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.

Index Words: Hemodialysis, heparin, sodium citrate, catheter lock