What should a respiratory therapist use immediately after inserting an indwelling arterial line to prevent clot formation?

The primary goal after inserting an indwelling arterial line is to ensure patency and prevent clot formation within the catheter. Attaching a pressurized bag of heparinized saline serves this purpose effectively. Heparin is an anticoagulant that helps prevent the coagulation of blood, thereby minimizing the risk of a thrombus forming in the catheter.

Additionally, the pressurized system ensures a steady flow of the saline solution through the catheter. This constant infusion helps to flush out any potential clots and keeps the line open, providing reliable access for blood sampling or monitoring arterial pressure. The use of heparinized saline is a standard protocol in maintaining arterial lines, particularly to prevent clotting and ensure the functionality of the catheter over time, which is critical for patient care.

Implementing the other options would not adequately prevent clot formation. For example, simply flushing the catheter with normal saline does not provide the anticoagulant properties necessary to prevent clotting, while allowing free-flow of blood could lead to a significant risk of clotting in areas outside the catheter. Meanwhile, keeping a cap securely on the end of the catheter does not facilitate clear and continuous flow or active maintenance required for preventing clot formation.