Do Differences in Dialysis Prescription Impact on KDOQI Bone Mineral Targets? The Pan Thames Renal Audit

Abstract

Background and Objectives:Patients achieving the Kidney Disease Outcomes Quality Initiative (KDOQI) bone mineral clinical practice guidelines have been reported to have improved survival. Many factors affecting calcium and phosphate control are not modifiable; however, we wished to determine whether differences in dialysis treatment could affect achievement of KDOQI clinical guideline targets. Methods: We audited pre-mid-week session calcium and phosphate levels in 5,324 adult patients receiving thrice weekly dialysis in the 14 Pan Thames centres: 60% male, mean age 62 ± 16 years, median dialysis vintage 29 months (14–58), 84% treated by haemodialysis, 16% by online haemodiafiltration, median session time 4.0 h (3.5–4.0). Results: Patients achieving the KDOQI guidelines varied between the centres: 23.4–60% for calcium, 31.7–56.7% for phosphate, 60–87.3% for calcium-phosphate product, 17.1–46.8% for parathyroid hormone (PTH) and 1.8–10.8% for all 4 targets. Those centres which used the highest dialysate calcium concentrations (1.5 mmol/l, 3 mEq/l) had more patients above the KDOQI serum calcium and more below the PTH target, than those centres using the lowest calcium dialysates (1 mmol/l, 2 mEq/l), with χ² = 85.1 and χ² = 52.4, p < 0.001, respectively. On logistic regression analysis, serum phosphate was negatively associated with duration of dialysis session time (F = 21.4, p = 0.000) and haemodiafiltration (F = 9.6, p = 0.000), respectively. Conclusions: Although many of the factors determining calcium and phosphate control in haemodialysis patients are unmodifiable, dialysate calcium concentration, the duration of the dialysis session and haemodiafiltration all had an impact on calcium, phosphate and PTH.

Haemodiafiltration versus High-Flux Haemodialysis: Effects on Phosphate Control and Erythropoietin Response

“…The Fresenius FX dialyzer series was designed to increase internal filtration [21], but even so haemodiafiltration reduced pre-session serum phosphate compared to high-flux dialysis. Phosphate clearance is also session time dependent [23], but in our study there was no difference in dialysis session times. Other reports have shown an improvement in serum phosphate control with shorter but more frequency haemodiafiltration [24], although the fall in serum phosphate was not as great as 0.49 mmol/l (1.27 mg/dl) reported with 5–6 nocturnal haemodialysis sessions per week [25].…”

The Effects of Racial Differences on Body Composition and Total Body Water Measured by Multifrequency Bioelectrical Impedance Analysis Influence Delivered Kt/V Dialysis Dosing

“…On the other hand, there appears to be a survival advantage for the morbidly obese (BMI >35) haemodialysis patient whereas in the general population, the morbidly obese have increased mortality. Kt/V-based dosing for haemodialysis could potentially lead to a shortening of dialysis session times for women but to extended times for the morbidly obese, potentially impacting on both phosphate and middle molecule clearances [24], but also on volume control and sodium balance [25]. …”

Compliance with Mineral Metabolism Targets in Haemodialysis Patients: Moving Backwards?

“…The rigorous development of clinical practice guidelines through a systematic evaluation of the available evidence is costly and time-consuming. To account for differences between healthcare systems and resource availability in different locations [30,31], guidelines can be locally adapted by a group of experts as a means of reducing costs and time, and avoiding unnecessary duplication of efforts in developing new guidelines. In this manner, in 2011, the Spanish Society of Nephrology updated its recommendations for controlling CKD-MBD in patients with CKD [10].…”