Hemodialysis and water quality

Over 383,900 individuals in the U.S. undergo maintenance hemodialysis that exposes them to water, primarily in the form of dialysate. The quality of water and associated dialysis solutions have been implicated in adverse patient outcomes and is therefore critical. The Association for the Advancement of Medical Instrumentation has published both standards and recommended practices that address both water and the dialyzing solutions. Some of these recommendations have been adopted into Federal Regulations by the Centers for Medicare and Medicaid Services as part of the Conditions for Coverage, which includes limits on specific contaminants within water used for dialysis, dialysate, and substitution fluids. Chemical, bacterial, and endotoxin contaminants are health threats to dialysis patients, as shown by the continued episodic nature of outbreaks since the 1960s causing at least 592 cases and 16 deaths in the U.S. The importance of the dialysis water distribution system, current standards and recommendations, acceptable monitoring methods, a review of chemical, bacterial, and endotoxin outbreaks, and infection control programs are discussed.

Effect of ultrapure dialysate on markers of inflammation, oxidative stress, nutrition and anemia parameters: a meta-analysis

BACKGROUND

Markers of inflammation are linked to malnutrition and confer an increased mortality risk in hemodialysis patients. Ultrapure dialysate might have a beneficial effect on markers of inflammation. We conducted a meta-analysis that examined the effect of ultrapure versus standard dialysate on markers of inflammation, oxidative stress, nutrition and anemia parameters.

METHODS

We performed a literature search using MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and scientific abstracts. Single-arm studies, nonrandomized and randomized controlled trials were included. We conducted random effects model meta-analyses to assess changes in the aforementioned outcomes.

RESULTS

We identified 16 single-arm studies, 2 crossover and 3 parallel-arm nonrandomized controlled trials and 5 crossover and 5 parallel-arm randomized controlled trials. In an analysis of 23 study arms or cohorts (n = 2221), ultrapure dialysate resulted in a significant decrease in C-reactive protein (-3.2 mg/L; 95% CI -4.6, -1.8; P < 0.001). Other markers of inflammation and oxidative stress displayed similar significant improvements. Ultrapure dialysate also resulted in a significant increase in serum albumin (0.11 g/dL; 95% CI 0.02, 0.19; P = 0.011) and hemoglobin (0.40 g/dL; 95% CI 0.06, 0.75; P = 0.022), and a decrease in the weekly erythropoietin dose (-273 units; 95% CI -420, -126; P < 0.001). The results remained significant in analyses restricted to controlled trials.

CONCLUSIONS

Use of ultrapure dialysate in hemodialysis patients results in a decrease in markers of inflammation and oxidative stress, an increase in serum albumin and hemoglobin and a decrease in erythropoietin requirement. Although improvement in these surrogate endpoints might confer a cardiovascular benefit, a large trial with hard clinical endpoints is required.

Endotoxemia after high cutoff hemodialysis for treatment of patient with multiple myeloma can be prevented by using ultrapure dialysate: a case report

To report endotoxemia presented in a case with multiple myeloma (MM) treated by high cutoff hemodialysis (HCO-HD) being prevented by using ultrapure dialysate. A female inpatient with MM received six times HCO-HD (HCO 2100 dialyzer) within 3 weeks after initiation of a chemotherapy based on vincristine+epirubicin+dexamethasone protocol. Conventional dialysate was used in the first three times and then changed to ultrapure dialysate due to elevation of body temperature after HCO-HD. Free light chains (FLC) and endotoxin levels in blood and dialysate were monitored. After six times HCO-HD, her serum FLC λ decreased from 4689 mg/L to 492.7 mg/L, with a trend of decline of serum creatinine. The clearance, reduction ratio, and removal amount of FLC λ was 38.4 mL/min, 71.0-85.2%, and 9.06-18.02 g, respectively, in the setting of dialysate flow rate 500 mL/min, while in the setting of dialysate flow rate 200 mL/min, the removal efficacy of FLC λ was lower than the former. A rise of body temperature up to 38.5°C after treatment and endotoxemia (endotoxin levels 0.122 EU/mL) was found when using conventional dialysate (endotoxin levels 0.112-0.145 EU/mL), but not seen after changing to ultrapure dialysate. Combined with appropriate chemotherapy, HCO-HD can effectively remove and reduce blood FLC. Attention should be paid to the endotoxemia and the rise of temperature after treatment when conventional dialysate is used, which can be prevented by using ultrapure dialysate.

High-flux dialyzers, backfiltration, and dialysis fluid quality

Currently, high-flux hemodialysis is the most common mode of dialysis therapy worldwide. Its steadily increasing use is largely based on the desire to reduce the excessively high morbidity and mortality of end-stage renal disease patients maintained on conventional dialysis (low-flux, mostly cellulosic membranes) by offering better biocompatibility and enhanced removal of uremic toxins. Two large randomized trials suggest a survival benefit for selected subgroups of high-flux dialysis patients such as diabetics, patients with hypoalbuminemia, or patients who have been on dialysis for a long period (>3.7 years). The major disadvantage of high-flux hemodialysis relates to the use of dialysis fluid, which is commonly not pure and may endanger patients treated with high-flux hemodialysis. Endotoxin fragments and other bacterial substances derived from bacteriologically contaminated dialysis fluid may, even at bacterial counts or endotoxin concentrations within the limits of accepted standards of dialysis fluid purity, enter from the dialysate into the patient's blood either by convective transfer (backfiltration) or by movement down the concentration gradient (backdiffusion). Repeated exposure of high-flux hemodialysis patients to backtransport of dialysate contaminants aggravates the uremia-associated inflammatory response syndrome and contributes to long-term morbidity. At present, the only solution to circumvent the risks of backtransport is the use of dry powder cartridges for bicarbonate concentrate and the use of bacteria- and endotoxin-retentive filters for the online production of ultrapure dialysis fluid. Use of ultrapure dialysis fluid (bacteria <0.1 CFU/ml and endotoxin <0.03 IU/ml) has been found to reduce inflammation and comorbidities in clinical investigations compared to commercial dialysis fluid. The European Renal Association and a number of national societies in Europe or in Japan strongly recommend the use of ultrapure dialysis for high-flux hemodialysis.