is the preferred anticoagulant for patients suffering from DVT, although fondaparinux can be used, it is recognised to be less effective. On the other hand, the anticoagulant fondaparinux is used for severe SVT. The most efficient method of administration for this anticoagulant is through injection. Fondaparinux is considered if the patient presents with a blood clot measuring 5 cm or more located within the saphenous or femoral veins.^7,8,9,10

DVT can also show progression to the lungs and cause pulmonary embolism (PE), which could stop the blood flow to the lungs. Prophylactic anticoagulants are proven to be the most effective in treating PE and high-risk DVT patients. Heparin is a type of prophylactic anticoagulant which is cost-effective and has proven safe for use in thrombosis. 

In certain situations, heparin may be insufficient, which is why warfarin is used as an anticoagulant for treating thrombotic conditions. However, warfarin is prescribed solely based on the patient's specific situation and requires monitoring due to the potential for interactions with other medications. People with kidney dysfunction also need to be closely observed while using warfarin, as their compromised renal system is less effective in eliminating warfarin from the body, thereby heightening the risk of bleeding.^11,12,13

Nevertheless, there are also direct oral anticoagulants (DOACs) such as rivaroxaban (rye-ver-ox-i-ban) and apixaban that are known to be an alternative for warfarin in the treatment of DVT and PE. They are taken orally, which makes them very convenient to use and does not require monitoring. DOACs have also proven rapid anticoagulation effects and show fewer dietary and medication interactions, making them a safer option for patients. These types of anticoagulants could be more suitable for patients who take a lot of medication and are at risk of medication interactions.¹⁴

Monitoring anticoagulation therapy

Although DOACs do not require frequent monitoring by a healthcare professional, other anticoagulants like heparin and warfarin must be monitored closely. Heparin should be monitored using laboratory assays to make sure that the doses given to the patients are within the therapeutic ranges. Partial thromboplastin time (PTT) is a type of blood test that measures the time it takes for a blood clot to form. 

Monitoring heparin is crucial as it evaluates how effective the heparin treatment is for a patient. This allows healthcare providers to determine if a dosage adjustment is needed or if a different anticoagulant should be considered.¹⁵

Warfarin requires careful monitoring through diagnostic testing, which involves a blood test known as the international normalised ratio (INR) to gauge the duration it takes for a blood clot to develop. This monitoring is necessary to ensure patients are administered safe doses of warfarin.¹⁶

Alternative therapies for thrombophlebitis

Compression therapy is a non-medical alternative to treating superficial thrombophlebitis, which could be used in combination with anticoagulants or on its own. Compression stockings are used most commonly to apply pressure to the legs and thighs, which compresses the superficial veins, increasing blood circulation. The advantages of this therapy are that it is readily available and helps with pain and swelling caused by thrombophlebitis. 

Thrombolysis is a medical treatment used in life-threatening conditions such as heart attacks and pulmonary embolism. The mechanism of action involves breaking the blood clots which block the blood flow. This is an alternative method to anticoagulants but is rarely used. 

Potential risks of anticoagulation

There are various risks associated with taking anticoagulants, and bleeding is the most common risk as anticoagulants reduce the chances of blood clots. People with genetically inherited bleeding disorders need to be careful when taking anticoagulants. Older patients carry the risk of haemorrhage when taking warfarin. This risk has also been associated with individuals with a background of diabetes and heart disease.

However, individuals who have undergone trauma or recent surgical procedures may also be at risk for bleeding related to anticoagulants. Furthermore, tools for predicting risk can be utilised to estimate these risks and assist in clinical decision-making.

Another potential risk of anticoagulants is their interactions with other drugs, food and food supplements. Specifically, when taking warfarin, the patient must avoid a diet rich in vitamin K because vitamin K decreases the effectiveness of warfarin. Vitamin K is higher in leafy green vegetables such as broccoli and spinach. 

Adverse effects associated with the use of warfarin, although rare, include skin necrosis, which is a severe condition causing skin cell death. It can develop if there is an overdose of warfarin in a short period.¹⁷

Summary

Thrombophlebitis is an inflammation of the veins that causes blood clots, mainly in the legs, leading to blocked veins. There are two types: superficial vein thrombophlebitis (SVT), which affects veins close to the skin, and deep vein thrombosis (DVT), which involves deeper veins. SVT needs treatment to prevent progression to DVT, which can have serious complications. The main treatment for thrombophlebitis is anticoagulation therapy, commonly using heparin to manage blood clot formation. Other methods include specific non-steroidal anti-inflammatory drugs (NSAIDs) and wearing elastic compression stockings. The choice of anticoagulants depends on the patient and the stage of thrombophlebitis. Thrombophlebitis can occur due to vein injury, blood stasis from inactivity, and hypercoagulability, known as Virchow’s triad.

Common symptoms of SVT include redness and warmth in the affected area, while DVT typically shows swelling and pain. SVT treatment is easier and can involve over-the-counter painkillers and compression socks, but surgery may be necessary if it worsens. DVT is managed with blood-thinning medications like heparin and fondaparinux. Monitoring is essential for anticoagulants like heparin and warfarin to ensure safe dosing. Compression therapy may also be used for SVT. Risks of anticoagulants include bleeding, interactions with medications and food, and rare adverse effects like skin necrosis. Patients must be cautious, especially those with other health conditions.