CITRATE VERSUS HEPARIN ANTICOAGULATION IN CHRONIC-HEMODIALYSIS PATIENTS

Anticoagulation with citrate at a rate of 0.68 mM/min in combination w ith 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 respect ively, was compared with low-dose heparin. The heparin dose was a load ing dose of 2500 IU and a sustaining infusion of 750-1250 IU/h; or a l oading 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 concomit antly coumarin anticoagulation for a Goretex shunt. Six chronic haemod ialysis patients changed from heparin to citrate anticoagulation becau se they reported bleeding between dialyses. Heparin, after 2 h dialysi s, induced a significant 10% prolongation of each patient's whole-bloo d 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 patie nt's WBACT was not prolonged but the WBACT at the dialyser outlet was 20-100% longer, indicating a better anticoagulation of the extracorpor eal system without systemic effects. With heparin the shunt pressure t ime (SPT), i.e. the time needed to stop bleeding from the puncture sit es of the Goretex shunts, was 12 of 28 times 20 min or more. Citrate r educed these episodes by 75%. Thus citrate should be considered for ch ronic haemodialysis patients who are at risk of bleeding because of th e concomitant use of anticoagulants. Other patients who could benefit from citrate are those with premorbid vascular abnormalities such as i ntestinal arteriovenous malformations, diabetic retinopathy, malignant hypertension or adult polycystic kidney disease. Claims that citrate gave improved biocompatibility, i.e. less leukopenia or thrombocytopen ia, were not confirmed. Indications that citrate caused better dialysi s efficiency were found, but should be confirmed in a greater number o f patients.