Vitamin K antagonists

We recommend that VKAs should not be interrupted in patients undergoing low bleeding risk procedures: skin surgery, dental and oral procedures, gastric and colonic endoscopies (even if biopsy is scheduled, but not polypectomies), nor for most ophthalmologic surgery [i.e. mainly anterior chamber (cataract)]. 1C

We recommend that for low or moderate thrombotic risk patients [e.g. atrial fibrillation patients with CHADS2 score ≤4; patients treated for >3 months for a nonrecurrent venous thromboembolism (VTE)] undergoing procedures requiring INR less than 1.5, VKA should be stopped 3 to 5 days before surgery (acenocoumarol, warfarin). No bridging therapy is needed. Measure INR on the day before surgery and give 5mg oral vitamin K if INR exceeds 1.5. 1C

We recommend bridging therapy for high thrombotic risk patients (e.g. atrial fibrillation patients with a CHADS2 score >4; patients with recurrent VTE treated for less than 3 months; patients with a prosthetic cardiac valve). Warfarin: last dose 5 days before surgery; 4 days before surgery, no heparin; 3, 2 and 1 day before surgery, LMWH (last dose 24 h before surgery) or SC UFH twice or thrice daily; day 0, surgery. Acenocoumarol: 3 days before surgery, last dose; 2 and 1 day before surgery, same protocol as for warfarin. 1C

We suggest that the therapeutic dose of LMWH or UFH should be tailored for each patient, depending on the respective thrombotic and bleeding risks. 2C

We recommend that for low bleeding risk patients, VKAs should be restarted during the evening or the day after the procedure (at least 6 h after). Therapeutic doses of LMWH should be given postoperatively until the target INR is observed in two following measurements. 1C

We recommend that for moderate to high thrombotic risk patients, prophylactic doses of heparin (UFH orLMWH) should be started during the evening or the day after the procedure (at least 6 h after) and given for up to 48 to 72 h, and then therapeutic anticoagulation should be resumed. VKA can restart at that time or later, only when surgical haemostasis is achieved. 1C

In VKA-treated patients undergoing an emergency procedure, we recommend that INR must be measured on the patient’s admission to the hospital, with the administration of four-factor PCC to reverse VKA anticoagulant effects (e.g. at an initial dose of 25 IU factor IX kg-1 at an INR of 4) rather than the transfusion of plasma. 1B

In bleeding patients where VKA-induced coagulopathy is considered a contributing factor, we recommend the administration of four-factor PCC 25 to 50 IU factor IX kg-1 plus 5 to 10mg IV vitamin K. 1B

If PCC is not available, then in bleeding patients where VKA-induced coagulopathy is considered a contributing factor, we recommend the transfusion of plasma (15 to 20 ml kg-1 plus 5 to 10mg IV vitamin K). 1C