Abstract: Objective To investigate the effectiveness of different calcium concentrations in dialysate for simplified citric acid anticoagulant hemodialysis.  Methods  A total of 32 hemodialysis patients with high risk of bleeding were treated with 1.25mmol/L (group A) or 1.5 mmol/L (group B) calcium-containing dialysate for 64 times of simplified citric acid anticoagulant hemodialysis by self-crossover control method. Blood free calcium level was measured at different dialysis time points, the pumping speed of citric acid was adjusted, and the dialysis indexes and dialysis adequacy (Kt/V) were recorded.  Results  ①The anticoagulant efficacies of group A and group B were 100% and 93.8% respectively. ②The pumping speed of citric acid in group A was lower than that in group B [(390.9±24.0) ml/h vs.（410.9±20.7）ml/h, t=-3.569, P=0.001]. In group A, the free calcium after the filter at 2 hours of dialysis [(0.66±0.13) mmol/L vs. (0.80±0.12) mmol/L, t=-4.428, P<0.001) and the free calcium before the filter at 4 hours of dialysis [(0.91±0.11) mmol/L vs. (1.00±0.13) mmol/L, t=-2.917, P=0.005) were lower than those in group B. ③There was no significant difference in Kt/V between the two groups [(1.16±0.22) mmol/L vs. (1.18±0.20)mmol/L, t=-0.380, P=0.706].  Conclusion  Dialysate containing calcium 1.5mmol/L can achieve effective anticoagulation with safer blood free calcium concentration, and it may be appropriate for simplified citric acid anticoagulant hemodialysis. 

Key words: Citric acid, Hemodialysis, Anticoagulation, Calcium-containing dialysate