Central venous catheter
A central venous catheter (CVC) or "central line" is a catheter put in a large vein in the neck, chest, or groin when a patient needs close cardiovascular monitoring, for assessment of fluid status, and so that intravenous drugs and fluids can be given to the patient more effectively.  The veins most commonly used are the internal jugular vein, the subclavian vein, and the femoral vein.