When is it appropriate for the nurse to change the primary IV fluid container for a patient receiving 0.45% normal saline, infusing at 100 mL/hr?

The most appropriate answer is the option regarding when the 0.45% normal saline has infused. This choice highlights the importance of monitoring IV fluid therapy in relation to the completion of the prescribed infusion. IV fluids should be changed and replaced as dictated by the rate of infusion and the total volume prescribed.

For a patient infusing at the specified rate, the nurse should monitor the fluid level in the IV bag. Once the prescribed volume has infused, it is essential to change the container to ensure the patient continues receiving the necessary hydration and electrolyte balance without interruption.

This practice also aligns with safety protocols to prevent complications such as air entering the IV line or running the line dry, which could potentially harm the patient. Regular assessment of the IV fluids being infused and timely changes to the IV container are crucial in delivering optimal patient care.