Citrate- vs. acetate-based dialysate in bicarbonate haemodialysis: consequences on haemodynamics, coagulation, acid-base status, and electrolytes

Abstract

Background: A concentrate for bicarbonate haemodialysis acidified with citrate instead of acetate has been marketed in recent years. The small amount of citrate used (one-fifth of the concentration adopted in regional anticoagulation) protects against intradialyser clotting while minimally affecting the calcium concentration. The aim of this study was to compare the impact of citrate- and acetate-based dialysates on systemic haemodynamics, coagulation, acid-base status, calcium balance and dialysis efficiency.

Methods: In 25 patients who underwent a total of 375 dialysis sessions, an acetate dialysate (A) was compared with a citrate dialysate with (C+) or without (C) calcium supplementation (0.25 mmol/L) in a randomised single-blind cross-over study. Systemic haemodynamics were evaluated using pulse-wave analysis. Coagulation, acid-base status, calcium balance and dialysis efficiency were assessed using standard biochemical markers.

Results: Patients receiving the citrate dialysate had significantly lower systolic blood pressure (BP) (-4.3 mmHg, p < 0.01) and peripheral resistances (PR) (-51 dyne.sec.cm-5, p < 0.001) while stroke volume was not increased. In hypertensive patients there was a substantial reduction in BP (-7.8 mmHg, p < 0.01). With the C+ dialysate the BP gap was less pronounced but the reduction in PR was even greater (-226 dyne.sec.cm-5, p < 0.001). Analyses of the fluctuations in PR and of subjective tolerance suggested improved haemodynamic stability with the citrate dialysate. Furthermore, an increase in pre-dialysis bicarbonate and a decrease in pre-dialysis BUN, post-dialysis phosphate and ionised calcium were noted. Systemic coagulation activation was not influenced by citrate.

Conclusion: The positive impact on dialysis efficiency, acid-base status and haemodynamics, as well as the subjective tolerance, together indicate that citrate dialysate can significantly contribute to improving haemodialysis in selected patients.

Trial registration: ClinicalTrials.gov NCT00718289.

Figure 1

Study design. Schematic representation of the study design.

Figure 2

Evaluation of the fluctuations in haemodynamic parameters. Schematic representation of the method used to calculate the maximum increase and decrease of each measured parameter during the dialysis session.

Figure 3

Systolic blood pressure. Systolic blood pressure as a function of the haemodialysis time using, respectively, acetate (A) (empty diamonds), calcium uncorrected citrate (C) (black squares) and calcium supplemented citrate dialysate (C+) (black triangles).

Figure 4

Diastolic blood pressure. Diastolic blood pressure as a function of the haemodialysis time using, respectively, acetate (A) (empty diamonds), calcium uncorrected citrate (C) (black squares) and calcium supplemented citrate dialysate (C+) (black triangles).

Figure 5

Heart rate. Heart rate as a function of the haemodialysis time using, respectively, acetate (A) (empty diamonds), calcium uncorrected citrate (C) (black squares) and calcium supplemented citrate dialysate (C+) (black triangles).

Figure 6

Blood volume. Blood volume as a function of the haemodialysis time using respectively acetate (A) (empty diamonds), calcium uncorrected citrate (C) (black squares) and calcium supplemented citrate dialysate (C+) (black triangles).

Figure 7

Stroke volume. Stroke volume as a function of the haemodialysis time using, respectively, acetate (A) (empty diamonds), calcium uncorrected citrate (C) (black squares) and calcium supplemented citrate dialysate (C+) (black triangles).

Figure 8

Peripheral resistance. Peripheral resistance as a function of the haemodialysis time using, respectively, acetate (A) (empty diamonds), calcium uncorrected citrate (C) (black squares) and calcium supplemented citrate dialysate (C+) (black triangles).

Figure 9

Systolic blood pressure in hypertensive patients. Systolic blood pressure as a function of the haemodialysis time using, respectively, acetate (A) (empty diamonds) and calcium uncorrected citrate (C) (black squares) dialysate in the subgroup of patients with an intradialytic systolic blood pressure increase during dialysis of more than 15 mmHg and at least one value of more than 150 mmHg (n = 8).