Perioperative Management of Anticoagulant Therapy
Mina Gaber Abd El-Shaheed Girgis;
Abstract
Hemostasis is one of the most significant maintenance systemsof human bodily homeostasis; hemostasis plays two roles in the human body: To provide blood flow through blood vessels, i.e., to maintain the liquid state of circulating blood and to stop bleeding that results from blood vessel damage.
Hemostasis is a complex system that includes the participation of several factors: Blood vessel endothelium, platelets, blood coagulation, fibrinolytic process, coagulation inhibitors.
Normal hemostasis starts with the vascular stage in the form of vasoconstriction, is then followed by the platelet stage, which creates a platelet clot, and finally ends with the mutual action of coagulation factors, resulting in plug formation.
Anticoagulants are a type of drug that reduces the body's ability to form clots in the blood. This type of medicine will not dissolve clots that already have formed, although it will help to stop an existing clot from getting larger.Anticoagulants are used both to prevent and treat thrombotic diseases.
Traditional methods of anticoagulation and thromboprophylaxis include vitamin K antagonists (VKA) such as warfarin, heparin; both low molecular weight (LMWH) e.g. enoxaparin and unfractionated (UFH) and fondaparinux. The new direct anticoagulant agents include the parenteral direct thrombin inhibitors (DTIs) and new oral anticoagulants (NOACs). The parenteral direct thrombin inhibitors (DTIs) include argatroban, bivalirudin, and desirudin. NOACs were developed to overcome the limitations ofwarfarin. These agents include dabigatran, which inhibitsthrombin, and rivaroxaban, apixaban, and edoxaban,which inhibit factorXa.
Long term oral anticoagulant therapy is indicated in some cases including: Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism. Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation and cardiac valve replacement.
The two main issues that need to be considered in perioperative managementof anticoagulant therapy is the patient risk of thromboembolic events when anticoagulant therapy is interrupted and the risk of bleeding that is associated with the surgery or procedure. Assessment of these factors will determine the perioperative management approach.
The assessment of the thromboembolic risk is according to three factors: The indication for anticoagulation (Atrial fibrillation, venous thromboembolism and artificial heart valves), presence of additional thromboembolic risk factors (malignancy, anti-phospholipid syndrome or hereditary thrombophilic disorders), and thrombotic risk of the procedure.
Surgical procedures differ in their risk for bleeding. Some procedures are with high risk (e.g., complex ophthalmic and cardiac operations), others with intermediate risk (e.g., abdominal and genitourinary operations), and finally there are procedures with low risk (e.g., dental and dermatological procedures).
Interruption of oral anticoagulation may not be required in patients undergoing certain procedures with a low bleeding risk (e.g., dental and dermatological procedures).
For patients on warfarin therapy undergoing elective surgery or procedures with a moderate to high bleeding risk; thromboembolic risk will determine whether warfarin can be safely withheld around the time of the surgery or procedures or bridging therapy would need to be considered.
Bridging therapy is a recent term used to describe the administration of a parenteral short term acting anticoagulant - such as low molecular weight heparin (LMWH) or unfractionated heparin (UFH) - while a long acting anticoagulant such as warfarin is withheld.
For patients on NOACs undergoing elective surgery or procedures; NOACs should be stopped twodays before a high risk procedure and one day before a low risk procedure. The time of discontinuation of NOACs before surgery increases in patients with renal impairment.
About the time of resumption of NOACs after surgery: For patients at low thromboembolic risk associated with a high bleeding risk; NOACs should be delayed for at least 48 hours postoperative, preferably 72 hours, particularly in view of a lack of an antidote for NOACs. For patients at high thromboembolic risk associated with a high bleeding risk; consider administering a reduced prophylactic dose of NOACs starting the evening after surgery and continue until it is safe to resume therapeutic doses or prophylactic dose of LMWH in patients who are unable to tolerate oral intake.
Hemostasis is a complex system that includes the participation of several factors: Blood vessel endothelium, platelets, blood coagulation, fibrinolytic process, coagulation inhibitors.
Normal hemostasis starts with the vascular stage in the form of vasoconstriction, is then followed by the platelet stage, which creates a platelet clot, and finally ends with the mutual action of coagulation factors, resulting in plug formation.
Anticoagulants are a type of drug that reduces the body's ability to form clots in the blood. This type of medicine will not dissolve clots that already have formed, although it will help to stop an existing clot from getting larger.Anticoagulants are used both to prevent and treat thrombotic diseases.
Traditional methods of anticoagulation and thromboprophylaxis include vitamin K antagonists (VKA) such as warfarin, heparin; both low molecular weight (LMWH) e.g. enoxaparin and unfractionated (UFH) and fondaparinux. The new direct anticoagulant agents include the parenteral direct thrombin inhibitors (DTIs) and new oral anticoagulants (NOACs). The parenteral direct thrombin inhibitors (DTIs) include argatroban, bivalirudin, and desirudin. NOACs were developed to overcome the limitations ofwarfarin. These agents include dabigatran, which inhibitsthrombin, and rivaroxaban, apixaban, and edoxaban,which inhibit factorXa.
Long term oral anticoagulant therapy is indicated in some cases including: Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism. Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation and cardiac valve replacement.
The two main issues that need to be considered in perioperative managementof anticoagulant therapy is the patient risk of thromboembolic events when anticoagulant therapy is interrupted and the risk of bleeding that is associated with the surgery or procedure. Assessment of these factors will determine the perioperative management approach.
The assessment of the thromboembolic risk is according to three factors: The indication for anticoagulation (Atrial fibrillation, venous thromboembolism and artificial heart valves), presence of additional thromboembolic risk factors (malignancy, anti-phospholipid syndrome or hereditary thrombophilic disorders), and thrombotic risk of the procedure.
Surgical procedures differ in their risk for bleeding. Some procedures are with high risk (e.g., complex ophthalmic and cardiac operations), others with intermediate risk (e.g., abdominal and genitourinary operations), and finally there are procedures with low risk (e.g., dental and dermatological procedures).
Interruption of oral anticoagulation may not be required in patients undergoing certain procedures with a low bleeding risk (e.g., dental and dermatological procedures).
For patients on warfarin therapy undergoing elective surgery or procedures with a moderate to high bleeding risk; thromboembolic risk will determine whether warfarin can be safely withheld around the time of the surgery or procedures or bridging therapy would need to be considered.
Bridging therapy is a recent term used to describe the administration of a parenteral short term acting anticoagulant - such as low molecular weight heparin (LMWH) or unfractionated heparin (UFH) - while a long acting anticoagulant such as warfarin is withheld.
For patients on NOACs undergoing elective surgery or procedures; NOACs should be stopped twodays before a high risk procedure and one day before a low risk procedure. The time of discontinuation of NOACs before surgery increases in patients with renal impairment.
About the time of resumption of NOACs after surgery: For patients at low thromboembolic risk associated with a high bleeding risk; NOACs should be delayed for at least 48 hours postoperative, preferably 72 hours, particularly in view of a lack of an antidote for NOACs. For patients at high thromboembolic risk associated with a high bleeding risk; consider administering a reduced prophylactic dose of NOACs starting the evening after surgery and continue until it is safe to resume therapeutic doses or prophylactic dose of LMWH in patients who are unable to tolerate oral intake.
Other data
| Title | Perioperative Management of Anticoagulant Therapy | Other Titles | التعامل مع مضادات التجلط قبل وأثناء وبعد العمليات الجراحية | Authors | Mina Gaber Abd El-Shaheed Girgis | Issue Date | 2016 |
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