What allergy should the nurse assess for before a patient undergoes cardiac catheterization?

Before a patient undergoes cardiac catheterization, it's crucial for the nurse to assess for an allergy to iodine. During the procedure, a contrast dye containing iodine is typically injected to visualize the coronary arteries. If a patient is allergic to iodine, exposure to the contrast medium can lead to serious allergic reactions, such as anaphylaxis, or other complications like contrast-induced nephropathy.

While iron, aspirin, and penicillin are also important to consider regarding allergic reactions in different medical contexts, they are not relevant for cardiac catheterization. Iron is not used in the contrast agents; aspirin is commonly used for cardiovascular patients and isn't directly connected to the catheterization process, and penicillin, an antibiotic, would not be a concern in this specific context. Ensuring the patient does not have an iodine allergy directly impacts the safety and success of the procedure.