Final answer:
NSAIDs are contraindicated after cardiac surgery, except for ASA used in antiplatelet therapy, due to an increased risk of bleeding by inhibiting prostaglandin synthesis.
Step-by-step explanation:
The question is regarding the contraindication of nonsteroidal anti-inflammatory drugs (NSAIDs) after a specific type of surgery, except for acetylsalicylic acid (ASA), which is used for antiplatelet therapy. NSAIDs are contraindicated after cardiac surgery. This contraindication is due to their action on prostaglandin synthesis, leading to an increased risk of bleeding. NSAIDs, including aspirin, ibuprofen, and naproxen, inhibit the enzyme cyclooxygenase (COX), which is necessary for the conversion of arachidonic acid into prostaglandins that cause inflammation and pain. While aspirin can inhibit COX irreversibly, it is allowed in antiplatelet doses because it plays a role in preventing blood clots. Other NSAIDs can potentially increase bleeding risk and are therefore generally not recommended following cardiac surgery.