Bleeding or High INR on Warfarin or other Anticoagulation

🩸 Key Principle: In any patient with life-threatening or uncontrolled bleeding while on anticoagulants, stop the anticoagulant immediately, resuscitate, identify the source of bleeding, and reverse anticoagulation urgently when indicated. Take senior and haematology advice early, especially if the patient is on multiple agents, has renal failure, liver disease, or possible intracranial haemorrhage.

🧭 Initial Assessment

• Assess whether the bleed is major / life-threatening:
  • haemodynamic instability
  • critical site bleeding (e.g. intracranial, retroperitoneal, pericardial)
  • Hb fall ≥2 g/dL
  • need for transfusion or procedural control
• Check:
  • which anticoagulant the patient is taking
  • when the last dose was taken
  • renal and liver function
  • other antithrombotics (antiplatelets, NSAIDs)
• Send urgent bloods:
  • FBC
  • PT/INR
  • APTT
  • fibrinogen
  • U&E / creatinine
  • LFTs
  • group and save / crossmatch
• Always investigate why the patient is over-anticoagulated or bleeding: drug interaction, renal impairment, liver disease, dosing error, underlying lesion, thrombocytopenia, DIC.

💥 Major Bleeding on Warfarin (VKA)

• Stop warfarin immediately. Give:
  • 4-factor PCC urgently (dose according to local protocol / product guidance)
  • IV vitamin K 5 mg
• PCC is preferred because it reverses warfarin rapidly and avoids the large volume load of FFP.
• FFP should generally be used only if PCC is unavailable. Repeat INR after reversal and reassess clinically.

🩹 Non-major Bleeding on Warfarin

• Hold warfarin and treat the source of bleeding.
• Low-dose vitamin K may be used depending on INR, bleeding severity, and thrombotic risk.
• Follow local warfarin over-anticoagulation protocols for repeat INR testing and dose adjustment.

⚖️ Raised INR Without Bleeding

• Management depends on the INR level and bleeding risk.
• Typical UK practice:
  • INR 5–8 or 5–10: hold warfarin; oral vitamin K may be considered if bleeding risk is high
  • INR ≥8 or ≥10: stop warfarin and give oral vitamin K
• Recheck INR and restart at a reduced dose when safe.

🧠 Suspected Intracranial Bleeding on Anticoagulants

• Urgent brain imaging is required. If the patient is on warfarin and intracranial haemorrhage is strongly suspected, urgent reversal with PCC + IV vitamin K is standard UK emergency practice.
• In DOAC-associated ICH, seek urgent stroke / neurosurgical / haematology input regarding specific reversal or PCC.

💉 Bleeding on Unfractionated Heparin (UFH)

• Stop UFH immediately.
• Check APTT and FBC. If bleeding is significant, give protamine sulphate.
• Protamine works quickly but heparin has a short half-life, so reassessment is important.

💉 Bleeding on LMWH

• Stop LMWH. Protamine sulphate only partially reverses LMWH effect, but it is still used in significant bleeding.
• The dose depends on timing and amount of the last LMWH dose.
• Seek haematology advice in ongoing or life-threatening bleeding.

💊 Bleeding on DOACs

• Stop the DOAC. Record the last dose and check renal function.
• Dabigatran: specific reversal with idarucizumab.
• Apixaban / rivaroxaban:
  • Andexanet alfa has a limited NICE role for life-threatening or uncontrolled GI bleeding
  • for other major bleeding, including many ICH cases, UK services often use PCC according to local protocol and specialist advice
• Edoxaban: no NICE-approved andexanet indication; reversal is generally protocol-driven with specialist input.

🧬 Bleeding After Thrombolysis

• Stop thrombolytic and any concurrent antithrombotic therapy.
• Send coagulation screen and fibrinogen urgently.
• If there is major bleeding or suspected thrombolysis-associated ICH, urgent specialist input is required.
• Management may include:
  • cryoprecipitate if fibrinogen is low
  • tranexamic acid
  • other blood products guided by results and clinical context

🔪 Anticoagulation Reversal Before Emergency Surgery

• If surgery can wait, lower anticoagulant effect in a controlled way if possible.
• If surgery is truly urgent and anticoagulation reversal is needed:
  • warfarin: PCC + IV vitamin K
  • UFH: protamine
  • LMWH: protamine partial reversal
  • DOACs: timing, renal function, and specific agent determine strategy

📚 Educational Summary

Anticoagulant reversal is a time-critical balance between haemostasis and thrombosis. For warfarin, the core message remains: PCC for rapid reversal, vitamin K for sustained reversal. For heparins, the antidote is protamine. For DOACs, modern practice increasingly depends on drug-specific reversal where available, local pathways, and specialist advice.

📚 References

• British Society for Haematology – Management of bleeding in patients on antithrombotic agents
• British Society for Haematology – Oral anticoagulation with warfarin (4th edition)
• NICE TA697 – Andexanet alfa for reversing anticoagulation from apixaban or rivaroxaban
• NICE TA1029 – Andexanet alfa for reversing anticoagulation in people with intracranial haemorrhage (terminated appraisal)
• BNF/NICE – Oral anticoagulants