Comparison of acetate-free citrate hemodialysis and bicarbonate hemodialysis regarding the effect of intra-dialysis hypotension and post-dialysis malaise.

Compared with acetate dialysate, bicarbonate dialysate has shown beneficial effects in reducing the morbidity associated with dialysis, but a small amount of acetate in bicarbonate dialysate may evoke hypotension or malaise. Acetate-free citrate hemodialysis (AFHD) may avoid these problems. In 44 hemodialysis patients bicarbonate hemodialysis (BHD) was conducted for three months, followed by a switch to AFHD for three months, and a further switch to bicarbonate hemodialysis (ReBHD). In BHD, AFHD and ReBHD, intra-dialysis hypotension and post-dialysis malaise were determined (hypotension: intra-dialysis systolic blood pressure (SBP) was expressed as a percentage of SBP at the start of hemodialysis, malaise was assessed by a self-reported 0 to 3 scale, 0: absence of malaise, 3: unbearable malaise). Compared with BHD, AFHD patients complained of less malaise but the intra-dialysis blood pressure change did not differ significantly (malaise: BHD 0.73 ± 0.76 vs. AFHD 0.32 ± 0.47, P < 0.0001, end hemodialysis SBP: BHD 93.6 ± 8.9 vs. AFHD 93.8 ± 10.1, P = NS). After switching to ReBHD from AFHD, the malaise score increased (AFHD 0.32 ± 0.47 vs. ReBHD 0.77 ± 0.89, P < 0.0001) and the intra-dialysis blood pressure dropped markedly (end hemodialysis SBP: AFHD 93.8 ± 10.1 vs. ReBHD 87.3 ± 10.5, P < 0.0001). Malaise was very severe in five patients who could not continue ReBHD. After ten days under ReBHD, ReBHD was changed to AFHD again in all patients. Although the exact mechanisms are not known, AFHD may be preferable to BHD to prevent hemodialysis-induced hypotension and malaise.