Should aspirin (acetylsalicylic acid) be held before thoracentesis?

From the Guidelines

Aspirin should be held before thoracentesis if possible, ideally for 5-7 days prior to the procedure, to minimize the risk of bleeding, as recommended by the most recent and highest quality study 1. When considering the management of antiplatelet therapy in patients undergoing elective invasive procedures like thoracentesis, it's crucial to weigh the risks of bleeding against the risks of thrombotic events.

• For patients on aspirin for secondary prevention, such as those with a history of heart attack or stroke, the decision to hold aspirin should be individualized based on the urgency of the thoracentesis and the patient's specific thrombotic risk, as suggested by 1 and 1.
• In high-risk cardiac patients, continuing aspirin may be reasonable due to the relatively low bleeding risk associated with thoracentesis when performed under ultrasound guidance.
• For patients on aspirin for primary prevention only, stopping the medication is usually safe, according to 1.
• If thoracentesis must be performed urgently while a patient is on aspirin, the procedure can still be undertaken with appropriate precautions, including ultrasound guidance and careful technique, as the concern with aspirin is its irreversible inhibition of platelet function, which increases bleeding risk during invasive procedures, as discussed in 1. The effect of aspirin persists for the lifespan of affected platelets (approximately 7-10 days), which is why the recommended holding period is 5-7 days to allow for sufficient new platelet production, as explained in 1. Key points to consider include:
• The haemostatic safety threshold guaranteeing the absence of perioperative risk of bleeding associated with aspirin treatment has not been established, as noted in 1.
• Functional platelet tests used in studies addressing this issue have yielded inconsistent results, making them not suitable for clinical practice in managing aspirin before an elective invasive procedure, as mentioned in 1.
• A three-day washout of aspirin may lead to an improvement in platelet functions but is often not sufficient for full correction, especially for procedures with a high risk of bleeding, where a five-day washout is proposed, as suggested in 1.

From the Research

Holding Aspirin for Thoracentesis

• The decision to hold aspirin before thoracentesis is a topic of discussion among medical professionals, with some studies suggesting that it may not be necessary to withhold aspirin in all cases 2, 3.
• A study published in the Annals of the American Thoracic Society found that thoracentesis can be safely performed without prior correction of coagulopathy, thrombocytopenia, or medication-induced bleeding risk, including aspirin 2.
• Another study published in BMJ open respiratory research found that performing thoracentesis without correction of underlying coagulopathy may be safe, and that the use of ultrasound guidance can decrease the risk of bleeding 3.
• A survey of physicians found that most would perform a thoracentesis in patients receiving acetylsalicylic acid (aspirin) without holding the medication, suggesting that many medical professionals do not consider aspirin to be a significant bleeding risk for this procedure 4.
• However, other studies have found that dual antiplatelet therapy, including aspirin and another antiplatelet agent, can increase the risk of bleeding after cardiac surgery, highlighting the importance of careful consideration of the risks and benefits of holding or continuing antiplatelet therapy in individual patients 5.

Key Findings

• Thoracentesis can be safely performed without prior correction of coagulopathy, thrombocytopenia, or medication-induced bleeding risk, including aspirin 2, 3.
• The use of ultrasound guidance can decrease the risk of bleeding during thoracentesis 3.
• Most physicians would perform a thoracentesis in patients receiving acetylsalicylic acid (aspirin) without holding the medication 4.
• Dual antiplatelet therapy, including aspirin and another antiplatelet agent, can increase the risk of bleeding after cardiac surgery 5.