What is the purpose of a heparin lock for CVADs?

• A. To disinfect the catheter
• B. To maintain patency and prevent thrombus formation
• C. To reduce infection risk
• D. To provide analgesia during insertion

Answer: (B)

The purpose of a heparin lock for Central Venous Access Devices (CVADs) is primarily to maintain patency and prevent thrombus formation. Heparin, an anticoagulant, is used in this context to help prevent blood clots from forming within the catheter lumen when it is not in use. Without such an intervention, stagnant blood could clot, leading to occlusion of the catheter, which would render it ineffective for future use.

By maintaining the patency of the catheter, the heparin lock ensures that the CVAD remains ready for administration of medications, fluids, or other treatments as needed. This utility is essential for the ongoing functionality of the device, especially in patients who require long-term access for intravenous therapy.

While other options may touch on important aspects of CVAD care—such as disinfection, reducing infection risks, or addressing pain—these do not reflect the primary biochemical action that heparin promotes within the locking mechanism of the catheter. Consequently, the central focus of using a heparin lock is to manage thrombus formation and ensure the catheter's ongoing usability.