No more heplock??? its citlock now.

Nephrol Dial Transplant. 2007 Feb;22(2):477-83. Epub 2006 Oct 2.

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

* Lok CE,
* Appleton D,
* Bhola C,
* Khoo B,
* Richardson RM.

Department of Medicine, Division of Nephrology, The Toronto General Hospital, 11 EN-216, 200 Elizabeth Street, Toronto, Ontario, M5G 2C4, Canada. charmaine.lok@uhn.on.ca.

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:

1. CVC exchange 2.98/1000 days (HP) vs 1.65/1000 days (CP) (P = 0.01);
   
2. TPA use 5.49/1000 (HP) vs 3.3/1000 days (CP) (P = 0.002);
   
3. hospitalizations 0.59/1000 days (HP) vs 0.28/1000 days (CP) (P = 0.49).
   
4. 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.