Sodium Citrate Versus Heparin Catheter Locks for Cuffed Central Venous Catheters: A Single-Center Randomized Controlled Trial

Background: Sodium citrate has antibacterial and anticoagulant properties that are confined to the catheter when used as a catheter lock. Studies of its use as a catheter lock have suggested its efficacy in preventing infection and bleeding complications compared with sodium heparin. Study Design: Open-label randomized controlled trial of 2 catheter locks to examine the hypothesis that sodium citrate catheter locks will reduce catheter-related bacteremia and exit-site infection. Settings & Participants: 232 consenting long-term hemodialysis patients in 4 satellite dialysis units to a large dialysis program with protocolized treatment and targets. All patients were using twin-catheter single-lumen Tesio-Caths (MedComp, Harleysville, PA). Intervention: 6 months' use of 46.7% sodium citrate (citrate) or 5% heparin (heparin) locked postdialysis in the dead space of the central venous catheter. Outcomes & Measurements: Primary end point of catheter-related bacteremia and exit-site infection. Secondary end points of catheter thrombosis defined by the use of urokinase lock and infusion, new catheter insertion, catheter-related admission, blood transfusions, parenteral iron, and erythropoietin requirements. Results: Catheter-related bacteremia did not differ in the 2 groups, with an incidence of 0.7 events/1,000 catheter-days. There was no significant difference in rates of exit-site infection (0.7 versus 0.5 events/1,000 catheter-days; P = 0.5). The secondary end point of catheter thrombosis defined by the use of a urokinase lock was significantly more common in the citrate group, with an incidence of 8 versus 4.3/1,000 catheter-days (P < 0.001). Other secondary end points did not differ. Citrate treatment was curtailed compared with heparin because of a greater incidence of adverse events, with a mean treatment duration before withdrawal of 4.8 +/- 2.0 versus 5.7 +/- 1.2 months, respectively (P < 0.001). Limitations: Low baseline catheter-related bacteremia and exit-site infection event rates may have underpowered this study. High adverse-event rates may have been related to high-concentration citrate that led to increased overspill and reduction in lock volume. This may also explain the increased rates of thrombosis in this group. Conclusion: Widespread and long-term use of 46.7% citrate catheter locks with Tesio-Cath access is not justified by this study. Am J Kidney Dis 53:1034-1041. (C) 2009 by the National Kidney Foundation, Inc.