If the nurse does not see blood return when aspirating the saline lock in preparation for an IV bolus medication, what is the next step?

The reason the first choice is the most appropriate action is that assessing the site for swelling or coolness while flushing the saline lock with normal saline is crucial to ensure the patency of the IV access. This step helps determine whether the saline lock is functioning properly or if there might be an issue, such as a blockage or infiltration.

Flushing the saline lock allows the nurse to check for any resistance or complications that may not be visible just by looking at the site. Assessing for swelling or coolness can indicate whether the IV line is still properly placed within the vein. This initial assessment is essential before taking further steps, as other actions may not be warranted if the saline lock is simply not in a position that allows for blood return.

In contrast, changing the IV tubing immediately may not be necessary if the issue is with the saline lock and not the tubing itself. Reporting findings to a physician might come after a proper assessment has been made. Similarly, replacing the saline lock with a new one should only occur if the current lock is confirmed as problematic after initial assessment steps are taken.