 Several alternative anticoagulation regimens have been proposed including heparin coating of the dialyzer membrane and regional citrate anticoagulation. Regional citrate anticoagulation is performed by infusing citrate into the arterial line of the dialysis tubing to reduce ionized calcium concentrations to very low levels 4,1. Ionized calcium concentrations are restored by calcium supplementation prior to reinfusion of the blood into the patient. Most often, calcium repletion is by calcium infusion into the venous line. Alternatively, a conventional calcium containing dialysate will restore calcium concentrations and, although the anticoagulant effect is blunted in the venous line, gives acceptable results 5. A previous study suggested that regional citrate anticoagulation is superior to heparin-coated polyacrylonitrile dialyzers AN69ST; Nephral 300ST, Gambro and resulted in in significantly greater instantaneous urea nitrogen clearances 3. 