Citrate vs. acetate dialysate on intradialytic heparin dose: A double blind randomized crossover study

Introduction Citrate containing dialysate has a calcium-binding anticoagulant effect compared to standard acetic acid containing dialysate. We performed a randomized, double-blind, crossover trial in maintenance HD patients to determine if citrate dialysate ("citrate") safely allows for a lower cumulative heparin dose ("heparin dose"). Methods Intradialytic heparin was adjusted to the minimum during a 2-week run-in phase. Patients remaining on heparin at the end of the run-in phase were then randomized to two weeks of HD with acetate dialysate ("acetate") followed by two weeks of citrate (sequence 1) or two weeks of citrate followed by two weeks of acetate (sequence 2). We estimated a minimum of 14 patients are required to show a 30% reduction in heparin dose per HD session with citrate compared with acetate. Twenty-five patients entered the run-in phase, 20 were randomized, and 19 completed the study. Findings The mean heparin dose was reduced by 19% (656 units, 95% CI -174 to -1139 units, P = 0.011) in the acetate group, and 30% (1046 units 95% CI -498 to 1594 units, P < 0.001) in the citrate group. There was no difference in the mean heparin dose reduction between the two dialysates (P > 0.05). The intradialytic ionized calcium in the citrate group was lowered by 0.10 mmol/L (95% CI 0.07 to 0.14 mmol/L, P < 0.001), and remained unchanged in the acetate group. Discussion Although citrate is a safe alternative to acetate, it does not result in additional heparin dose reduction.