Venous Thromboembolism¶
Kenna Koehler
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), IBD, liver disease, hereditary thrombophilia
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 patient has a low pre-test probability, a negative D-dimer can rule out DVT
- In a high pre-test probability patient 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)
- Oral factor Xa inhibitors (rivaroxaban, apixaban)
- Intravenous unfractionated heparin
- Warfarin (with bridge therapy)
- Duration of treatment
- Provoked: 3 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)
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 patients 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
Last update:
2022-06-24 23:35:57