Skip to content

Venous Thromboembolism

Lamiya Rodriguez

Background

  • Includes both deep vein thrombosis (DVTs) and pulmonary embolism (PE). See “Pulmonary Embolism” section in cardiology for more information on PEs
  • Risk factors for provoked DVT/PE
    • Major risk factors: major surgery >30 minutes, hospitalization > 3 days, C-section
    • Minor Risk Factors: surgery <30 minutes, hospitalization <3 days, pregnancy, estrogen therapy, reduced mobility >3 days
  • Non-transient risk factors: malignancy (active), myeloproliferative disorders, IBD, liver disease, hereditary thrombophilia (factor V Leiden and prothrombin gene mutations most common), antiphospholipid syndrome.

Evaluation

  • Asymmetric calf swelling of >2cm sensitivity and specificity for DVT of 60-70%
  • Wells’ Criteria for DVT can help guide diagnostic testing
    • If a pt has a low pre-test probability, a negative D-dimer can rule out DVT
    • In a high pre-test probability pt a negative D-dimer is less helpful
  • Whole-leg ultrasounds with doppler

Management

  • Prophylaxis: Padua score
    • Score > 4 high risk, recommend pharmacologic prophylaxis
      • Subcutaneous Low Molecular Weight Heparin (LMWH) or Subcutaneous Heparin
    • Score <4 is low risk; recommend ambulation and SCDs
  • Treatment (see anticoagulation section)
    • Subcutaneous low molecular weight heparin (LMWH, twice a day dosing)
    • Oral factor Xa inhibitors: rivaroxaban, apixaban
    • Intravenous unfractionated heparin
    • Warfarin (with bridge therapy)
  • Duration of treatment
    • Provoked: 3-6 months or until provoking factor (trauma, surgery, malignancy) is removed
    • Unprovoked: typically requires life-long anticoagulation along with assistance from hematology
  • Anticoagulation in malignancy
    • LMWH or DOAC (most evidence for apixaban and rivaroxaban) while malignancy still active
    • Avoid Rivaroxaban and Edoxaban in GI malignancies (increased rates of bleeding)
      • Note – in Anti-phospholipid syndrome, can only use warfarin

Additional Information

  • Should we get a follow up ultrasound?
    • A follow up ultrasound at the CONCLUSION of anticoagulation can help establish a post-treatment baseline and provide a baseline study for future comparison that can be critical for the diagnosis of recurrent/new DVT (which is very difficult to determine radiographically without a comparison imaging study)
  • What about IVC filters?
    • Select circumstances for these: In pts with acute DVT or PE and in whom anti-coagulation is absolutely contraindicated (thrombocytopenia, recent intra-cranial bleed, recent GI bleed) placement of a retrievable IVC filter should be discussed with Hematology and IR