Perioperative Anticoagulation Management

• Consider the risks of hemorrhage or thromboembolism versus the benefit from the operation
• When considering noncardiac surgery, weigh the risk of hemorrhage against that of thromboembolism on an individual patient basis.
• If surgery decided then 3 options:
  1. Continue warfarin therapy
  2. Withhold warfarin therapy for a period of time before and after the procedure
  3. Temporarily withhold warfarin therapy and also provide a "heparin bridge" during the perioperative period
• No consensus exists regarding the optimal perioperative management
• Some prospective studies have suggested that patients on long-term warfarin therapy who undergo minor invasive procedures and are taken off their oral anticoagulation for up to 5 days have a less than 1% risk of experiencing a thromboembolic event.

Guidelines (American College of Chest Physicians)

• In patients with a mechanical heart valve or atrial fibrillation or venous thromboembolism (VTE):
  • At high risk for thromboembolism, bridging anticoagulation is recommended with therapeutic-dose subcutaneous LMWH or intravenous unfractionated heparin (UFH) rather than no bridging.
  • At moderate risk for thromboembolism, it is proposed to consider bridging versus no bridging on the individual patient basis.
  • At low risk for thromboembolism, low-dose SC LMWH or no bridging.
• In patients with a bare metal coronary stent who require surgery within 6 weeks of stent placement, the ACCP recommends to continue aspirin and clopidogrel in the perioperative period
• In patients with a drug-eluting coronary stent who require surgery within 12 months of stent placement, continuing aspirin and clopidogrel in the perioperative period is recommended.
• In minor dental procedures, continue the oral anticoagulants around the time of the procedure as well as coadminister an oral prohemostatic agent.
• In minor dermatologic procedures or cataract removal, continue the anticoagulants perioperatively.

Some more points:

• If the risk for thromboembolism is low, warfarin therapy can be withheld for 4-5 days before the procedure without bridging.
• Patients with prosthetic heart valves : Some prospective studies have suggested that patients on long-term warfarin therapy who undergo minor invasive procedures and are taken off their oral anticoagulation for up to 5 days have a less than 1% risk of experiencing a thromboembolic event
• The perioperative risk of bleeding when using a heparin bridge appears to be higher but the risk of thromboembolic events appears to be lower.
• N-acetylcysteine is known to impair hemostasis, so avoid in such cases.
• Almost all patients will achieve an international normalized ration (INR) of < 1.5 within 4 - 5 days of stopping warfarin, although patients with a higher (2.5 – 3.5) target INR and the elderly (> 70 years) will require a longer period of warfarin withdrawal before surgery