Patients are increasingly treated with direct oral anticoagulants (DOACs) for the prevention of stroke due to non-valvular atrial fibrillation and for the treatment of venous thromboembolism. When these patients present for urgent or emergent surgical procedures, they present a challenge to the anesthesiologist who must manage perioperative risk due to anticoagulation. The purpose of this module is to review the literature surrounding the perioperative management of DOACs. Timing, laboratory monitoring, and availability of reversal agents are important considerations to optimize patients being treated with DOACs who require emergent surgery.
Laboratory tests are not recommended for routine monitoring of DOACs since they do not correlate well with anticoagulant activity. The most widely available laboratory tests lack the sensitivity to detect anticoagulant effects at low plasma concentrations. However, a normal thrombin time for dabigatran excludes clinically significant drug levels. If the risk of bleeding is judged to be high because of a recent dose of DOAC, various options are available to mitigate bleeding. When possible, surgery should be delayed for at least 12 hr after the last dose of DOAC. Activated charcoal may mitigate the anticoagulant effect caused by DOACs if administered less than two hours after the drug was ingested. Four-factor prothrombin complex concentrates (PCCs) may be useful to reduce life-threatening bleeding associated with factor Xa inhibitors. Activated PCCs have been shown to reverse abnormal coagulation tests associated with all DOACs, but there is a lack of reported evidence of clinical benefit. Idarucizumab is a specific antidote that is effective for reversal of anticoagulation due to dabigatran. An antidote for rivaroxaban and apixaban (andexanet alfa) as well as a universal antidote for all DOACs and heparin (PER977) are in clinical development.
Perioperative management of anticoagulation due to DOACs is a growing concern as the number of patients prescribed these medications increases each year. These patients can be safely optimized for urgent or emergent surgery by giving appropriate consideration to timing, monitoring, and reversal agents.
Objectives of this Continuing Professional Development (CPD) module:
After reading this module, the reader should be able to:
- Describe the mechanism of action of direct oral anticoagulants (DOACs).
- Describe the limitations and most appropriate laboratory tests to assess the activity of DOACs.
- Explain the current evidence for reversal of anticoagulation by DOACs, including the dabigatran reversal agent idarucizumab (Praxbind®).
- Describe the perioperative management of patients on DOACs.