Aspirin and Spinal Anesthesia Bleeding Risk

Introduction to Aspirin and Spinal Anesthesia

The American Society of Anesthesiologists recommends that aspirin is not a contraindication to central neuraxial anesthesia, including spinal anesthesia, if the benefit-risk ratio is favorable and there is no associated abnormality of hemostasis, as agreed upon by the French Working Group on Perioperative Haemostasis, French Study Group on Thrombosis and Haemostasis, and French Society for Anaesthesia and Intensive Care Medicine in 2018 1

Aspirin monotherapy carries a very low bleeding risk for neuraxial procedures, unlike P2Y12 inhibitors, according to the French Society for Anaesthesia and Intensive Care Medicine 2, 3
Central neuraxial anesthesia is absolutely contraindicated in patients on P2Y12 inhibitors unless discontinued 5-7 days prior, as recommended by the American College of Cardiology 1, 4
The bleeding risk hierarchy is: P2Y12 inhibitors > dual antiplatelet therapy > aspirin monotherapy, as stated by the European Society of Cardiology 5

Single-puncture spinal anesthesia is preferable to epidural anesthesia in patients on aspirin, as it involves less trauma and lower bleeding risk, according to the American Society of Anesthesiologists 1, 2, 3

No concurrent anticoagulation or other hemostatic abnormalities must be present, as recommended by the American College of Cardiology 1, 2, 3

History of GI bleeding or peptic ulcer disease increases bleeding risk, as stated by the American Gastroenterological Association 6
Concurrent NSAIDs increase GI bleeding risk 3-6 fold, according to the American College of Gastroenterology 7
Uncontrolled hypertension increases bleeding risk, as recommended by the American Heart Association 7

150mg aspirin carries intermediate GI bleeding risk with an odds ratio of 3.2 compared to 2.3 for 75mg and 3.9 for 300mg, as stated by the American College of Cardiology 6
Lower doses (75mg) reduce bleeding risk by 30% compared to 150mg for systemic bleeding complications, according to the European Society of Cardiology 6, 7
For neuraxial anesthesia, the dose difference between 75-325mg aspirin does not significantly alter the safety profile, as recommended by the American Society of Anesthesiologists 1, 2