Mortality risk by hemodialyzer reuse practice and dialyzer membrane characteristics: results from the usrds dialysis morbidity and mortality study

Survival with low- and high-flux dialysis

Background

Besides advances in haemodialysis (HD), mortality rates are still high. The effect of the different types of HD membranes on survival is still a controversial issue. The aim of this COSMOS (Current management Of Secondary hyperparathyroidism: a Multicentre Observational Study) analysis was to survey, in HD patients, the relationship between the use of conventional low- or high-flux membranes and all-cause and cardiovascular mortality.

Methods

COSMOS is a multicentre, open-cohort, 3-year prospective study, designed to evaluate mineral and bone disorders in the European HD population. The present analysis included 5138 HD patients from 20 European countries, 3502 randomly selected at baseline (68.2%), plus 1636 new patients with <1 year on HD (31.8%) recruited to replace patients who died, were transplanted, switched to peritoneal dialysis or lost to follow-up by other reasons. Cox-regression analysis with time-dependent variables, propensity score matching and the use of an instrumental variable (facility-level analysis) were used.

Results

After adjustments using three different multivariate models, patients treated with high-flux membranes showed a lower all-cause and cardiovascular mortality risks {hazard ratio (HR) = 0.76 [95% confidence interval (CI) 0.61-0.96] and HR = 0.61 (95% CI 0.42-0.87), respectively}, that remained significant after matching by propensity score for all-cause mortality (HR = 0.69, 95% CI 0.52-0.93). However, a facility-level analysis showed no association between the case-mix-adjusted facility percentage of patients dialysed with high-flux membranes and all-cause and cardiovascular mortality.

Conclusions

High-flux dialysis was associated with a lower relative risk of all-cause and cardiovascular mortality. However, dialysis facilities using these dialysis membranes to a greater extent did not show better survival.

Metabolic acidosis in hemodialysis: a neglected problem in Brazil

Introduction:

Metabolic acidosis is associated with the high mortality seen in hemodialysis patients. The panorama of metabolic acidosis in hemodialysis in Brazil is unclear since 1996 when the analysis of bicarbonate levels was no longer a compulsory exam. We aimed to establish the prevalence of metabolic acidosis in a hemodialysis population and analyze the factors associated with low bicarbonate levels.

Methods:

A cross-sectional study was carried out to assess the prevalence of metabolic acidosis in adults undergoing regular hemodialysis from January to April 2017, in four dialysis centers from Niteroi, Rio de Janeiro, Brazil, and surroundings. For blood gas analysis, samples of 2 mL were collected in heparinized syringes before a midweek dialysis session.

Results:

384 patients with a mean age of 58.1 ± 15.8 years (54.5% men and 63.0%, non-white) were included. Approximately 30% had diabetes and 48%, hypertension. Nearly 88% used primary arteriovenous fistula as vascular access. The pre-dialysis mean serum tCO² in the midweek session was 22.7 ± 3.0 mEq/L. The prevalence rate of serum bicarbonate below DOQI recommendation (22 mEq/L or higher) was 40.3%, and 6.5% had serum bicarbonate < 18 mEq/L. The dialyzer use count and the use of low-flux dialyzers were negatively associated whereas age and the standard Kt/V values were positively associated with the serum bicarbonate levels.

Conclusion:

The findings were in agreement with global data reported in previous studies. However, because the sample was relatively small and non-representative of the Brazilian population, a more comprehensive study, addressing national data is necessary to substantiate our findings.

Improvement in Clinical Outcome by Early Nephrology Referral in Type Ii Diabetics on Maintenance Peritoneal Dialysis

← Objectives

To evaluate the influence of early nephrology referral on clinical outcome in type II diabetes mellitus patients on maintenance peritoneal dialysis (PD).

← Design

This is a retrospective study in a single University Hospital in Taiwan.

← Patients

This study analyzed the type II diabetic patients entering our PD program from February 1988 to June 2000. Patients that were presented to a nephrologist more than 6 months before starting dialysis were defined as early referrals (ER). Patients were considered late referrals (LR) if they were transferred to the nephrology department within 6 months before initial dialysis.

← Main Outcome Measures

Patient survival and technique survival curves were derived from Kaplan–Meier analysis and were compared using the Cox–Mantel log rank test. Covariates were analyzed with Cox proportional hazards model.

← Results

52 type II diabetic patients were enrolled in this study: 16 in the ER group and 36 in the LR group. Patient survival was better in the ER group than in the LR group {relative risks [exp(coef)] 0.42; 95% confidence interval 0.152 – 0.666; p < 0.05}. The improved survival in the ER group was independent of age at dialysis, good glycemic control, and residual renal function, as indicated in the multivariate analysis with stepwise regression by Cox proportional hazards model. The ER group was also associated with better technique survival.

← Conclusions

These results suggest that early nephrology referral before initiating dialysis is associated with improved long-term clinical outcome in type II diabetics on maintenance PD.

Reprocessing and reuse of single-use medical devices in China: a pilot survey

Background

In China, reprocessing and reuse of single-use medical devices (SUDs) are banned. However, the actual situation has not been reported so far. The study aims to clarify the perceptions and concerns of various sectors of the community on the reuse of SUDs, and whether such practice exists. In addition, we are also wondering how acceptable the respondents are on this matter.

Methods

A cross-sectional study based on a national survey which was conducted on the professional online questionnaire survey platform (www.wjx.cn) from July 26 to August 4, 2015. We analyzed the data according to the work fields, sex, age, education level, professional background and participants’ answers to 49 other questions.

Results

Five hundred forty-four nationwide respondents belong to nine different work fields. In general, participants had positive attitudes towards the reprocessing and reuse of SUDs. However, many respondents doubted the hygienic and functional safety of the reprocessed SUDs. They also tended to think that the reuse of SUDs should have lower prices and more technical training as well as patient advocacy. Further analysis demonstrated the work fields, education level and professional background of respondents were statistically associated with their responses to certain questions.

Conclusions

The research indicated that although the reuse of SUDs is prohibited legally in China, there were extensive reprocessing and reuse in hospitals. Most responses tended to accept reprocessed SUDs if safety and low prices were guaranteed. These existing contradictions and the lack of relevant research led to policy makers in China will confront numerous challenges in building and improving this use system of medical devices to meet escalating demands of social sectors.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6835-9) contains supplementary material, which is available to authorized users.

Clinical and microbiological effects of dialyzers reuse in hemodialysis patients

Introduction:

Chronic kidney disease (CKD) has a high prevalence and is a worldwide public health problem. Reuse of dialyzers is a cost reduction strategy used in many countries. There is controversy over its effects on clinical parameters and microbiological safety.

Methods:

In this clinical crossover study, 10 patients performed consecutive hemodialysis (HD) sessions divided in two phases: "single use" sessions (N = 10 HD sessions) followed by "dialyzer reuse" sessions (N = 30 HD sessions). Clinical, laboratory, and microbiological parameters were collected in the following time points: "single use", 1^st, 6^th, and 12^th sessions with reuse of dialyzers, including bacterial cultures, endotoxins quantification in serum and dialyzer blood chamber, and detection of hemoglobin and protein residues in dialyzers.

Results:

Mean age of the sample was 37 ± 16 years, 6 (60%) were men, and 5 (50%) were white. CKD and HD vintage were 169 ± 108 and 47 (23-111) months, respectively. Serum C-reactive protein (CRP) [4.9 (2.1) mg/mL], ferritin (454 ± 223 ng/mL), and endotoxin levels [0.76 (0.61-0.91) EU/mL] were high at baseline. Comparison of pre- and post-HD variations of serum levels of CRP and endotoxins in the "single use" versus "reuse" phases did not result in differences (p = 0.8 and 0.4, respectively). Samples of liquid in the dialyzer inner chamber were negative for the growth of bacteria or endotoxins. There was no significant clinical manifestation within and between the phases.

Conclusion:

Dialyzers reuse was safe from a clinical, microbiological, and inflammatory point of view. The dialyzer performance remained adequate until the 12^th reuse.

Choosing a dialyzer: What clinicians need to know

The objectives of hemodialysis have moved from the diffusive clearance of small molecular weight uremic toxins and achieving dialyzer urea adequacy targets to emphasis on improving clinical outcomes in end stage renal failure patients by increasing larger sized uremic toxin clearance. Clinical emphasis in the last few decades has focused on increasing middle molecule weight toxin clearance by hemodiafiltration. Although long-term data is still lacking, short-term outcomes appear promising. Advancements in nanotechnology have now introduction a new generation of medium cut-off membrane dialyzers which allow diffusive clearance of similar middle molecular weight uremia toxin clearance as hemodiafiltration, without increased albumin losses. As these dialyzers have only recently been introduced into clinical practice, no long-term outcomes are available to determine the relative benefits or advantages of this approach. As dialyzers are now designed to maximize diffusive or convective clearance, or provide a combination, then clinicians can now choose dialyzers tailored to the individual patient needs depending on clinical circumstances. We review the key important features in choosing a dialyzer for patients with end stage renal failure and acute kidney injury.

The Role of Big Data in the Development and Evaluation of US Dialysis Care

Rapid growth in electronic communications and digitalization, combined with advances in data management, analysis, and storage, have led to an era of "Big Data." The Social Security Amendments of 1972 turned end-stage renal disease (ESRD) care into a single-payer system for most patients requiring dialysis in the United States. As a result, there are few areas of medicine that have been as influenced by Big Data as dialysis care, for which Medicare's large administrative data sets have had a central role in the evaluation and development of public policy for several decades. In the 1970/1980s, Medicare data helped identify concerning trends in costs, access to dialysis care, and quality of care delivered. As the research community and policymakers made Medicare's administrative data increasingly accessible for investigation, analyses of Medicare claims have had a large role in facilitating policy synthesis and refinement. Efforts to address the skyrocketing cost of injectable drugs in the 1990s and 2000s exemplify this expanded role of Big Data. Although there are opportunities for large government and nongovernmental administrative data sets to continue serving a critical role in the evaluation and development of ESRD policies, it is important to understand challenges and limitations associated with their use.

The influence of mortality rate from membrane flux for end-stage renal disease: A meta-analysis

To evaluate the influence of the high-flux hemodialysis (HFHD) and the low-flux hemodialysis (LFHD) on mortality rate for end-stage renal disease (ESRD). Four electronic databases including PubMed, EMBASE, the Cochrane Library, and ClinicalTrails were searched to identify relevant randomized clinical trials up to 31 August 2015. Seven studies enrolling a total of 4412 patients were included in this meta-analysis. For all-cause mortality comparing with LFHD, the result showed that there were significant difference (RR=0.75; 95% CI [0.60-0.94]; I²=84%; P<0.00001). For death due to infection comparing with LFHD, the result showed that there was no significant difference (RR=0.92; 95% CI [0.75-1.13]; I²=0%; P=0.86). For cardiovascular mortality, the overall meta-analysis result showed that there was a significant difference between the HFHD versus the LFHD (RR=0.75; 95% CI [0.60-0.94]; I²=55%; P=0.11). Publication bias was not detected by funnel plot. Based on these results, our study suggests that the HFHD has superior effectiveness over LFHD for long-term survival in ESRD.

Factors Affecting Hemodialysis Adequacy in Cohort of Iranian Patient with End Stage Renal Disease

BACKGROUND

There are many factors that can affect dialysis adequacy; such as the type of vascular access, filter type, device used, and the dose, and rout of erythropoietin stimulation agents (ESA) used. The aim of this study was investigating factors affecting Hemodialysis adequacy in cohort of Iranian patient with end stage renal disease (ESRD).

METHODS

This is a cross-sectional study conducted on 133 Hemodialysis patients referred to two dialysis units in Sistan-Baluchistan province in the cities of Zabol and Iranshahr, Iran. We have looked at, (the effects of the type of vascular access, the filter type, the device used, and the dose, route of delivery, and the type of ESA used) on Hemodialysis adequacy. Dialysis adequacy was calculated using kt/v formula, two-part information questionnaire including demographic data which also including access type, filter type, device used for hemodialysis (HD), type of Eprex injection, route of administration, blood groups and hemoglobin response to ESA were utilized. The data was analyzed using the SPSS v16 statistical software. Descriptive statistical methods, Mann-Whitney statistical test, and multiple regressions were used when applicable.

RESULTS

The range of calculated dialysis adequacy is 0.28 to 2.39 (units of adequacy of dialysis). 76.7% of patients are being dialyzed via AVF and 23.3% of patients used central venous catheters (CVC). There was no statistical significant difference between dialysis adequacy, vascular access type, device used for HD (Fresenius and B. Braun), and the filter used for HD (p> 0.05). However, a significant difference was observed between the adequacy of dialysis and Eprex injection and patients' time of dialysis (p <0.05).

CONCLUSION

Subcutaneous ESA (Eprex) injection and dialysis shift (being dialyzed in the morning) can have positive impact on dialysis adequacy. Patients should be educated on the facts that the type of device used for HD and the vascular access used has no significant effects on dialysis adequacy.

Influence of dialysis modality and membrane flux on insomnia severity in haemodialysis patients

AIM

Insomnia is an important problem in dialysis patients. A greater prevalence of insomnia in chronic kidney disease compared with non-renal patients suggests a role for uraemic toxins in contributing to insomnia. The aim of this study was to examine if dialysis modality and membrane permeability is associated with the frequency and severity of insomnia in haemodialysis patients.

METHODS

In our cross-sectional study, we evaluated 122 patients who were divided into three groups: on-line haemodiafiltration, high flux haemodialysis and low flux haemodialysis. The frequency and severity of insomnia was evaluated with the Insomnia Severity Index.

RESULTS

Insomnia was present in 47.5% of all patients. The majority of patients who reported insomnia were receiving low flux haemodialysis (80%), followed by patients on high flux haemodialysis (43.6%) and haemodiafiltration (20.9%). Patients using low flux membranes, had a significantly higher Insomnia Severity Index (11.9 ± 6.6) compared with patients receiving high flux haemodialysis (6.8 ± 6.3) and haemodiafiltration (5.2 ± 7.0). The insomnia severity index did not differ between patients receiving high flux haemodialysis compared with on-line haemodiafiltration.

CONCLUSION

This study indicates that different haemodialysis modalities are associated with insomnia and suggests a potential benefit of using high flux membranes.

The impact of high-flux dialysis on mortality rates in incident and prevalent hemodialysis patients

BACKGROUND/AIMS

The effect of high-flux (HF) dialysis on mortality rates could vary with the duration of dialysis. We evaluated the effects of HF dialysis on mortality rates in incident and prevalent hemodialysis (HD) patients.

METHODS

Incident and prevalent HD patients were selected from the Clinical Research Center registry for end-stage renal disease (ESRD), a Korean prospective observational cohort study. Incident HD patients were defined as newly diagnosed ESRD patients initiating HD. Prevalent HD patients were defined as patients who had been receiving HD for > 3 months. The primary outcome measure was all-cause mortality.

RESULTS

This study included 1,165 incident and 1,641 prevalent HD patients. Following a median 24 months of follow-up, the mortality rates of the HF and low-flux (LF) groups did not significantly differ in the incident patients (hazard ratio [HR], 1.046; 95% confidence interval [CI], 0.592 to 1.847; p = 0.878). In the prevalent patients, HF dialysis was associated with decreased mortality compared with LF dialysis (HR, 0.606; 95% CI, 0.416 to 0.885; p = 0.009).

CONCLUSIONS

HF dialysis was associated with a decreased mortality rate in prevalent HD patients, but not in incident HD patients.

Comparison of the impact of high-flux dialysis on mortality in hemodialysis patients with and without residual renal function

Background

The effect of flux membranes on mortality in hemodialysis (HD) patients is controversial. Residual renal function (RRF) has shown to not only be as a predictor of mortality but also a contributor to β2-microglobulin clearance in HD patients. Our study aimed to determine the interaction of residual renal function with dialyzer membrane flux on mortality in HD patients.

Methods

HD Patients were included from the Clinical Research Center registry for End Stage Renal Disease, a prospective observational cohort study in Korea. Cox proportional hazards regression models were used to study the association between use of high-flux dialysis membranes and all-cause mortality with RRF and without RRF. The primary outcome was all-cause mortality.

Results

This study included 893 patients with 24 h-residual urine volume ≥100 ml (569 and 324 dialyzed using low-flux and high-flux dialysis membranes, respectively) and 913 patients with 24 h-residual urine volume <100 ml (570 and 343 dialyzed using low-flux and high-flux dialysis membranes, respectively). After a median follow-up period of 31 months, mortality was not significantly different between the high and low-flux groups in patients with 24 h-residual urine volume ≥100 ml (HR 0.86, 95% CI, 0.38–1.95, P = 0.723). In patients with 24 h-residual urine volume <100 ml, HD using high-flux dialysis membrane was associated with decreased mortality compared to HD using low-flux dialysis membrane in multivariate analysis (HR 0.40, 95% CI, 0.21–0.78, P = 0.007).

Conclusions

Our data showed that HD using high-flux dialysis membranes had a survival benefit in patients with 24 h-residual urine volume <100 ml, but not in patients with 24 h-residual urine volume ≥100 ml. These findings suggest that high-flux dialysis rather than low-flux dialysis might be considered in HD patients without RRF.

Evidence-based cardiology in hemodialysis patients

Cardiac events are the major cause of death in hemodialysis patients. Because of the paucity of randomized clinical trials (RCTs) in hemodialysis patients, most cardiovascular therapies in this population are based on observational studies or results extrapolated from studies that excluded hemodialysis patients. However, associations discovered in observational studies do not prove causality, and these studies often report surrogate outcomes rather than clinical end points. Furthermore, interventions that show effectiveness in the general population may have drastically different outcomes and side effect profiles in hemodialysis patients. This review discusses the results of RCTs undertaken recently to evaluate cardiovascular therapies in hemodialysis patients and emphasizes clinically relevant outcomes. Although some interventions have produced similar outcomes in hemodialysis patients and the general population, others have not, suggesting that the management of cardiovascular disease in hemodialysis patients may require strategies that differ from the best practice guidelines applied to general population.

The impact of membrane permeability and dialysate purity on cardiovascular outcomes

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.

Water quality in conventional and home haemodialysis

Dialysis water can be contaminated by chemical and microbiological factors, all of which are potentially hazardous to patients on haemodialysis. The quality of dialysis water has seen incremental improvements over the years, with advances in water preparation, monitoring and disinfection methods, and high standards are now readily achievable in clinical practice. Advances in dialysis membrane technology have refocused attention on water quality and its potential role in the bioincompatibility of haemodialysis circuits and adverse patient outcomes. The role of ultrapure dialysate is increasingly being advocated, given its proposed clinical benefits and relative ease of production as a result of the widespread use of reverse osmosis and ultrafiltration. Many of the issues pertaining to water quality in hospital-based dialysis units are also pertinent to haemodialysis in the home. Furthermore, an increased awareness of the environmental and financial consequences of home haemodialysis has resulted in the development of automated and more efficient dialysis machines. These new machines have an increased emphasis on water conservation and recycling along with a decreased need for a complex infrastructure for water purification and maintenance.

High-flux versus low-flux membranes for end-stage kidney disease

BACKGROUND

Clinical practice guidelines regarding the use of high-flux haemodialysis membranes vary widely.

OBJECTIVES

We aimed to analyse the current evidence reported for the benefits and harms of high-flux and low-flux haemodialysis.

SEARCH METHODS

We searched Cochrane Renal Group's specialised register (July 2012), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1948 to March 2011), and EMBASE (1947 to March 2011) without language restriction.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared high-flux haemodialysis with low-flux haemodialysis in people with end-stage kidney disease (ESKD) who required long-term haemodialysis.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two authors for study characteristics (participants and interventions), risks of bias, and outcomes (all-cause mortality and cause-specific mortality, hospitalisation, health-related quality of life, carpal tunnel syndrome, dialysis-related arthropathy, kidney function, and symptoms) among people on haemodialysis. Treatment effects were expressed as a risk ratio (RR) or mean difference (MD), with 95% confidence intervals (CI) using the random-effects model.

MAIN RESULTS

We included 33 studies that involved 3820 participants with ESKD. High-flux membranes reduced cardiovascular mortality (5 studies, 2612 participants: RR 0.83, 95% CI 0.70 to 0.99) but not all-cause mortality (10 studies, 2915 participants: RR 0.95, 95% CI 0.87 to 1.04) or infection-related mortality (3 studies, 2547 participants: RR 0.91, 95% CI 0.71 to 1.14). In absolute terms, high-flux membranes may prevent three cardiovascular deaths in 100 people treated with haemodialysis for two years. While high-flux membranes reduced predialysis beta-2 microglobulin levels (MD -12.17 mg/L, 95% CI -15.83 to -8.51 mg/L), insufficient data were available to reliably estimate the effects of membrane flux on hospitalisation, carpal tunnel syndrome, or amyloid-related arthropathy. Evidence for effects of high-flux membranes was limited by selective reporting in a few studies. Insufficient numbers of studies limited our ability to conduct subgroup analyses for membrane type, biocompatibility, or reuse. In general, the risk of bias was either high or unclear in the majority of studies.

AUTHORS' CONCLUSIONS

High-flux haemodialysis may reduce cardiovascular mortality in people requiring haemodialysis by about 15%. A large well-designed RCT is now required to confirm this finding.

Influence of dialysis modality and membrane flux on quality of life in hemodialysis patients

BACKGROUND

The quality of life in patients undergoing hemodialysis is significantly disturbed. There are data that hemodiafiltration (HDF) may be more effective than conventional hemodialysis in the removal of uremic toxins and may reduce frequency and severity of intradialytic and postdialysis adverse symptoms in patients. Also, some researchers suggest advantages of using high-flux membranes compared with low-flux.

OBJECTIVE

The aim of this study was to examine whether hemodialysis modality and membrane flux, independent of membrane biocompatibility, make differences in quality of life in patients.

METHODS

In our cross-sectional study, we evaluated 124 patients who were divided, based on therapy, into three groups: online HDF, high-flux hemodialysis, and low-flux hemodialysis. Data were collected using the Short Form-36 questionnaire combined with special questionnaire, which included demographic and clinically related questions.

RESULTS

Health-related quality of life was better in patients on HDF compared with patients on hemodialysis, especially compared with low-flux hemodialysis patients in most of the scales and in both dimensions: physical component scale and mental component scale. There were no statistically significant differences in Short Form-36 domains between high-flux hemodialysis and low-flux hemodialysis.

CONCLUSION

Our data suggest the potential advantages of HDF with regard to influence on quality of life, which is sufficient to justify further research in prospective and longitudinal study design.

Novel dialysis modalities: do we need new metrics to optimize treatment?

Delivered dose of hemodialysis has long been an important predictor of mortality. The limitations of conventional hemodialysis treatments have led to a renewed interest in more frequent and longer hemodialysis treatments. As alternative hemodialysis schedules have become more prevalent, a need for modified metrics to measure adequacy has emerged. In addition, there is an interest in finding measures of hemodialysis adequacy that are more reliable in certain subgroups of patients, such as women, ethnic minority groups, or people with small body size. Finally, extended hemodialysis schedules suggest a need for metrics that can measure the clearance of solutes other than urea, such as middle-size molecules, and solutes for which clearance depends on intercompartmental transport across membranes. New metrics to quantify clearance in extended and alternate hemodialysis schedules are needed. As new metrics are developed, it is anticipated that they will also contribute to more accurate assessments of associations between clinical outcomes and delivered dose of dialysis in more intensive, nontraditional hemodialysis schedules. This review provides a historical prospective of dialysis dose and adequacy and describes the need for new metrics from both solute type and dialysis dose prospective as alternative hemodialysis schedules have emerged and become more prevalent.

Dialyzer reuse and mortality risk in patients with end-stage renal disease: a systematic review

BACKGROUND AND AIM

Robust evidence about dialyzer reuse effects on mortality is not available. Our aim was to summarize the evidence for the effectiveness of dialyzer reuse compared to single use in patients with end-stage renal disease.

METHODS

We searched MEDLINE, Embase, CINAHL, SciELO, LILACS, USRDS ADR, universities' theses databases and annals of congress from major nephrology societies. Reviewers performed the study selection and data extraction independently. We used the GRADE approach to assess the quality of the evidence. Mortality was the primary outcome.

RESULTS

A total of 1,190 studies were retrieved, and 14 were included in the review (n = 956,807 patients). The disinfectants used on dialyzer reprocessing were hypochlorite, formaldehyde, glutaraldehyde, and peracetic acid. The evidence available from the studies was of very low quality. Most studies found no differences between groups. In studies with statistically significant differences, these differences were not observed in all groups and they varied by the type of disinfectant, time of observation and treatment unit.

CONCLUSIONS

No significant differences were identified for the superiority or inferiority of dialyzer reuse versus single use when assessing the mortality of patients with end-stage renal disease. Studies of higher quality, including randomized clinical trials, are required to provide conclusive evidence regarding the effectiveness and safety of dialyzer reuse.

Dialyzer reuse with peracetic acid does not impact patient mortality

BACKGROUND AND OBJECTIVES

Numerous studies have shown the overall benefits of dialysis filter reuse, including superior biocompatibility and decreased nonbiodegradable medical waste generation, without increased risk of mortality. A recent study reported that dialyzer reprocessing was associated with decreased patient survival; however, it did not control for sources of potential confounding. We sought to determine the effect of dialyzer reprocessing with peracetic acid on patient mortality using contemporary outcomes data and rigorous analytical techniques.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a series of analyses of hemodialysis patients examining the effects of reuse on mortality using three techniques to control for potential confounding: instrumental variables, propensity-score matching, and time-dependent survival analysis.

RESULTS

In the instrumental variables analysis, patients at high reuse centers had 16.2 versus 15.9 deaths/100 patient-years in nonreuse centers. In the propensity-score matched analysis, patients with reuse had a lower death rate per 100 patient-years than those without reuse (15.2 versus 15.5). The risk ratios for the time-dependent survival analyses were 0.993 (per percent of sessions with reuse) and 0.995 (per unit of last reuse), respectively. Over the study period, 13.8 million dialyzers were saved, representing 10,000 metric tons of medical waste.

CONCLUSIONS

Despite the large sample size, powered to detect miniscule effects, neither the instrumental variables nor propensity-matched analyses were statistically significant. The time-dependent survival analysis showed a protective effect of reuse. These data are consistent with the preponderance of evidence showing reuse limits medical waste generation without negatively affecting clinical outcomes.

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.

Benefits of first-half intensive haemodiafiltration for the removal of uraemic solutes

AIM

Haemodiafiltration (HDF) is the most efficient blood purification method and can remove a wide spectrum of solutes of different molecular weights (MW). The purpose of this study was to investigate whether the removed amounts of solutes, especially the larger molecules, could be increased by changing the HDF filtration procedure.

METHODS

A new first-half intensive HDF treatment (F-HDF) was designed, whereby convective clearance is intensively forced during the first half of a HDF session. We compared the removed amounts of solutes in the same group of nine patients treated by F-HDF, constant rate-replacing HDF (C-HDF) and a high-flux haemodialysis (HD).

RESULTS

F-HDF can remove significantly larger amounts of α(1) -microglobulin (MG), molecular weight (MW) 33,000, compared with HD and C-HDF (30.1 ± 15.1 vs 12.4 ± 0.3, 15.0 ± 3.1 mg, P < 0.01). Regarding the removal amounts and clear space of β(2) MG, MW 11,800, there were no significant differences between the three treatment modalities. Regarding amounts of creatinine, urea nitrogen and phosphorus, there were no significant differences between the three treatment modalities.

CONCLUSION

In post-replacement HDF with a high-flux membrane dialyzer, the method used in the present study in which replacement is completed during the first half of the process, is associated with a greater rate of larger molecule removal than the conventional uniform replacement method.

Review: membranes for haemodialysis

Haemodialysis, by design, uses a semipermeable membrane to separate blood from dialysate. The qualities of this membrane determine the nature of the 'traffic' between the blood and dialysate. In this sense, the qualities of the membrane determine what size molecules move from one compartment to the other, the amount and rate at which they might move and the amount and rate of water movement across the membrane. In addition, the nature of the membrane influences the biological response of the patient both in terms of what is or is not removed by the dialysis process and by way of the reaction to the biocompatibility of the membrane. This brief review will explore aspects of dialysis membrane characteristics.

Multidisciplinary evaluation for severity of hazards applied to hemodialysis devices: an original risk analysis method

BACKGROUND AND OBJECTIVES

Risk analysis for medical devices is a crucial process to grant adequate levels of safety. Identification of device exposure-related hazards is one of the main objectives.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Hazard analysis for hemodialysis devices has been performed by a multidisciplinary team involving engineers and clinical experts. A potential harm list was identified from clinical and technical experience, postproduction information, and literature. Various hazardous situations (circumstances when the use of the dialysis device may lead to described harms) were described. Such hazardous situations were correlated to the extent of the deviation of a specific device parameter from expected ranges. The clinical severity that was relevant to any specific harm was categorized for each hazardous situation using a descriptive and numerical scale with five levels (from negligible [i.e., discomfort only] to catastrophic [i.e., potentially lethal]).

RESULTS

Harms in which the deviation of a parameter strictly coincides with the clinically measured effect on the patient are defined as "direct." Otherwise, when another clinical parameter must be involved to quantify severity, the related harm is considered "indirect." Two complete examples of multidisciplinary evaluation for severity of hazards (MESH) are given for a direct harm (air embolism) and for an indirect harm (hypothermia). For other harms, the maximum value of severity involved is provided.

CONCLUSIONS

MESH represents a possible example of risk management for dialysis equipment in which, although the manufacturer is directly responsible, a multidisciplinary task force may contribute to a better link between engineering and clinical perspectives.

Back to the future: middle molecules, high flux membranes, and optimal dialysis

Middle molecules can be defined as compounds with a molecular weight (MW) above 500 Da. An even broader definition includes those molecules that do not cross the membranes of standard low-flux dialyzers, not only because of molecular weight, but also because of protein binding and/or multicompartmental behavior. Recently, several of these middle molecules have been linked to the increased tendency of uremic patients to develop inflammation, malnutrition, and atheromatosis. Other toxic actions can also be attributed to the middle molecules. In the present publication we will consider whether improved removal of middle molecules by large pore membranes has an impact on clinical conditions related to the uremic syndrome. The clinical benefits of large pore membranes are reduction of uremia-related amyloidosis; maintenance of residual renal function; and reduction of inflammation, malnutrition, anemia, dyslipidemia, and mortality. It is concluded that middle molecules play a role in uremic toxicity and especially in the processes related to inflammation, atherogenesis, and malnutrition. Their removal seems to be related to a better outcome, although better biocompatibility of membranes might be a confounding factor.

Can convective therapies improve dialysis outcomes?

PURPOSE OF REVIEW

Convective treatments are characterized by enhanced removal of middle and large molecular weight solutes, important in the genesis of many complications of hemodialysis, compared with conventional low-flux hemodialysis. The availability of these techniques represented an intriguing innovation and a possible means to improve the still poor prognosis of hemodialysis patients. In this study we will critically review the most important published studies evaluating the impact of convective treatments on dialysis outcomes.

RECENT FINDINGS

The Hemodialysis (HEMO) study showed that greater urea removal nonsignificantly reduces the relative risk of mortality and that also high-flux hemodialysis was associated with a nonsignificant reduction, although a secondary analysis pointed to an advantage for high-flux membranes in subgroups of patients. More recently, the Membrane Permeability Outcome (MPO) study found that survival could be improved by use of high-flux membranes compared with low-flux dialysis in high-risk patients as identified by serum albumin < or =4 g/dl as well as in people with diabetes. In an observational study, hemodiafiltration with large reinfusion volume has been associated with a lower relative risk of mortality, compared with low-flux hemodialysis.

SUMMARY

The biologic plausibility of advantages of convective treatments and the results of the MPO and Dialysis Outcomes and Practice Patterns (DOPPS) studies are supporting rationales for the use of convective treatments to improve survival and delay long-term complications of hemodialysis patients.

Effect of membrane permeability on survival of hemodialysis patients

The effect of high-flux hemodialysis membranes on patient survival has not been unequivocally determined. In this prospective, randomized clinical trial, we enrolled 738 incident hemodialysis patients, stratified them by serum albumin < or = 4 and >4 g/dl, and assigned them to either low-flux or high-flux membranes. We followed patients for 3 to 7.5 yr. Kaplan-Meier survival analysis showed no significant difference between high-flux and low-flux membranes, and a Cox proportional hazards model concurred. Patients with serum albumin < or = 4 g/dl had significantly higher survival rates in the high-flux group compared with the low-flux group (P = 0.032). In addition, a secondary analysis revealed that high-flux membranes may significantly improve survival of patients with diabetes. Among those with serum albumin < or = 4 g/dl, slightly different effects among patients with and without diabetes suggested a potential interaction between diabetes status and low serum albumin in the reduction of risk conferred by high-flux membranes. In summary, we did not detect a significant survival benefit with either high-flux or low-flux membranes in the population overall, but the use of high-flux membranes conferred a significant survival benefit among patients with serum albumin < or = 4 g/dl. The apparent survival benefit among patients who have diabetes and are treated with high-flux membranes requires confirmation given the post hoc nature of our analysis.

A quality and cost-benefit analysis of dialyzer reuse in hemodialysis patients

BACKGROUND

To evaluate the benefits of dialyzer reuse for hemodialysis (HD) patients, including the cost of HD treatment and patient's survival, a comparison was made regarding the standard practice of single-use dialysis.

METHODS

From January 1, 2005, to December 31, 2005, a total of 128,232 successive HD treatments in 822 patients in Chang Gung Memorial Hospital-Kaohsiung Medical Center were included in this study.

RESULTS

Approximately 54.25% (446/822) of patients reused dialyzers. The average times of dialyzer reuse was 2.54. The annual hollow fiber cost is reduced by $241,054.08 U.S. dollars (NT $7,834,257.60). The annual cost of hollow fiber was reduced by $540.48 U.S. dollars (NT $17,565.60) in one patient with dialyzer reuse. The mortality rates in dialyzer reuse and single use groups were 3.1% and 10.9% within one year (p < 0.0001). Multiple logistic regressions showed that single use compared with reuse was associated with higher mortality after adjusting co-morbid conditions including age, diabetes mellitus, etc. CONCLUSIONS. We concluded that the benefits of dialyzer reuse included safety in our center and reduction in cost during a 12-month period. Dialyzer reuse may be a safe alternative.

Serum beta2-microglobulin level is a significant predictor of mortality in maintenance haemodialysis patients

BACKGROUND

Beta(2)-microglobulin (beta(2)-M) is recognized as a surrogate marker of middle-molecule uraemic toxins and is a key component in the genesis of dialysis-associated amyloidosis. Few studies have evaluated the association of beta(2)-M levels with clinical outcome in dialyzed patients.

METHODS

The prognostic implication of serum beta(2)-M levels for the survival of haemodialysis patients was examined in 490 prevalent haemodialysis patients (60.1 +/- 11.8 years, haemodialysis duration of 87.4 +/- 75.7 months, 288 males and 202 females; 24% diabetics). The patients were divided into two groups according to their serum beta(2)-M levels: lower beta(2)-M group (n = 245) with serum beta(2)-M <32.2 mg/L (the median serum beta(2)-M) and higher beta(2)-M group (n = 245) with that >or=32.2 mg/L.

RESULTS

During the follow-up period of 40 +/- 15 months, there were 91 all-cause deaths, and out of them, 36 were from cardiovascular diseases. Kaplan-Meier analysis revealed that all-cause mortality in the higher beta(2)-M group was significantly higher compared to that in the lower beta(2)-M group (P < 0.001). Multivariate Cox proportional hazards analyses showed that serum beta(2)-M level was a significant predictor for all-cause mortality (hazard ratio, 1.05; 95% CI, 1.01-1.08; P = 0.005), and for non-cardiovascular mortality (hazard ratio, 1.06; 95% CI, 1.02-1.10; P = 0.006), after adjustment for age, gender, haemodialysis duration, the presence of diabetes, serum albumin and serum C-reactive protein.

CONCLUSION

These results demonstrate that the serum beta(2)-M level is a significant predictor of mortality in haemodialysis patients, independent of haemodialysis duration, diabetes, malnutrition and chronic inflammation, suggesting the clinical importance of lowering serum beta(2)-M in these patients.

What is new in uremic toxicity?

Uremic syndrome results from a malfunctioning of various organ systems due to the retention of compounds which, under normal conditions, would be excreted into the urine and/or metabolized by the kidneys. If these compounds are biologically active, they are called uremic toxins. One of the more important toxic effects of such compounds is cardio-vascular damage. A convenient classification based on the physico-chemical characteristics affecting the removal of such compounds by dialysis is: (1) small water-soluble compounds; (2) protein-bound compounds; (3) the larger "middle molecules". Recent developments include the identification of several newly detected compounds linked to toxicity or the identification of as yet unidentified toxic effects of known compounds: the dinucleotide polyphosphates, structural variants of angiotensin II, interleukin-18, p-cresylsulfate and the guanidines. Toxic effects seem to be typically exerted by molecules which are "difficult to remove by dialysis". Therefore, dialysis strategies have been adapted by applying membranes with larger pore size (high-flux membranes) and/or convection (on-line hemodiafiltration). The results of recent studies suggest that these strategies have better outcomes, thereby clinically corroborating the importance attributed in bench studies to these "difficult to remove" molecules.

Single-UseversusReusable Dialyzers: The Known Unknowns

The practice of reusing dialyzers has been widespread in the United States for decades, with single use showing signs of resurgence in recent years. Reprocessing of dialyzers has traditionally been acknowledged to improve blood-membrane biocompatibility and prevent first-use syndromes. These proposed advantages of reuse have been offset by the introduction of more biocompatible membranes and favorable sterilization techniques. Moreover, reuse is associated with increased health hazard from germicide exposure and disposal. Some observational studies have also pointed to an increased mortality risk with dialyzer reuse, and the potential for legal liability is another concern. The desire to save cost is the major driving force behind the continued practice of dialyzer reuse in the United States. It is imperative that future research focus on the environmental consequences of dialysis, including the need for more optimal management of disinfectant-related waste with reuse, and solid waste with single use. The dialysis community has a responsibility to explore ways to mitigate environmental consequences before single-use and a more frequent dialysis regimen becomes a standard practice in the United States.

Dialyzer membrane characteristics and outcome of patients with type 2 diabetes on maintenance hemodialysis

BACKGROUND

Effects of dialyzer membrane characteristics on morbidity and mortality are highly controversial.

METHODS

Post hoc, we analyzed data from the German Diabetes and Dialysis Study that evaluated atorvastatin in high-risk patients. Four groups were identified being constantly dialyzed with high-flux synthetic (n = 241), low-flux synthetic (n = 247), low-flux semisynthetic (n = 119), or cellulosic low-flux membranes (n = 41). Two end points were investigated: (1) a cardiovascular end point consisting of cardiac death, nonfatal myocardial infarction, and stroke and (2) death.

RESULTS

After 4 years of follow-up, adjusted multivariate relative risks (RRs) were calculated. The RR to reach a cardiovascular end point was greater for patients dialyzed with cellulosic low-flux (RR, 2.33; 95% confidence interval [CI], 1.38 to 3.94; P = 0.002), low-flux semisynthetic (RR, 1.92; 95% CI, 1.35 to 2.73; P = 0.0003), or low-flux synthetic membranes (RR, 1.35; 95% CI, 0.99 to 1.85; P = 0.06) than for those treated with high-flux synthetic dialyzers. The likelihood to die was greater with cellulosic low-flux (RR, 4.14; 95% CI, 2.79 to 6.15; P < 0.0001), low-flux semisynthetic (RR, 2.24; 95% CI, 1.66 to 3.02; P < 0.0001), and low-flux synthetic membranes (RR, 1.59; 95% CI, 1.22 to 2.07; P = 0.0006) than with high-flux synthetic membranes. With respect to low-flux synthetic membranes, RRs of mortality for patients using cellulosic low-flux and low-flux semisynthetic membranes were 161% (RR, 2.61; 95 % CI, 1.80 to 3.79; P < 0.0001) and 41% (RR, 1.41; 95% CI, 1.07 to 1.86; P = 0.016) greater. Cellulosic low-flux membrane use was associated with an 85% (RR, 1.85; 95% CI, 1.24 to 2.76; P = 0.0025) greater RR of death than low-flux semisynthetic membranes.

CONCLUSION

These data suggest that biocompatibility and permeability may impact on death and cardiovascular events in hemodialysis patients with type 2 diabetes mellitus.

Extracorporeal strategies for the removal of middle molecules

Uremic toxins with a molecular weight of less than 500 Da are classified as small nitrogenous waste products. They are highly water soluble, relatively homogeneous, and have no protein binding. Other uremic retention toxins differ significantly from the small nitrogenous metabolite class in molecular weight, heterogeneity, protein binding, and hydrophobicity. The European Uremic Toxin Work Group subdivided molecules into two categories: protein-bound solutes and middle molecules. Middle molecules were defined as toxins in the molecular weight range of 500-60,000 Da, which exceeds the molecular weight of 2000 Da defined in the original middle molecule hypothesis. Under this new proposed definition, most of these middle molecules are low molecular weight peptides and proteins (LMWPs). This concise review focuses on LMWPs. The metabolism of LMWPs is described, including molecular weight, physical conformation, and charge. Factors influencing dialytic removal of LMWPs such as membrane characteristics, protein-membrane interactions, and solute removal mechanisms, as well as strategies to enhance clearance of these compounds are discussed.

Online Hemodiafiltration

Online hemodiafiltration (HDF) is an extracorporeal technique for solute removal in renal failure, which takes advantage of an enhancement of convective treatment by the large amount of ultrapure nonpyrogen dialysate being used for substitution of the ultrafiltered volume. It offers many advantages aside from its safe inflammatory profile, which is attributable to the use of ultrapure dialysate and highly biocompatible dialysis membranes. Due to an improved convective clearance, significantly increased removal of large or protein-bound uremic retention solutes can be achieved, with a potential benefit on cardiovascular morbidity and mortality. Recent observational data indicate that online HDF offers a survival advantage even after adjustment for comorbidity and dialysis efficiency. Research has been ongoing to maximize further the effectiveness of the technique by new technical innovations such as transmembrane-pressure feedback control or mid-dilution online HDF.

Dialyzer Reuse-Part II: Advantages and Disadvantages

Although single dialyzer use and reuse by chemical reprocessing are both associated with some complications, there is no definitive advantage to either in this respect. Some complications occur mainly at the first use of a dialyzer: a new cellophane or cuprophane membrane may activate the complement system, or a noxious agent may be introduced to the dialyzer during production or generated during storage. These agents may not be completely removed during the routine rinsing procedure. The reuse of dialyzers is associated with environmental contamination, allergic reactions, residual chemical infusion (rebound release), inadequate concentration of disinfectants, and pyrogen reactions. Bleach used during reprocessing causes a progressive increase in dialyzer permeability to larger molecules, including albumin. Reprocessing methods without the use of bleach are associated with progressive decreases in membrane permeability, particularly to larger molecules. Most comparative studies have not shown differences in mortality between centers reusing and those not reusing dialyzers, however, the largest cluster of dialysis-related deaths occurred with single-use dialyzers due to the presence of perfluorohydrocarbon introduced during the manufacturing process and not completely removed during preparation of the dialyzers before the dialysis procedure. The cost savings associated with reuse is substantial, especially with more expensive, high-flux synthetic membrane dialyzers. With reuse, some dialysis centers can afford to utilize more efficient dialyzers that are more expensive; consequently they provide a higher dose of dialysis and reduce mortality. Some studies have shown minimally higher morbidity with chemical reuse, depending on the method. Waste disposal is definitely decreased with the reuse of dialyzers, thus environmental impacts are lessened, particularly if reprocessing is done by heat disinfection. It is safe to predict that dialyzer reuse in dialysis centers will continue because it also saves money for the providers. Saving both time for the patient and money for the provider were the main motivations to design a new machine for daily home hemodialysis. The machine, developed in the 1990s, cleans and heat disinfects the dialyzer and lines in situ so they do not need to be changed for a month. In contrast, reuse of dialyzers in home hemodialysis patients treated with other hemodialysis machines is becoming less popular and is almost extinct.

Resolving controversies regarding hemodiafiltration versus hemodialysis: the Dutch Convective Transport Study

Hemodialysis patients suffer from a high incidence of cardiovascular disease. Among the many predisposing factors, such as high blood pressure, dyslipidemia, and fluid overload, the accumulation of high molecular weight uremic toxins, the so-called middle molecules, may play an important role. Since convective therapies such as online hemodiafiltration have a better clearance profile for these compounds than standard hemodialysis, it has been suggested that these dialysis strategies may reduce cardiovascular morbidity and mortality. As reliable data on these issues are not available, the Dutch Convective Transport Study (CONTRAST) was recently initiated. This prospective randomized trial was designed to compare online hemodiafiltration with low-flux hemodialysis with respect to cardiovascular morbidity and mortality.

Clinical waste generation from renal units: implications and solutions

The treatment of end-stage renal disease (ESRD) makes extensive use of presterilized disposable items which, after use, are contaminated by blood. The preferred route of disposal of such items is by incineration. Disposal costs have risen and this increase in costs has not been matched by waste management programs in renal units. Many of the waste items generated also contain polyvinyl chloride (PVC) whose incineration is environmentally sensitive. Furthermore blood tubing sets contain plasticizers such as di(2-ethylhexyl) phthalate (DEHP), which is known to pose health risks to specific groups of patients. The generation of clinical waste in a dialysis unit is analyzed, issues associated with disposal are discussed, and approaches toward a cost-effective, environmentally sustainable clinical waste management program are reviewed.

UNRESOLVED ISSUES IN DIALYSIS: Dialyzer Best Practice: Single Use or Reuse?

Outcome studies have shown either no additional risk or a small additional risk for hospitalization and mortality associated with reprocessing dialyzers. Although the risks from reprocessing dialyzers have yet to be fully elucidated, reuse can be done safely if it is performed in full compliance with the standards of Association for the Advancement of Medical Instrumentation (AAMI). Like most industrial processes, however, complete control of the reuse process in a clinical environment and full compliance with regulations at all times is difficult. Potential errors and breakdowns in the reuse process are continuing concerns. The quality controls for reprocessing of dialyzers are not equal to the rigor of the manufacturing process under the purview of the U.S. Food and Drug Administration (FDA). Therefore, if one were to determine "best practice," single use is preferable to reuse of dialyzers based on medical criteria and risk assessment. The long-term and cumulative effects of exposure to reuse reagents are unknown and there is no compelling medical indication for reprocessing of dialyzers. The major impediment when deciding to convert from reuse to single use of dialyzers is economic. The experience in Fresenius Medical Care-North America (FMCNA) facilities demonstrates that converting from a practice of reuse to single use is achievable. However, the overall economic impact of conversion to single use is provider specific. The dominance of reuse has been negated of late by a major shift in practice toward single use. Physicians and patients should be well informed in making decisions regarding the practice of single use versus reuse of dialyzers.