Which condition contraindicates the use of ASA for a patient with cardiac ischemia?

The use of acetylsalicylic acid (ASA), commonly known as aspirin, in patients with cardiac ischemia is generally indicated due to its ability to inhibit platelet aggregation, thus reducing the risk of further myocardial damage. However, there are certain contraindications to its use.

A previous allergy to NSAIDs is significant because ASA is classified as a nonsteroidal anti-inflammatory drug (NSAID). If a patient has a known allergy to NSAIDs, administering ASA can elicit an allergic reaction, which can range from mild to severe, including anaphylaxis. This poses a greater risk to the patient's health and may worsen their condition rather than help it.

In contrast, an unaltered mental status indicates that the patient is likely capable of understanding and participating in their care decisions, normal blood pressure reflects hemodynamic stability, and being age 18 or older does not inherently contraindicate the use of ASA. While other factors must be considered in emergency medicine, the previous allergy to NSAIDs remains the most critical contraindication when administering ASA in cases of cardiac ischemia.