Anticoagulants, or drugs that reduces clotting in the blood, may be used in various surgical contexts in addition to medical contexts like having a high risk of ischemicstroke 1. These drugs primarily affect either platelet activity or the coagulation cascade. An increasing number of preoperative patients, for example, receive oral anticoagulant (e.g. warfarin) or antiplatelet drugs to prevent complications related to clots. To date, multiple guidelines and recommendations have been developed to guide the perioperative use of antiplatelet and anticoagulant drugs. This article discusses the uses and risks of anticoagulant drugs within anesthesia and surgery.
Anticoagulation therapy is most commonly indicated for atrial fibrillation, pulmonary embolism, deep venous thrombosis, and following the placement of prosthetic heart valves. Patients with a past medical history of stroke, essential thrombocytosis, or a coronary artery by-pass graft could also require antithrombotic therapy 2. Meanwhile, patients who have undergone percutaneous coronary interventions typically receive two types of antiplatelet medicines, or dual antithrombotic therapy. In the end, however, each patient undergoing anesthesia and surgery has a unique risk-benefit ratio , and appropriate anticoagulant drugs need to be selected according to their situation.
Warfarin remains the most commonly used long-term oral anticoagulant. Its use in the perioperative period requires careful consideration and planning given its long duration of action and the fact that many other drugs interact with it. This said, new anti-platelet agents have also emerged, capitalizing on a range of different mechanisms of action. These must also be carefully administered if selected, since they often have long durations of action also, and some cannot be reversed by platelet transfusion 3.
Performing a neuraxial block, one type of anesthesia, in the presence of anticoagulant drugs has a risk of epidural hematoma and spinal cord injury. As a result, a safe delay should be respected between administration of these agents and the performance of a block 3.
When to stop administering the anticoagulant depends on the periprocedural bleeding risk and the specific drug being used. This said, bridging anticoagulation may represent a viable clinical method of weaning a patient off a drug via the administration of a short-acting anticoagulant. Low molecular weight heparin is typically used during the interruption of a longer-acting agent (typically warfarin). The goal is to minimize the risk of perioperative thromboembolism.
There are two primary complications linked to the poor management of perioperative anticoagulation 2. The first is bleeding, which occurs if the clinical provider fails to interrupt the anticoagulation therapy rapidly enough. In contrast, patients in whom the anticoagulation therapy is interrupted too early are at higher risk of developing thromboembolic events since surgical procedures themselves induce a hypercoagulable state.
In some contexts, such as for urgent or emergency procedures or to treat perioperative bleeding, a patient’s usual anticoagulant may need to be reversed. Agents with a prothrombotic effect (including but not limited to immediate reversal agents, prothrombin complex concentrates, or plasma products) should be reserved for the treatment of severe bleeding (such as in the context of intracranial hemorrhage or an emergency major surgery) 2.
Additional research is required to better understand and specify best practices for the use of anticoagulant drugs in the context of anesthesia and surgery, especially as new medications in this category are developed 4. Meanwhile, whereas common recommendations are valid for many patients, individual decision-making is required according to specific clinical contexts.
References
1. Yamamoto, K. Anticoagulant or antiplatelet drugs and anesthesia. Japanese J. Anesthesiol. (2010).
2. Gutierrez, J. J. P. & Rocuts, K. R. Perioperative Anticoagulation Management. StatPearls (2022).
3. Oranmore-Brown, C. & Griffiths, R. Anticoagulants and the perioperative period. Contin. Educ. Anaesth. Crit. Care Pain 6, 156–159 (2006).
4. Moster, M. & Bolliger, D. Perioperative Guidelines on Antiplatelet and Anticoagulant Agents: 2022 Update. Curr. Anesthesiol. Rep. 12, 286–296 (2022).
