Which instruction reflects the nurse's correct understanding of the role of nursing assistive personnel (NAP) in caring for a patient receiving an intravenous (IV) antibiotic medication by piggyback?

The instruction to let the nursing assistive personnel (NAP) know immediately if the patient complains of pain at the IV site is a correct understanding of the role of NAP in this context. This choice emphasizes the importance of communication and monitoring for potential complications associated with intravenous therapy. NAPs are trained to observe the patient and report any changes in their condition, including any discomfort or adverse reactions at the IV site. Prompt reporting of pain can help ensure timely intervention, which is critical for managing potential issues such as infiltration or phlebitis.

The other options involve activities that typically fall outside the scope of practice for NAPs. Monitoring vital signs, for instance, may be a nursing responsibility depending on the patient's condition and the facility's protocols. Documentation of medication administration is usually performed by licensed nurses to maintain the accuracy and integrity of medical records. Changing the IV site is also a task that requires specialized training and is generally done by a nurse to prevent complications.