minimum coagulation parameters for safe invasive procedures in the ED

see also:

• clinical procedures in the ED

• need to weigh risk of causing a serious spinal haematoma or other bleeding complication vs benefits, if moderate risk but LP needed, consider flouroscopic LP to minimise bleeding risk
• aspirin and s/cut. heparin doses < 10,000 units/day are generally not regarded a C/I to LP - no evidence of any increased bleeding
• it is probably reasonable to continue thienopyridines such as clopidogrel if LP is emergent and needed to diagnose a life threatening disease ¹⁾
• avoid emergent LP if either:
  • clinical bleeding due to a coagulopathy
  • severe thrombocytopenia < 50-80,000/uL
  • INR > 1.4
  • anticoagulant Rx
    • if high thrombotic risk in cessation Rx and LP is needed to exclude life-threatening disease,consider emergent LP without reversing coagulopathy pending risk-benefit analysis (if on DOAC, consider with-holding and postponing LP for one day)
    • if low thrombotic risk, consider reversing coagulopathy and perform LP when INR is 1.5 or below
  • known haemophilia or von Willebrand disease
• elective LP and patients on antiplatelets / anticoagulants, if clinically permissible to with-hold ²⁾:
  • cease unfractionated intravenous heparin infusion 4 hours prior or after aPTT is in the normal range
  • cease subcutaneous unfractionated heparin 4-6hrs prior
  • cease LMW heparin 12hrs prior
    • In patients with renal insufficiency and in patients using therapeutic doses of enoxaparin this time should be prolonged to 24 hours
  • cease dabigatran 1-2 days prior, and use bridging unfractionated heparin as above if high thrombotic risk, and then can resume DOAC 6-7hrs after LP
  • cease warfarin 5-7 days prior
  • cease thienopyridines such as clopidogrel 1-2wks prior, and use aspirin instead
  • cease GP IIb/IIIa receptor antagonists such as tirofiban for 8hrs

• The efficacy of prophylactic FFP and platelet transfusions to avoid bleeding has never been demonstrated
• 4 units of FFP (volume 1200mL) increases most clotting factors by only ~10%
• Inappropriate FFP administration may cause the patient harm
  • Evidence from cardiac and liver surgery has demonstrated that morbidity and mortality are increased with increasing levels of blood product transfusion
  • Blood product transfusion leads to a linear increase in portal pressure and this is more likely to cause haemorrhage than the procedure itself
  • Other potential risks of inappropriate FFP administration include severe allergic reactions, transfusion associated circulatory overload (TaCO) and transfusion associated acute lung injury (TRALI). The most common cause of TRALI is FFP and platelet administration due to the high concentration of anti-leukocyte antibodies
  • AASLD guidelines recommend AGAINST the use of FFP administration before liver biopsies or paracentesis

• One apheresis unit is equivalent to 1 pool
• The usual dose in an adult patient is 1 pool and would be expected to increase the platelet count of a 70 kg adult by 20–40 x 10⁹/L
• Platelets should be transfused immediately before or during an invasive procedure for maximally effectiveness
• crossmatching is not required however platelets should be ABO and Rh (D) compatible with the recipient.

• Crossmatching is not required however cryoprecipitate should be ABO compatible with the recipient
• Cryoprecipitate is issued thawed by the hospital transfusion laboratory (time to thaw approx. 30 minutes).
• IF Fibrinogen is < 0.5g/L: transfuse ten (10) units of cryoprecipitate
• 1 unit of cryoprecipitate would be expected to increase the fibrinogen level by 0.1g/L
• Cryoprecipitate should be transfused one (1) prior to an invasive procedure
• If required, fibrinogen level can be measured 30 minutes after completion of the transfusion to determine if additional doses are needed.