Venous Thromboembolism (VTE)

Definition

Venous thromboembolism (VTE) is a condition that includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT is the formation of a blood clot in a deep vein, usually in the leg, while PE occurs when a part of the clot breaks off and travels to the lungs, potentially causing life-threatening complications.

Aetiology

VTE can result from a combination of inherited and acquired risk factors:

Genetic predisposition (e.g., Factor V Leiden mutation, prothrombin gene mutation)
Acquired conditions (e.g., cancer, pregnancy, obesity)
Prolonged immobility (e.g., long-haul flights, bed rest)
Surgery, particularly orthopaedic surgery
Use of hormone replacement therapy or oral contraceptives
Recent trauma or injury

Pathophysiology

The pathophysiology of VTE involves the triad of Virchow:

Hypercoagulability: Increased tendency of blood to clot due to genetic or acquired factors.
Venous stasis: Reduced blood flow, often due to immobility or prolonged bed rest.
Endothelial injury: Damage to the inner lining of blood vessels, often due to surgery or trauma.

Risk Factors

Age over 60
Obesity
Smoking
History of VTE
Hormone replacement therapy or contraceptive pill use
Pregnancy and the postpartum period
Prolonged immobility
Major surgery or trauma
Cancer
Inflammatory diseases (e.g., rheumatoid arthritis, Crohn’s disease)

Signs and Symptoms

Common signs and symptoms of DVT include:

Throbbing or cramping pain in one leg (rarely both legs), usually in the calf or thigh
Swelling in one leg (rarely both legs)
Warm skin around the painful area
Red or darkened skin around the painful area
Swollen veins that are hard or sore when touched

Symptoms of PE include:

Unexplained shortness of breath
Chest pain that worsens with breathing
Coughing up blood

Investigations

Clinical history and physical examination
Blood tests, including D-dimer
Ultrasound scan of the leg to confirm DVT
CT pulmonary angiography (CTPA) for suspected PE
Venography or MRI in certain cases

Management

Primary Care Management

Immediate referral: Suspected VTE cases should be referred to the hospital urgently.
Initial anticoagulation: Administering low molecular weight heparin (LMWH) or direct oral anticoagulants (DOACs) while awaiting confirmation.

Specialist Management

Anticoagulation therapy: DOACs (e.g., apixaban, rivaroxaban) or warfarin for at least 3 months.
Compression stockings: To reduce swelling and prevent post-thrombotic syndrome.
Thrombectomy: Surgical removal of the clot in severe cases.
Long-term monitoring: Regular follow-ups to monitor anticoagulation therapy and assess for complications.

References

NHS. (2024). Deep Vein Thrombosis (DVT). Retrieved from NHS
NHS. (2024). Blood Clots. Retrieved from NHS
Hull University Teaching Hospitals NHS Trust. (2024). Venous Thromboembolism (VTE) – Reducing the Risk. Retrieved from Hull NHS
Buckinghamshire Healthcare NHS Trust. (2024). Advice for Patients Following Venous Thromboembolism (VTE). Retrieved from Bucks NHS