II. Indications

  1. Patients on Anticoagulation undergoing surgery

III. Background

  1. Follow decision tree below for whether Bridging Therapy is required (based on surgical bleeding risk and Thromboembolism risk)

IV. Pitfalls

  1. Over Anticoagulation or premature use results in significantly increased bleeding complications
  2. Bleeding complications result in transfusions and stopping Anticoagulation which risks clots

V. Protocol: Simplified Bridging Protocol

  1. Day -7: Stop Aspirin (if appropriate), Obtain INR
  2. Day -5: Stop Warfarin, Check INR
  3. Day -3: Start Low Molecular Weight Heparin (LMWH) at full dose given every 12-24 hours
  4. Day -1:
    1. Stop or give half dose LMWH 12-24 hours before procedure
    2. Administer Vitamin K 1 mg PO if INR >1.5 (see normalization protocol below)
  5. Day 0: Surgery
    1. No LMWH
    2. Consider Fresh Frozen Plasma (FFP) if INR not at goal (see normalization protocol below)
    3. Restart Warfarin at 12-24 hours on evening of surgery (if adequate hemostasis and approved by surgery)
  6. Day 1:
    1. Continue Warfarin (if started)
    2. Consider restarting LMWH per therapeutic or prophylactic dosing depending on bleeding risk
      1. Surgeon decides the time to restart LMWH or Heparin based on surgery bleeding risk
        1. Restart of Anticoagulation is modified for active bleeding, Thrombocytopenia and other complications
        2. LMWH (typically Enoxaparin or Lovenox) is preferred over Unfractionated Heparin for bridging
        3. Moderate-High thromboembolic risk (see below)
          1. Consider low dose prophylactic dosing of Heparin or LMWH until surgery allows full Anticoagulation
        4. Moderate bleeding risk procedure
          1. May start Heparin or LMWH 24 hours after procedure (per surgeon discretion)
        5. High bleeding risk procedure
          1. May start Heparin or LMWH 48-72 hours after procedure (per surgeon discretion)
      2. Consult hematology for complex cases
      3. See below for how to choose dosing regimen
  7. Day 2-10: Obtain INR and stop LMWH when INR >2 for 2 consecutive days
    1. Anticipate by Day 5
    2. Use caution in postoperative Anticoagulation (risk of bleeding events)

VI. Protocol: Invasive procedures with moderate bleeding risk

  1. Indications: Procedures with high bleeding risk
    1. Neurosurgery
    2. Abdominal or pelvic procedures
    3. Orthopedic joint procedures
    4. Major ENT or oral surgery
    5. Endoscopy with biopsy
    6. Epidural Anesthesia
    7. Prolonged general anesthesia with intubation
  2. Low risk for Thromboembolism (<4% risk/year)
    1. Indications
      1. Single Venous Thromboembolism >12 months prior and no other Hypercoagulable risk factors
      2. Chronic Atrial Fibrillation without stroke and CHADS2 score <3
      3. New bileaflet aortic valve replacement (St. Jude or Medtronic)
        1. No Atrial Fibrillation or other stroke risk
    2. Management
      1. See bridging protocol above
      2. Stop Warfarin 4 days before surgery
      3. Allow INR to normalize
      4. Post-operative DVT Prophylaxis if indicated
      5. Restart Warfarin postoperatively
  3. Intermediate risk for Thromboembolism (4-10% risk/year)
    1. Indications
      1. Atrial Fibrillation with CHADS-2 Score 3-4
      2. Venous Thromboembolism in the last 3-12 months
      3. Recurrent Venous Thromboembolism
      4. Active cancer (treated in the last 6 months or on palliative cancer management)
      5. Non-severe Thrombophilia (e.g. Heterozygous Factor V Leiden, prothrombin gene mutation)
      6. Bileaflet aortic valve replacement and at least one risk factor
        1. Atrial Fibrillation
        2. Prior Cerebrovascular Accident or TIA
        3. Hypertension
        4. Diabetes Mellitus
        5. Congestive Heart Failure
        6. Age >75 yearsold
    2. Management
      1. See bridging protocol above
      2. Stop Warfarin 4 days before surgery
      3. Allow INR to decrease
      4. Start Anticoagulation 2 days before surgery
        1. Low dose Heparin 5000 U SC or
        2. Low Molecular Weight Heparin at prophylactic doses
      5. Restart low dose Heparin or LMWH postoperatively (hold for 24-48 hours postoperatively)
      6. Restart Warfarin immediately postoperatively
  4. High risk for Thromboembolism (>10% risk/year)
    1. Indications
      1. Venous Thromboembolism (PE, DVT) within last 3 months
      2. Cardiac Thromboembolism (any cause) within 1 month
      3. Cerebrovascular Accident in the last 6 months
      4. Atrial Fibrillation with one or more additional risks
        1. CHADS-2 Score 5-6 or
        2. Cerebrovascular Accident (CVA) in last 3 months or
        3. Rheumatic Valvular Disease
      5. Strong Thrombophilia
        1. Two or more Thrombophilia risks
        2. Antiphospholipid Antibody Syndrome (uncommon)
        3. Antithrombin III deficiency (rare)
        4. Protein C Deficiency
        5. Protein S Deficiency
      6. Mechanical Heart Valves
        1. Mitral valve replacement (any)
        2. Caged-Ball, Tilting disc or other older aortic valve replacement
        3. Higher risks
          1. Comorbidity (e.g. Congestive Heart Failure)
          2. Atrial Fibrillation with mechanical valve
        4. Exceptions: Lower risks (not needing bridging)
          1. New aortic valves (see above)
    2. Management
      1. See Bridging protocol above
      2. Stop Warfarin 4 days before surgery
      3. Allow INR to decrease
      4. Start Anticoagulation 2 days before surgery
        1. Full dose Heparin or
        2. Full dose Low Molecular Weight Heparin
      5. Hold Heparin before surgery
        1. Hold Heparin IV for 4-5 hours before surgery
        2. Hold LMWH for 12-24 hours before surgery
      6. Restart Heparin after procedure
      7. Restart Warfarin postoperatively

VII. Protocol: Procedures with low risk of bleeding

  1. Low risk of bleeding: Orthopedic or Gynecologic Surgery
    1. Lower Warfarin dose 4 to 5 days before surgery
    2. Target INR of 1.3 to 1.5 before surgery
    3. Restart Warfarin at regular dosing after surgery
    4. Consider adjunctive Heparin at 5000 U SC post-op
  2. Very low risk of bleeding
    1. Procedures
      1. Dental procedures (dental extraction, restoration, endodontic surgery)
      2. Cataract Surgery
      3. Dermatologic procedures
      4. Pacemaker and IACD placement
      5. Endoscopy without biopsy
    2. Protocol
      1. Continue Warfarin at current dose
      2. Keep INR < 3.0
      3. Only discontinue Warfarin for high bleeding risk
      4. Consider local bleeding control if needed (dental)
        1. Tranexamic acid
        2. Epsilon aminocaproic acid (Amicar) mouthwash (discuss with hematology and surgeon)

VIII. Protocol: Normalization of INR after stopping Coumadin

  1. Anticipate INR normalization after stopping for 4 days
    1. Bleeding risk is low when INR <1.5
  2. Indications for transiently stopping Coumadin
    1. Prolonged INR
    2. Surgery
  3. Factors predicting delayed INR decrease
    1. Advanced age (80 years or older)
    2. Coumadin sensitive (maintenance dose <15 mg/week)
    3. Decompensated Congestive Heart Failure
    4. Active malignancy
    5. Liver disease
    6. Concurrent medications that potentiate Coumadin
      1. See Coumadin Drug Interactions
  4. Options for reversal
    1. Vitamin K (preferred if >12 hours pre-operative)
      1. Time to surgery >24 hours
        1. Vitamin K 1.0-2.5 mg PO one dose
        2. Maximum Vitamin K dose: 5 mg (risk of resistance)
      2. Time to surgery 12-24 hours
        1. Vitamin K 0.5 mg IV slow infusion one dose
    2. Clotting Factor replacement (within 12 hours)
      1. Fresh Frozen Plasma (FFP) 15 ml/kg
  5. Example Protocol
    1. PM prior to surgery: Vitamin K 1-2.5 mg PO x1 dose
    2. AM of surgery: FFP if INR >1.5
    3. Post-operatively (12-24 hours): Anticoagulate
      1. See protocols above for agents and dosing

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