Neuraxial Anesthesia in the Anticoagulated Pt

This is a summary derived from the 2010 ASRA guidelines on neuraxial anesthesia and anticoagulation.  The following statements are assuming that there are no other diseases or drugs present that alter coagulation.  In those instances, variations may occur at the discretion of the attending anesthesiologist/surgeon.  In addition, the risk benefit ratio for each individual patient must be assessed and may require variance from these suggested guidelines.  The reader is referred to the complete article found in RAPM, 35 (1) 2010 for more information.
Unfractionated Heparin.

1.  During subcutaneous 5000U q12h prophylaxis there is no contraindication to the use of neuraxial techniques.  The risk of neuraxial bleeding may be reduced by delaying the heparin until after the block.  Epidural catheters should be removed just prior to the next dose of heparin and the dose delayed 2 hours.

2.  The risk of neuraxial bleeding may be increased in debilitated patients after prolonged therapy.

3.  Since heparin-induced thrombocytopenia may occur during heparin administration, patients receiving heparin for greater than four days should have a platelet count assessed prior to neuraxial block and catheter removal.

4.  Heparin 5000U sc q8h may lead to increased risk of bleeding.  Risks and benefits should be assessed on an individual basis and avoid other medications that may alter coagulation (ie nsaids).  ASRA advises that patients not receive q8h heparin while epidural analgesia is maintained, but recognizes that many centers do it.

5.  Neuraxial techniques with intra-operative iv heparin during vascular surgery:
    •    Heparin administration should be delayed for 1 hour after needle placement.
    •    Avoid if patient has other coagulopathies
    •    Monitor neurological function postoperatively
    •    Although the occurrence of a bloody or difficult neuraxial needle placement may increase risk, there are no data to support mandatory cancellation of a case. Direct communication with the surgeon and a specific risk-benefit decision about proceeding in each case is warranted.

Low Molecular Weight Heparin (LMWH)
1.  Preoperative LMWH   
    •    If LMWH has been administered preoperatively LMWH should be held for 24 hrs prior to a neuraxial technique.

2.  Postoperative LMWH  
    •    Avoid other drugs that affect hemostasis
    •    Presence of blood during needle or catheter placement does not necessitate postponement of surgery.  In those cases the first dose of LMWH should be delayed for 24 hrs postoperatively and it is the responsibility of the anesthesiologist to discuss this with the surgeon.  At KGH, LMWH is routinely given at 0900h each day.
    •    Twice daily dosing. It is recommended that the first dose of LMWH be administered no earlier than 24 hours postoperatively.  Indwelling catheters should be removed prior to initiation of LMWH thromboprophylaxis.
    •    Single daily dosing. It is recommended that the first postoperative LMWH dose be administered no sooner than 6-8 hours postoperatively. The second postoperative dose should occur no sooner than 24 hours after the first dose.

Oral Anticoagulants
1.  The anticoagulant therapy (warfarin) must be stopped 5 days prior to the planned procedure

2.  PT/INR measured prior to initiation of neuraxial block.  INR should be within the normal range   for any neuraxial technique

3.  Catheters should not be removed unless the INR is <1.5.  Neurological assessments may be continued for 24 hours in certain instances
 
Antiplatelet Medications
1.  ASA and NSAIDs, when prescribed on their own, appear to present no added significant risk for the development of spinal hematoma in patients having epidural or spinal anesthesia.

2.  The suggested time interval between discontinuation of thienopyridine therapy and neuraxial blockade is 14 days for ticlopidine (Ticlid) and 7 days for clopidogrel (Plavix).  There is no data available for Aggrenox so, until we have appropriate data to the contrary, we suggest discontinuation 7-14 days before neuraxial blockade.

3.  Following administration, the time to normal platelet aggregation is 24-48 hours for abciximab and 4-8 hours for eptifibatide and tirofiban. GP IIb/IIIa antagonists are contraindicated within four weeks of surgery.
 
Herbal Therapy
1.  The use of herbal medications alone does not create a level of risk that will interfere with the performance of neuraxial blocks.
 
Direct Thrombin Inhibitors
1.  ASRA recommends against performance of neuraxial techniques in patients receiving these drugs 
 
Fondaparinux
1.  Until there is more data, neuraxial techniques should be avoided unless under conditions used in clinical trials.

Peripheral Nerve Blocks
1.  For patients undergoing deep plexus or peripheral nerve blcok, it is recommended to follow the guidelines for neuraxial techniques