Which instruction is critical for a client undergoing radioactive iodine therapy?

The correct instruction for a client undergoing radioactive iodine therapy is to use disposable utensils for meals. This recommendation is crucial to minimize exposure to radiation. Radioactive iodine therapy involves administering a form of iodine that emits radiation, which can pose potential risks to others, particularly in the first week following treatment when the body still excretes the radioactive material.

Using disposable utensils allows the client to avoid contaminating shared or reusable items, thereby reducing the chance of radiation exposure to family members, caregivers, or others in close contact. It is particularly emphasized that, as a safety precaution, the patient's bodily fluids, including saliva, can carry radiation, and using disposable items ensures that any residual radioactive material is disposed of properly and does not pose a risk to others.

The instruction to stay away from crowded places for one week is also important, as it reduces the risk of radiation exposure to others, but it does not directly address the practical daily activities such as eating. Avoiding drinking fluids for 24 hours is not relevant to the care protocol for radioactive iodine therapy, as proper hydration is typically encouraged to help flush out the radioactive iodine from the body. Similarly, the use of non-disposable utensils does not offer the same protective measures as using disposable ones.