Final answer:
The nurse should manually slow down the rate of the TPN infusion using a syringe while waiting for a new pump.
Step-by-step explanation:
While waiting for a new infusion pump, the nurse should slow down the rate of the TPN infusion manually with a syringe (Option B). The nurse can use a syringe to temporarily regulate the flow of the TPN by adjusting it to deliver the necessary volume over the desired time period.
Administering a bolus of TPN (Option A) is not recommended as it can lead to complications and may overload the patient's system. Starting an IV line with a different solution (Option C) is unnecessary and can disrupt the continuous infusion of TPN.
Discontinuing the TPN infusion and closely monitoring the client (Option D) is not the appropriate course of action, as it can lead to nutritional deficiencies and compromised patient care.