Discrepancy between aPTT and AntiXa with UFH Table
  aPTT > target range aPTT in target range aPTT < target range
       
Anti Xa < target range Increase UFH Increase UFH
  • Refer to Anti Xa target only
  • Search for other causes of prolonged aPTT:
    • Factor VII, Factor IX, fibrinogen deficiency (>> consider repletion)
    • Factor XII deficiency (common, no increased bleeding risk)
    • Lupus anticoagulant, antiphospholipid antibodies (increased risk for thrombosis)
Anti Xa in target range
  • Consider hypercoagulable state
  • No change in UFH dose
 No change in UFH dose
Anti Xa > target range
  • Unlikely to occur;
  • Consider repeating labs
  • Consider repeating labs
  • Consider hypercoagulable state
 Decrease UFH