Citrate versus heparin anticoagulation in chronic haemodialysis patients

Anticoagulation with citrate at a rate of 0.68 mM/min in combination with a calcium and magnesium-free dialysate and i.v. supplementation of calcium and magnesium at rates of 0.18 mM/min and 0.08 mM/min respectively, was compared with low-dose heparin. The heparin dose was a loading dose of 2500 IU and a sustaining infusion of 750-1250 IU/h; or a loading dose of 1250 IU and a sustaining infusion of 500-750 IU/h until 1 h before the end of the dialysis if the patient was taking concomitantly coumarin anticoagulation for a Goretex shunt. Six chronic haemodialysis patients changed from heparin to citrate anticoagulation because they reported bleeding between dialyses. Heparin, after 2 h dialysis, induced a significant 10% prolongation of each patient's whole-blood activated clotting time (WBACT) as compared to the predialysis value; while the WBACT at the dialyser outlet was less than 3% prolonged as compared to the patient's WBACT. However, after 2 h citrate the patient's WBACT was not prolonged but the WBACT at the dialyser outlet was 20-100% longer, indicating a better anticoagulation of the extracorporeal system without systemic effects. With heparin the shunt pressure time (SPT), i.e. the time needed to stop bleeding from the puncture sites of the Goretex shunts, was 12 of 28 times 20 min or more. Citrate reduced these episodes by 75%. Thus citrate should be considered for chronic haemodialysis patients who are at risk of bleeding because of the concomitant use of anticoagulants.(ABSTRACT TRUNCATED AT 250 WORDS)