Deep Vein Thrombosis- Treatment
Cardiovascular, Hematological / Oncological
Context
- Deep vein thrombosis (DVT) is common, with over 45,000 cases diagnosed in Canada each year.
- Complications can include pulmonary embolism (PE) and post-thrombotic syndrome.
- The mainstay of treatment is anticoagulation.
- Of note, the misleadingly named superficial femoral vein is a part of the deep venous system, and thrombus identified in this vein must be treated.
Recommended Treatment
- Most patients with DVT can be treated with oral anticoagulation therapy alone. There are a number of initial treatment regimens recommended by Thrombosis Canada but the two more commonly recommended regimes are:
- Apixaban 10 mg PO BID for 1 week before reducing dose to 5 mg PO BID.
- 10 mg BID for 7 days, followed by 5 mg BID. Apixaban is not recommended in patients with CrCl <15 mL/min or for those undergoing dialysis.
- Rivaroxaban 15 mg PO BID for 3 weeks before reducing dose to 20 mg PO once daily.
- Same cautions with respect to renal function as with Apixaban.
- Equally efficacious with less bleeding complications.
- Apixaban 10 mg PO BID for 1 week before reducing dose to 5 mg PO BID.
- Duration of therapy is a minimum of three months.
- Other regimes include:
- Full-dose low molecular weight heparin (LMWH) overlapping with warfarin for at least 5 days and until the INR > 2.0 for >2 days.
- Full-dose IV heparin overlapping with warfarin for at least 5 days and until the INR is at least 2.0 for at least 2 days.
- Full-dose SC LMWH or IV heparin for at least 5-10 days before switching to dabigatran 150 mg PO BID.
- Full-dose LMWH for the 1st month or so before switching to a DOAC or warfarin.
- Special Situations
- Pregnancy/Breastfeeding
- LMWH alone recommended. Dalteparin or enoxaparin.
- DOAC’s contraindicated.
- Malignancy: Case by case decision: risk of thrombosis/ bleeding, specific malignancy, prognosis.
- Heart Valve Replacements: LMWH and Warfarin only.
- Massive DVT: For patients with massive lower extremity DVT (Phlegmasia Cerulea Dolens – severe cyanosis and swelling of the affected leg – and Phlegmasia Alba Dolens – thrombosis without ischemic changes as some collateral flow) involving the proximal deep veins mechanical and catheter-directed thrombolysis can be considered within 14 days of symptom onset. Intravenous UFH should be used pre-thrombolytic therapy.
- Pregnancy/Breastfeeding
- Isolated distal DVT
- Anticoagulation is generally suggested if:
- Severe symptoms.
- Risk factors for extension (thrombus greater than 5 cm in length, involvement of multiple deep veins, close to the popliteal vein, no reversible risk factor, previous VTE, in-patient, active cancer, or positive D-dimer),
- Unable or unwilling to return for serial studies.
- Has progression of the DVT on repeat imaging.
- Duration at least 3 months.
- Anticoagulation is generally suggested if:
- Upper extremity DVT (UEDVT)
- Treatment should generally follow the principles for lower extremity DVT.
- Thrombolysis may be considered on a case-by-case basis if limb compromise.
- Superficial vein thrombosis (SVT)
- If within 3 cm of saphenofemoral junction or the saphenopopliteal junction treat DVT as high risk of progression into the deep venous system. These patients should also receive therapeutic doses of anticoagulation for 3 months.
- In patients with a contraindication to anticoagulation or increased risk of bleeding a vena cava filter can be considered to reduce the risk of pulmonary embolism.
Criteria For Hospital Admission
- Outpatient treatment of DVT is preferred.
- Factors that may contribute to hospitalization of patients with DVT include severe symptoms, phlegmasia cerulea dolens, hemodynamic instability, high risk of bleeding and renal failure.
Criteria For Transfer To Another Facility
- Transfer to an acute care centre may be indicated for patients that are hemodynamically unstable, or require further management such as mechanical and catheter-directed thrombolysis or vena cava filter insertion.
Criteria For Close Observation And/or Consult
- Consider internal medicine consult for patients that meet criteria for hospital admission.
- Referral to a venous thromboembolism or internal medicine clinic should be considered for optimization of anticoagulation choice and regimen.
Criteria For Safe Discharge Home
- Criteria for safe discharge home may differ on a case-by-case basis but generally includes patients that:
- Are hemodynamically stable.
- Are ambulatory.
- Have a low risk of bleeding on anticoagulation.
- Do not have renal failure.
- Are compliant with their treatment regimen.
- Have a plan to follow up in the community.
Quality Of Evidence?
High
We are highly confident that the true effect lies close to that of the estimate of the effect. There is a wide range of studies included in the analyses with no major limitations, there is little variation between studies, and the summary estimate has a narrow confidence interval.
Moderate
We consider that the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. There are only a few studies and some have limitations but not major flaws, there are some variations between studies, or the confidence interval of the summary estimate is wide.
Low
When the true effect may be substantially different from the estimate of the effect. The studies have major flaws, there is important variations between studies, of the confidence interval of the summary estimate is very wide.
Justification
This management strategy has been approved and developed by Thrombosis Canada.
Related Information
Reference List
Thrombosis Canada – DVT Clinical Guides, 2016.
Thrombosis Canada – Indications for Vena Cava Filter (VCF), 2015.
Kearon C. Natural history of venous thromboembolism.Circulation 2003;107:I22-30.
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Mammen EF. Pathogenesis of venous thrombosis. Chest. 1992 Dec;102(6 Suppl):640S-644S.
Wells PS, Forgie MA, Rodger MA. Treatment of venous thromboembolism. JAMA 2014;311(7):717- 728.
Relevant Resources
DISCLAIMER
The purpose of this document is to provide health care professionals with key facts and recommendations for the diagnosis and treatment of patients in the emergency department. This summary was produced by Emergency Care BC (formerly the BC Emergency Medicine Network) and uses the best available knowledge at the time of publication. However, healthcare professionals should continue to use their own judgment and take into consideration context, resources and other relevant factors. Emergency Care BC is not liable for any damages, claims, liabilities, costs or obligations arising from the use of this document including loss or damages arising from any claims made by a third party. Emergency Care BC also assumes no responsibility or liability for changes made to this document without its consent.
Last Updated Dec 04, 2020
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