Anesthesia Considerations for Aspirin

Aspirin is widely used for its antiplatelet effects in the prevention of cardiovascular events, but it also raises specific considerations in the context of anesthesia due to its impact on bleeding risk. The primary concern with aspirin in the perioperative setting is its irreversible inhibition of cyclooxygenase-1 (COX-1), which leads to decreased thromboxane A2 production, impairing platelet aggregation and prolonging bleeding time (1). This effect requires careful management strategies, particularly when neuraxial anesthesia or other regional anesthetic techniques are planned, as these are associated with a risk of hematoma formation.

The American Society of Regional Anesthesia and Pain Medicine (ASRA) guidelines indicate that low-dose aspirin therapy does not significantly increase the risk of spinal hematoma following epidural or spinal anesthesia and can generally be continued in the perioperative period (2). However, other studies emphasize the need for vigilance and individualized assessment, especially in patients receiving higher doses or those with other risk factors for bleeding (3). The decision to continue or discontinue aspirin therapy must balance the risk of thrombosis against the potential for bleeding complications, taking into account the specific surgical procedure, patient comorbidities, and type of anesthesia.

The perioperative continuation of aspirin in patients at risk for vascular complications, such as those with coronary stents, is supported by evidence that the benefits of maintaining aspirin therapy generally outweigh the risks (4). Discontinuation of aspirin therapy can lead to a rebound prothrombotic state, increasing the likelihood of myocardial infarction or stroke, particularly in high-risk patients (5). This is particularly relevant in non-cardiac surgery, where the risk of bleeding is lower, and the consequences of a thrombotic event can be severe.

On the other hand, for procedures where major bleeding would pose significant risks, such as intracranial procedures, the decision-making process becomes more complex. In these scenarios, some guidelines suggest stopping aspirin at least seven days before surgery and anesthesia to allow for sufficient platelet recovery, while others emphasize a case-by-case approach (1). This is further complicated by the lack of a reliable, rapid method to reverse aspirin’s effects, unlike other anticoagulants for which specific reversal agents exist.

The importance of interdisciplinary communication cannot be overstated in managing anesthesia for patients on aspirin therapy. Anesthesiologists must work closely with surgeons and the patient’s primary care or cardiology teams to evaluate the risks and benefits of continuing aspirin therapy perioperatively. The anesthetic plan should include strategies for managing potential bleeding, such as availability of blood products and the use of less invasive surgical techniques where feasible.

Anesthesia considerations for patients on aspirin therapy require a nuanced approach that weighs the thrombotic risks of discontinuation against the bleeding risks of continuation. Guidelines generally support the continuation of low-dose aspirin for most surgeries, especially where the risk of major bleeding is low, but emphasize individual risk assessment for each patient. Anesthesia providers must remain vigilant and adaptable, employing a multidisciplinary approach to optimize patient outcomes.

References

1. Song JW, Soh S, Shim JK. Dual antiplatelet therapy and non-cardiac surgery: evolving issues and anesthetic implications. Korean J Anesthesiol. 2017.
2. Horlocker TT, Wedel DJ, Benzon H, et al. Regional anesthesia in the anticoagulated patient: defining the risks (the second ASRA Consensus Conference on Neuraxial Anesthesia and Anticoagulation). Reg Anesth Pain Med. 2003.
3. Macdonald R. Aspirin and extradural blocks. Br J Anaesth. 1991;66(1):1-6.
4. Vela Vásquez RS, et al. Aspirin and spinal haematoma after neuraxial anaesthesia: Myth or reality? Br J Anaesth. 2015;115(5):688-695.
5. Devereaux PJ, Mrkobrada M, Sessler DI, et al. Aspirin in patients undergoing noncardiac surgery. N Engl J Med. 2014;370(16):1494-1503