Final answer:
The nurse should call the Rapid Response Team for a pulse change from 85 to 160 beats/minute lasting over 10 minutes, as it could indicate a severe underlying condition and immediate intervention may be vital.
Step-by-step explanation:
The nurse should call the Rapid Response Team (RRT) if she observes a pulse change from 85 to 160 beats/minute lasting more than 10 minutes. This significant increase in heart rate can indicate a severe underlying condition, such as hemorrhage, sepsis, or other forms of shock. The RRT is equipped to provide immediate intervention which could be lifesaving. While other options such as fresh bleeding on a wound dressing, elevated temperature and WBC count, or symptoms like weakness and diaphoresis with lowered blood pressure are concerning, the drastic and sustained change in pulse rate could represent the most imminent threat to the patient's stability.