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Patients with chronic kidney disease in the hemodialysis program are exposed to large amounts of water, as this constitutes about 96% of the dialysis fluid. It is known that the use of better quality water decreases the state of chronic inflammation in dialysis patients. Disinfection as part of water treatment plays an important role in meeting the established quality standards; currently, heat disinfection is highly recommended, however its dose is not clearly established in the literature. The objective of this review is to know what is available in the literature on the dose of heat disinfection that should be used in hemodialysis and to present our experience with this method at a set dose of 12.000 A 0 ., (Copyright © 2019 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.)

Metabolic acidosis is a common complication of chronic kidney disease; it is typically caused by the accumulation of sulfate, phosphorus, and organic anions. Metabolic acidosis is correlated with several adverse outcomes, such as morbidity, hospitalization, and mortality. Thus, correction of metabolic acidosis is fundamental for the adequate management of many systemic complications of chronic kidney disease. In patients undergoing hemodialysis, acid-base homeostasis depends on many factors including the following: net acid production, amount of alkali given by the dialysate bath, duration of the interdialytic period, and residual diuresis, if any. Recent literature data suggest that the development of metabolic alkalosis after dialysis may contribute to adverse clinical outcomes. Our review is focused on the potential effects of different dialysate bicarbonate concentrations on hard outcomes such as mortality. Unfortunately, no randomized studies exist about this issue. Acid-base equilibrium is a complex and vital system whose regulation is impaired in chronic kidney disease. We await further studies to assess the extent to which acid-base status is a major determinant of overall survival in patients undergoing hemodialysis. For the present, the clinician should understand that target values for predialysis serum bicarbonate concentration have been established primarily based on observational studies and expert opinion. Based on this, we should keep the predialysis serum bicarbonate level at least at 22 mmol/l. Furthermore, a specific focus should be addressed by the attending nephrologist to the clinical and nutritional status of the major outliers on both the acid and alkaline sides of the curve., (Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

A Best Practice Guideline about Dialysis fluid purity was developed under the leadership of the Spanish Society of Nephrology in 2004. The second edition revised Guideline considered new evidences and International Standard. The Guideline has established recommendations for standards for preparing dialysate: water, concentrates and hemodialysis proportioning systems. This Guideline is based on the ISO13959, European Pharmacopoeia, the Real Farmacopea Española, the AAMI Standards and Recommended Practices, European Best Practice Guidelines for Haemodialysis, literature reviews, according to their level of evidence, and the opinion of the expert Spanish group. Two levels of quality of water were defined: purified water and high purified water (ultra pure) and for dialysate: ultra pure dialysate. Regular use of ultra pure dialysate is recommended for all type of hemodialysis to prevent and delay the occurrence of complications: inflammation, malnutrition, anaemia and amiloidosis. Water, concentrates and dialysate quality requirements are defined as maximum allowable contaminant levels: chemicals (4.1.2), conductivity, microbial and endotoxins (4.1.1): Monitoring frequency, maintenance and corrective actions were specified. Methods of sampling and analysis were described in appendix (anexos). For microbiological monitoring, R2A medium is recommended, incubated during 7-14 days at a temperature of 17-23°C. The dialysate quality assurance process involves all dialysis staff members and requires strict protocols. The physician in charge of hemodialysis has the ultimate responsibility for dialysate quality. All suggestions and questions about this Guideline are wellcome to www.senefro.org., (Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.)

The effects of high-flux dialysis and ultrapure dialysate on survival of hemodialysis patients are incompletely understood. We conducted a randomized controlled trial to investigate the effects of both membrane permeability and dialysate purity on cardiovascular outcomes. We randomly assigned 704 patients on three times per week hemodialysis to either high- or low-flux dialyzers and either ultrapure or standard dialysate using a two-by-two factorial design. The primary outcome was a composite of fatal and nonfatal cardiovascular events during a minimum 3 years follow-up. We did not detect statistically significant differences in the primary outcome between high- and low-flux (HR=0.73, 95% CI=0.49 to 1.08, P=0.12) and between ultrapure and standard dialysate (HR=0.90, 95% CI=0.61 to 1.32, P=0.60). Posthoc analyses suggested that cardiovascular event-free survival was significantly better in the high-flux group compared with the low-flux group for the subgroup with arteriovenous fistulas, which constituted 82% of the study population (adjusted HR=0.61, 95% CI=0.38 to 0.97, P=0.03). Furthermore, high-flux dialysis associated with a lower risk for cardiovascular events among diabetic subjects (adjusted HR=0.49, 95% CI=0.25 to 0.94, P=0.03), and ultrapure dialysate associated with a lower risk for cardiovascular events among subjects with more than 3 years of dialysis (adjusted HR=0.55, 95% CI=0.31 to 0.97, P=0.04). In conclusion, this trial did not detect a difference in cardiovascular event-free survival between flux and dialysate groups. Posthoc analyses suggest that high-flux hemodialysis may benefit patients with an arteriovenous fistula and patients with diabetes and that ultrapure dialysate may benefit patients with longer dialysis vintage.

The composition and quality of the dialysis fluid play an important role in the modulation of dialysis-related complications. During hemodialysis, patient's blood has a contact with dialysate through a semipermeable membrane. Bacterial endotoxins can pass through the membrane pores into the patient's blood and cause a silent chronic microinflammation. The aim of this study was to determine the level of endotoxins in hemodialysis water and dialysate in Lithuanian hemodialysis centers. Dialysis water (n=50) and dialysate (n=50) were collected from 91% (n=50) of all hemodialysis centers. The presence of bacterial endotoxins was evaluated using a sensitive Limulus amebocyte lysate test, which detects intact lipopolysaccharides. The level of endotoxins was lower than 0.25 EU/mL in 43 (86%) dialysis water samples and in 46 (92%) dialysate samples, and complied with the recommendations of the European Pharmacopoeia and the European Best Practice Guidelines for pure dialysis fluid. The dialysate of 39 (78%) Lithuanian hemodialysis centers complied with the definition of an ultrapure dialysis fluid. The water and dialysate were of insufficient quality in 14% and in 8% of Lithuanian hemodialysis centers, respectively, and this could be improved by the establishment of routine investigation of endotoxins.

Unlabelled: Hemodialysis is a process when the blood of patients contacts with dialysate through a semipermeable membrane. Water used for dialysis is not sterile. Microorganisms cannot pass through the membrane pores, but bacterial endotoxins can diffuse to the blood of patients. Several acute and long-term complications (pyrogenic reactions, silent chronic inflammation, malnutrition) in dialysis patients might be associated with dialysate contamination. The aim of this study was to determine the level of endotoxins in hemodialysis water and dialysate in several hemodialysis centers of different Lithuanian cities., Material and Methods: Material was dialysis water (n=6) and dialysate (n=14) from six hemodialysis centers in three different cities of Lithuania. Bacterial endotoxin levels were measured using a sensitive Limulus Amebocyte Lysate (LAL) assay., Results and Conclusions: The level of endotoxins was less than 0.25 endotoxin unit (EU)/mL in all hemodialysis water (n=6) and dialysate (n=14) samples. One sample of water (16.7%) and two of dialysate (14.3%) had the level of endotoxins above 0.03 EU/mL. Therefore, the level of endotoxins in hemodialysis water and dialysate in studied Lithuanian hemodialysis centers (n=6) complied with the recommendations of the European Pharmacopoeia and the ERA-EDTA best practice guidelines for conventional dialysis modalities. The level of endotoxins in dialysate of five Lithuanian hemodialysis centers complied with the recommendations of the ERA-EDTA best practice guidelines for ultrapure dialysate.

Background: Routine water monitoring in a haemodialysis centre revealed high trichloroethylene (TCE) concentrations. The aim of this study is to describe the measures adopted after organic contamination of dialysis water in order to avoid the possibility of patient exposure. We also carried out in vitro experiments to evaluate the accumulation of TCE in various devices normally used in a dialysis water treatment system (DWTS)., Methods: In vivo and in vitro blood and water TCE levels were determined by means of solid phase microextraction-gas chromatography/mass spectrometer., Results: High TCE concentrations were found throughout the DWTS; acceptably low levels were obtained only by replacing the activated charcoal, ionic-exchange resins, microfilters and PVC pipes. The adsorption and realising capacities of these devices were tested in vitro, and the elimination curves made it possible to calculate the total percentage of the previously absorbed TCE mass released into the water. Evidence of exposure was confirmed by the relatively high TCE levels in the patient blood samples taken 30 days after the last exposure even if the subjects were asymptomatic. In vivo experiments showed that the blood gain of TCE through the low flux membrane during the course of dialysis was about 77+/-10.4% of the amount carried by dialysis fluid as calculated on the basis of its partition coefficient value (K(b/w) 3.75)., Conclusions: This study shows that, when present in dialysis water, the lipophilic TCE contaminant can accumulate in various devices, thus transforming them into possible sources of exposure. This highlights the importance of periodically monitoring dialysis water for organic substances that have a great affinity to the blood compartment, in order to prevent occasional or chronic patient exposure.

Background: The K/DOQI Clinical Practice Guidelines for Bone Metabolism and Disease in Chronic Kidney Disease was published in October 2003. The objective of this study was to analyse the effect of the application of those guidelines on clinical practices and on the achievement of bone disease targets and quality standards., Methods: We included in the study 342 patients dialysed in our three HD units during 2003 and 2004. Starting October 2003, the K-DOQI recommendations were introduced into practice. Parathyroid hormone (PTH) was measured every 3 months and the serum Ca and P levels, monthly. In patients whose medications were modified, PTH was measured monthly and Ca and P levels, weekly or biweekly., Results: The following are the main findings for 2004 (post-K/DOQI): an increased use of dialysates with a Ca concentration of 2.5 mEq/l (27.2-50.9%, P<0.001) and a reduced use of a dialysate calcium of 3.0 mEq/l (44.6-39.6%, P: NS) and 3.5 mEq/l (28-9.4%, P<0.001); a reduced use of calcium-based phosphate binders (891.9-565.5 mg Ca/day, P<0.001) and increased use of sevelamer hydrochloride (800 mg) (from 4.86 to 7.51 mg, tablets/day, P<0.001) lower serum Ca levels (9.7-9.4 mg/dl, P<0.01), and higher intact PTH levels (201.4-311.8 pg/ml, P<0.001), without changes in serum P levels; an increased proportion of patients with serum Ca levels within the K/DOQI target range (38.7-46.6%, P<0.01), resulting mainly from the reduced percentage of patients with hypercalcaemia (55-44.4%, P<0.01); a decreased proportion of patients with PTH<150 pg/ml (53.8-31.4%, P<0.001) but an increased proportion of patients with PTH>300 pg/ml, with no change in the proportion of patients with PTHs within the K/DOQI target range. Phosphorus levels and targets did not show significant differences between 2003 and 2004 (56.9-56.2%, P: NS)., Conclusions: The only way to ensure that K/DOQI guidelines actually improve medical outcomes is to emphasize implementation strategies and also the scientific evaluation of their effectiveness in clinical settings. In spite of the application of the K-DOQI recommendations, a large proportion of our patients stayed outside the proposed targets, which points to the need for more effective therapeutic options.

Background: The risks connected with dialysis fluid contamination are well established. Epidemiological studies have demonstrated just how difficult it is to obtain permanently satisfactory quality standards. Therefore, dialysis centers must have effective and regular quality control programs, particularly with the growing and widespread use of online convective dialysis treatments. Considering this, we conducted a national survey of water treatment systems and monitoring in Italian dialysis centers., Methods: Two independent questionnaires were prepared and distributed in 1999 and 2001. The questions were designed to acquire information on structural and procedural elements. Responses to similar questions from both questionnaires were analyzed together., Results: Responses to questionnaires were received from 148 centers (17% of dialysis centers in Italy). In accordance with the European Best Practice Guidelines (EBPG) published recently concerning dialysis fluid purity, in the majority of centers (97%) the water treatment system consisted of at least pre-treatment and reverse osmosis (RO) modules. However, only one stage RO module was implemented (71%), there was a water storage tank (65%) and water pipe distribution loop was made of sanitary polyvinyl chloride (85%). Analysis of procedural elements--the timing and type of disinfection procedures used for the waterline system and monitors, the timing and type of water treatment quality control procedures--revealed a striking variability among centers in terms of the types and frequency of checks performed., Conclusions: Taking into account the EBPG, this survey revealed both bright and dark spots, calling for a national initiative aimed at defining a standard periodicity of loop disinfection, points in the water pipe line to be tested, and the frequency and type of tests.

Background: Microbial contamination is characterized not only by the presence of bacteria, but also by high concentrations of biologically active by-products. They are potentially able to cross ultrafiltration and dialysis membranes and stimulate immunocompetent blood cells to synthesize cytokines. In turn, cytokine induction causes acute symptoms and has been incriminated in the long-term complications of haemodialysis patients. Infusion of large volumes of substitution fluids following ultrafiltration of microbially contaminated dialysis fluids may place patients on on-line therapies at particular risk., Methods: In this study we evaluated 30 machines with a two-stage ultrafiltration system in routine clinical haemodiafiltration settings in six centres for 6 months. Microbiological safety was assessed monthly and at the last use of the filters by determining microbial counts, endotoxin concentration and cytokine-inducing activity., Results: No pyrogenic episodes were observed during the study period. Double-filtration of standard dialysis fluid (range, <1-895 cfu/ml, 0.0028-4.6822 IU/ml) resulted in sterile substitution fluids with endotoxin concentrations well below the Ph.Eur. standard for haemofiltration solutions (range, 0.0014-0.0281 vs 0.25 IU/ml). Moreover, they did not differ from commercial haemofiltration solutions and depyrogenated saline. Likewise, there was no difference in the cytokine-inducing activity between the solutions tested. The high microbiological quality of the ultrafiltered dialysis fluid, which was in the same range as substitution fluid, translates into both the absence of cytokine induction by dialyser back-transport and a redundant safety mode of the on-line system by a second filtration step., Conclusion: On-line HDF treatment can routinely be provided with ultra-pure dialysis fluids and sterile substitution fluids at pyrogen-free levels. The online preparation of substitution fluids thus can be considered microbiologically safe.

To help prevent pyrogenic reactions and bacteremia in hemodialysis patients, the Association for the Advancement of Medical Instrumentation and the Centers for Disease Control recommend microbiologic assay of hemodialysis fluids at least monthly. Five commercially available assay systems were evaluated by using the membrane filtration technique with standard methods agar and trypticase soy agar as the standards for comparison. Each assay system was challenged with dialysate and reverse-osmosis water from local dialysis centers, aqueous suspensions of eight laboratory strains of gram-negative bacilli and nontuberculous mycobacteria, and a mixed microbial flora inoculated into reverse-osmosis water and laboratory-prepared dialysate. Mean viable counts from triplicate samples were obtained after incubation at 37 degrees C for up to 72 h. The efficiency of recovery varied with the specific type of microbial challenge. The SPC water sampler (Millipore Corp., Bedford, Mass.) was the most consistent in obtaining the highest viable counts. Other commercial systems were comparable to each other in overall performance. All assay systems tested provided an acceptable balance between microbial recovery and required sampling time, equipment, and expertise.