Deep Vein Thrombosis

• What does Deep Vein Thrombosis (DVT) refer to?


  Intra-luminal occlusion of a deep vein with a blood clot
• Where do DVTs commonly occur?


  In the legs
• How are DVTs categorized?


  As "provoked" or "unprovoked"
• What are key signs and symptoms of DVT?


  Leg pain, unilateral erythema, warmth, swelling, and distention of superficial veins
• What is the Wells score used for?


  To assess the likelihood of a DVT based on clinical findings and risk factors
• What is the first-line investigation for a likely DVT?


  A proximal leg vein ultrasound scan
• What is the management strategy for DVT?


  Usually with anticoagulation
• What is the annual incidence of VTE?


  1. 2 per 1000 people per year
• What proportion of VTE cases are DVT?


  2/3 cases
• What is a common setting for DVT occurrence?


  In unwell patients in hospital
• What are some risk factors for thrombosis?


  Thrombophilia, hormonal factors, family history, older age, malignancy, bone fractures, obesity, smoking, immobilization, and sickness
• What are the typical presentations of DVT?


  Unilateral erythema, warmth, swelling, and pain in the affected area
• How can you differentiate DVT from cellulitis?


  Cellulitis often has other signs of infection like fever and wounds
• What is a significant difference in calf circumference for DVT diagnosis?


  A 3 cm difference between the legs is significant
• What should be measured to assess calf circumference?

  10 cm below the tibial tuberosity
• What is the role of the D-dimer test in DVT diagnosis?


  To help rule out DVT if negative
• What should be done if a DVT is 'likely' and the ultrasound is negative?


  A D-dimer test should be arranged
• What is the first-line treatment for DVT?

  Direct oral anticoagulants (DOACs) like apixaban or rivaroxaban
• What should be done if a patient has active cancer and DVT?


  Use DOAC unless contraindicated
• How long should anticoagulation be continued for all patients?


  At least 3 months
• What determines the continuation of anticoagulation after 3 months?


  Whether the VTE was provoked or unprovoked
• What is the ORBIT score used for?


  To assess the risk of bleeding
• What are potential complications of DVT?


  Pulmonary embolism, post-thrombotic syndrome, and complications of anticoagulation
• What are the management strategies for DVT?

  • First-line: Direct oral anticoagulants (DOACs) like apixaban or rivaroxaban
  • If not suitable: LMWH followed by dabigatran/edoxaban or vitamin K antagonist (warfarin)
  • For active cancer: DOAC unless contraindicated
  • For severe renal impairment: LMWH/unfractionated heparin/LMWH followed by VKA
  • For antiphospholipid syndrome: LMWH followed by VKA
• What are the differences between provoked and unprovoked VTE?


  • Provoked VTE: Due to an obvious precipitating event (e.g., immobilization after surgery)
  • Unprovoked VTE: Occurs without an obvious precipitating event, indicating potential unknown risk factors
• What are the key differential diagnoses for DVT?


  • Cellulitis: Erythema, warmth, swelling, pain, often with signs of infection
  • Calf muscle tear: Swelling, erythema, pain with a history of trauma
  • Superficial thrombophlebitis: Localized pain in a thrombosed vein
  • Compartment syndrome: Severe pain out of proportion to clinical signs, often after trauma
• What are the key signs and symptoms of DVT?


  • Unilateral erythema
  • Warmth
  • Swelling
  • Pain in the affected area
  • Distention of superficial veins
• What are the steps in the Two-Level DVT Wells Score assessment?


  1. If 'likely' (2 points or more): Proximal leg vein ultrasound within 4 hours

  • Positive: Start anticoagulant treatment
  • Negative: Arrange D-dimer test

  1. If 'unlikely' (1 point or less): Perform D-dimer test within 4 hours

  • Positive: Proximal leg vein ultrasound within 4 hours
  • Negative: DVT unlikely