Final answer:
The nurse should flush the patient's PICC line that has a valved tip with normal saline solution to maintain patency, following the healthcare facility's protocol.
Step-by-step explanation:
When preparing to flush a patient's peripherally inserted central catheter (PICC) that has a valved tip, the appropriate action for the nurse to take is to flush the catheter with normal saline solution. Valved PICC lines are designed to prevent blood from entering the catheter when not in use, thereby reducing the risk of clotting and eliminating the need for a heparin flush. Therefore, only a saline flush is typically required to maintain patency of a valved PICC line, following the specific protocol of the healthcare facility.