PrintDownload PDFGet Adobe ReaderDownload to WordDownload as HTMLDownload as XMLCitation Manager
Save to Favorites
Guideline Summary
Guideline Title
Warfarin therapy - management during invasive procedures and surgery.
Bibliographic Source(s)
Medical Services Commission. Warfarin therapy - management during invasive procedures and surgery. Victoria (BC): British Columbia Medical Services Commission; 2010 Oct 1. 7 p. [8 references]
Guideline Status

This is the current release of the guideline.

Scope

Disease/Condition(s)

Conditions requiring invasive procedures and surgery in patients on warfarin therapy

Guideline Category
Management
Prevention
Risk Assessment
Clinical Specialty
Anesthesiology
Family Practice
Hematology
Internal Medicine
Pharmacology
Surgery
Intended Users
Physicians
Guideline Objective(s)

To provide recommendations for the management of warfarin therapy in British Columbia when the patient (19 years of age and over) requires invasive procedures and surgery

Target Population

Patients (19 years of age and over) in British Columbia requiring invasive procedures and surgery

Interventions and Practices Considered

Risk Assessment

  1. Pre-operative international normalization ratio (INR)
  2. Target peri-operative INR
  3. Risk of bleeding or thrombosis based on procedure
  4. Risk of thrombosis with warfarin discontinuation

Management

  1. Vitamin K
  2. Virally inactivated plasma-derived concentrate (Octaplex®)
  3. Frozen plasma
  4. Periprocedural bridging therapy
  5. Anesthetist and surgeon consultations
  6. Timing of procedure including warfarin reversal in elective surgeries/procedures and in urgent or emergent surgeries/procedures
  7. Type of anesthesia based on procedure
  8. Management based on risk of thrombosis including:
    • Discontinuation and restart of warfarin
    • Frequency of INR measurements
    • Differential diagnosis if no response to vitamin K
    • Use of low-molecular-weight heparin (LMWH)
Major Outcomes Considered
  • Incidence of hemorrhage
  • Incidence of thrombosis
  • Mortality
  • Change in international normalization ratio (INR)

Methodology

Methods Used to Collect/Select the Evidence
Searches of Electronic Databases
Description of Methods Used to Collect/Select the Evidence

Evidence was obtained through a systematic review of peer-reviewed literature (up to December 2009) using the databases MEDLINE, PubMed, EBSCO, Ovid, and the Cochrane Collaboration's Database for Systematic Reviews. Clinical practice guidelines from other jurisdictions for the management of warfarin during the peri-operative period, peri-operative bridging, excessive anticoagulation, virally inactivated plasma-derived concentrate, frozen plasma and target international normalized ratio (INR) during the peri-operative period were also reviewed (up to December 2009).

Number of Source Documents

Not stated

Methods Used to Assess the Quality and Strength of the Evidence
Not stated
Rating Scheme for the Strength of the Evidence

Not applicable

Methods Used to Analyze the Evidence
Review of Published Meta-Analyses
Systematic Review
Description of the Methods Used to Analyze the Evidence

Not stated

Methods Used to Formulate the Recommendations
Expert Consensus
Description of Methods Used to Formulate the Recommendations

Not stated

Rating Scheme for the Strength of the Recommendations

Not applicable

Cost Analysis

A formal cost analysis was not performed and published cost analyses were not reviewed.

Method of Guideline Validation
External Peer Review
Internal Peer Review
Description of Method of Guideline Validation

The guideline was developed by the Guidelines and Protocols Advisory Committee, approved by the British Columbia Medical Association, and adopted by the Medical Services Commission.

Recommendations

Major Recommendations

Therapeutic Measures for Reversal of Warfarin Therapy

Vitamin K

  • Intravenous (IV) delivery is the fastest and most reliable way to obtain the effect of vitamin K.
  • Intramuscular (IM) or subcutaneous delivery should be avoided.
  • If the procedure is in more than 24 hours, there is no difference between using IV and oral (PO).
  • Useful for post-operative periods as well
  • Excessive dose of vitamin K can lead to difficulty with re-anticoagulation.
  • Effect on international normalized ratio (INR) is observed after 8 to 12 hours, depending on route of administration. Recommended doses:
    • Oral 1 to 2 mg
    • IV 5 mg in 50 cc normal saline infused over 30 minutes

Virally Inactivated Plasma-derived Concentrate (Octaplex®)

  • Use only in consultation with specialist
  • Preferred product for rapid reversal of warfarin when available
  • Duration of action is about 6 hours, typically only one dose is needed
  • Virally inactivated plasma-derived concentrate containing factors II, VII, IX, X and Protein C and Protein S
  • Must be used in conjunction with IV vitamin K
  • Indicated for immediate INR reversal in patients:
    • With active, serious bleeding
    • Who require surgery within next 6 hours
  • Contains heparin and is contraindicated in patients with heparin induced thrombocytopenia and liver insufficiency (see product monograph)
  • May be associated with clinically important thrombosis

Frozen Plasma (FP)

  • Short duration (about 4 hours) of action
  • Indicated for rapid reversal when Octaplex® is not available
  • Slight risk of infectious agent transmission
  • Available in large centres; rural centres can have FP shipped quickly from nearby larger centres as needed

Considerations for Perioperative Anticoagulation

Note: Always consult with the surgeon and anesthesiologist about:
  • Risk of bleeding
  • Goal INR
  1. Acceptable INR for surgery
    1. Baseline INR is recommended in every case and this will guide further therapy.
    2. Always discuss with surgeon and anesthesiologist what the INR should be before surgery (goal INR).
    3. An INR <1.5 is generally acceptable except for neurosurgery, ocular surgery and procedures requiring spinal anesthesia or epidural analgesia (Horlocker et al., 2003).
  1. Risk of bleeding
    1. In general, the type of procedure determines the risk of bleeding and how long anticoagulation must be withheld post-operatively.
    2. Discontinuation of warfarin is essential for these procedures associated with a high risk of bleeding:
      1. Procedures that the body cavity is entered, e.g., open thoracic, abdominal or pelvic surgery
      2. Percutaneous needle procedures in non-compressible sites, including organ biopsies
      3. Any type of prostatic surgery
      4. Surgery sites where minor bleeding can cause significant morbidity (e.g., central nervous system [CNS] and intraocular procedures)
      5. Major arthroplasty surgery, e.g., hip or knee replacement
    1. Discontinuation of warfarin is usually not necessary for these procedures associated with a low risk of bleeding:
      1. Percutaneous needle procedures in readily compressible sites (e.g., peripheral venous access)
      2. Many skin procedures
      3. Routine dental procedures (e.g., hygiene, simple extractions, restorations, endodontics, prosthetics)
      4. Endoscopy without biopsy
    1. Assess the risk of bleeding from the procedure with the assistance of the surgeon and anesthesiologist.
  1. Risk of thrombosis and need for peri-procedural bridging therapy
    1. Determine risk of thrombosis
      1. Assess the risk of thrombosis from pre-existing conditions:

        Lower Risk Conditions

        • Newer model mechanical aortic valve prostheses and any tissue valves
        • Atrial fibrillation without additional risk factors for stroke
        • Deep vein thrombosis (DVT)/pulmonary embolism (PE) occurring more than three months ago
        • Hypercoagulable state without recent thrombotic episode, recurrent thrombosis or history of life-threatening thrombosis

        Higher Risk Conditions

        • Mechanical mitral valve & old model aortic prosthesis (e.g., ball, Bjork-Shiley, Lillehei-Kaster)
        • Atrial fibrillation plus, either history of stroke/transient ischemic attack (TIA), or ≥2 additional risk factors for cardioembolic events (recent cardiac failure, hypertension, age >75 years, diabetes – see the Medical Services Commission, British Columbia's guideline on Stroke and transient ischemic attack--management and prevention External Web Site Policy)
        • DVT/PE occurring within past three months
        • DVT/PE in patients with active cancer
        • Hypercoagulable state with recent thrombotic episode, recurrent thrombosis or history of life- threatening thrombosis
      1. Assess the risk of thrombosis from the procedure with the assistance of the anesthesiologist and surgeon.
  1. Management based on risk of thrombosis
    1. See Appendix A: Management Tool for Physicians in the original guideline document.
    2. Low risk of thrombosis (including risk associated with procedure)
      1. Discontinue warfarin 5 days prior to surgery (i.e., give last dose on day -6; to achieve 5 warfarin free days; day of surgery = day 0).
      2. Check INR the day before procedure to ensure it is lower than the goal INR (<1.5 for most procedures). If INR is higher than goal INR, discuss with physician performing procedure.
      3. Restart warfarin at pre-operative dose as soon as hemostasis is assured and only after epidural catheters are removed post surgery.
      4. Recheck INR within one week after starting warfarin at the last stable dose and resume regular monitoring and dose adjustment. Warfarin doses may change postoperatively if there were significant changes, for example, medication changes or change in nutrition.
    1. High risk of thrombosis (including risk associated with procedure)
      1. Discontinue warfarin at least 5 days prior to surgery (i.e., give last dose day -6 to achieve 5 warfarin free days; day of surgery = day 0). Stop 6 days prior if the target INR is 3.0 (range 2.5 to 3.5) (i.e., give last dose day -7 to achieve 6 warfarin free days; day of surgery = day 0).
      2. If indicated, start therapeutic dose of low-molecular-weight heparin (LMWH) on day -3 in consultation with local expert.
      3. Last dose of LMWH is generally not given any later than 24 hours before the procedure. Exact timing of the last LMWH dose will depend on the type and dose of LMWH and risk of thrombosis.
      4. Check INR the day before procedure to ensure it is below the goal INR (<1.5 for most procedures). If INR is higher than goal INR, discuss with physician performing the procedure.
      5. In the absence of an indicated procedure-specific thromboprophylactic regimen, start therapeutic or prophylactic dose LMWH 12 to 24 hours after surgery/procedure provided hemostasis is assured. Discuss dose and timing of post-operative LMWH with surgeon.
      6. Restart warfarin at pre-operative dose as soon as hemostasis is assured and only after epidural catheters are removed post surgery.
      7. Continue LMWH until the INR is in therapeutic range for two consecutive days.
      8. See Patient Guide: Schedule for Anticoagulation Medications in the original guideline document (see also "Patient Resources" field).
  1. Timing of procedure
    1. Whenever possible, surgery in a chronically anticoagulated patient should be undertaken on an elective basis to allow for planned anticoagulant reversal.
    2. In patients receiving a fixed duration of anticoagulation (e.g., 3 months), consider delaying invasive procedures until after the completion of anticoagulation.
    3. Urgent or emergent surgery/procedure - when an urgent or emergent surgery/procedure is required and warfarin reversal is indicated, perform a baseline INR and proceed as follows:
      1. Surgery/procedure to be done in <24 hours
        • Discontinue warfarin and administer IV vitamin K.
        • If surgery will be performed within 6 hours, Octaplex® is recommended (if not available then give FP).
        • Check INR immediately after product infusion and prior to surgery to document correction. If INR not corrected, consider repeat administration of Octaplex® or FP in consultation with specialist.
      1. Surgery/procedure to be done in 24 to 96 hours
        • Discontinue warfarin and administer IV or oral vitamin K.
        • Check INR in 24 hours.
        • If INR is not corrected after a dose of vitamin K, give another dose of IV vitamin K and recheck INR in 12 hours.
        • If INR is not corrected after 2 doses of vitamin K, consider other conditions that may elevate INR (e.g., disseminated intravascular coagulation [DIC], liver disease).
        • Check INR immediately prior to surgery to document correction.
      1. Elective surgery with planned anticoagulant reversal
        • Patient should be 5 or 6 days warfarin-free prior to surgery depending on therapeutic INR range.
        • Consider need for LMWH bridging therapy (see "Management based on risk of thrombosis" above and Patient Guide: Schedule for Anticoagulation Medications in the original guideline document; see also "Patient Resources" field).
        • Check INR one day prior to surgery or on day of surgery if possible, especially with high risk bleeding procedures.
  1. Type of anesthesia: elective, urgent, or emergent surgery/procedure
    1. Local and general anesthesia can be safely administered to a patient on warfarin.
    2. Neuraxial blocks (e.g., epidural analgesia, spinal anesthesia and retrobulbar blocks) should not be performed on patients on warfarin.
    3. If central venous access is needed, a compressible site is preferred.
    4. In patients with epidural catheters:
      1. Prophylactic dosing of LMWH is okay with an epidural in place.
      2. Do not give a therapeutic level dosing of LMWH with an epidural in place.
      3. Catheter should not be removed within 12 hours after a dose of LMWH.
      4. Do not start warfarin until epidural catheter is removed.
      5. Do not give LMWH until after 2 hours of catheter removal.
Clinical Algorithm(s)

A clinical algorithm on management of warfarin therapy during invasive procedures and surgery for a desired reversal INR of 1.5 or lower is provided in the appendices of the original guideline document.

Evidence Supporting the Recommendations

References Supporting the Recommendations
Type of Evidence Supporting the Recommendations

The type of supporting evidence is not specifically stated for each recommendation.

Benefits/Harms of Implementing the Guideline Recommendations

Potential Benefits

Adequate management of patients on warfarin undergoing invasive procedures and surgery to balance the risk of hemorrhage if the procedure were performed while on warfarin, and the risk of thrombosis if warfarin were discontinued

Potential Harms
  • An excessive dose of vitamin K can lead to difficulty with re-anticoagulation.
  • Virally inactivated plasma-derived concentrate (Octaplex®) may be associated with clinically important thrombosis.
  • There is a slight risk with frozen plasma of infectious agent transmission.

Contraindications

Contraindications

Octaplex® contains heparin and is contraindicated in patients with heparin-induced thrombocytopenia and liver insufficiency.

Qualifying Statements

Qualifying Statements

The Clinical Practice Guidelines (the "Guidelines") have been developed by the Guidelines and Protocols Advisory Committee on behalf of the Medical Services Commission. The Guidelines are intended to give an understanding of a clinical problem, and outline one or more preferred approaches to the investigation and management of the problem. The Guidelines are not intended as a substitute for the advice or professional judgment of a health care professional, nor are they intended to be the only approach to the management of clinical problems.

Implementation of the Guideline

Description of Implementation Strategy

An implementation strategy was not provided.

Implementation Tools
Clinical Algorithm
Patient Resources
Quick Reference Guides/Physician Guides
For information about availability, see the Availability of Companion Documents and Patient Resources fields below.

Institute of Medicine (IOM) National Healthcare Quality Report Categories

IOM Care Need
Staying Healthy
IOM Domain
Effectiveness
Patient-centeredness
Safety

Identifying Information and Availability

Bibliographic Source(s)
Medical Services Commission. Warfarin therapy - management during invasive procedures and surgery. Victoria (BC): British Columbia Medical Services Commission; 2010 Oct 1. 7 p. [8 references]
Adaptation

Not applicable: The guideline was not adapted from another source.

Date Released
2010 Oct 1
Guideline Developer(s)
Medical Services Commission, British Columbia - State/Local Government Agency [Non-U.S.]
Source(s) of Funding

Medical Services Commission, British Columbia

Guideline Committee

Guidelines and Protocols Advisory Committee

Composition of Group That Authored the Guideline

Not stated

Financial Disclosures/Conflicts of Interest

Not stated

Guideline Status

This is the current release of the guideline.

Guideline Availability

Electronic copies: Available in Portable Document Format (PDF) from the British Columbia Ministry of Health Web site External Web Site Policy.

Availability of Companion Documents

The following is available:

  • Warfarin therapy - management during invasive procedures and surgery. Summary of guideline. Victoria (BC): British Columbia Medical Services Commission; 2010 Oct. 2 p. Electronic copies: Available in Portable Document Format (PDF) from the British Columbia Ministry of Health Web site External Web Site Policy.
Patient Resources

The following is available:

  • Schedule for anticoagulation medications before and after surgery/procedure. Patient guide. Victoria (BC): British Columbia Medical Services Commission; 2010 Oct. 1 p. Electronic copies: Available in Portable Document Format (PDF) from the British Columbia Ministry of Health Web site External Web Site Policy.

Please note: This patient information is intended to provide health professionals with information to share with their patients to help them better understand their health and their diagnosed disorders. By providing access to this patient information, it is not the intention of NGC to provide specific medical advice for particular patients. Rather we urge patients and their representatives to review this material and then to consult with a licensed health professional for evaluation of treatment options suitable for them as well as for diagnosis and answers to their personal medical questions. This patient information has been derived and prepared from a guideline for health care professionals included on NGC by the authors or publishers of that original guideline. The patient information is not reviewed by NGC to establish whether or not it accurately reflects the original guideline's content.

NGC Status

This NGC summary was completed by ECRI Institute on March 31, 2011. The information was verified by the guideline developer on May 12, 2011. This summary was updated by ECRI Institute on March 10, 2014 following the U.S. Food and Drug Administration advisory on Low Molecular Weight Heparins.

Copyright Statement

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.

Disclaimer

NGC Disclaimer

The National Guideline Clearinghouse™ (NGC) does not develop, produce, approve, or endorse the guidelines represented on this site.

Read full disclaimer...