Prescription of twice-weekly hemodialysis in the USA

Risk factors associated with mortality among patients on maintenance hemodialysis: The Thailand Renal Replacement Therapy registry

INTRODUCTION

End-stage kidney disease (ESKD) has been increasing in prevalence across the world, including Thailand, and patients with ESKD on hemodialysis have a high mortality risk.

METHODS

A retrospective cohort study was performed across 855 hemodialysis centers in the Thailand Renal Replacement Therapy registry. The database and mortality data were analyzed.

RESULTS

A total of 58 952 patients were included. The survival rates at 1, 3, and 5 years were 93.5%, 69.7%, and 41.2%, respectively. On multivariate analysis, factors such as aging, permanent catheter or arteriovenous graft, twice-weekly hemodialysis, low levels of urea reduction ratio, normalized protein catabolic rate, hemoglobin, transferrin saturation, serum albumin, LDL-cholesterol, intact-parathyroid hormone, uric acid, sodium, phosphate, and bicarbonate were significantly related to death.

CONCLUSION

Mortality is high in ESKD patients on hemodialysis. Age, type of vascular access, twice-weekly hemodialysis, inadequate dialysis, low protein intake, anemia, abnormal electrolytes, and bone mineral disorders are associated with all-cause mortality.

Incremental versus conventional haemodialysis in end-stage kidney disease: a systematic review and meta-analysis

Background

Appropriate dialysis prescription in the transitional setting from chronic kidney disease to end-stage kidney disease is still challenging. Conventional thrice-weekly haemodialysis (HD) might be associated with rapid loss of residual kidney function (RKF) and high mortality. The benefits and risks of incremental HD compared with conventional HD were explored in this systematic review and meta-analysis.

Methods

We searched MEDLINE, Scopus and Cochrane Central Register of Controlled Trials up to April 2023 for studies that compared the impacts of incremental (once- or twice-weekly HD) and conventional thrice-weekly HD on cardiovascular events, RKF, vascular access complications, quality of life, hospitalization and mortality.

Results

A total of 36 articles (138 939 participants) were included in this meta-analysis. The mortality rate and cardiovascular events were similar between incremental and conventional HD {odds ratio [OR] 0.87 [95% confidence interval (CI)] 0.72-1.04 and OR 0.67 [95% CI 0.43-1.05], respectively}. However, hospitalization and loss of RKF were significantly lower in patients treated with incremental HD [OR 0.44 (95% CI 0.27-0.72) and OR 0.31 (95% CI 0.25-0.39), respectively]. In a sensitivity analysis that included studies restricted to those with RKF or urine output criteria, incremental HD had significantly lower cardiovascular events [OR 0.22 (95% CI 0.08-0.63)] and mortality [OR 0.54 (95% CI 0.37-0.79)]. Vascular access complications, hyperkalaemia and volume overload were not statistically different between groups.

Conclusions

Incremental HD has been shown to be safe and may provide superior benefits in clinical outcomes, particularly in appropriately selected patients. Large-scale randomized controlled trials are required to confirm these potential advantages.

Modeling Factors Associated with Dialysis Adequacy Using Longitudinal Data Analysis: Generalized Estimating Equation Versus Quadratic Inference Function

BACKGROUND

In hemodialysis patients, changes in dialysis adequacy (DA) are examined longitudinally. The aim of this study was to determine factors affecting DA using the generalized estimating equation (GEE) and to compare them with the quadratic inference function (QIF).

STUDY DESIGN

A longitudinal study.

METHODS

This longitudinal study examined the records of 153 end-stage renal disease (ESRD) patients. The longitudinal data on the DA and baseline demographic and clinical characteristics were obtained from patients' files. The GEE1, GEE2, and QIF models were fitted with different correlation structures, and then the best correlation structure was selected using the quasi-likelihood information criterion (QIC), Akaike information criterion (AIC), and Bayes information criterion (BIC) fitting criteria.

RESULTS

The majority of patients (59.5%) had unfavorable DA (KT/V<1.2). Women and patients<60 years had more favorable DA. In the GEE model, the coefficients of female gender (β=0.079, 95% confidence interval [CI]: 0.032, 0.062), age at starting dialysis (β=-0.002, 95% CI: -0.004, -0.0001), hypertension (HTN, β=-0.055, 95% CI: -0.007, -0.103), diabetes (β=-0.088,95% CI: -0.021, -0.155), dialysis duration (β=0.132, 95% CI: 0.085, 0.178), and weight (β=-0.004, 95% CI: -0.006, -0.003) demonstrated a significant relationship with DA. The three models resulted in a similar estimate of regression coefficients. The relative efficiencies of QIF versus GEE1, QIF versus GEE2, and GEE2 versus GEE1 were 1.175, 1.056, and 1.113, respectively.

CONCLUSION

DA is not optimal in most hemodialysis patients, and gender, age at the start of dialysis, HTN, diabetes, dialysis duration, and weight had a significant association with DA. The three different models yielded quite similar coefficient estimates, but the QIF model resulted more efficient than GEE1 and GEE2.

Australian Workshops on Patients' Perspectives on Hemodialysis and Incremental Start

Introduction

Most patients with kidney failure commence and continue hemodialysis (HD) thrice weekly. Incremental initiation (defined as HD less than thrice weekly) is increasingly considered to be safe and less burdensome, but little is known about patients' perspectives. We aimed to describe patients' priorities and concerns regarding incremental HD.

Methods

Patients currently, previously, or soon to be receiving HD in Australia participated in two 90-minute online workshops to discuss views about HD focusing on incremental start and priorities for trial outcomes. Transcripts were analyzed using thematic analysis. Outcomes were ranked on the basis of the sum of participants' priority scores (i.e., single allocation of 3 points for most important, 2 for second, and 1 for third most important outcome).

Results

All 26 participants (1 caregiver and 25 patients) preferred an incremental HD approach. The top prioritized outcomes were quality of life (QOL) (56 points), residual kidney function (RKF) (27 points), and mortality (16 points). The following 4 themes underpinning outcome priorities, experience, and safety concerns were identified: (i) unpreparedness and pressure to adapt, (ii) disruption to daily living, (iii) threats to safety, and (iv) hope and future planning.

Conclusion

Patients with kidney failure preferred an incremental start to HD to minimize disruption to daily living and reduce the negative impacts on their education, ability to work, and family life. QOL was the most critically important outcome, followed by RKF and survival.

Impact of incremental initiation of haemodialysis on mortality: a systematic review and meta-analysis

BACKGROUND

Incremental haemodialysis initiation entails lower sessional duration and/or frequency than the standard 4 h thrice-weekly approach. Dialysis dose is increased as residual kidney function (RKF) declines. This systematic review evaluates its safety, efficacy and cost-effectiveness.

METHODS

We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library databases from inception to 27 February 2022. Eligible studies compared incremental haemodialysis (sessions either fewer than three times weekly or of duration <3.5 h) with standard treatment. The primary outcome was mortality. Secondary outcomes included treatment-emergent adverse events, loss of RKF, quality of life and cost effectiveness. The study protocol was prospectively registered. Risk of bias assessment used the Newcastle-Ottawa Scale and the revised Cochrane risk of bias tool, as appropriate. Meta-analyses were undertaken in Review Manager, Version 5.4.

RESULTS

A total of 644 records were identified. Twenty-six met the inclusion criteria, including 22 cohort studies and two randomized controlled trials (RCTs). Sample size ranged from 48 to 50 596 participants (total 101 476). We found no mortality differences (hazard ratio = 0.99; 95% CI 0.80-1.24). Cohort studies suggested similar hospitalization rates though the two small RCTs suggested less hospitalization after incremental initiation (relative risk = 0.31; 95% CI 0.18-0.54). Data on other treatment-emergent adverse events and quality of life was limited. Observational studies suggested reduced loss of RKF in incremental haemodialysis. This was not supported by RCT data. Four studies reported reduced costs of incremental treatments.

CONCLUSIONS

Incremental initiation of haemodialysis does not confer greater risk of mortality compared with standard treatment. Hospitalization may be reduced and costs are lower.

Twice versus thrice weekly hemodialysis: A systematic review

INTRODUCTION

Thrice weekly hemodialysis (HD) is currently the norm in high income countries but there is mounting interest in twice weekly HD in certain settings. We performed this systematic review to summarize the available evidence comparing twice to thrice weekly HD.

METHODS

A systematic literature search was performed in Ovid MEDLINE, Ovid Embase, and the Cochrane Central Register of Controlled Trials to identify cohort and randomized controlled trials evaluating outcomes of twice versus thrice weekly HD. The bibliographies of identified studies were hand searched to find any additional studies. Risk of bias was assessed using the Newcastle-Ottawa scale for observational studies.

FINDINGS

No randomized controlled trials and 21 cohort studies were identified. Overall study quality was modest with high risk of selection bias and inadequate controlling for confounders. The most commonly evaluated outcome measures were survival and residual kidney function. No studies assessed quality of life. Study results were variable and there was no clear signal for overwhelming risk or benefit of twice versus thrice weekly HD with the exception of residual kidney function which consistently showed slower decline in the twice weekly group.

DISCUSSION

There is a paucity of high quality data comparing the risks and benefits of twice vs thrice weekly HD. Randomized controlled trial evidence is required to inform clinicians and HD prescription guidelines.

Assessment of quality of life determinants in hemodialysis patients of a developing country: A cross-sectional study during ongoing COVID-19 pandemic

BACKGROUND AND OBJECTIVES

Patients of end-stage renal disease are prone to have a very low quality of life (QoL). Variety of factors influence the QoL among sufferers of chronic kidney disease comprising of type of dialysis, sufficiency/adequacy of dialysis, and associated burden of disease. We conducted this study amidst the pandemic to determine the associated factors for poor QoL in hemodialysis patients during the ongoing pandemic.

PATIENTS AND METHODS

This cross-sectional study was conducted in a hemodialysis unit of a tertiary care hospital. A total of 118 participants responded to the validated questionnaire of Quality of Life Index-dialysis version-III (QLI). Higher scores signify good QoL, total scores are further categorized into subgroups desirable, relatively desirable and undesirable.

RESULTS

The mean age of the participants was 57.36 ± 10.03 years and mean body mass index of 26.73 ± 5.54 kg/m2. The mean total QoL of the study population was found quite low (12.99 ± 5.89). Majority of respondents fell in undesirable category of QoL (49.2%). Total QoL (P = 0.004) and subscale health/functioning (P = 0.003) were significantly lower in females. All the subscales along with total QoL scores were found lower in twice-weekly dialyzed patients (P < 0.001). Marital status (P = 0.049) and twice-weekly dialysis (P < 0.001) were found significant with undesirable QoL. On multivariate analysis, significant determinants of undesirable QoL were twice-weekly dialysis (P = 0.001), catheter access (P = 0.034), phosphate (P = 0.005) and uric acid (P = 0.006).

CONCLUSION

Inadequate dialysis due to lesser frequency per week leading to poorly cleared toxic substances were most significant contributors of poor QoL in our study.

Outcomes of incident patients treated with incremental haemodialysis as compared with standard haemodialysis and peritoneal dialysis

BACKGROUND

Residual kidney function is considered better preserved with incremental haemodialysis (I-HD) or peritoneal dialysis (PD) as compared with conventional thrice-weekly HD (TW-HD) and is associated with improved survival. We aimed to describe outcomes of patients initiating dialysis with I-HD, TW-HD or PD.

METHODS

We conducted a retrospective analysis of a prospectively assembled cohort in a single university centre including all adults initiating dialysis from January 2013 to December 2020. Primary and secondary endpoints were overall survival and hospitalization days at 1 year, respectively.

RESULTS

We included 313 patients with 234 starting on HD (166 TW-HD and 68 I-HD) and 79 on PD. At the end of the study, 10 were still on I-HD while 45 transitioned to TW-HD after a mean duration of 9.8 ± 9.1 months. Patients who stayed on I-HD were less frequently diabetics (P = .007). Mean follow-up was 33.1 ± 30.8 months during which 124 (39.6%) patients died. Compared with patients on TW-HD, those on I-HD had improved survival (hazard ratio 0.49, 95% confidence interval 0.26-0.93, P = .029), while those on PD had similar survival. Initial kidney replacement therapy modality was not significantly associated with hospitalization days at 1 year.

CONCLUSIONS

I-HD is suitable for selected patients starting dialysis and can be maintained for a significant amount of time before transition to TW-HD, with diabetes being a risk factor. Although hospitalization days at 1 year are similar, initiation with I-HD is associated with improved survival as compared with TW-HD or PD. Results of randomized controlled trials are awaited prior to large-scale implementation of I-HD programmes.

Incremental Hemodialysis: What We Know so Far

Traditionally, patients that develop progressive chronic kidney disease in need of kidney replacement therapy are prescribed thrice weekly in-center hemodialysis sessions at the beginning of therapy. This empiric prescription is based on historic trials that were comprised of mostly prevalent patients. Incremental hemodialysis is the process of performing <3 sessions of dialysis per week or limiting dialysis dose by duration at the initial onset of treatment to provide a more gradual transition, mimicking the progressive nature of kidney disease. Adding clearance contributions from residual kidney function is the standard of care with peritoneal dialysis but has not routinely been employed with hemodialysis. Accounting for residual kidney function accompanied by improvement in adjuvant pharmacotherapy, such as newer potassium binding agents and dietary modification, can augment dialytic clearances and allow for an incremental approach. Utilizing incremental dialysis has been associated with both preserving residual kidney function as well as improving patient quality of life. Barriers to this approach include concerns regarding patient acceptance of dialysis prescription changes, adherence to therapy, and provider factors that would require a restructuring of the current thrice weekly hemodialysis rubric. Candidacy for incremental therapy has shown the best outcomes when urea clearances exceed 3 mL/min and urine volumes are >500 mL/day, although these measures have been deemed conservative. A significant amount of retrospective and registry data has been supportive of initiating incremental hemodialysis and several pilot studies have shown the feasibility of implementing such an approach. Larger, randomized control trials are needed to fully evaluate safety and efficacy to allow for more widespread acceptance of this patient-centered approach to chronic kidney disease.

Knowledge and Practice of Incremental Hemodialysis: A Survey of Canadian Nephrologists

BACKGROUND

Incremental hemodialysis, a strategy to individualize dialysis prescription based on residual kidney function, may be associated with enhanced quality of life and decreased health care costs compared with conventional hemodialysis.

OBJECTIVE

We surveyed practicing Canadian nephrologists to assess knowledge, perceptions, and practice pattern on the use of incremental hemodialysis.

DESIGN/SETTING

We distributed a cross-sectional, web-based survey. We asked about incremental hemodialysis prescribing practices, including frequency of prescription, clinical factors used to determine suitability for treatment, and barriers to implementation. The survey was conducted from September 21 to October 30, 2020.

PARTICIPANTS

We distributed the survey to practicing Canadian nephrologists identified from a private membership list of the Canadian Society of Nephrology (CSN), as well as to nephrologists named on a publicly available national list of practicing Canadian nephrologists created from provincial College of Physician registries. These were samples of convenience.

METHODS

We conducted descriptive analysis of categorical data including frequencies for nominal variables and measures of central tendency (mean) and dispersion (standard deviation) for ordinal variables. We used chi-square analysis to identify association between participant and practice characteristics and their opinions and attitudes toward incremental dialysis. We used simple thematic analysis on free-text responses on questions regarding the prescription of incremental hemodialysis, focusing on age and baseline management of cardiac and noncardiac comorbidities.

RESULTS

The response rate was 35% (243/691). Most (138/211, 65%) of the participants prescribed incremental hemodialysis using an individualized approach at the nephrologist's discretion. Most participants (200/203, 98%) did not report any policy for implementation. Residual urine output was identified as the most important factor for eligibility (112/172, 65%), followed by electrolyte stability (76/172, 44%) and patient goals of care (69/117, 40%). Most participants agreed that dialysis prescriptions should take residual kidney function into consideration; however, 74% of the participants disagreed with a statement that there was strong evidence supporting incremental hemodialysis. Barriers identified included patient safety, patient acceptance of dose escalation, and logistics of scheduling. Despite these barriers, 82% of participants felt that that incremental hemodialysis is feasible with their current resources and 78% agreed that with specific criteria, it is a safe option.

LIMITATIONS

The generalizability of our study is limited by its response rate of 35%; however, this is comparable with typical response rates seen in electronic surveys. Most participants practice in an academic setting, which may have introduced bias to the results.

CONCLUSIONS

Despite the perception of limited evidence and a lack of guidance on implementation, incremental hemodialysis is frequently practiced by Canadian nephrologists. Barriers to implementation were identified, highlighting the need for research to guide practice.

The role of once-weekly online hemodiafiltration with low protein diet for initiation of renal replacement therapy: A case series

Incremental hemodialysis (HD) has become an exciting approach according to the recognition of the importance of preserving residual kidney function (RKF). However, not all incident HD patients are suitable for this approach, particularly once-weekly HD. This is the first study which reported the effectiveness of once-weekly online-hemodiafiltration (OL-HDF) plus low protein diet (LPD) in incident HD patients. All stage 5 CKD patients who had chosen HD as their treatment modality at the HD center of King Chulalongkorn Memorial Hospital, Bangkok, Thailand, with RKF ⩾ 3 mL/min calculated by renal clearance of urea and urine output ⩾ 800 mL/day, started the treatment with once-weekly OL-HDF. Dietitians advised patients to consume LPD (0.6-0.8 g/kg/day) on non-dialysis days and a regular protein diet on the dialysis day (1.2 g/kg/day). Eleven incident HD patients were enrolled in the study. The mean RKF and urine volume at baseline were 4.56 ± 2.21 mL/min and 2,019.54 ± 743.73 mL/day, respectively. After 6 and 12 months of follow-up, the mean RKF of the patients who remained in the once-weekly OL-HDF protocol were 3.82 ± 1.68 mL/min and 3.28 ± 0.95 mL/min, respectively. The median duration of once-weekly OL-HDF before transitioning to twice- or thrice-weekly OL-HDF was 7 months (3-24 months). The most common indication for stepping prescription was too low RKF. We reported that dialysis initiation in the university-based center with once-weekly OL-HDF in carefully selected incident HD patients combined with LPD under serial monitoring is practical. Further studies on the clinical benefits of once-weekly OL-HDF are still required.

A multicenter feasibility randomized controlled trial to assess the impact of incremental versus conventional initiation of hemodialysis on residual kidney function

Twice-weekly hemodialysis, as part of incremental initiation, has reported benefits including preservation of residual kidney function (RKF). To explore this, we initiated a randomized controlled feasibility trial examining 55 incident hemodialysis patients with urea clearance of 3 ml/min/1.73 m² or more across four centers in the United Kingdom randomized to standard or incremental schedules for 12 months. Incremental hemodialysis involved twice-weekly sessions, upwardly adjusting hemodialysis dose as RKF was lost, maintaining total (Dialysis+Renal) Std Kt/V above 2. Standard hemodialysis was thrice weekly for 3.5-4 hours, minimum Dialysis Std Kt/V of 2. Primary outcomes were feasibility parameters and effect size of group differences in rate of loss of RKF at six months. Health care cost impact and patient-reported outcomes were explored. Around one-third of patients met eligibility criteria. Half agreed to randomization; 26 received standard hemodialysis and 29 incremental. At 12 months, 21 incremental patients remained in the study vs 12 in the standard arm with no group differences in the urea clearance slope. Ninety-two percent of incremental and 75% of standard arm patients had a urea clearance of 2 ml/min/1.73 m² or more at six months. Serious adverse events were less frequent in incremental patients (Incidence Rate Ratio 0.47, confidence interval 0.27-0.81). Serum bicarbonate was significantly lower in incremental patients indicating supplementation may be required. There were three deaths in each arm. Blood pressure, extracellular fluid and patient-reported outcomes were similar. There was no signal of benefit of incremental hemodialysis in terms of protection of RKF or Quality of Life score. Median incremental hemodialysis costs were significantly lower compared to standard hemodialysis. Thus, incremental hemodialysis appears safe and cost-saving in incident patients with adequate RKF, justifying a definitive trial.

Demographics, Cost, and Sustainability of Haemodialysis among End-Stage Kidney Disease Patients in Southern Nigeria: A Single-Center Study

Context

Access to chronic hemodialysis for patients with end-stage kidney disease has improved over the years. However, it is unclear if this has resulted in lower cost and improved dialysis vintage.

Aim

We aimed to assess the demographics, cost implication, and sustainability of maintenance hemodialysis in our cohort of end-stage kidney disease (ESKD) patients.

Methods

Retrospective descriptive study of ESKD patients on maintenance HD from 2014 to 2018 using hemodialysis records. Time-to-HD discontinuation and reasons for discontinuation were recorded. Using Kaplan-Meier graphs, the time-to-dialysis discontinuation experience of the cohort was shown. Log-rank test was used to compare the experience between both genders. Univariable and multivariable Cox proportional hazard models were built to identify independent associations with time-to-dialysis discontinuation.

Results

Over the 5-year period, 702 individuals initiated HD, males were older than females, the complete cohort contributed 65,714 person-days to the study and the median time-to-HD discontinuation was 10 days (interquartile range, 2-42). Females had a shorter time to HD discontinuation (8 days [1-32 days]) compared to males (11 days [2-48 days]). Only 28.5%, 15.3% and 8.3% of the patients had HD beyond 30, 90, and 180 days, respectively. About 128 (18.2%) had thrice-weekly HD. Most sustained the treatment for the 1^st week. Majority (98.4%) of the patients were presumed dead, while 4 (0.65%) were still alive and 6 (0.98%) had renal transplantation. All patients who discontinued dialysis did so for financial reasons. Multivariable Cox proportional hazards model showed that individuals who could afford dialysis more than once a week had reduced hazard of dialysis discontinuation.

Conclusion

Most patients cannot sustain HD beyond a few weeks for financial reasons. Several cost containment strategies need to be deployed to bring down the cost of care.

Impact of incremental versus conventional initiation of haemodialysis on residual kidney function: study protocol for a multicentre feasibility randomised controlled trial

INTRODUCTION

Preserving residual kidney function (RKF) may be beneficial to patients on haemodialysis (HD) and it has been proposed that commencing dialysis incrementally rather than three times a week may preserve RKF. In Incremental HD, target dose includes a contribution from RKF, which is added to HD dose, allowing individualisation of the HD prescription. We will conduct a feasibility randomised controlled trial (RCT) comparing incremental HD and conventional three times weekly treatments in incident HD patients. The study is designed also to provide pilot data to allow determination of effect size to power a definitive study.

METHODS AND ANALYSIS

After screening to ensure native renal urea clearance >3 mL/min/1.73 m², the study will randomise 54 patients within 3 months of HD initiation to conventional in-centre thrice weekly dialysis or incremental in-centre HD commencing 2 days a week. Subjects will be followed up for 12 months. The study will be carried out across four UK renal centres.The primary outcome is to evaluate the feasibility of conducting a definitive RCT and to estimate the difference in rate of decline of RKF between the two groups at 6 and 12 months time points. Secondary outcomes will include the impact of dialysis intensity on vascular access events, major adverse cardiac events and survival. Impact of dialysis intensity on patient-reported outcomes measures, cognition and frailty will be assessed using EQ-5D-5L, PHQ-9, Illness Intrusiveness Rating Score, Montreal Cognitive assessment and Clinical Frailty Score. Safety outcomes include hospitalisation, fluid overload episodes, hyperkalaemia events and vascular access events.This study will inform the design of a definitive study, adequately powered to determine whether RKF is better preserved after incremental HD initiation compared with conventional initiation.

ETHICS AND DISSEMINATION

Ethics approval has been granted by Cambridge South Research Ethics Committee, United Kingdom(REC17/EE/0311). Results will be disseminated via peer-reviewed publication.

TRIAL REGISTRATION NUMBER

NCT03418181.

Can incremental haemodialysis reduce early mortality rates in patients starting maintenance haemodialysis?

PURPOSE OF REVIEW

Early mortality rates after the start of maintenance haemodialysis therapy are high. Compared with three-times weekly haemodialysis, incremental haemodialysis is associated with better preservation of residual renal function (RRF) and at least equivalent mid-term to long-term survival. However, there is paucity of data in relation to its use as a means of helping patients through the transitional period, when they first become dialysis dependent.

RECENT FINDINGS

Studies of incremental haemodialysis have overlooked early mortality as an outcome measure. This is primarily due to their retrospective design which makes it difficult to link early deaths to the frequency of haemodialysis. New data confirm previous observations associating incremental haemodialysis with favourable outcomes. They also raise the possibility that in selected groups and for short periods, the pursuit of set clearance targets during the early days of dialysis may not necessarily bring additional short-term gains.

SUMMARY

We argue that, while simpler ways of estimating RRF are being explored, future trials must consider implementing incremental haemodialysis focusing on practical aspects of care in the transitional period; safety monitoring in such regimes should be undertaken using conventional methods. Such an approach is likely to benefit a larger subset of haemodialysis population.

Impact of twice- or three-times-weekly maintenance hemodialysis on patient outcomes: A multicenter randomized trial

AIM

Maintenance hemodialysis (MHD) frequency is associated with survival and complication rates. Achieving the optimal balance between healthcare, quality of life (QOL), and medical costs is challenging. We compared complications, inflammatory status, nutritional status, and QOL between patients with different MHD frequencies.

MATERIAL AND METHODS

This was a multicenter randomized trial of patients treated between May 2011 and August 2017 at 3 tertiary hospitals in Wenzhou. Patients were grouped according to their treatment schedule over 1 year: twice-weekly or 3-times-weekly. Complications, biochemistry parameters, and QOL (KDQOL-SFTM 1.3 scale) were assessed.

RESULTS

One hundred forty patients were included aged 29 to 68 years (mean age, 50.9 ± 4.3 years). There were no significant differences in infection, heart failure, or cerebral hemorrhage complications between the 2 groups (P = .664). Pre-dialysis hemoglobin, high-sensitivity C-reactive protein, serum albumin, total cholesterol, triglyceride, calcium, phosphate, parathyroid hormone, and ejection fraction were similar in both groups (P > .05). After 1 year of MHD, both groups exhibited significant improvements in these parameters (all P < .05) with no significant differences between groups. Serum creatinine, blood urea nitrogen (BUN), and weekly standard hemodialysis treatment adequacy did not improve after treatment (all P > .05), although a difference in BUN was observed between the 2 groups (P < .001). QOL was superior in the twice-weekly group than in the 3-times-weekly group (all P < .05), except for social support, which was slightly better in the 3-times-weekly group than in the twice-weekly group.

CONCLUSIONS

Twice- and 3-times-weekly MHD resulted in comparable inflammatory and nutritional clinical outcomes and adverse events. QOL was better for the twice-weekly schedule. Even for patients with economic constraints, twice- or 3-times-weekly MHD should be selected with caution after consideration of BUN levels at baseline.

Ultrafiltration Rate, Residual Kidney Function, and Survival Among Patients Treated With Reduced-Frequency Hemodialysis

RATIONALE & OBJECTIVE

Patients receiving twice-weekly or less-frequent hemodialysis (HD) may need to undergo higher ultrafiltration rates (UFRs) to maintain acceptable fluid balance. We hypothesized that higher UFRs are associated with faster decline in residual kidney function (RKF) and a higher rate of mortality.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

1,524 patients with kidney failure who initiated maintenance HD at a frequency of twice or less per week for at least 6 consecutive weeks at some time between 2007 and 2011 and for whom baseline data for UFR and renal urea clearance were available.

PREDICTOR

Average UFR during the first patient-quarter during less-frequent HD (<6, 6-<10, 10-<13, and≥13mL/h/kg).

OUTCOME

Time to all-cause and cardiovascular death, slope of decline in RKF during the first year after initiation of less-frequent HD (with slopes above the median categorized as rapid decline).

ANALYTICAL APPROACH

Cox proportional hazards regression for time to death and logistic regression for the analysis of rapid decline in RKF.

RESULTS

Among 1,524 patients, higher UFR was associated with higher all-cause mortality; HRs were 1.43 (95% CI, 1.09-1.88), 1.51 (95% CI, 1.08-2.10), and 1.76 (95% CI, 1.23-2.53) for UFR of 6 to<10, 10 to<13, and≥13mL/h/kg, respectively (reference: UFR < 6mL/h/kg). Higher UFR was also associated with higher cardiovascular mortality. Baseline RKF modified the association between UFR and mortality; the association was attenuated among patients with renal urea clearance≥5mL/min/1.73m². Higher UFR had a graded association with rapid decline in RKF; ORs were 1.73 (95% CI, 1.18-2.55), 1.89 (95% CI, 1.12-3.17), and 2.75 (95% CI, 1.46-5.18) at UFRs of 6 to<10, 10 to<13, and≥13mL/h/kg, respectively (reference: UFR < 6mL/h/kg).

LIMITATIONS

Residual confounding from unobserved differences across exposure categories.

CONCLUSIONS

Higher UFR was associated with worse outcomes, including shorter survival and more rapid loss of RKF, among patients receiving regular HD treatments at a frequency of twice or less per week.

Narrative Review of Incremental Hemodialysis

The prescription of hemodialysis (HD) in patients with incident end-stage kidney disease (ESKD) is fundamentally empirical. The abrupt transition from nondialysis chronic kidney disease (CKD) to thrice-weekly in-center HD of much the same dialysis intensity as in those with prevalent ESKD underappreciates the progressive nature of kidney disease whereby the decline in renal function has been gradual and ongoing-including at the time of HD initiation. Adjuvant pharmacologic treatment (i.e., diuretics, acid buffers, potassium binders), coupled with residual kidney function (RKF), can complement an initial HD regimen of lower intensity. Barriers to less intensive HD in incident ESKD include risk of inadequate clearance of uremic toxins due to variable and unexpected loss of RKF, lack of patient adherence to assessments of RKF or adjustment of HD intensity, increased burden for all stakeholders in the dialysis units, and negative financial repercussions. A stepped dialysis regimen with scheduled transition from time-delineated twice-weekly HD to thrice-weekly HD could represent an effective and safe strategy to standardize incremental HD in patients with CKD transitioning to early-stage ESKD. Patients' adherence and survival as well as other clinical outcomes should be rigorously evaluated in clinical trials before large-scale implementation of different incremental schedules of HD. This review discusses potential benefits of and barriers to alternative dialysis regimens in patients with incident ESKD, with emphasis on twice-weekly HD with pharmacologic therapy, and summarizes in-progress clinical trials of incremental HD schedules.

Renal Association Clinical Practice Guideline on Haemodialysis

This guideline is written primarily for doctors and nurses working in dialysis units and related areas of medicine in the UK, and is an update of a previous version written in 2009. It aims to provide guidance on how to look after patients and how to run dialysis units, and provides standards which units should in general aim to achieve. We would not advise patients to interpret the guideline as a rulebook, but perhaps to answer the question: "what does good quality haemodialysis look like?"The guideline is split into sections: each begins with a few statements which are graded by strength (1 is a firm recommendation, 2 is more like a sensible suggestion), and the type of research available to back up the statement, ranging from A (good quality trials so we are pretty sure this is right) to D (more like the opinion of experts than known for sure). After the statements there is a short summary explaining why we think this, often including a discussion of some of the most helpful research. There is then a list of the most important medical articles so that you can read further if you want to - most of this is freely available online, at least in summary form.A few notes on the individual sections: 1. This section is about how much dialysis a patient should have. The effectiveness of dialysis varies between patients because of differences in body size and age etc., so different people need different amounts, and this section gives guidance on what defines "enough" dialysis and how to make sure each person is getting that. Quite a bit of this section is very technical, for example, the term "eKt/V" is often used: this is a calculation based on blood tests before and after dialysis, which measures the effectiveness of a single dialysis session in a particular patient. 2. This section deals with "non-standard" dialysis, which basically means anything other than 3 times per week. For example, a few people need 4 or more sessions per week to keep healthy, and some people are fine with only 2 sessions per week - this is usually people who are older, or those who have only just started dialysis. Special considerations for children and pregnant patients are also covered here. 3. This section deals with membranes (the type of "filter" used in the dialysis machine) and "HDF" (haemodiafiltration) which is a more complex kind of dialysis which some doctors think is better. Studies are still being done, but at the moment we think it's as good as but not better than regular dialysis. 4. This section deals with fluid removal during dialysis sessions: how to remove enough fluid without causing cramps and low blood pressure. Amongst other recommendations we advise close collaboration with patients over this. 5. This section deals with dialysate, which is the fluid used to "pull" toxins out of the blood (it is sometimes called the "bath"). The level of things like potassium in the dialysate is important, otherwise too much or too little may be removed. There is a section on dialysate buffer (bicarbonate) and also a section on phosphate, which occasionally needs to be added into the dialysate. 6. This section is about anticoagulation (blood thinning) which is needed to stop the circuit from clotting, but sometimes causes side effects. 7. This section is about certain safety aspects of dialysis, not seeking to replace well-established local protocols, but focussing on just a few where we thought some national-level guidance would be useful. 8. This section draws together a few aspects of dialysis which don't easily fit elsewhere, and which impact on how dialysis feels to patients, rather than the medical outcome, though of course these are linked. This is where home haemodialysis and exercise are covered. There is an appendix at the end which covers a few aspects in more detail, especially the mathematical ideas. Several aspects of dialysis are not included in this guideline since they are covered elsewhere, often because they are aspects which affect non-dialysis patients too. This includes: anaemia, calcium and bone health, high blood pressure, nutrition, infection control, vascular access, transplant planning, and when dialysis should be started.

A swan song for Kt/Vurea

Dialyzer clearance of urea multiplied by dialysis time and normalized for urea distribution volume (Kt/V_urea or simply Kt/V) has been used as an index of dialysis adequacy since more than 30 years. This article reviews the flaws of Kt/V, starting with a lack of proof of concept in three randomized controlled hard outcome trials (RCTs), and continuing with a long list of conditions where the concept of Kt/V was shown to be flawed. This information leaves little room for any conclusion other than that Kt/V, as an indicator of dialysis adequacy, is obsolete. The dialysis patient might benefit more if, instead, the nephrology community concentrates in the future on pursuing the optimal dialysis dose that conforms with adequate quality of life and on factors that are likely to affect outcomes more than Kt/V. These include residual renal function, volume status, dialysis length, ultrafiltration rate, the number of intra-dialytic hypotensive episodes, interdialytic blood pressure, serum potassium and phosphate, serum albumin, and C reactive protein.

Precision Medicine in the Transition to Dialysis and Personalized Renal Replacement Therapy

Launched in 2016, the overarching goal of the Precision Medicine Initiative is to promote a personalized approach to disease management that takes into account an individual's unique underlying biology and genetics, lifestyle, and environment, in lieu of a one-size-fits-all model. The concept of precision medicine is pervasive across many areas of nephrology and has been particularly relevant to the care of advanced chronic kidney disease patients transitioning to end-stage kidney disease (ESKD). Given many uncertainties surrounding the optimal transition of incident ESKD patients to dialysis and transplantation, as well as the high mortality rates observed during this delicate transition period, there is a pressing urgency for implementing precision medicine in the management of this population. Although the traditional paradigm has been to commence incident hemodialysis patients on a 3 times/week treatment regimen, largely driven by adequacy targets, there has been growing recognition that alternative treatment regimens (ie, incremental hemodialysis) may be preferred among certain subpopulations when taking into consideration factors such as patients' residual kidney function, volume status fluctuations, symptoms, and preferences. In this review, we examine the origins of current practices in how dialysis is initiated among incident ESKD patients; incremental dialysis therapy as a dynamic and patient-centric approach that is tailored to patients' unique characteristics; recent data on the incremental hemodialysis regimen and outcomes; and future research directions using a precision nephrology approach to ESKD management with the potential to develop novel approaches, tools, and collaborative efforts to improve the health, well-being, and survival of this population.

Individualized Hemodialysis Treatment: A Perspective on Residual Kidney Function and Precision Medicine in Nephrology

Background: Residual kidney function (RKF) is often expected to inevitably and rapidly decline among hemodialysis patients and, hence, has been inadvertently ignored in clinical practice. The importance of RKF has been revisited in some recent studies. Given that patients with end-stage renal disease now tend to initiate maintenance hemodialysis therapy with higher RKF levels, there seem to be important opportunities for incremental hemo­dialysis by individualizing the dose and frequency according to their RKF levels. This approach is realigned with precision medicine and patient-centeredness. Summary: In this article, we first review the available methods to estimate RKF among hemodialysis patients. We then discuss the importance of maintaining and monitoring RKF levels based on a variety of clinical aspects, including volume overload, blood pressure control, mineral and bone metabolism, nutrition, and patient survival. We also review several potential measures to protect RKF: the use of high-flux and biocompatible membranes, the use of ultrapure dialysate, the incorporation of hemodiafiltration, incremental hemodialysis, and a low-protein diet, as well as general care such as avoiding nephrotoxic events, maintaining appropriate blood pressure, and better control of mineral and bone disorder parameters. Key Message: Individualized hemodialysis regimens may maintain RKF, lead to a better quality of life without compromising long-term survival, and ensure precision medicine and patient-centeredness in nephrology practice.

Dialysis Modality and Incident Atrial Fibrillation in Older Patients With ESRD

RATIONALE & OBJECTIVE

Atrial fibrillation (AF) is common in patients with kidney failure treated by maintenance dialysis. Whether the incidence of AF differs between patients receiving hemodialysis and peritoneal dialysis is uncertain.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Using the US Renal Data System, we identified older patients (≥67 years) with Medicare Parts A and B who initiated dialysis therapy (1996-2011) without a diagnosis of AF during the prior 2 years.

EXPOSURE

Dialysis modality at incident end-stage renal disease (ESRD) and maintained for at least 90 days.

OUTCOME

Patients were followed up for 36 months or less for a new diagnosis of AF.

ANALYTICAL APPROACH

Time-to-event analysis using multivariable Cox proportional hazards regression to estimate cause-specific HRs while censoring at modality switch, kidney transplantation, or death.

RESULTS

Overall, 271,722 older patients were eligible; 17,487 (6.9%) were treated with peritoneal dialysis, and 254,235 (93.1%), with hemodialysis, at the onset of ESRD. During 406,225 person-years of follow-up, 69,705 patients had AF newly diagnosed. Because the proportionality assumption was violated, we introduced an interaction term between time (first 90 days vs thereafter) and modality. The AF incidence during the first 90 days was 187/1,000 person-years on peritoneal dialysis therapy and 372/1,000 person-years on hemodialysis therapy. Patients on peritoneal dialysis therapy had an adjusted 39% (95% CI, 34%-43%) lower incidence of AF than those on hemodialysis therapy. From day 91 onward, AF incidence was ∼140/1,000 person-years with no major difference between modalities.

LIMITATIONS

Residual confounding from unobserved differences between exposure groups; ascertainment of AF from billing claims; study of first modality may not generalize to patients switching modalities; uncertain generalizability to younger patients.

CONCLUSIONS

Although patients initiating dialysis therapy using peritoneal dialysis had a lower AF incidence during the first 90 days of ESRD, there was no major difference in AF incidence thereafter. The value of interventions to reduce the early excess AF risk in patients receiving hemodialysis may warrant further study.

Twice-Weekly Hemodialysis and Clinical Outcomes in the China Dialysis Outcomes and Practice Patterns Study

INTRODUCTION

In China, a quarter of patients are undergoing 2-times weekly hemodialysis. Using data from the China Dialysis Outcomes and Practice Patterns Study (DOPPS), we tested the hypothesis that whereas survival and hospitalizations would be similar in the presence of residual kidney function (RKF), patients without RKF would fare worse on 2-times weekly hemodialysis.

METHODS

In our cohort derived from 15 units randomly selected from each of 3 major cities (total N = 45), we generated a propensity score for the probability of dialysis frequency assignment, estimated a survival function by propensity score quintiles, and averaged stratum-specific survival functions to generate mean survival time. We used the proportional rates model to assess hospitalizations. We stratified all analyses by RKF, as reported by patients (urine output <1 vs. ≥1 cup/day).

RESULTS

Among 1265 patients, 123 and 133 were undergoing 2-times weekly hemodialysis with and without evidence of RKF. Over 2.5 years, adjusted mean survival times were similar for 2- versus 3-times weekly dialysis groups: 2.20 versus 2.23 and 2.20 versus 2.15 for patients with and without RKF (P = 0.65). Hazard ratios for hospitalization rates were similar for 2- versus 3-times weekly groups, with (1.15, 95% confidence interval = 0.66-2.00) and without (1.10, 95% confidence interval 0.68-1.79]) RKF. The normalized protein catabolic rate was lower and intradialytic weight gain was not substantially higher in the 2- versus 3-times weekly dialysis group, suggesting greater restriction of dietary sodium and protein.

CONCLUSION

In our study of patients in China's major cities, we could not detect differences in survival and hospitalization for those undergoing 2- versus 3-times weekly dialysis, regardless of RKF. Our findings indicate the need for pragmatic studies regarding less frequent dialysis with associated nutritional management.

Incremental dialysis for preserving residual kidney function-Does one size fit all when initiating dialysis?

While many patients have substantial residual kidney function (RKF) when initiating hemodialysis (HD), most patients with end stage renal disease in the United States are initiated on 3-times per week conventional HD regimen, with little regard to RKF or patient preference. RKF is associated with many benefits including survival, volume control, solute clearance, and reduced inflammation. Several strategies have been recommended to preserve RKF after HD initiation, including an incremental approach to HD initiation. Incremental HD prescriptions are personalized to achieve adequate volume control and solute clearance with consideration to a patient's endogenous renal function. This allows the initial use of less frequent and/or shorter HD treatment sessions. Regular measurement of RKF is important because HD frequency needs to be increased as RKF inevitably declines. We narratively review the results of 12 observational cohort studies of twice-weekly compared to thrice-weekly HD. Incremental HD is associated with several benefits including preservation of RKF as well as extending the event-free life of arteriovenous fistulas and grafts. Patient survival and quality of life, however, has been variably associated with incremental HD. Serious risks must also be considered, including increased hospitalization and mortality perhaps related to fluid and electrolyte shifts after a long interdialytic interval. On the basis of the above literature review, and our clinical experience, we suggest patient characteristics which may predict favorable outcomes with an incremental approach to HD. These include substantial RKF, adequate volume control, lack of significant anemia/electrolyte imbalance, satisfactory health-related quality of life, low comorbid disease burden, and good nutritional status without evidence of hypercatabolism. Clinicians should engage patients in on-going conversations to prepare for incremental HD initiation and to ensure a smooth transition to thrice-weekly HD when needed.

Once-weekly hemodialysis combined with low-protein and low-salt dietary treatment as a favorable therapeutic modality for selected patients with end-stage renal failure: a prospective observational study in Japanese patients

Background

For patients with end-stage renal failure (ESFR), thrice-weekly hemodialysis is a standard care. Once-weekly hemodialysis combined with low-protein and low-salt dietary treatment (OWHD-DT) have been rarely studied. Therefore, here, we describe our experience on OWHD-DT, and assess its long-term effectiveness.

Methods

We instituted OWHD-DT therapy in 112 highly motivated patients with creatinine clearance below 5.0 mL/min. They received once-weekly hemodialysis on a diet of 0.6 g/kg/day of protein adjusted for sufficient energy intake, and less than 6 g/day of salt intake. Serial changes in their clinical, biochemical and nutritional parameters were prospectively observed, and the weekly time spent for hospital visits as well as their monthly medical expenses were compared with 30 age, sex- and disease-matched thrice-weekly hemodialysis patients.

Results

The duration of successfully continued OWHD-DT therapy was more than 4 years in 11.6% of patients, 3 years in 16.1%, 2 years in 24.1% and 1 year in 51.8%. Time required per week for hospital attendance was 66.7% shorter and monthly medical expenses were 50.5% lower in the OWHD-DT group than in the thrice-weekly hemodialysis group (both p < 0.001). Patient survival rates in the OWHD-DT group were better than those in the Japan Registry (p < 0.001). Serum urea nitrogen significantly decreased; hemoglobin significantly increased; and albumin and body mass index were not significantly different from baseline values. In the OWHD-DT patients, serum albumin at 1 and 2 years after initiation of therapy was significantly higher compared with prevalent thrice-weekly hemodialysis patients. Furthermore, residual urine output was significantly higher in the OWHD-DT patients than in those receiving thrice-weekly hemodialysis (p < 0.05). Interdialytic weight gain over the course of the entire week between treatments in patients on OWHD-DT were 0.9 ± 1.0, 2.0 ± 1.3, 1.9 ± 1.2, 1.9 ± 1.5 and 1.8 ± 1.0 kg at 1, 6, 12, 18 and 24 months, respectively, though the weekly weight gain for thrice-weekly hemodialysis group (summed over all 3 treatments) was 8.6 ± 0.63 kg, p < 0.001.

Conclusions

OWHD-DT may be a favorable therapeutic modality for selected highly motivated patients with ESRF. However, this treatment cannot be seen as a general maintenance strategy.

Trial registration

UMIN000027555, May 30, 2017 (retrospectively registered).

Comparison of outcomes between the incremental and thrice-weekly initiation of hemodialysis: a propensity-matched study of a prospective cohort in Korea

Background

Recent reports have suggested the possible benefit of beginning hemodialysis (HD) at a rate less frequent than three times weekly and incrementally increasing the dialysis dose. However, the data regarding the benefits and safety of incremental HD are insufficient.

Methods

We analyzed 927 patients with newly initiated HD from the Clinical Research Center for End-Stage Renal Disease cohort from 2008 to 2014. The patients were classified into a thrice-weekly initiation group or an incremental initiation group (one to two sessions per week) according to the frequency of HD per week at baseline. We compared health-related quality of life (HRQOL), daily urine volume at 12 months and all-cause mortality between the groups. We matched the thrice-weekly and incremental groups at a 1:2 ratio using propensity score matching.

Results

A total of 312 patients (207 in the thrice-weekly group and 105 in the incremental group) were selected. All-cause mortality was comparable between the two groups before and after propensity score matching. The HRQOL tended to be better in the incremental group for the majority of domains of the Kidney Disease Quality of Life Short Form and Beck's Depression Inventory; however, only the symptoms and problems domain was significantly better in the incremental group at 3 months after HD. At 12 months after HD, there were no differences between the groups. The daily urine volume at 12 months after HD was similar between the two groups.

Conclusions

Incremental HD initiation showed comparable results to thrice-weekly initiation for HRQOL, residual renal function and all-cause mortality. Incremental HD may be considered an additional option for HD initiation in selected patients.

Can twice weekly hemodialysis expand patient access under resource constraints?

The convention of prescribing hemodialysis on a thrice weekly schedule began empirically when it seemed that this frequency was convenient and likely to treat symptoms for a majority of patients. Later, when urea was identified as the main target and marker of clearance, studies supported the prevailing notion that thrice weekly dialysis provided appropriate clearance of urea. Today, national guidelines on hemodialysis from most countries recommend patients receive at least thrice weekly therapy. However, resource constraints in low- and middle-income countries (LMIC) have resulted in a substantial proportion of patients using less frequent hemodialysis in these settings. Observational studies of patients on twice weekly dialysis show that twice weekly therapy has noninferior survival rates compared with thrice weekly therapy. In fact, models of urea clearance also show that twice weekly therapy can meet urea clearance "targets" if patients have significant residual function or if they follow a protein-restricted diet, as may be common in LMIC. Greater reliance on twice weekly therapy, at least at the start of hemodialysis, therefore has potential to reduce health care costs and increase access to renal replacement therapy in low-resource settings; however, randomized control trials are needed to better understand long-term outcomes of twice versus thrice weekly therapy.

Incremental Hemodialysis: The University of California Irvine Experience

Incremental hemodialysis has been examined as a viable hemodialysis regimen for selected end-stage renal disease (ESRD) patients. Preservation of residual kidney function (RKF) has been the driving impetus for this approach given its benefits upon the survival and quality of life of dialysis patients. While clinical practice guidelines recommend an incremental start of dialysis in peritoneal dialysis patients with substantial RKF, there remains little guidance with respect to incremental hemodialysis as an initial renal replacement therapy regimen. Indeed, several large population-based studies suggest that incremental twice-weekly vs. conventional thrice-weekly hemodialysis has favorable impact upon RKF trajectory and survival among patients with adequate renal urea clearance and/or urine output. In this report, we describe a case series of 13 ambulatory incident ESRD patients enrolled in a university-based center's Incremental Hemodialysis Program over the period of January 2015 to August 2016 and followed through December 2016. Among five patients who maintained a twice-weekly hemodialysis schedule vs. eight patients who transitioned to thrice-weekly hemodialysis, we describe and compare patients' longitudinal case-mix, laboratory, and dialysis treatment characteristics over time. The University of California Irvine Experience is the first systemically examined twice-weekly hemodialysis practice in North America. While future studies are needed to refine the optimal approaches and the ideal patient population for implementation of incremental hemodialysis, our case-series serves as a first report of this innovative management strategy among incident ESRD patients with substantial RKF, and a template for implementation of this regimen.

Twice-Weekly Hemodialysis in China: Can It Be A Better Option for Initiation or Maintenance Dialysis Therapy?

Cumulative evidence indicates it may be worthwhile revisiting the twice-weekly hemodialysis (HD) regimen as a valid option for individualized or incremental treatments for selected patients with end-stage renal disease. In this article, we will review the current evidences on the potential pros and cons of twice-weekly HD compared to thrice-weekly HD including China's experience in the practice of twice-weekly HD. A prudent patient selection and close dialysis adequacy monitoring might be necessary for this medical treatment choice. More randomized prospective controlled studies for the critical evaluation of twice-weekly dialysis are encouraged.

Is incremental hemodialysis ready to return on the scene? From empiricism to kinetic modelling

Most people who make the transition to maintenance dialysis therapy are treated with a fixed dose thrice-weekly hemodialysis regimen without considering their residual kidney function (RKF). The RKF provides effective and naturally continuous clearance of both small and middle molecules, plays a major role in metabolic homeostasis, nutritional status, and cardiovascular health, and aids in fluid management. The RKF is associated with better patient survival and greater health-related quality of life, although these effects may be confounded by patient comorbidities. Preservation of the RKF requires a careful approach, including regular monitoring, avoidance of nephrotoxins, gentle control of blood pressure to avoid intradialytic hypotension, and an individualized dialysis prescription including the consideration of incremental hemodialysis. There is currently no standardized method for applying incremental hemodialysis in practice. Infrequent (once- to twice-weekly) hemodialysis regimens are often used arbitrarily, without knowing which patients would benefit the most from them or how to escalate the dialysis dose as RKF declines over time. The recently heightened interest in incremental hemodialysis has been hindered by the current limitations of the urea kinetic models (UKM) which tend to overestimate the dialysis dose required in the presence of substantial RKF. This is due to an erroneous extrapolation of the equivalence between renal urea clearance (Kru) and dialyser urea clearance (Kd), correctly assumed by the UKM, to the clinical domain. In this context, each ml/min of Kd clears the urea from the blood just as 1 ml/min of Kru does. By no means should such kinetic equivalence imply that 1 ml/min of Kd is clinically equivalent to 1 ml/min of urea clearance provided by the native kidneys. A recent paper by Casino and Basile suggested a variable target model (VTM) as opposed to the fixed model, because the VTM gives more clinical weight to the RKF and allows less frequent hemodialysis treatments at lower RKF. The potentially important clinical and financial implications of incremental hemodialysis render it highly promising and warrant randomized controlled trials.

Incremental Hemodialysis - A European Perspective

Most patients initiating hemodialysis have residual renal function (RRF). Whereas RRF is monitored prior to commencing hemodialysis, once dialysis is started most centres simply rely on dialyzer urea clearance to determine adequate uremic toxin clearance and disregard the effect of RRF. However sustaining RRF is important for the dialysis patient, as RRF reduces inter-dialytic weight gains, increases middle molecule and protein bound toxin clearances and is associated with better quality of life assessments. Paradoxically, more frequent dialysis and longer dialysis sessions appear to be associated with more rapid loss of RRF. As such, starting patients with less frequent or shorter dialysis sessions, depending upon individual patient comorbidity, may lead to better preservation of RRF. However to prevent inadequate uremic toxin clearance or volume overload, RRF needs to be regularly monitored. Unfortunately, the 24-hour urine collection for urea and creatinine clearance remains the mainstay for RRF assessment. This measurement chiefly represents glomerular clearance rather than tubular function, but the latter may be also important for the dialysis patients. Incremental dialysis with less initial dialysis treatment may lower costs and will allow others to dialyze more frequently. The key to start a successful incremental hemodialysis approach is the regular monitoring of the patient, so that as RRF is lost an appropriate decision can be made regarding increasing dialysis session duration and frequency on an individual patient basis or consider switching modalities to hemodiafiltration.

Incremental and infrequent hemodialysis: a new paradigm for both dialysis initiation and conservative management

Registry or national dialysis data show that a sizeable proportion of contemporary dialysis patients have substantial levels of residual kidney function especially upon transitioning to dialysis therapy. However, among incident hemodialysis patients, the prevailing paradigm has been to initiate "full-dose" triweekly treatment schedules irrespective of native kidney function in most developed countries. Recognizing the benefits of residual kidney function upon the health and survival of dialysis patients, there has been growing interest in incremental hemodialysis, in which dialysis frequency and dose are tailored according to the degree of patients' residual kidney function. Infrequent hemodialysis can also be used for those who prefer a more conservative approach in managing uremia. Clinical practice guidelines support the use of twice-weekly hemodialysis among patients with adequate residual kidney function (renal urea clearance >3 mL/min/1.73 m2), and a growing body of evidence indicates that incremental hemodialysis is associated with better preservation of residual kidney function without adversely impacting survival. Nonetheless, incremental hemodialysis remains an underutilized approach in this population. In this review, we will discuss the history of the twice- versus triweekly hemodialysis schedules; current clinical practice guidelines regarding infrequent hemodialysis; emerging data on incremental treatment regimens and outcomes; and guidelines for the practical implementation of incremental and infrequent hemodialysis in the clinical setting.

Concurrence of Serum Creatinine and Albumin With Lower Risk for Death in Twice-Weekly Hemodialysis Patients

OBJECTIVE

Markers of better nutritional status including both higher levels of serum albumin (as a measure of visceral proteins) and creatinine (as a measure of the muscle mass) are associated with lower mortality in conventional (thrice weekly) hemodialysis patients. However, data for these associations in twice-weekly hemodialysis patients, in whom less frequent hemodialysis may confound nutritional predictors, are lacking.

DESIGN AND SUBJECTS

We identified 1,113 twice-weekly and matched 4,448 thrice-weekly hemodialysis patients from a large national dialysis cohort of incident hemodialysis patients over 5 years (2007-2011). Mortality risk, adjusted for potential confounders, was examined across two-by-two combinations of serum creatinine (<6 vs. ≥6 mg/dL) and albumin (<3.5 g/dL vs. ≥3.5 g/dL) for each treatment frequency yielding a total of 8 groups.

RESULTS

Patients were aged 70 ± 14 years and included 48% women and 55% diabetics. Using the thrice-weekly hemodialysis patients with creatinine ≥ 6 mg/dL and albumin ≥ 3.5 g/dL as reference, patients with creatinine <6 mg/dL and albumin <3.5 g/dL had a 1.8-fold higher risk of mortality (hazard ratio: 1.75, 95% confidence interval: 1.33-2.30) in twice-weekly and 2.2-fold increased risk of mortality (hazard ratio: 2.21, 95% confidence interval: 1.81-2.70) in thrice-weekly hemodialysis patients, respectively in fully adjusted models adjusted for demographics, comorbidities, and markers of malnutrition and inflammation. A test for interaction showed that there was no significant difference in albumin creatinine mortality associations between twice-weekly and thrice-weekly hemodialysis patients (P-for-interaction = .7667).

CONCLUSIONS

Surrogate markers of higher visceral protein and muscle mass combined may confer greatest survival in both twice-weekly and thrice-weekly hemodialysis patients.

Hemodialysis Time and Kt/V: Less May Be Better

Current guidelines focus on conventional dialysis defined as 3-5 hours, three times per week, and suggest that longer or more frequent dialysis be considered. This paper presents the case for considering that shorter or less frequent dialysis should also be considered. More frequent and/or longer dialysis facilitates control of fluid overload, blood pressure, and phosphate levels. These benefits will require time to translate into probable hard outcome improvement. Patients are unlikely to participate in productive or pleasurable activities while undergoing dialysis in center or traveling to treatment. So any increase in dialysis time or frequency, during awake hours, will result in an immediate and quantifiable reduction in quality of life. Conventional measures of dialysis adequacy consider only urea clearance. This poorly reflects middle molecule clearance, renal function, and management of fluid and phosphate overload, all of which have a greater impact on outcome than urea clearance. Fluid, phosphate, and uremic toxin overload may be better and less invasively controlled by continuous means such as dietary modification, binders, and preserving renal function. Bioimpedance, blood volume monitoring, and lung ultrasound provide means for improved control of fluid homeostasis. The probability of renal function recovery or preservation is increased by avoiding dehydration. An ideal strategy would be to preserve renal function and employ as little dialysis as possible (if it cannot be avoided altogether). Fluid overload, blood pressure, uremic toxin, and phosphate levels would be monitored and controlled using any means available, preferably by less invasive means than dialysis. Kt/V is useful in controlling the prescribed dose of dialysis, but the achievement of a universal target should not be an end in itself.

Treatment frequency and mortality among incident hemodialysis patients in the United States comparing incremental with standard and more frequent dialysis

Most patients with end-stage renal disease in the United States are initiated on thrice-weekly hemodialysis (HD) regimens. However, an incremental approach to HD may provide several patient benefits. We tested whether initiation of incremental HD does or does not compromise survival compared with a conventional HD regimen. The survival of 434 incremental, 50,162 conventional, and 160 frequent HD patients were compared using Cox regression analysis after matching for demographic and comorbid factors in a longitudinal national cohort of adult incident HD patients enrolled between January 2007 and December 2011. Sensitivity analysis included adjustment for residual kidney function. After adjustment for residual kidney function, all-cause mortality was not significantly different in the incremental compared with conventional HD group (hazard ratio 0.88, 95% confidence interval 0.72-1.08), but was higher in the frequent compared with the conventional HD group (hazard ratio, 1.56, 95% confidence interval 1.21-2.03). The comorbidity burden modified the association of treatment frequency and mortality, with higher comorbidity associated with higher mortality in the incremental HD group (hazard ratio, 1.77, 95% confidence interval 1.20-2.62) for a Charlson Comorbidity Index of ≥5. Thus, among incident HD patients with low or moderate comorbid disease, survival was similar for patients initiated on an incremental or conventional HD regimen. Clinical trials are needed to examine the safety and effectiveness of incremental HD and the selected patient populations who may benefit from an incremental approach to HDs initiation.

Preservation of residual kidney function in hemodialysis patients: reviving an old concept

Residual kidney function (RKF) may confer a variety of benefits to patients on maintenance dialysis. RKF provides continuous clearance of middle molecules and protein-bound solutes. Whereas the definition of RKF varies across studies, interdialytic urine volume may emerge as a pragmatic alternative to more cumbersome calculations. RKF preservation is associated with better patient outcomes including survival and quality of life and is a clinical parameter and research focus in peritoneal dialysis. We propose the following practical considerations to preserve RKF, especially in newly transitioned (incident) hemodialysis patients: (1) periodic monitoring of RKF in hemodialysis patients through urine volume and including residual urea clearance with dialysis adequacy and outcome markers such as anemia, fluid gains, minerals and electrolytes, nutritional, status and quality of life; (2) avoidance of nephrotoxic agents such as radiocontrast dye, nonsteroidal anti-inflammatory drugs, and aminoglycosides; (3) more rigorous hypertension control and minimizing intradialytic hypotensive episodes; (4) individualizing the initial dialysis prescription with consideration of an incremental/infrequent approach to hemodialysis initiation (e.g., twice weekly) or peritoneal dialysis; and (5) considering a lower protein diet, especially on nondialysis days. Because RKF appears to be associated with better patient outcomes, it requires more clinical and research focus in the care of hemodialysis and peritoneal dialysis patients.

Incremental Hemodialysis, Residual Kidney Function, and Mortality Risk in Incident Dialysis Patients: A Cohort Study

BACKGROUND

Maintenance hemodialysis is typically prescribed thrice weekly irrespective of a patient's residual kidney function (RKF). We hypothesized that a less frequent schedule at hemodialysis therapy initiation is associated with greater preservation of RKF without compromising survival among patients with substantial RKF.

STUDY DESIGN

A longitudinal cohort.

SETTING & PARTICIPANTS

23,645 patients who initiated maintenance hemodialysis therapy in a large dialysis organization in the United States (January 2007 to December 2010), had available RKF data during the first 91 days (or quarter) of dialysis, and survived the first year.

PREDICTOR

Incremental (routine twice weekly for >6 continuous weeks during the first 91 days upon transition to dialysis) versus conventional (thrice weekly) hemodialysis regimens during the same time.

OUTCOMES

Changes in renal urea clearance and urine volume during 1 year after the first quarter and survival after the first year.

RESULTS

Among 23,645 included patients, 51% had substantial renal urea clearance (≥3.0mL/min/1.73m(2)) at baseline. Compared with 8,068 patients with conventional hemodialysis regimens matched based on baseline renal urea clearance, urine volume, age, sex, diabetes, and central venous catheter use, 351 patients with incremental regimens exhibited 16% (95% CI, 5%-28%) and 15% (95% CI, 2%-30%) more preserved renal urea clearance and urine volume at the second quarter, respectively, which persisted across the following quarters. Incremental regimens showed higher mortality risk in patients with inadequate baseline renal urea clearance (≤3.0mL/min/1.73m(2); HR, 1.61; 95% CI, 1.07-2.44), but not in those with higher baseline renal urea clearance (HR, 0.99; 95% CI, 0.76-1.28). Results were similar in a subgroup defined by baseline urine volume of 600mL/d.

LIMITATIONS

Potential selection bias and wide CIs.

CONCLUSIONS

Among incident hemodialysis patients with substantial RKF, incremental hemodialysis may be a safe treatment regimen and is associated with greater preservation of RKF, whereas higher mortality is observed after the first year of dialysis in those with the lowest RKF. Clinical trials are needed to examine the safety and effectiveness of twice-weekly hemodialysis.

Comparison of Clinical Outcome Between Twice-Weekly and Thrice-Weekly Hemodialysis in Patients With Residual Kidney Function

Residual kidney function (RKF) contributes to improved survival in hemodialysis (HD) patients. However, it is not clear whether RKF allows a comparable survival rate in patients undergoing twice-weekly HD compared with thrice-weekly HD.We enrolled 685 patients from a prospective multicenter observational cohort. RKF and HD adequacy was monitored regularly over 3-year follow-up. Patients with RKF were divided into groups undergoing twice-weekly HD (n = 113) or thrice-weekly HD (n = 137). Patients without RKF undergoing thrice-weekly HD (n = 435) were included as controls. Fluid balance and dialysis-associated characteristics were followed and clinical outcomes evaluated using all-cause mortality and cardiovascular events (CVE).In patients with RKF, baseline and follow-up RKF were significantly higher in patients undergoing twice-weekly HD than in those undergoing thrice-weekly HD. Total Kt/V urea (dialysis plus residual renal) in patients with RKF undergoing twice-weekly HD was greater than or equal to those in patients with or without RKF undergoing thrice-weekly HD. Compared with patients with RKF undergoing thrice-weekly HD, patients with RKF undergoing twice-weekly HD had no fluid excess, but their normalized protein catabolic rate became lower since 24-month follow up. In multivariable analyses, patients with RKF undergoing twice-weekly HD had a noninferior risk of mortality (hazard ratio [HR], 0.83; 95% confidence interval [95% CI], 0.34-2.01, P = 0.68) and of CVE (HR, 0.60; 95% CI, 0.28-1.29, P = 0.19) compared with patients without RKF undergoing thrice-weekly HD. However, this group showed an independent association with a greater risk of mortality compared with patients with RKF undergoing thrice-weekly HD (HR, 4.20; 95% CI, 1.02-17.32, P = 0.04).In conclusion, patients with RKF undergoing twice-weekly HD had an increased risk of mortality compared with those undergoing thrice-weekly HD. Decisions about twice-weekly HD should consider not only RKF, but also other risk factors such as normalized protein catabolic rate.

What Is Known and Unknown About Twice-Weekly Hemodialysis

BACKGROUND

The 2006 Kidney Disease Outcomes Quality Initiative guidelines suggest twice-weekly or incremental hemodialysis for patients with substantial residual kidney function (RKF). However, in most affluent nations de novo and abrupt transition to thrice-weekly hemodialysis is routinely prescribed for all dialysis-naïve patients regardless of their RKF. We review historical developments in hemodialysis therapy initiation and revisit twice-weekly hemodialysis as an individualized, incremental treatment especially upon first transitioning to hemodialysis therapy.

SUMMARY

In the 1960's, hemodialysis treatment was first offered as a life-sustaining treatment in the form of long sessions (≥10 hours) administered every 5 to 7 days. Twice- and then thrice-weekly treatment regimens were subsequently developed to prevent uremic symptoms on a long-term basis. The thrice-weekly regimen has since become the 'standard of care' despite a lack of comparative studies. Some clinical studies have shown benefits of high hemodialysis dose by more frequent or longer treatment times mainly among patients with limited or no RKF. Conversely, in selected patients with higher levels of RKF and particularly higher urine volume, incremental or twice-weekly hemodialysis may preserve RKF and vascular access longer without compromising clinical outcomes. Proposed criteria for twice-weekly hemodialysis include urine output >500 ml/day, limited interdialytic weight gain, smaller body size relative to RKF, and favorable nutritional status, quality of life, and comorbidity profile.

KEY MESSAGES

Incremental hemodialysis including twice-weekly regimens may be safe and cost-effective treatment regimens that provide better quality of life for incident dialysis patients who have substantial RKF. These proposed criteria may guide incremental hemodialysis frequency and warrant future randomized controlled trials.

Progressive Hemodialysis: Is It The Future?

Progressive hemodialysis is based on the simple idea of adjusting its dose according to residual renal function (RRF). The progressive, infrequent paradigm is slowly gaining a foothold among nephrologists, despite a lot of skepticism in the scientific world. Given the importance of RRF preservation in conservative therapy, it seems a contradiction to ignore the contribution of RRF when patients initiate hemodialysis (HD), especially when it is routinely considered with peritoneal dialysis. While a three-times-weekly HD regimen is broadly considered the standard starting regimen for new patients, twice-weekly HD has been used in selected patients and is currently a common practice in South-East Asia. Small studies indicate that a once-weekly HD regimen may be a viable starting option as well. Progressive hemodialysis still requires validation, yet it is promising. We share the belief that a randomized clinical trial to investigate progressive hemodialysis is much needed, but we also strongly recommend including a once-weekly HD starting dose as part of any such investigation.

Pro and con arguments in using alternative dialysis regimens in the frail and elderly patients

In the last decade, an increasing number of patients over 75 years of age are starting renal replacement therapy. Frailty is highly prevalent in elderly patients with end-stage renal disease (ESRD) in the context of the increased prevalence of some ESRD-associated conditions: protein-energy wasting, inflammation, anaemia, acidosis or hormonal disturbances. There are currently no hard data to support guidance on the optimal duration of dialysis for frail/elderly ESRD patients. The current debate is not about starting dialysis or managing conservatory frail ESRD patients, but whether a more intensive regimen once dialysis is initiated (for whatever reasons and circumstances) would improve patients' outcome. The most important issue is that all studies performed with extended/alternative dialysis regimens do not specifically address this particular type of patients and therefore all the inferences are derived from the general ESRD population. Care planning should be responsive to end-of-life needs whatever the treatment modality. Care in this setting should focus on symptom control and quality of life rather than life extension. We conclude that, similar to the general dialysed population, extensive application of more intensive dialysis schedules is not based on solid evidence. However, after a thorough clinical evaluation, a limited period of a trial of intensive dialysis could be prescribed in more problematic patients.