Understanding Why Aspirin Prescriptions Differ Before and After Surgery

The decision to prescribe aspirin before or after surgery is a critical one, crafted to balance risk and benefit. There is a common misconception that doctors prescribe aspirin before surgery, which is actually quite rare due to certain risks associated with the use of such medications during the perioperative period. Instead, aspirin and other blood-thinning medications are typically discontinued a few days to a week before surgery to minimize the risk of excessive bleeding.

The Role of Aspirin Before Surgery

During surgery, it is crucial to minimize blood loss and ensure that the patient can maintain stable hemodynamics. Certain medications, such as non-steroidal anti-inflammatory drugs (NSAIDs), have been shown to increase the risk of bleeding, leading to guidelines that recommend their discontinuation for a period before surgery. Aspirin, while classified as an anticoagulant, has a more complex impact on blood clotting. When taken long-term, aspirin reduces platelet aggregation, which can contribute to a lower risk of heart attack and stroke. However, the effects of aspirin on blood clotting are not as pronounced or as immediate as those of warfarin, a more potent anticoagulant.

For this reason, doctors typically stop aspirin shortly before surgery to avoid any potential bleeding issues during the procedure. This decision is usually made several days to a week before surgery, depending on the individual patient’s condition and the specific surgical procedure involved. The exact time frame can vary based on individual risk factors and the surgeon's recommendations.

Beneficial Effects of Aspirin After Surgery

After surgery, the situation changes. The risk of blood clots (thromboembolic events) is significantly increased due to immobility, prolonged bed rest, and the inherent post-operative inflammation. Aspirin, with its anti-platelet properties, is prescribed to reduce the risk of clot formation and pulmonary embolism. Pulmonary embolism can be a life-threatening condition where a blood clot from a deep vein in the leg (deep vein thrombosis, DVT) travels to the lungs and blocks a pulmonary artery, causing lung tissue death and respiratory distress.

In the case of my two recent surgeries on my right leg, the course of treatment included aspirin at 81 mg twice daily for a month after surgery, along with intermittent compression devices to further reduce the risk of DVT. The use of aspirin in this context is to ensure that the patient remains in a low-risk state for blood clot formation, which is especially important given the reduced mobility and limited physical activity post-surgery.

Conclusion: Balancing Risk and Benefit

The prescription of aspirin before and after surgery is a matter of precision medicine, carefully balancing the risks and benefits. The decision to stop aspirin before surgery is driven by the need to minimize bleeding risks, while the prescription of aspirin post-surgery is aimed at reducing the risk of clot formation due to immobility and inflammation. It is important for patients to follow their surgeon's and pharmacist's instructions closely to ensure optimal recovery and reduce the risk of post-operative complications.