What action should the nurse take after aspirating a blood return in a lumen of a triple lumen catheter before administering medication?

After aspirating a blood return in a lumen of a triple lumen catheter, the appropriate action is to flush the lumen with saline and then administer the medication through that lumen. This procedure ensures that the medication is delivered through a patent line, confirming that the lumen is functioning properly, and that the medication will reach the systemic circulation without any obstruction. Flushing with saline also helps to clear any blood that may have pooled in the catheter, minimizing the risk of clot formation or medication interaction with previously infused substances in the line.

Using saline to flush is an established protocol to maintain the patency of intravenous lines, especially after verifying blood return, which indicates that the catheter is correctly positioned within the vascular system. This step is crucial before administering medications to ensure that the full dose of the medication is delivered effectively and to prevent complications associated with administering medication into a blocked or non-functioning line.

The other options presented do not align with standard nursing practices for medication administration via an intravenous line. For instance, using a PRN prescription for a thrombolytic agent is not appropriate unless there is evidence of a clot that needs to be addressed, which is not indicated simply by observing blood return. Clamping the lumen and preparing a heparin solution is unnecessarily complicated if the