Abstract: 【Abstract】 Objective Symptomatic intra-dialysis hypotension (IDH) continues to be a common problem. In this study, we investigated the changes in hemodynamic parameters induced by calcium concentration in dialysate in IDH patients.  Methods Single-blinded and crossover design was used. Sixteen maintenance hemodialysis patients with IDH were randomized into two groups, beginning by changing the calcium concentration in dialysate either to 1.25mmol/L or 1.75mmol/L. The first 2-week intervention phase was followed by two-week of wash out with calcium concentration in dialysate as 1.5mmol/L, switching round the calcium concentration compared to the initial randomization, by a second 2-week intervention phase.  Results Fourteen patients finished the trial, and two patients withdrew due to infection. Compared to lower calcium concentration (1.25mmol/L), dialysate with higher calcium concentration elevated mean intradialytic systolic blood pressure (mSBP) (P＜0.05), decreased the maximum difference of SBP (the difference between predialytic SBP and the lowest intradialytic SBP), while the incident of symptomatic IDH and stopping hemodialysis did not decreased significantly. Medium calcium concentration in dialysate did not have any effect on such parameters.  Conclusion Higher calcium concentration in dialysate can partially improve the hemodynamic stability in IDH patients. Multiple-centered clinical trial with larger samples is needed.   

Key words: Intradialytic hypotension, Calcium ion concentration, Hemodynamics