Gastroenterological Endoscopy. Группа авторов

Чтение книги онлайн.

      11.2.2 Anticoagulants Agents

      Anticoagulants prevent the clotting of blood by interfering with the native clotting cascade. Warfarin (Coumadin, Bristol-My-ers Squibb Company, Princeton, New Jersey, United States) is an oral anticoagulant that inhibits the vitamin K–dependent clotting factors II, VII, IX, and X and proteins C and S.^10,11 Heparin derivatives (unfractionated heparin [UFH] and low-molecular-weight heparin [LMWH]) are administered intravenously and should be administered 4 to 6 hours and 24 hours, respectively, before high-risk procedures.^10,11 Fondaparinux (Arixtra, GlaxoSmithKline, Research Triangle Park, North Carolina, United States) is a specific inhibitor of factor Xa, with anticoagulant effects lasting for at least 36 hours.^10,11 Rivaroxaban (Xarel-to, Janssen Pharmaceuticals, Inc, Raritan, New Jersey, United States), apixaban (Eliquis, Bristol-Myers Squibb Company, Princeton, New Jersey, United States), and edoxaban (Savaysa, Daiichi Sankyo Co, LTD, Tokyo, Japan) are direct factor Xa inhibitors, while dabigatran (Pradaxa, Boehringer Ingelheim Pharmaceuticals Inc, Ridgefield, Connecticut, United States), hirudins, and argatroban (Acova, Abbott Laboratories, North Chicago, Illinois, United States) are direct thrombin inhibitors.^10,11 Direct oral anticoagulants (DOACs) reach a maximum effect 1.25 to 3 hours after ingestion and should be discontinued ≥ 48 hours before a high-risk procedure.¹¹ These agents overcome some of the vitamin K antagonists (VKAs) pitfalls such as their narrow therapeutic window, the need for frequent monitoring, and dose adjustments as well as the interaction with foods and/or other drugs. However, specific antidotes are limited, with only idarucizumab (Praxbind, Boehringer Ingelheim, Inc, Ridgefield, Connecticut, United States) approved for use in cases of life-threatening uncontrolled bleeding or prior to emergency surgery in patients on dabigatran.¹² Prothrombin time and activated partial thromboplastin time are poor measures of drug effect and are insensitive and often minimally prolonged or normal in spite of therapeutic drug levels.¹³

      Procedure Risks

      There is an intrinsic risk of hemorrhage associated with endoscopic procedures. Hemorrhage may be immediately apparent at the time of endoscopy or may be delayed for up to 2 weeks following the procedure.

      In general, a patient undergoing a procedure associated with low risk of bleeding (low-risk procedure) can (and should) safely continue antithrombotic therapy, particularly if the patient is at high risk for a thromboembolic event (high-risk patient).¹ Conversely, a patient undergoing a high-risk procedure can temporarily discontinue antithrombotic agents safely if the patient is at low risk for a thromboembolic event (low-risk patient).¹ The decision-making process is challenging when patients at moderate-to-high risk for thromboembolic events undergo high-risk procedures. Management also differs between elective and emergency procedures.¹ Elective endoscopic procedures should be deferred until short-term anticoagulation therapy is completed.

      Common endoscopic procedures vary in their potential to induce bleeding (

      Assessment of Thrombotic Risk

      The probability of a thromboembolic event related to the temporary interruption of antithrombotic therapy for an endoscopic procedure depends on the indication for antithrombotic therapy and individual patient characteristics (

      Antiplatelet Agents Management

      While the American Society for Gastrointestinal Endoscopy (ASGE) recommends continuation of low-dose aspirin and nonsteroidal anti-inflammatory drugs in the periendoscopic period,¹¹ the European Society for Gastrointestinal Endoscopy (ESGE) recommends continuing aspirin for all endoscopic procedures, with the exception of endoscopic submucosal dissection, large colonic endoscopic mucosal resection (EMR) (>2 cm), upper GI EMR, and ampullectomy (

Table 11.1 Risk stratification of endoscopic procedures based on the risk of hemorrhage