warfarin high risk

Preoperative

• Withold warfarin 5 days prior to surgery

• Monitor INR; once <2 start S/C enoxaparin 1.5mg/kg OD. (Reduce dose to 1mg/kg OD if creatinine clearance <30ml/min).

• Day prior to surgery; if INR >1.,5 give 1-2mg Po vitamin K. Last dose of enoxaparin must be at least 24 hours prior to surgery.

• Morning of surgery; if INR >1.5 defer sugery or if urgent consider Prothrombinex-VF (30-50 U/kg) plus FFP (1 unit, 275ml).

Postoperative

• Restart on the night of surgery, at the previous maintenance dose, only if there is no evidince of significant haemorrhage.

• 12-24hrs post op: If low bleeding risk, start therapeutic LMWH or herparin. If using UFH, aim to prolong the APTT by 1.5 times.

• If bleeding risk is high, use prophylactic dose LMWH or UFH.

• Intermediate dosing (40mg BD) may be appropriate for patients with AF or VTE within the preceeding months when bridging is needed but concerns about bleeding are greater.

• Delay therapeutic LMWH for 48-72 hours postop as long as there is evidence of bleeding.

Cease heparin or LMWH 48 hours after the target INR is reached.