Final answer:
The nurse's first action when directed to take an unsafe patient assignment is to speak up immediately if there are concerns.
Step-by-step explanation:
The most appropriate first action of the nurse when directed to take an unsafe patient assignment is to speak up immediately if there are concerns about the task. The nurse has the right to refuse the assignment if they believe it is unsafe, as long as they have a valid reason. According to the information provided, the nurse should always prioritize patient safety and advocate for the best care. It is important to communicate any concerns about the assignment or patient care to the appropriate authority.
In this situation, the nurse can refer to the guidelines that suggest speaking up if there are any issues with equipment, patient name labeling, or any other concerns related to the patient's recovery and care.