Perioperative Management of a Patient on Anticoagulation

The planned management is partly appropriate but requires modification. Stopping warfarin 5 days before the procedure is correct, as the INR should normalise. Bridging with enoxaparin is indicated for a mechanical mitral valve (high thrombotic risk), but the dose and timing should be adjusted: enoxaparin 1 mg/kg twice daily is a therapeutic dose, which is appropriate for bridging, but the last dose should be given 24 hours before the procedure (or 12 hours if renal impairment) to reduce bleeding risk. Aspirin: for a mechanical valve, aspirin is often continued, but for colonoscopy with polypectomy, the bleeding risk is moderate; aspirin can usually be continued, but if bleeding risk is high, it may be stopped 3–5 days prior. However, in a patient with a mechanical valve, aspirin is usually continued because the thrombotic risk outweighs bleeding. The decision should be individualised. The polypectomy may increase bleeding risk, so the endoscopist should be informed. After the procedure, warfarin should be restarted within 24 hours if haemostasis is secure, and bridging continued until INR is therapeutic.

Recommend: check INR 5 days before procedure; stop warfarin; start enoxaparin 1 mg/kg twice daily when INR <2.0. Last enoxaparin dose 24 hours before procedure. Continue aspirin if bleeding risk is acceptable; if not, stop 3–5 days before. For colonoscopy with polypectomy, consider whether polypectomy can be deferred or performed with minimal bleeding risk. If polypectomy is necessary, ensure the endoscopist is aware of anticoagulation. Post-procedure: restart warfarin on the evening of the procedure (if no bleeding) and continue enoxaparin until INR ≥2.0. Monitor for bleeding. If bleeding occurs, consider reversal with vitamin K and prothrombin complex concentrate. Educate the patient about signs of bleeding and thrombosis. Coordinate with cardiology and haematology as needed.