Immediate Warfarin Reversal
› First-line management
› Stop warfarin immediately upon clinical suspicion
› Do not wait for biopsy confirmation before stopping warfarin
› Document warfarin as causative adverse drug reaction in medical record
› Vitamin K (phytonadione) IV for warfarin reversal
› Dose: phytonadione 10 mg IV over 30-60 minutes
› Repeat dosing based on INR response at 6-12 hours
› Oral vitamin K 5-10 mg daily for ongoing reversal in stable patients
› Continued anticoagulation strategy
› Therapeutic unfractionated heparin (UFH) for ongoing anticoagulation
› UFH bolus 80 units/kg IV followed by infusion 18 units/kg/hour
› Titrate to aPTT 60-100 seconds (1.5-2.5 times normal)
› Confirm HIT excluded before initiating heparin
› If HIT confirmed or suspected, use argatroban or fondaparinux instead of heparin
› Argatroban 2 mcg/kg/minute IV infusion, titrate to aPTT 1.5-3 times baseline
› Maximum argatroban 10 mcg/kg/minute; reduce to 0.5 mcg/kg/minute in hepatic impairment
› Protein C repletion therapy
› Protein C concentrate (human): first-line if available
› Dose: 60-80 units/kg IV based on protein C activity level
› Goal protein C activity level >100% of normal
› Demonstrated arrest of necrosis progression within 24 hours
› Adjust dose by monitoring protein C activity every 6-12 hours
› Fresh frozen plasma (FFP): alternative if protein C concentrate unavailable
› Dose: 10-15 mL/kg IV; provides protein C and other clotting factors
› Less effective than protein C concentrate due to volume limitations
› Repeat every 8-12 hours as needed for protein C repletion
› Surgical and wound care
› Surgical debridement of clearly necrotic tissue
› Timing: once anticoagulation established and necrosis fully demarcated
› Avoid premature debridement before necrosis demarcation
› Wound dressings: moist wound environment to promote healing
› Negative pressure wound therapy for large wounds post-debridement
› Skin grafting for extensive full-thickness wounds following debridement
› Split-thickness skin graft once wound bed clean and vascular supply confirmed
› Monitor for secondary bacterial infection with wound cultures if purulence develops
Long-Term Anticoagulation Strategy
› Post-acute anticoagulation planning
› Transition to direct oral anticoagulant (DOAC) if continued anticoagulation indicated
› DOACs (apixaban, rivaroxaban, dabigatran) do not carry risk of WISN
› Preferred over warfarin rechallenge in patients with WISN history
› If warfarin must be restarted (rare, high-risk situations only)
› Initiate at low dose 2-5 mg/day, never use loading doses
› Concurrent therapeutic heparin or LMWH bridging for minimum 5-7 days
› Ensure therapeutic INR on two consecutive days before stopping heparin bridge
› Document WISN as warfarin allergy/adverse drug reaction in all medical records
Show 19 more ▾