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  • Rare incidence of neurologic complications due to hematoma formation
  • Epidural incidence <1:150,000
  • Spinal incidence <1:220,000
  • Risk factors:
    • Increased age
    • Spinal cord/spine abnormality
    • Underlying coagulopathy
    • Difficult/traumatic needle placement
    • Indwelling catheter during sustained anticoagulation therapy
    • If treatment with UFH or LMWH >4 days: check platelets prior to neuraxial anesthesia
    • LMWH high dose SC: enoxaparin 1 mg/kg q12 hours, enoxaparin 1.5 mg/kg q day, dalteparin 120 U/kg q12 hours, dalteparin 200 U/kg q day, tinzaparin 175 U/kg q day
  • Review medical record to determine concurrent use of medications that affect other components of clotting mechanism
  • Traumatic tap in the setting of anticipated full anticoagulation with heparin: delay case for 24 hours


  • Morbidity of spinal hematoma is due to bleeding into a fixed space. Risk of nerve ischemia may be reduced when there is bleeding into peripheral neurovascular sheath as the sheath is an expandable space
  • Twenty-six published cases of significant bleeding after PNB, all of which resulted in neurologic recovery in 6–12 months
  • Risk of peripheral technique is not defined, but published cases suggest the greatest risk is blood loss as opposed to neurologic injury
  • No definitive recommendations for PNB
  • Deep plexus or PNB (paravertebral, psoas compartment, sciatic, possibly infraclavicular): ASRA recommends following neuraxial recommendations; probably too restrictive

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ASRA Guidelines for Neuraxial Blocks with Medications Interfering with Coagulation
DrugDoseIndicationTime from last dose to wait prior to catheter placementTime from last dose to wait prior to catheter removalTime needed to wait to redose after catheter removal
ASA, NSAIDsNo contraindication if only agent and no other concerns (e.g., thrombocytopenia)
Unfractionated heparin (UFH)5,000 U SQ q12ThromboprophylaxisNoneNoneNone
UFH5,000 U SQ q8ThromboprophylaxisNot recommended
UFHTherapeutic IV infusionDVT/PE treatment
  • 4–6 h
  • Check PTT
  • 2–4 h
  • Check PTT
1 h
UFHSurgeon-specificIntraoperative heparinization (vascular surgery)Catheter placement prior to UFH. Wait 1 h from needle placement to UFH administration
  • 2–4 h
  • Check PTT
1 h
UFHFullCPBInsufficient data
Low-molecular-weight heparin (LMWH)Low dose, q day dosingThromboprophylaxis10–12 h12 h2 h
LMWHLow dose, BID dosingThromboprophylaxisNot recommendedRemove catheter prior to initiating LMWH
  • 2 h
  • Wait 24 h postoperatively regardless of anesthetic technique
LMWHHigh doseThromboembolism treatment24 h. Ideally catheter removed prior to treatment initiation24 h2 h
WarfarinTherapeutic4–5 days; check INR:
  • INR normal if therapeutic
  • INR <1.5 if only one dose given
Clopidogrel (Plavix®)7 daysWithin 24 h of starting dose. If greater than 48 h, wait 7 days24 h
Ticlopidine (Ticlid®)14 days14 days24 h
Abciximab (ReoPro®)24–48 h
Eptifibatide (Integrilin®)4–8 h
Tirofiban (Aggrastat®)4–8 h
  • Fondaparinux (Arixtra®)
  • Indirect factor Xa inhibitor
  • 2.5 mg SQ q day
  • 5–10 mg SQ q day
  • DVT prophylaxis
  • DVT/PE therapy
24 h36 h12 h
  • Rivaroxaban (Xarelto®)
  • Direct factor Xa inhibitor
  • 10 mg ...

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