What is the function of heparin in a heparin lock?

Heparin functions as an anticoagulant, which is critical in preventing blood from clotting within a heparin lock. A heparin lock is a device used in intravenous therapy that maintains a catheter's patency between infusions or draws, allowing for quick access to the bloodstream without the need for repeated needle insertions. By adding heparin to the flush solution, the risk of clot formation inside the catheter is significantly reduced, ensuring that it remains open and functional.

This function is paramount to the device's effectiveness, as clotting could lead to complications, including decreased flow rates and the need for catheter replacement. The other options, while relevant to other aspects of intravenous therapy, do not accurately describe the vital role of heparin in preventing clot formation within the heparin lock.