Dialysate Calcium: A Lot More Than 'Set It and Forget It'

Hemodialysis Procedures for Stable Incident and Prevalent Patients Optimize Hemodynamic Stability, Dialysis Dose, Electrolytes, and Fluid Balance

The demographic profile of patients transitioning from chronic kidney disease to kidney replacement therapy is changing, with a higher prevalence of aging patients with multiple comorbidities such as diabetes mellitus and heart failure. Cardiovascular disease remains the leading cause of mortality in this population, exacerbated by the cardiovascular stress imposed by the HD procedure. The first year after transitioning to hemodialysis is associated with increased risks of hospitalization and mortality, particularly within the first 90-120 days, with greater vulnerability observed among the elderly. Based on data from clinics in Fresenius Medical Care Europe, Middle East, and Africa NephroCare, this review aims to optimize hemodialysis procedures to reduce mortality risk in stable incident and prevalent patients. It addresses critical aspects such as treatment duration, frequency, choice of dialysis membrane, dialysate composition, blood and dialysate flow rates, electrolyte composition, temperature control, target weight management, dialysis adequacy, and additional protocols, with a focus on mitigating prevalent intradialytic complications, particularly intradialytic hypotension prevention.

Personalizing electrolytes in the dialysis prescription: what, why and how?

Maintenance hemodialysis patients suffer from multiple comorbidities and treatment-related complications. A personalized approach to hemodialysis prescription could reduce some of these burdens by preventing complications such as excessive changes in blood pressure, arrhythmias, post-dialysis fatigue and decreased quality of life. A patient-centered approach to dialysate electrolyte concentrations represents one such opportunity. In addition to modifications in dialysate electrolyte concentrations, consideration of individual factors such as patients' serum concentrations, medication profiles, nutritional status and comorbidities is critical to tailoring hemodialysis prescriptions to optimize patient outcomes. The development of personalized dialysis treatment depends on the collection of comprehensive patient data, advances in technology, resource allocation and patient involvement in decision-making. This review discusses how the treatment of maintenance hemodialysis patients could benefit from individualized changes in certain dialysis fluid components.

Dialysate calcium, alfacalcidol, and clinical outcomes: A post-hoc analysis of the J-DAVID trial

The selection of dialysate calcium concentration (D-Ca) is still controversial among chronic hemodialysis (HD) regimens. We examined the trajectories of CKD MBD parameters among the J-DAVID trial participants to see the effect of D-Ca and alfacalcidol. The trial was an open-label randomized clinical trial including 976 HD patients with intact PTH of 180 pg/mL or lower which compared the users of vitamin D receptor activator (oral alfacalcidol) and non-users over a median of 4 years. The main D-Ca used at baseline were 3.0 mEq/L in 70% and 2.5 mEq/L in 25%, respectively. The primary endpoint was the composite of fatal and non-fatal cardiovascular events and the secondary endpoint was all-cause mortality. Multivariable Cox proportional hazard regression analyses in which D-Ca was included as a possible effect modifier and serum laboratory data as time-varying covariates showed no significant effect modification for composite cardiovascular events or all-cause mortality. This post hoc analysis showed that the effects of alfacalcidol on cardiovascular outcomes were not significantly modified by D-Ca.

Developing a Selective Zirconium Phosphate Cation Exchanger to Adsorb Ammonium: Effect of a Gas-Permeable and Hydrophobic Coating

A sorbent with a high enough capacity for NH₄⁺ could serve as an oral binder to lower urea levels in end-stage kidney disease (ESKD) patients. A hydrogen-loaded cation exchanger such as zirconium phosphate Zr(HPO₄)₂·H₂O (ZrP) is a promising candidate for this application. However, the NH₄⁺ binding selectivity versus other ions must be improved. Here, we have developed a gas-permeable and hydrophobic surface coating on an amorphous form of ZrP using tetraethyl orthosilicate and methoxy-terminated polydimethylsiloxane. The hydrophobic coating serves as a barrier to ions in water solution from reaching the ion-exchanger's surface. Meanwhile, its gas-permeable nature allows for gaseous ammonia transfer to the cation exchanger. In vitro studies were designed to replicate the small intestine's expected ion concentrations and exposure time to the sorbent. The effectiveness of the coating was measured with NH₄⁺ and Ca²⁺ solutions and uncoated ZrP as the negative control. X-ray photoelectron spectroscopy and scanning electron microscopy measurements show that the coating successfully modifies the surface of the cation exchanger─ZrP. Water contact angle studies indicate that coated ZrP is hydrophobic with an angle of (149.8 ± 2.5°). Simulated small intestine solution studies show that the coated ZrP will bind 94% (±11%) more NH₄⁺ than uncoated ZrP in the presence of Ca²⁺. Meanwhile, Ca²⁺ binding decreases by 64% (±6%). The nearly fourfold increase in NH₄⁺ selectivity can be attributed to the gas-permeable and hydrophobic coating applied on the ZrP surface. This work suggests a novel pathway to develop a selective cation exchanger for treating ESKD patients.