 Methods: Patients will be randomized to three intervention groups: a frequent 6 days moving of catheters to new sites; an alternating schedule of wire exchanges and new sites every 6 and 12 days; and a less frequent moving of catheters to new sites 12 days without wire exchange. This project requires enough patients to show a difference between three intervention groups. A significant decrease in infection rate would be from the current 20 infections per 1000 catheter days to approximately 15 per 1000 catheter days. This would require a minimum of 1000 catheter days per group. 