How to reverse anticoagulation with Warfarin (Coumadin) for surgical procedures?

From the Guidelines

To reverse Coumadin (warfarin) for surgery, stop the medication 3 to 4 days before the procedure and restart postoperatively as soon as bleeding risk allows, with bridging anticoagulation with intravenous UFH or subcutaneous LMWH started when the INR falls below the therapeutic threshold, usually 36 to 48 hours before surgery, and stopped 4 to 6 hours before the procedure. For patients at high risk of thromboembolism, bridging with low molecular weight heparin (LMWH) such as enoxaparin 1 mg/kg twice daily, starting 3 days after stopping warfarin and continuing until 24 hours before surgery, is recommended 1. For urgent reversal, administer vitamin K 2.5-5 mg orally or 1-2 mg IV, which will begin lowering the INR within 4-6 hours but takes 24 hours for full effect 1. For immediate reversal in emergency situations, use prothrombin complex concentrate (PCC) at 25-50 units/kg or fresh frozen plasma (FFP) at 10-15 mL/kg, along with vitamin K 1. After surgery, restart warfarin 12-24 hours post-procedure if hemostasis is adequate, and continue bridge therapy with LMWH until the INR returns to therapeutic range. Monitor INR closely during this transition period.

Some key points to consider:

• The management of patients treated with warfarin who require interruption of anticoagulation for surgery or other invasive procedures can be problematic, and several approaches can be taken according to the risk of thromboembolism 1.
• For patients with mechanical valves on long-term VKA therapy who require emergency surgery or invasive procedures, anticoagulation can be reversed by administration of intravenous prothrombin complex concentrate 1.
• The duration of interruption and timing of resumption of anticoagulation after the procedure are guided by individualized consideration of the risk of thrombotic events and the severity of the operative and perioperative bleeding risk 1.
• The choice of reversal agent depends on the severity of bleeding, with fresh frozen plasma, 4-factor PCC, and vitamin K being options for VKA reversal 1.

It is essential to individualize decisions about bridging anticoagulation, considering the trade-offs between thrombosis and bleeding, and to monitor INR closely during the transition period.

From the FDA Drug Label

The management of patients who undergo dental and surgical procedures requires close liaison between attending physicians, surgeons and dentists. PT/INR determination is recommended just prior to any dental or surgical procedure. In patients undergoing minimal invasive procedures who must be anticoagulated prior to, during, or immediately following these procedures, adjusting the dosage of warfarin sodium tablets to maintain the PT/INR at the low end of the therapeutic range may safely allow for continued anticoagulation Some dental or surgical procedures may necessitate the interruption of warfarin sodium tablets therapy When discontinuing warfarin sodium tablets even for a short period of time, the benefits and risks should be strongly considered. Excessive anticoagulation, with or without bleeding, may be controlled by discontinuing warfarin sodium tablets therapy and if necessary, by administration of oral or parenteral vitamin K1. If minor bleeding progresses to major bleeding, give 5 to 25 mg (rarely up to 50 mg) parenteral vitamin K1. In emergency situations of severe hemorrhage, clotting factors can be returned to normal by administering 200 to 500 mL of fresh whole blood or fresh frozen plasma, or by giving commercial Factor IX complex

To reverse Coumadin (warfarin) for surgery, the following steps can be taken:

• Discontinue warfarin sodium tablets therapy
• Administer oral or parenteral vitamin K1 if necessary
• Monitor PT/INR to ensure the patient is within a safe range for surgery
• In cases of major bleeding, consider administering 5 to 25 mg of parenteral vitamin K1 or using fresh whole blood or fresh frozen plasma in emergency situations
• The decision to reverse anticoagulation should be made after careful consideration of the benefits and risks 2 2

From the Research

Reversing Coumadin for Surgery

• The management of patients on chronic Coumadin therapy undergoing subsequent surgical procedures requires careful consideration of perioperative anticoagulation management to prevent hemorrhage or thrombosis 3.
• Discontinuing Coumadin 5 days before surgery and beginning intravenous heparin with adjustment to keep partial thromboplastin times at therapeutic levels is a common protocol 3.
• Heparin is stopped early on the morning of surgery and restarted at 200-400 units/hr at 4 to 6 hours after surgery, and Coumadin is restarted as soon as the patient can tolerate it 3.
• It is considered safe to operate only when the prothrombin time is less than 13 seconds 3.

Anticoagulation Reversal Agents

• Prothrombin complex concentrates (PCCs) are superior to fresh frozen plasma (FFP) for emergency reversal of vitamin K antagonists, with a reduction in 90-day all-cause mortality, better reversal of INR, and lower risk of treatment-related adverse events 4, 5.
• PCCs are associated with a significant reduction in all-cause mortality compared to FFP, and a higher proportion of patients receiving PCCs achieve haemostasis and normalization of INR 5.
• The use of PCCs for warfarin reversal is also associated with a more rapid INR reduction and less volume overload without an increased risk of thromboembolic events 5.

Selection of Reversal Agents

• Intravenous vitamin K1 should be used for procedures that can be delayed for six to 12 hours, as it results in the activation of existing clotting factors and has a relatively rapid onset of action 6.
• PCCs should be given if surgery cannot be delayed, and intravenous vitamin K1 should be infused concurrently to ensure sustained reversal of anticoagulation 6.
• Plasma should be used only if PCCs are unavailable or are contraindicated, such as in patients with heparin-induced thrombocytopenia 6.