What is the management plan for a patient with a history of thromboembolic events on warfarin (anticoagulant) who develops a gluteal hematoma?

Management of Gluteal Hematoma in a Patient on Warfarin

Immediately discontinue warfarin and administer 4-factor prothrombin complex concentrate (PCC) 25-50 U/kg IV plus vitamin K 5-10 mg by slow IV infusion over 30 minutes, targeting INR <1.5. 1, 2

Immediate Reversal Strategy

For a gluteal hematoma in a warfarin-anticoagulated patient, this represents major bleeding requiring urgent reversal. The specific PCC dosing should be based on the presenting INR: 2

• 25 U/kg for INR 2-4
• 35 U/kg for INR 4-6
• 50 U/kg for INR >6

Always co-administer vitamin K 5-10 mg IV by slow infusion over 30 minutes because factor VII in PCC has only a 4-6 hour half-life, requiring vitamin K to stimulate endogenous production of clotting factors and prevent rebound elevation of INR. 1, 2

Why PCC Over Fresh Frozen Plasma

4-factor PCC is superior to fresh frozen plasma (FFP) for warfarin reversal because it achieves INR correction within 5-15 minutes versus hours with FFP, requires no ABO blood group matching, and carries minimal risk of fluid overload or transfusion-related acute lung injury. 1, 2 The 2024 World Society of Emergency Surgery guidelines give a strong recommendation (1A evidence) for using 4-factor PCC with vitamin K for life-threatening bleeding, and recommend FFP only if no other treatment is available. 1

Monitoring and Supportive Care

• Obtain baseline hemoglobin and recheck serially to assess for ongoing bleeding 3
• Use restrictive transfusion thresholds: hemoglobin trigger of 70 g/L with target 70-90 g/L in stable patients, or trigger of 80 g/L with target 100 g/L in patients with cardiovascular disease 1
• Recheck INR after reversal to confirm adequate correction to <1.5 1, 2
• Consider imaging (CT or ultrasound) of the gluteal region to assess hematoma size and rule out active extravasation or compartment syndrome

Critical Vitamin K Dosing Considerations

Use the full 5-10 mg dose of vitamin K for major bleeding. While lower doses (<5 mg) may be considered in patients requiring early re-anticoagulation to reduce warfarin resistance, a gluteal hematoma represents significant bleeding that warrants full reversal. 2 High-dose vitamin K (≥10 mg) creates a prothrombotic state and prevents re-warfarinization for several days, which is appropriate in this acute bleeding scenario. 2

Timing of Warfarin Resumption

Do not restart warfarin within the first 3 days due to twofold increased risk of rebleeding. 2, 4 The timing of resumption depends on thromboembolic risk stratification: 1, 4

• High thrombotic risk patients (prosthetic metal heart valve in mitral position, atrial fibrillation with prosthetic valve or mitral stenosis, <3 months after venous thromboembolism): Consider bridging with low molecular weight heparin at 48 hours after hemostasis is achieved 4

• Low thrombotic risk patients (standard atrial fibrillation without high-risk features): Resume warfarin at 7-15 days after hemorrhage stops, as this window reduces thromboembolic events and mortality without increasing rebleeding 1, 4

Common Pitfalls to Avoid

• Do not delay PCC administration waiting for INR results - treat based on clinical suspicion when warfarin use is known 1
• Do not use FFP as first-line therapy when PCC is available, as it is inferior for rapid reversal 1, 5
• Do not omit vitamin K when giving PCC, as this leads to rebound INR elevation after factor VII wears off 1, 2
• Do not restart warfarin too early (<3 days) as this doubles rebleeding risk without reducing thrombotic complications 2, 4
• Do not use recombinant factor VIIa as first-line therapy for warfarin reversal 1