The study is a randomized, double blinded, prospective, multicenter, clinical trial. All patients requiring vascular access with a tunneled central venous catheter for hemodialysis are eligible for enrollment. Patients will be randomized to receive either Heparin 1,000 U/ml in a volume sufficient to fill the catheter length in both ports or to receive 4% Sodium Citrate with Gentamicin 320 mcg/mL in a volume sufficient to fill the catheter length in both ports.We hypothesize that the device related infection rate in the Citrate/Gentamicin group will be less than the heparin arm.