Final answer:
The most appropriate new IV insertion site for an adult patient who has had a complication with a previous IV would be proximal to the previous site. The antecubital fossa is also a common choice, but not as practical for mobile patients, whereas the foot is considered a last resort.
Step-by-step explanation:
When an adult patient experiences a complication with their IV and requires continued IV fluids, the most appropriate site for the nurse to choose for a new IV insertion would be proximal to the previous site. Placing the IV catheter proximal (toward the torso) to a previous site helps prevent infection and inflammation that could possibly propagate from the older site. It is typically discouraged to use a site distal to the previous one (further down the arm away from the torso) because if there is a complication with the previous site, it can affect the new site. Using the antecubital fossa is often preferable, as this area contains veins such as the median cubital vein that are suitable for venous access; however, it is less practical for mobile patients, as it may limit mobility and can bend more easily, which could impede the flow of IV fluids. Inserting an IV in the foot is generally considered a last resort because it is less comfortable and has a higher risk of infection.