Abstract: Objective To investigate the influence of calcium concentration in dialysate on dialysis-related refractory hypertension in maintenance hemodialysis (HD) patients. Methods Twenty HD patients with refractory hypertension were enrolled in this study. Patients were first used dialysate containing Ca2+ 1.75mmol/L for 15 times of HD and then that containing Ca2+ 1.5mmol/L for another 15 times of HD. Blood pressure was measured at 0, 1, 2 and 3h during HD and after the HD. Serum calcium, phosphate, intact parathyroid hormone (iPTH) and other clinical parameters were determined before and after the change of calcium concentration in dialysate. Results Blood pressure lowered in patients used Ca2+ 1.5mmol/L in dialysate, especially at 3h during HD and after the HD, as compared with that in patients used Ca2+ 1.75mmol/L in dialysate (P＜0.05 or P＜0.01). Serum calcium and calcium-phosphate product were also decreased in those used Ca2+ 1.5mmol/L in dialysate (P< 0.01). Conclusion Lower calcium in dialysate may be favorable in control of hemodialysis-related refractory hypertension.

Key words: Calcium, Refractory hypertension, Dialysate