Canterbury DHB

Anticoagulation during Stem Cell Harvest

• The major adverse risk of all anticoagulant medications is bleeding.
• The potential bleeding risk must be balanced against the risk of developing a thrombosis while off anticoagulation.
• Consider the bleeding risk associated with indwelling catheters.
• The final decision on whether to stop anticoagulation and when is taken by the Haematologist caring for that patient.

General Guidelines for the Management of Patients on Oral Anticoagulation who are Undergoing a Procedure

• Those patients with a venous thromboembolism (VTE) within the previous 3 months; patients with atrial fibrillation (AF) and previous stroke, or TIA, or multiple other risk factors, and patients with a mitral mechanical heart valve (MHV) prosthesis should be considered for bridging therapy.
• Those patients with VTE more than 3 months earlier can be given prophylactic dose Low Molecular Weight Heparin (LMWH).
• Those patients with low risk AF (and with no prior stroke or TIA) do not require bridging therapy.
• Those patients with a bileaflet aortic MHV with no other risk factors do not require bridging.

Risk factors include: TIAs, CVAs, systemic emboli, AF, severe LV systolic dysfunction, recurrent CHF, prior VTE, hypercoagulable conditions.

Pre-Procedural Assessment:

• Reason for anticoagulation, type of anticoagulation taken, and the length of time the patient has been on anticoagulation.
• Can anticoagulation be safety withheld for the period of the procedure?
• What venous access will be used for the stem cell harvest?

Pre-Procedural Anticoagulation:

• Warfarin:

  Warfarin’s plasma half life is about 40 hours. The time to peak concentration is 24-48 hours.

  Reversal agent - Vitamin K for elective reversal in 6-8 hours, or Prothombinex for immediate reversal.

  • Check with Haematologist what the target INR is for the procedure.
  • If stopping warfarin, the patient will take their last dose of warfarin 5 days prior to the procedure.
  • Three days prior to the procedure check the patient’s INR, and if sub-therapeutic (i.e. <2.0) commence LMWH if indicated. If INR still over 2.0, recheck the INR the following day.
  • In patients who are receiving pre- procedure bridging with LMWH the last dose should be at least 24 h before procedure.
  • Warfarin can be resumed, at the normal maintenance dose, the evening of procedure or the next day as per haematologist instruction.
• Low Molecular Weight Heparin:

  The half life of Clexane is 4-5 hours.

  • For patients on LWMH, the last injection should be at least 24hrs pre-procedure.
  • Commencement of LMWH post-procedure is at the discretion of the Haematologist.
• New Oral Anticoagulants – Dabigatran:
  • Dabigatran - Pradaxa:

    Dabigatran (a direct factor lla, or thrombin, inhibitor) half-life is 12-14 hours. The agent reaches maximum effect 1.5 to 3 hours after an oral dose.

    Daracizumab (Praxbind) is a monoclonal antibody which binds to and reverses the effect of dabigatran.

    • If stopping dabigatran, discontinue drug 24 hours before procedure and measure thrombin time. The thrombin time is sensitive to the presence of dabigatran and a normal result confirms the absence of dabigatran. If the patient has renal impairment dabigatran may need to be stopped greater than 24 hours pre-procedure.
    • Commencement of Dabigatran post-procedure is at the discretion of the Haematologist.

References

Haemostasis Service Standing Orders – June 2011.

CDHB Haematology Service Protocols and Guidelines “The Red Book” – Thrombotic Disorders.

CDHB Management Guidelines For Common Medical Conditions “The Blue Book" (15th Edition, 2013) - Haematology.

‘New Anticoagulant Reversal’ Document -July 2010

PHARMAC Guidelines for Testing and Peri-operative Management of Dabigatran.

Topic Code: 86787