<prompt> A 60-year-old man with no significant past medical history is scheduled for elective cholecystectomy. He has been taking aspirin daily. Preoperative recommendations should include which of the following?Determination of prothrombin time PTEstimation of platelet countDiscontinuation of aspirin 2 days before surgeryDiscontinuation of aspirin at least 1 week before surgery  <response>: Discontinuation of aspirin at least 1 week before surgery. Aspirin inactivates platelet cyclo-oxygenase and thus inhibits platelet aggregation. The effect of aspirin is irreversible and lasts for the entire life span of the platelets. Therefore, aspirin should be discontinued for at least 1 week before surgery. 