American Board of Internal Medicine (ABIM) Certification Practice Exam

Before surgeries that carry a standard risk for bleeding, how long before the procedure should new oral anticoagulants be stopped?

1. 6-12 hours

2. 12-24 hours

3. 24-36 hours

4. 36-48 hours

The correct answer is: 24-36 hours

The appropriate duration for stopping new oral anticoagulants (NOACs) such as dabigatran, rivaroxaban, apixaban, and edoxaban before surgeries that have a standard risk for bleeding is indeed 24-36 hours. This timeframe allows for adequate clearance of the anticoagulant from the body, significantly reducing the risk of perioperative bleeding while maintaining an effective level of anticoagulation prior to the procedure. NOACs have a specific half-life that varies depending on the particular drug and the renal function of the individual. For example, dabigatran has a half-life of approximately 12-17 hours in healthy individuals, while rivaroxaban and apixaban have half-lives of around 9-13 hours and 8-15 hours, respectively. Therefore, stopping the anticoagulant within 24-36 hours before surgery aligns with the pharmacokinetics of these medications, allowing for a safer surgical environment without compromising the patient's overall management plan. Choosing a period shorter than 24 hours could potentially increase the risk of bleeding due to insufficient drug clearance, while extending the cessation to more than 36 hours may unnecessarily expose the patient to an increased risk of thromboembolism, especially