Question: Discuss guidelines for anticoagulation and taking for non cardiac surgery.
Asked by: Dr Jayprakash
- Use of therapeutic or full-dose anticoagulants (as opposed to the lower-dose anticoagulation often used for prevention of deep venous thrombosis) is generally discouraged because of their harmful effect on the ability to control and contain surgical blood loss.
- Vitamin K antagonists (warfarin) are prescribed for stroke prevention in patients with AF, for prevention of thrombotic and thromboembolic complications in patients with prosthetic valves, and in patients requiring deep venous thrombosis prophylaxis and treatment.
- Factor Xa inhibitors ( Rivaroxaban, apixaban) and direct thrombin inhibitors (hirudin, bivalirudin) are alternative anticoagulants.
- Factor Xa inhibitors are prescribed for prevention of stroke in the management of AF. They are not recommended for long-term anticoagulation of prosthetic valves because of an increased risk of thrombosis when compared with warfarin.
- The risks of bleeding for any surgical procedure must be weighed against the benefit of remaining on anticoagulants on a case-by-case basis.
- In some instances in which there is minimal to no risk of bleeding, such as cataract surgery or minor dermatologic procedures, it may be reasonable to continue anticoagulation perioperatively.
- Although research with newer agents (e.g., prothrombin complex concentrates for reversal of direct factor Xa inhibitor effect) is ongoing, the novel oral anticoagulant ( dabigatran, rivaroxaban) agents do not appear to be acutely reversible.
- Patients with prosthetic valves taking vitamin K antagonists may require bridging therapy with either unfractionated heparin or low-molecular-weight heparin, depending on the location of the prosthetic valve and associated risk factors for thrombotic and thromboembolic events.
- For patients with a mechanical mitral valve, regardless of the absence of additional risk factors for thromboembolism, or patients with an aortic valve and ?1 additional risk factor (such as AF, previous thromboembolism, LV dysfunction, hypercoagulable condition, or an older-generation prosthetic aortic valve), bridging anticoagulation may be appropriate when interruption of anticoagulation for perioperative procedures is required and control of hemostasis is essential.
- For patients requiring urgent reversal of vitamin K antagonists, vitamin K and FFP or the newer PCC are options; however, vitamin K is not routinely recommended for reversal because the effect is not immediate and the administration of vitamin K can significantly delay the return to a therapeutic level of anticoagulation once vitamin K antagonists have been restarted.
- Factor Xa inhibitors do not have a reversible agent available at this time. For patients with AF and normal renal function undergoing elective procedures during which hemostatic control is essential, such as major surgery, spine surgery, and epidural catheterization, discontinuation of anticoagulants for ?48 hours is suggested.
- Monitoring activated partial thromboplastin time for dabigatran and prothrombin time for apixaban and rivaroxaban may be helpful; a level consistent with control levels suggests a low serum concentration of the anticoagulant.
- by Dr Amarja