RECENT UPDATES IN PERI-OPERATIVE ANESTHETIC MANAGEMENT OF ADULT ANTICOAGULATED PATIENT UNDERGOING MINOR SURGERY

Abstract

SUMMARY B lood coagulation forms part of a series of haemostatic reactions, including plasma, platelets, and vascular components. Platelets adhere to the damaged endothelium or to the subendothelium under the effect of adhesive proteins, and after being activated they aggregate and expose binding sites for the coagulation factors. Therefore, platelets help to concentrate and potentiate the coagulation reactions on damaged blood vessels. Following interaction of the 'contact' factors XI and XII, a cascade of activation occurs to the coagulation protease zymogens. This results in the conversion of fibrinogen to fibrin, the formation of thrombin and finally a platelet-fibrin plug. During healing process, fibrin deposition and removal is regulated by the fibrinolytic system. Anticoagulants are considered the primary line for preventing and treating thrombosis. New oral anticoagulants such as rivaroxaban, apixaban and dabigatran are expected to replace the older drugs for being easier to use and for having better pharmacodynamic profiles. However, the international normalized ratio cannot be used to monitor the coagulation profile and currently no antidotes are available. The main adverse effect with all anticoagulants is hemorrhage thus, it is important for physicians to be familiar with their pharmacology, dosing, and toxicity. Management of anticoagulants in elective and emergency procedures requires knowing the last time of drug intake, the current renal function of the patient and the surgery planned to be performed in order to assess the bleeding risk. Haemodialysis may be considered as an option in cases of bleeding occuring with the use of dabigatran. Better options for reversing the effects of these novel oral anticoagulants are still being studied. Anesthesiologists consider many patients receiving drugs that affect the function of platelets as an essential part of primary and secondary management of the atherosclerotic thrombotic diseases. In clinical practice multiple antiplatelet drugs are available for use and several other newer drugs such as cangrelor and ticagrelor are still under investigation. Aspirin and clopidogrel (either alone or combined) have been studied the most and have the most favorable risk benefit profile of the available drugs. Prasugrel was approved recently for patients with acute coronary syndrome and undergoing a percutaneous intervention. Antiplatelet agents used for primary prevention or for treatment of AF can be discontinued safely before the procedure. However, recent studies suggest that (with some exceptions), proceeding with surgery while patient is on DAPT is a relatively safe option. In cases of life-threatening hemorrhage, platelet transfusion is considered.