Final answer:
The nurse should call the Rapid Response Team if the client's pulse changes from 85 to 160 beats/minute lasting more than 10 minutes.
Step-by-step explanation:
The observation that should alert the nurse to call the Rapid Response Team (RRT) is the pulse change from 85 to 160 beats/minute lasting more than 10 minutes. This significant increase in heart rate could indicate a serious cardiovascular or hemodynamic issue, such as a heart problem or shock. Rapid assessment and intervention by the RRT are necessary to address the situation and prevent any further complications.
The other observations mentioned, such as fresh bleeding on the surgical wound dressing, a temperature of 103.1 F (39.5 C) with an elevated white blood cell count, and weakness, diaphoresis, and low blood pressure, also require attention and intervention. However, the pulse change is the most critical observation that warrants immediate action.