II. Precuations: Venous Thromboembolism Risk Reduction

  1. Early mobilization after surgery is critical
  2. Perioperative risk of VTE varies by surgery, anesthesia
  3. Decision to anticoagulate is individualized to patients
    1. Does the risk of bleeding outweigh the VTE Risk

III. Management: General

  1. Anticoagulation start varies per medication and risk
  2. Continue Anticoagulation for at least 10 days post-orthopedic surgery
  3. Indications for extended Anticoagulation (28-35 days)
    1. Total hip replacement
    2. Hip Fracture
    3. Other risk factors
      1. Obesity
      2. Prior Venous Thromboembolism
      3. Immobility
      4. Advanced age
      5. Comorbid active malignancy

IV. Management: Perioperative protocol for the Highest Risk Patients

  1. Criteria
    1. Major surgery in high risk patient over age 40 years
      1. Venous Thromboembolism
      2. Cancer
      3. Thrombophilia
    2. Surgery at highest risk of Thromboembolism
      1. Hip or knee arthroplasty
      2. Hip Fracture surgery
      3. Major surgery
      4. Acute spinal cord injury
  2. Management
    1. Anticoagulation options
      1. Low Molecular Weight Heparin
        1. Enoxaparin (Lovenox)
          1. Start: 40 mg SC 1-2 hours before surgery
          2. Then: 30 mg SC q12 hours (8-12 hours post-op)
        2. Dalteparin (Fragmin)
          1. Start: 5000 units SC 8-12 hours pre-op
          2. Then: 5000 units SC daily
      2. Warfarin with target INR 2-3
      3. Unfractionated Heparin 5000 units q8-12 hours
      4. Weight based Heparin nomogram
      5. Aspirin (not a first-line agent)
        1. Chest guidelines approved Aspirin for use as of 2012 in total knee arthroplasty or total hip arthroplasty (as alternative agent)
        2. However, Low Molecular Weight Heparin prevents 11 more major VTE events than Aspirin per 1000 patients when used for 35 days
        3. Dose 162 mg daily for at least 10-14 days (preferably 35 days in hip or knee replacement)
        4. (2012) Presc Lett 19(3): 16 [PubMed]
    2. Additional strategies (with Anticoagulation)
      1. Intermittent Pneumatic Compression stockings or
      2. Graduated Compression stockings or
      3. Foot and calf pumping devices
  3. Special circumstances: Prophylaxis after Total Knee Arthroplasty (TKA) or Total Hip Arthroplasty (THA)
    1. DVT Prophylaxis is recommended for a minimum of 14 days after TKA or THA (and ideally up to 35 days depending on mobility)
    2. Low Molecular Weight Heparin (e.g. Enoxaparin or Lovenox)
      1. Gold standard Subcutaneous Injection therapy continued for 14 days after surgery (no monitoring needed)
    3. Apixaban (Eliquis)
      1. Dose 2.5 mg orally twice daily for 14 days
      2. Compared with LMWH, Apixaban has equivalent efficacy in DVT Prophylaxis
    4. Rivoroxaban (Xarelto)
      1. Dose: 10 mg orally once daily for 14 days (no monitoring needed)
      2. Compared with LMWH, prevents 4 more DVTs, but is associated with 9 more serious bleeding events per 1000 patients
    5. Warfarin
      1. Variable dosing orally for 14 days (requires monitoring)
      2. Compared with LMWH, prevents 3 fewer DVTs, but is associated with 2 more fatal bleeding events per 1000 patients
    6. Aspirin
      1. Not recommended (see above)
    7. Dabigatran (Pradaxa)
      1. Not available in appropriate 220 mg dose for VTE prophylaxis in United States
    8. References
      1. (2014) Presc Lett 21(6): 31-2
  4. Special circumstances: Hip Fracture protocol
    1. Fondaparinux is preferred
    2. Heparin or LMWH started pre-operatively
      1. Delay 12-24 hours post-op if bleeding high-risk
    3. Continue LMWH, Warfarin or Fondaparinux post-op
      1. Continue for at least 10-14 days after surgery
      2. Consider continuing for 28 to 35 days post-op
  5. Special circumstances: Elective hip surgery
    1. Lose weight before surgery
    2. Ambulation before the second post-surgical day
  6. Special circumstances: Gynecologic Surgery
    1. Unfractionated Heparin is the preferred agent

V. Management: Perioperative for High Risk Patients

  1. Criteria
    1. Patient with Thromboembolism risk and
      1. Age over 60 years and nonmajor surgery or
      2. Age over 40 years and major surgery
  2. Management
    1. Low Molecular Weight Heparin or
      1. Enoxaparin (Lovenox)
        1. Start: 40 mg SC 1-2 hours before surgery
        2. Then: 30 mg SC q12 hours (8-12 hours post-op)
      2. Dalteparin (Fragmin)
        1. Start: 5000 units SC 8-12 hours pre-op
        2. Then: 5000 units SC daily (12-24 hours post-op)
    2. Unfractionated Heparin 5000 units q8-12 hours or
    3. Intermittent Pneumatic Compression stockings

VI. Management: Perioperative for Moderate Risk Patients

  1. Criteria
    1. Orthopedic Surgery (40-60% Thromboembolism risk)
    2. Thromboembolism risk and minor surgery
    3. No Thromboembolism risk
      1. Age over 60 years and nonmajor surgery or
      2. Age over 40 years and major surgery
  2. Management
    1. Low Molecular Weight Heparin (preferred) or
      1. Enoxaparin (Lovenox)
        1. 30 mg SC q12 hours (start 12-24 hours post-op) or
        2. 40 mg SC daily (start 12 hours post-op)
      2. Dalteparin (Fragmin)
        1. Start: 5000 units SC 8-12 hours pre-op
        2. Then: 5000 units SC daily (12-24 hours post-op)
      3. Tinzaparin (Innohep)
        1. Start: 3500 units SC 2 hours before surgery
        2. Then: 3500 units SC daily
    2. Unfractionated Heparin 5000 units q8-12 hours or
    3. Intermittent Pneumatic Compression stockings or
  3. Special Circumstances: Total Knee Replacement
    1. Low Molecular Weight Heparin is preferred

VII. Management: Perioperative for Low Risk Patients

  1. Criteria
    1. Minor surgery in age <40 and no Thromboembolism risk
  2. Management
    1. No Anticoagulation
    2. Early mobilization
    3. Consider graduated Compression stockings

VIII. Management: Other indications for prophylaxis

  1. Major Trauma or acute spinal cord injury
    1. Assumes patient is hemodynamically stable
    2. Start 12 to 24 hours after injury
    3. Enoxaparin (Lovenox) 30 mg SC every 12 hours
  2. Long leg cast above knee (especially in elderly)
    1. Kock (1995) 346:459-61 [PubMed]

IX. Resources

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