Anticoagulation during haemodialysis using a citrate-enriched dialysate: a feasibility study

The feasibility of anticoagulating the extracorporeal circuit during haemodialysis using a simple citrate-enriched dialysate was evaluated in a prospective, randomised, cross-over study of 24 patients who were at high risk for bleeding. A dialysate, with a citrate level of 3 mEq/L (1 mmol/L), was generated by adding citrate to the conventional liquid 'bicarbonate concentrate' of a regular, dual-concentrate, bicarbonate-buffered dialysate delivery system. Each of the 24 patients received two dialysis treatments. For anticoagulation of the extracorporeal circuit, one treatment used the citrate-enriched dialysate (Citrate Group), while the other treatment used conventional saline flushing (Saline Group). The order of the two treatments was randomised. With either method, a heparinized, saline-rinsed dialyser was used, and no heparin was administered during dialysis. Ninety-two per cent (22 out of 24) and 100% of patients tolerated the procedure well in the Citrate Group and the Saline Group, respectively. Eight per cent (two out of 24) of the treatments in each group had to be abandoned because of clotting in the extracorporeal circuit. Significantly less thrombus formation in the venous air traps was detected in the Citrate Group. No patients from either group suffered from hypocalcaemic or bleeding complications, but the immediate post-dialysis and 0.5-h post-dialysis plasma levels of ionised calcium and of magnesium were slightly lower in the Citrate Group than in the Saline Group. Our findings suggest that it is feasible to use the present simple citrate-enriched dialysate to dialyse patients safely and effectively. Furthermore, the approach is much simpler than a conventional, intermittent, saline-flushing method.