Trisodium citrate 4%--an alternative to heparin capping of haemodialysis catheters

Abstract

Background: Central venous catheters (CVCs) continue to be used at a high rate for dialysis access and are frequently complicated by thrombus-related malfunction. Prophylactic locking with an anticoagulant, such as heparin, has become standard practice despite its associated risks. Trisodium citrate (citrate) 4% is an alternative catheter locking anticoagulant.

Methods: The objective was to prospectively study the clinical effectiveness, safety and cost of citrate 4% vs heparin locking by comparing rates of CVC exchanges, thrombolytic use (TPA) and access-associated hospitalizations during two study periods: heparin period (HP) (1 June 2003-15 February 2004) and Citrate Period (CP) 15 March-15 November 2004. Incident catheters evaluated did not overlap the two periods.

Results: There were 176 CVC in 121 patients (HP) and 177 CVC in 129 patients (CP). The event rates in incident CVC were: CVC exchange 2.98/1000 days (HP) vs 1.65/1000 days (CP) (P = 0.01); TPA use 5.49/1000 (HP) vs 3.3/1000 days (CP) (P = 0.002); hospitalizations 0.59/1000 days (HP) vs 0.28/1000 days (CP) (P = 0.49). There was a longer time from catheter insertion to requiring CVC exchange (P = 0.04) and TPA (P = 0.006) in the citrate compared with the heparin lock group. Citrate locking costs less than heparin locking but a formal economic analysis including indirect costs was not done.

Conclusion: Citrate 4% has equivalent or better outcomes with regards to catheter exchange, TPA use and access-related hospitalizations compared with heparin locking. It is a safe and less expensive alternative. Randomized trials comparing these anticoagulants with a control group would definitively determine the optimal haemodialysis catheter locking solution.