A practical approach to implementing incremental haemodialysis

The majority of end-stage kidney disease patients are treated with haemodialysis (HD). Starting HD can pose physical, social, and psychological challenges to patients, and mortality rates within the first 6 months are disproportionately high, with intensive HD regimens implicated as a potential factor. Starting HD with an incremental approach, taking residual kidney function (RKF) into account, potentially allows for a gentle start with reduced dialysis intensity. Dialysis intensity (session time or frequency) can then be proportionally increased as RKF reduces. This approach to starting HD has been reported in observational studies to result in better patient self-reported health quality of life and reduced costs, and now several definitive randomised controlled trials are underway comparing an incremental approach to the conventional thrice weekly paradigm. Physician concerns over the risk of inadequate dialysis, with consequent increased emergency admissions, and practical challenges of how to estimate RKF and implement incremental dialysis have impeded widespread adoption. Addressing these challenges is paramount to increasing the uptake of incremental HD. Careful patient selection lies at the heart of a successful incremental HD programme. Generally, patients with a residual urea clearance of > 3 ml/min/1.73 m2 can be considered suitable for starting with incremental HD provided they comply with fluid intake, salt and other dietary recommendations. Calculating RKF from regular interdialytic urine collections and appropriately adjusting sessional HD clearance targets are practical and conceptual challenges. In this report we aim to disentangle these complexities and provide a step-by-step guide for patient selection and adjusting dialysis sessional targets.

Relationship between number of daily exchanges at CAPD start with clinical outcomes

BACKGROUND

Peritoneal dialysis (PD) continues to be demanding for patients affected by kidney failure. In kidney failure patients with residual kidney function, the employment of incremental PD, a less onerous dialytic prescription, could translate into a decrease burden on both health systems and patients.

METHODS

Between 1st January 2009 and 31st December 2021, 182 patients who started continuous ambulatory peritoneal dialysis (CAPD) at our institution were included in the study. The CAPD population was divided into three groups according to the initial number of daily CAPD exchanges prescribed: one or two (50 patients, CAPD-1/2 group), three (97 patients, CAPD-3 group) and four (35 patients, CAPD-4 group), respectively.

RESULTS

Multivariate analysis showed a difference in term of peritonitis free survival in CAPD-1/2 in comparison to CAPD-3 (hazard ratio (HR): 2.20, p = 0.014) and CAPD-4 (HR: 2.98, p < 0.01). A tendency towards a lower hospitalisation rate (CAPD-3 and CAPD-4 vs. CAPD-1/2, p = 0.11 and 0.13, respectively) and decreased mortality (CAPD-3 and CAPD-4 vs. CAPD-1/2, p = 0.13 and 0.22, respectively) in patients who started PD with less than three daily exchanges was detected. No discrepancy of the difference of the mean values between baseline and 24 months residual kidney function was observed among the three groups (p = 0.33).

CONCLUSIONS

One- or two-exchange CAPD start was associated with a lower risk of peritonitis in comparison to three- or four-exchange start. Furthermore, an initial PD prescription with less than three exchanges may be associated with an advantage in term of hospitalisation rate and patient survival.

Construction of an Early Alert System for Intradialytic Hypotension before Initiating Hemodialysis Based on Machine Learning

Introduction

Intradialytic hypotension (IDH) is prevalent and associated with high hospitalization and mortality rates. The purpose of this study was to explore the risk factors for IDH and use artificial intelligence to establish an early alert system before hemodialysis sessions to identify patients at high risk of IDH.

Materials and Methods

We obtained data on 314,534 hemodialysis sessions conducted at Sichuan Provincial People's Hospital from the renal disease treatment information system. IDH was defined as a systolic blood pressure drop ≥20 mm Hg, a mean arterial pressure drop ≥10 mm Hg during dialysis, or the occurrence of clinical hypotensive events requiring nursing intervention. After pre-processing, the data were randomly divided into training (80%) and testing (20%) sets. Four interpolation methods, three feature selection methods, and 18 machine learning algorithms were used to construct predictive models. The area under the receiver operating characteristic curve (AUC) was the main indicator for evaluating the performance of the models, while Shapley Additive ExPlanation was used to explain the contribution of each variable to the best predictive model.

Results

A total of 3,906 patients and 314,534 dialysis sessions were included, of which 142,237 cases showed IDH (incidence rate, 45.2%). Nineteen parameters were identified through artificial intelligence feature screening. They included age, pre-dialysis weight, dry weight, pre-dialysis blood pressure, heart rate, prescribed ultrafiltration, blood cell counts (neutrophil, lymphocyte, monocyte, eosinophil, lymphocyte, and platelet counts), hematocrit, serum calcium, creatinine, urea, glucose, and uric acid. Random forest, gradient boosting, and logistic regression were the three best models, and the AUCs were 0.812 (95% confidence interval [CI], 0.811-0.813), 0.748 (95% CI, 0.747-0.749), and 0.743 (95% CI, 0.742-0.744), respectively.

Conclusion

Our dialysis software-based artificial intelligence alert system can be used to predict IDH occurrence, enabling the initiation of relevant interventions.

Efficacy and safety of low- versus high-dose glucocorticoid regimens for induction of remission of anti-neutrophil cytoplasm antibody-associated vasculitis: a systematic review and meta-analysis

OBJECTIVE

Glucocorticoids (GCs) remain a cornerstone of the initial management of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV), but have several dose-dependent side effects, in particular infections. The optimal dosing and tapering of oral GCs for remission induction are unknown. A systematic review and meta-analysis was undertaken to determine the efficacy and safety of low- versus high-dose GC regimens.

METHOD

A systematic search of MEDLINE, Embase, and PubMed databases was conducted. Clinical studies using a GC-based induction protocol were selected. A daily dose of 0.5 mg/kg or < 30 mg/day oral prednisolone equivalent by the start of week 4 of the induction tapering schedule marked the threshold between high- and low-dose GCs. Risk ratios (RRs) were calculated by the random effects model for outcomes of remission and infection. Relapse events were summarized using risk differences with 95% confidence intervals (CIs).

RESULTS

In total, 1145 participants were included in three randomized controlled trials and two observational studies, of whom 543 were assigned to the low-dose GC group and 602 to the high-dose GC group. A low-dose GC regimen was non-inferior to high-dose GCs with respect to outcomes of remission (RR 0.98, 95% CI 0.95-1.02, p = 0.37; I2 = 0%) and relapse (risk difference 0.03, 95% CI -0.01 to 0.06, p = 0.15; I2 = 12%), while significantly reducing the incidence of infection (RR 0.60, 95% CI 0.39-0.91, p = 0.02; I2 = 65%).

CONCLUSION

Studies with low-dose GC regimens in AAV are associated with fewer infections while obtaining equivalent efficacy.

COMMD5 is involved in the mechanisms of hypotension after parathyroidectomy in patients receiving hemodialysis

BACKGROUND

Secondary hyperparathyroidism (SHPT) is a common complication of end-stage renal disease. Parathyroidectomy (PTx) is often employed for treatment of severe SHPT. However, PTx may cause hypotension via unknown mechanisms. COMM domain-containing protein 5 (COMMD5) in the parathyroid glands has been linked to blood pressure regulation of spontaneously hypertensive rats.

OBJECTIVE

To explore the relationship between COMMD5 levels and reduced BP after PTx in patients receiving hemodialysis (HD).

METHODS AND RESULTS

(1) The study cohort included 31 patients receiving HD who underwent PTx. Serum COMMD5 levels were higher post-PTx vs. pre-PTx. (2) Sprague-Dawley rats (n = 22) were assigned to a 5/6 nephrectomy group or sham surgery group, vascular rings of the thoracic aorta from rats with CKD were incubated with COMMD5, and changes in vascular tension were compared. COMMD5 inhibited vasoconstriction of vascular rings with intact endothelium, but had no effect on vascular rings without the endothelium. (3) Human umbilical vein endothelial cells were stimulated with COMMD5 or small interfering RNA (siRNA). The expression levels of atrial natriuretic peptide (ANP) and endothelial nitric oxide synthase (eNOS) were up-regulated and down-regulated, respectively.

CONCLUSIONS

Serum COMMD5 levels were increased after PTx in SHPT patients. COMMD5 promoted high expression of ANP and eNOS in endothelial cells, leading to vasodilation and resulting in hypotension.

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.

Safety and Efficacy of Short Daily Hemodialysis with Physidia S3 System: Clinical Performance Assessment during the Training Period

Background: A growing body of scientific evidence indicates that clinical outcomes of hemodialysis patients can be improved with short daily dialysis treatment. Current in-center hemodialysis machines do not fulfill the requirements needed for self-care home hemodialysis (HHD) treatment. In line with the reviviscence of home therapy, several hemodialysis devices have been developed and deployed for treatment. Physidia S³ is one of these new dialysis delivery systems featuring an appealing design and functionalities intended for daily HHD treatment. Methods: In this French multicenter proof-of-concept study enrolling 13 training centers, we report our preliminary experience with a special focus on quantifying clinical performances in short daily HHD treatment performed during the training period of the patients. Results: Among the 80 patients included in this study, a total of 249 sessions could be analyzed. Dialysis dose, estimated from weekly standardized Kt/V, was maintained at 2.22 [1.95–2.61] with a normalized protein catabolic rate of 0.93 [0.73–1.18] g/kg/24 h. Furthermore, anemia and nutritional status were adequately controlled as indicated by 11.6 ± 1.4 g/dL of hemoglobin level and 39.4 ± 5.7 g/L of serum albumin as well as electrolyte disorders. Conclusions: The safety and efficacy of the S³ therapy concept relying on a short daily hemodialysis treatment using a bagged delivery system are in total agreement with daily HHD recommendations. Clinical performances are aligned to the metabolic needs of the vast majority of HHD patients. Currently ongoing studies at home will provide further evidence and value of this therapeutic approach.

Hidden risks associated with conventional short intermittent hemodialysis: A call for action to mitigate cardiovascular risk and morbidity

The development of maintenance hemodialysis (HD) for end stage kidney disease patients is a success story that continues to save many lives. Nevertheless, intermittent renal replacement therapy is also a source of recurrent stress for patients. Conventional thrice weekly short HD is an imperfect treatment that only partially corrects uremic abnormalities, increases cardiovascular risk, and exacerbates disease burden. Altering cycles of fluid loading associated with cardiac stretching (interdialytic phase) and then fluid unloading (intradialytic phase) likely contribute to cardiac and vascular damage. This unphysiologic treatment profile combined with cyclic disturbances including osmotic and electrolytic shifts may contribute to morbidity in dialysis patients and augment the health burden of treatment. As such, HD patients are exposed to multiple stressors including cardiocirculatory, inflammatory, biologic, hypoxemic, and nutritional. This cascade of events can be termed the dialysis stress storm and sickness syndrome. Mitigating cardiovascular risk and morbidity associated with conventional intermittent HD appears to be a priority for improving patient experience and reducing disease burden. In this in-depth review, we summarize the hidden effects of intermittent HD therapy, and call for action to improve delivered HD and develop treatment schedules that are better tolerated and associated with fewer adverse effects.

Incremental Versus Standard (Full-Dose) Peritoneal Dialysis

Incremental peritoneal dialysis (PD), defined as less than “standard dose” PD prescription, has a number of possible benefits, including better preservation of residual kidney function (RKF), reduced risk of peritonitis, lower peritoneal glucose exposure, lesser environmental impact, and reduced costs. Patients commencing PD are often new to kidney replacement therapy and possess substantial RKF, which may allow safe delivery of an incremental prescription, often in the form of lower frequency or duration of PD. This has the potential to help improve quality of life (QOL) and life participation through reducing time requirements and burden of treatment. Alternatively, incremental PD could potentially contribute to reduced small solute clearance, fluid overload, or patient reluctance to increase dialysis prescription when later needed. This review discusses the definition, rationale, uptake, potential advantages and disadvantages, and clinical trial evidence pertaining to the use of incremental PD.

Patient-centred approaches for the management of unpleasant symptoms in kidney disease

Patients with chronic kidney disease (CKD) frequently experience unpleasant symptoms. These can be gastrointestinal (constipation, nausea, vomiting and diarrhoea), psychological (anxiety and sadness), neurological (lightheadedness, headache and numbness), cardiopulmonary (shortness of breath and oedema), dermatological (pruritus and dry skin), painful (muscle cramps, chest pain and abdominal pain) or involve sexual dysfunction, sleep disorders and fatigue. These symptoms often occur in clusters, with one of them as the lead symptom and others as secondary symptoms. Uraemic toxins (also called uremic toxins) are often considered to be the main cause of CKD-associated symptom burden, but treatment of uraemia by dialysis often fails to resolve them and can engender additional symptoms. Indeed, symptoms can be exacerbated by comorbid conditions, pharmacotherapies, lifestyle and dietary regimens, kidney replacement therapy and ageing. Patients with kidney disease, including those who depend on dialysis or transplantation, should feel actively supported in their symptom management through the identification and targeting of unpleasant symptoms via a tailored palliative care approach. Such an approach may help minimize the burden and consequences of kidney disease, and lead to improved patient outcomes including health-related quality of life and better life participation.

Benefits of Incremental Hemodialysis Seen in a Historical Cohort Study

Purpose

Previous research on incremental hemodialysis transition has mainly focused on one or two benefits or prognoses. We aimed to conduct a comprehensive analysis by investigating whether incremental hemodialysis was simultaneously associated with adequate dialysis therapy, stable complication indicators, long-lasting arteriovenous vascular access, and long-lasting preservation of residual kidney function (RKF) without increasing mortality or hospitalization.

Patients and Methods

Incident hemodialysis patients from Huashan Hospital in Shanghai, China, over the period of 2012 to 2019, were enrolled and followed every three months until death or the time of censoring. Changes in complication indicators from baseline to all post-baseline visits were analyzed by mixed-effects models. The outcomes of RKF loss, arteriovenous vascular access complications, and the composite of all-cause mortality and cardiovascular events were compared between incremental and conventional hemodialysis by Cox proportional hazards model.

Results

Of the 113 patients enrolled in the study, 45 underwent incremental and 68 conventional hemodialysis. There were no significant differences in the changes from baseline to post-baseline visits in complication indicators between the two groups. Incremental hemodialysis reduced the risks of RKF loss (HR, 0.33; 95% CI, 0.14–0.82), de novo arteriovenous access complication (HR, 0.26; 95% CI, 0.08–0.82), and recurrent arteriovenous access complications under the Andersen–Gill (AG) model (HR, 0.27; 95% CI, 0.10–0.74) and the Prentice, Williams and Peterson Total Time (PWP-TT) model (HR, 0.31; 95% CI, 0.12–0.80). There were no significant differences in all-cause hospitalization or the composite outcome between groups.

Conclusion

Incremental hemodialysis is an effective dialysis transition strategy that preserves RKF and arteriovenous access without affecting dialysis adequacy, patient stability, hospitalization risk and mortality risk. Randomized controlled trials are warranted.

Toward an individualized determination of dialysis adequacy: a narrative review with special emphasis on incremental hemodialysis

INTRODUCTION

The search for the 'perfect' renal replacement therapy has been paralleled by the search for the perfect biomarkers for assessing dialysis adequacy. Three main families of markers have been assessed: small molecules (prototype: urea); middle molecules (prototype β2-microglobulin); comprehensive and nutritional markers (prototype of the simplified assessment, albumin levels; composite indexes as malnutrition-inflammation score). After an era of standardization of dialysis treatment, personalized dialysis schedules are increasingly proposed, challenging the dogma of thrice-weekly hemodialysis.

AREAS COVERED

In this review, we describe the advantages and limitations of the approaches mentioned above, focusing on the open questions regarding personalized schedules and incremental hemodialysis.

EXPERT OPINION

In the era of personalized dialysis, the assessment of dialysis adequacy should be likewise personalized, due to the limits of 'one size fits all' approaches. We have tried to summarize some of the relevant issues regarding the determination of dialysis adequacy, attempting to adapt them to an elderly, highly comorbidity population, which would probably benefit from tailor-made dialysis prescriptions. While no single biomarker allows precisely tailoring the dialysis dose, we suggest using a combination of clinical and biological markers to prescribe dialysis according to comorbidity, life expectancy, residual kidney function, and small and medium-size molecule depuration.

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.

Age, Gender and Diabetes as Risk Factors for Early Mortality in Dialysis Patients: A Systematic Review

Objective: To study the impact of age, gender, and presence of diabetes (any type) on the risk of early deaths (180-day mortality) in patients starting long-term hemodialysis (HD) therapy.Design: Systematic review of the literature.Setting: Out-patient (non-hospitalized), community-based HD therapy world-wide.Participants: Patients with advanced chronic kidney disease (CKD) starting long-term HD treatment for end-stage renal disease (ESRD).Methods: Medline and EMBASE were searched for studies published between 1/1/1985 and 12/31/2017. Observational studies involving adult subjects commencing HD were included. Data extracted included population characteristics and settings. In addition, patient or treatment related factors studied with reference to their relationship with the risk of early mortality were documented. The Quality in Prognosis Studies tool was used to assess risk of bias in individual studies. Findings were summarized, and a narrative account was drawn.Results: Included were 26 studies (combined population 1,098,769; representing 287,085 person-years of observation for early mortality). There were 17 cohort and 9 case-control studies. Risk of bias was low in 13 and high in a further 13 studies. Patients who died in the early period were older than those who survived. Mortality rates increased with advancing age. Female gender was associated with slightly increased early mortality rates in larger and higher quality studies. The available data showed conflicting results in relation to the association of diabetes and risk of early mortality.Conclusions: This systematic review evaluated the impact of key demographic and co-morbid factors on risk of early mortality in patients starting maintenance HD. The information could help in delivering more tailored prognostic information and planning of future interventions.

Routine assessment of kidney urea clearance, dialysis dose and protein catabolic rate in the once-weekly haemodialysis regimen

BACKGROUND

The dialysis dose (Kt/V) and normalized protein catabolic rate (PCRn) are the most useful indices derived from the urea kinetic model (UKM) in haemodialysis (HD) patients. The kidney urea clearance (Kru) is another important UKM parameter which plays a key role in the prescription of incremental HD. Ideally, the three kinetic parameters should be assessed using the complex software Solute Solver based on the double pool UKM. In the clinical setting, however, the three indices are estimated with simplified formulae. The recently introduced software SPEEDY assembles the aforementioned equations in a plain spreadsheet, to produce quite accurate results of Kru, Kt/V and PCRn. Unfortunately, specific equations to compute Kt/V and PCRn for patients on a once-weekly HD regimen (1HD/wk) were not available at the time SPEEDY was built-up. We devised a new version of SPEEDY (SPEEDY-1) and an even simpler variant (SPEEDY-1S), using two recently published equations for the 1HD/wk schedule . Moreover, we also added a published equation to estimate the equivalent renal clearance (EKR) normalized to urea distribution volume (V) of 35 L (EKR₃₅) from Kru and Kt/V . Aim of the present study was to compare the results obtained using the new methods (SPEEDY-1 and SPEEDY-1S) with those provided by the reference method Solute Solver.

SUBJECTS AND METHODS

One hundred historical patients being treated with the once-weekly HD regimen were enrolled. A total of 500 HD sessions associated to the availability of monthly UKM studies were analysed in order to obtain Kru, single pool Kt/V (spKt/V), equilibrated Kt/V (eKt/V), V, PCRn and EKR₃₅ values by using Solute Solver, SPEEDY-1 and SPEEDY-1S.

RESULTS

When comparing the paired values of the above UKM parameters, as computed by SPEEDY-1 and Solute Solver, respectively, all differences but one were statistically significant at the one-sample t-test; however, the agreement limits at Bland-Altman analysis showed that all differences were negligible. When comparing the paired values of the above UKM parameters, as computed by SPEEDY-1S and Solute Solver, respectively, all differences were statistically significant; however, the agreement limits showed that the differences were negligible as far as Kru, spKt/V and eKt/V are concerned, though much larger regarding V, PCRn and EKR₃₅.

CONCLUSIONS

We implemented SPEEDY with a new version specific for the once-weekly HD regimen, SPEEDY-1. It provides accurate results and is presently the best alternative to Solute Solver. Using SPEEDY-1S led to a larger difference in PCRn and EKR₃₅, which could be acceptable for clinical practice if SPEEDY-1 is not available.

Lowering dialysis sessions duration may be dangerous

Dialysis session in less duration - either to give a better quality of life for the patient or to optimize the organization the dialysis institution - may have bad repercussions on the quality of the treatment and therefore the quality of life of the patient. According to the result of the publications listed in this work, we conclude that it is necessary to perform either longer sessions or more frequent treatments to limit the interval time between two sessions. As this is difficult to perform by the providers, we recommend to develop home dialysis to obtain the best result.

Predictive modeling of blood pressure during hemodialysis: a comparison of linear model, random forest, support vector regression, XGBoost, LASSO regression and ensemble method

BACKGROUND

Intradialytic hypotension (IDH) is commonly occurred and links to higher mortality among patients undergoing hemodialysis (HD). Its early prediction and prevention will dramatically improve the quality of life. However, predicting the occurrence of IDH clinically is not simple. The aims of this study are to develop an intelligent system with capability of predicting blood pressure (BP) during HD, and to further compare different machine learning algorithms for next systolic BP (SBP) prediction.

METHODS

This study presented comprehensive comparisons among linear regression model, least absolute shrinkage and selection operator (LASSO), tree-based ensemble machine learning models (random forest [RF] and extreme gradient boosting [XGBoost]), and support vector regression to predict the BP during HD treatment based on 200 and 48 maintenance HD patients containing a total of 7,180 and 2,065 BP records for the training and test dataset, respectively. Ensemble method also was computed to obtain better predictive performance. We compared the developed models based on R², root mean square error (RMSE) and mean absolute error (MAE).

RESULTS

We found that RF (R²=0.95, RMSE=6.64, MAE=4.90) and XGBoost (R²=1.00, RMSE=1.83, MAE=1.29) had comparable predictive performance on the training dataset. However, RF (R²=0.49, RMSE=16.24, MAE=12.14) had more accurate than XGBoost (R²=0.41, RMSE=17.65, MAE=13.47) on testing dataset. Among these models, the ensemble method (R²=0.50, RMSE=16.01, MAE=11.97) had the best performance on testing dataset for next SBP prediction.

CONCLUSIONS

We compared five machine learning and an ensemble method for next SBP prediction. Among all studied algorithms, the RF and the ensemble method have the better predictive performance. The prediction models using ensemble method for intradialytic BP profiling may be able to assist the HD staff or physicians in individualized care and prompt intervention for patients' safety and improve care of HD patients.

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.

Aspectos clave en el mantenimiento de la diuresis residual en pauta de hemodiálisis incremental. Experiencia de diez años

Introducción: La hemodiálisis incremental o progresiva es una modalidad de inicio de hemodiálisis, basada en la diuresis residual y adaptada a las necesidades del paciente, poco extendida pese a sus potenciales beneficios. Para su correcto seguimiento es necesario establecer unas pautas específicas en cada sesión de hemodiálisis, que deben ser conocidas por el personal que atiende a estos pacientes de forma regular. Objetivo: analizar la evolución de los pacientes que han iniciado tratamiento renal sustitutivo con hemodiálisis incremental. Material y Método: Estudio observacional retrospectivo de pacientes incidentes en tratamiento renal sustitutivo mediante hemodiálisis incremental en nuestro centro en los últimos 10 años. Comparación de resultados basales y a los 12 meses de seguimiento. Resultados: En este periodo de tiempo se han incluido 49 pacientes en técnica de hemodiálisis incremental. Aunque la diuresis residual desciende en el primer año de 2030±600 ml/día a 1300±500 (p<0,05), ésta se mantiene por encima de un litro en la mayoría de los casos. El aclaramiento de urea también desciende de 5,7±1,6 ml/min a 3,4±1,6 ml/min al año (p<0,05). Conclusiones: Iniciar tratamiento renal sustitutivo con hemodiálisis incremental puede mantener más tiempo la diuresis residual, para eso es clave el conocimiento de la técnica y su correcto manejo durante las sesiones de diálisis.

Initiating haemodialysis twice-weekly as part of an incremental programme may protect residual kidney function

BACKGROUND

Initiating twice-weekly haemodialysis (2×HD) in patients who retain significant residual kidney function (RKF) may have benefits. We aimed to determine differences between patients initiated on twice- and thrice-weekly regimes, with respect to loss of kidney function, survival and other safety parameters.

METHODS

We conducted a single-centre retrospective study of patients initiating dialysis with a residual urea clearance (KRU) of ≥3 mL/min, over a 20-year period. Patients who had 2×HD for ≥3 months during the 12 months following initiation of 2×HD were identified for comparison with those dialysed thrice-weekly (3×HD).

RESULTS

The 2×HD group consisted of 154 patients, and the 3×HD group 411 patients. The 2×HD patients were younger (59 ± 15 versus 62 ± 15 years: P = 0.014) and weighed less (70 ± 16 versus 80 ± 18 kg: P < 0.001). More were females (34% versus 27%: P = 0.004). Fewer had diabetes (25% versus 34%: P = 0.04) and peripheral vascular disease (PVD) (13% versus 23%: P = 0.008). Baseline KRU was similar in both groups (5.3 ± 2.4 for 2 × HD versus 5.1 ± 2.8 mL/min for 3 × HD: P = 0.507). In a mixed effects model correcting for between-group differences in comorbidities and demographics, 3×HD was associated with increased rate of loss of KRU and separation of KRU. In separate mixed effects models, group (2×HD versus 3×HD) was not associated with differences in serum potassium or phosphate, and the groups did not differ with respect to total standard Kt/V. Survival, adjusted for age, gender, weight, baseline KRU and comorbidity (prevalence of diabetes, cardiac disease, PVD and malignancy) was greater in the 2×HD group (hazard ratio 0.755: P = 0.044). In sub-analyses, the survival benefit was confined to women, and those of less than median bodyweight.

CONCLUSION

2×HD initiation as part of an incremental programme with regular monthly monitoring of KRU was safe and associated with a reduced rate of loss of RKF early after dialysis initiation and improved survival. Randomized controlled trials of this approach are indicated.

Initiating renal replacement therapy through incremental haemodialysis: Protocol for a randomized multicentre clinical trial

Background

Thrice-weekly haemodialysis is the usual dose when starting renal replacement therapy; however, this schedule is no longer appropriate since it does not consider residual renal function. Several reports have suggested the potential benefit of beginning haemodialysis less frequently and incrementally increasing the dose as the residual renal function decreases. However, all the data published so far are from observational studies. Thus, this clinical trial avoids any potential selection bias and will assess the possible benefits that have been observed in observational studies.

Methods/design

This report describes the study protocol of a randomized prospective multi-centre open-label clinical trial to evaluate whether starting renal replacement therapy with twice-weekly haemodialysis sessions preserves residual renal function better than the standard thrice-weekly regimen. We also explore other clinical parameters, such as concentrations of uremic toxins, dialysis doses, control of anaemia, removal of medium-weight uremic toxins, nutritional status, quality of life, hospital admissions and mortality. Only incident haemodialysis patients who can maintain a urea clearance rate KrU ≥ 2.5 mL/min/1.73 m² are eligible. Patient recruitment began on 1 January 2017 and will last for 2 years or until the required sample size has been recruited to ensure the established statistical power has been reached. The minimum follow-up period will be 1 year. Anuric patients with acute renal failure and patients who return to haemodialysis after a kidney transplant failure are excluded. It has been calculated that 44 patients should be recruited into each group to achieve a power of 80% in a two-sided comparison of means with a usual significance level of 0.05. A time-to-event analysis will estimate the probability of kidney function survival in both groups using the Kaplan–Meier method. Survival curves will be compared with log-rank tests. This survival analysis will be complemented with a proportional hazard model to estimate the hazard ratio of kidney function survival adjusted for any confounding factors. Analyses will be carried out in accordance with the intention-to-treat principle.

Discussion

The incremental initiation of dialysis may preserve residual renal function better than the conventional treatment, with similar or higher survival rates, as reported by observational studies. To our knowledge, this is the first clinical trial to evaluate whether initiating renal replacement therapy with twice-weekly haemodialysis sessions preserves residual renal function better than beginning with the standard thrice-weekly regimen.

Trial registration

ClinicalTrials.gov, NCT03302546. Registered on 5 October 2017.

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.

Predicting Residual Function in Hemodialysis and Hemodiafiltration-A Population Kinetic, Decision Analytic Approach

In this study, we introduce a novel framework for the estimation of residual renal function (RRF), based on the population compartmental kinetic behavior of beta 2 microglobulin (B2M) and its dialytic removal. Using this model, we simulated a large cohort of patients with various levels of RRF receiving either conventional high-flux hemodialysis or on-line hemodiafiltration. These simulations were used to estimate a novel population kinetic (PK) equation for RRF (PK-RRF) that was validated in an external public dataset of real patients. We assessed the performance of the resulting equation(s) against their ability to estimate urea clearance using cross-validation. Our equations were derived entirely from computer simulations and advanced statistical modeling and had extremely high discrimination (Area Under the Curve, AUC 0.888–0.909) when applied to a human dataset of measurements of RRF. A clearance-based equation that utilized predialysis and postdialysis B2M measurements, patient weight, treatment duration and ultrafiltration had higher discrimination than an equation previously derived in humans. Furthermore, the derived equations appeared to have higher clinical usefulness as assessed by Decision Curve Analysis, potentially supporting decisions for individualizing dialysis prescriptions in patients with preserved RRF.

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.

Incremental hemodialysis, a valuable option for the frail elderly patient

Management of older people on dialysis requires focus on the wider aspects of aging as well as dialysis. Recognition and assessment of frailty is vital in changing our approach in elderly patients. Current guidelines in dialysis have a limited evidence base across all age group, but particularly the elderly. We need to focus on new priorities of care when we design guidelines "for people not diseases". Patient-centered goal-directed therapy, arising from shared decision-making between physician and patient, should allow adaption of the dialysis regime. Hemodialysis (HD) in the older age group can be complicated by intradialytic hypotension, prolonged time to recovery, and access-related problems. There is increasing evidence relating to the harm associated with the delivery of standard thrice-weekly HD. Incremental HD has a lower burden of treatment. There appears to be no adverse clinical effects during the first years of dialysis in presence of a significant residual kidney function. The advantages of incremental HD might be particularly important for elderly patients with short life expectancy. There is a need for more research into specific topics such as the assessment of the course of frailty with progression of chronic kidney disease and after dialysis initiation, the choice of dialysis modality impacting on the trajectory of frailty, the timing of dialysis initiation impacting on frailty or on other outcomes. In conclusion, understanding each individual's goals of care in the context of his or her life experience is particularly important in the elderly, when overall life expectancy is relatively short, and life experience or quality of life may be the priority.

IHDIP: a controlled randomized trial to assess the security and effectiveness of the incremental hemodialysis in incident patients

BACKGROUND

Most people who make the transition to renal replacement therapy (RRT) are treated with a fixed dose thrice-weekly hemodialysis réegimen, without considering their residual kidney function (RKF). Recent papers inform us that incremental hemodialysis is associated with preservation of RKF, whenever compared with conventional hemodialysis. The objective of the present controlled randomized trial (RCT) is to determine if start HD with one sessions per week (1-Wk/HD), it is associated with better patient survival and other safety parameters.

METHODS/DESIGN

IHDIP is a multicenter RCT experimental open trial. It is randomized in a 1:1 ratio and controlled through usual clinical practice, with a low intervention level and non-commercial. It includes 152 incident patients older than 18 years, with a RRF of ≥4 ml/min/1.73 m2, measured by renal clearance of urea (KrU). The intervention group includes 76 patients who will start with incremental HD (1-Wk/HD). The control group includes 76 patients who will start with thrice-weekly hemodialysis régimen. The primary outcome is assessing the survival rate, while the secondary outcomes are the morbidity rate, the clinical parameters, the quality of life and the efficiency.

DISCUSSION

This study will enable to know the number of sessions a patient should receive when starting HD, depending on his RRF. The potentially important clinical and financial implications of incremental hemodialysis warrant this RCT.

TRIAL REGISTRATION

U.S. National Institutes of Health, ClinicalTrials.gov . Number: NCT03239808 , completed 13/04/2017.

SPONSOR

Foundation for Training and Research of Health Professionals of Extremadura.

Residual renal function in incremental dialysis

Incremental haemodialysis has the potential to allow better preservation of renal function, is less invasive to the patient and has lower cost. Despite these advantages, it is not commonly applied. This may be due to uncertainty about how to account for renal function in the prescription of dialysis and measurement of dose. In this issue, Vartia describes the practical basis for including the effect of renal function in the prescription and quantification of dialysis. He uses a well-known and validated urea kinetic model to calculate time average urea concentrations and the equivalent renal clearance (EKR) from dialysis. The effect of renal function is amplified by a weighting factor to account for the relatively greater effect of renal function compared with dialysis with the same urea clearance. In that way, patients on differing dialysis regimens can be dialysed with the same target dose. A further step would be to use a downward adjusting factor for dialysis to convert the urea clearance by dialysis (as EKR) to a glomerular filtration rate (GFR) equivalent. A factor of 0.75 is suggested. In that way, dialysis dose can be reported as GFR equivalent in mL/min/1.73 m2, comparable between different types of dialysis and also to renal function without dialysis.

Rationale and design of DiPPI: A randomized controlled trial to evaluate the safety and effectiveness of progressive hemodialysis in incident patients

INTRODUCTION

Progressive haemodialysis (HD) is a starting regime for renal replacement therapy (RRT) adapted to each patient's necessities. It is mainly conditioned by the residual renal function (RRF). The frequency of sessions with which patients start HD (one or two sessions per week), is lower than that for conventional HD (three times per week). Such frequency is increased (from one to two sessions, and from two to three sessions) as the RRF declines.

METHODOLOGY/DESIGN

IHDIP is a multicentre randomised experimental open trial. It is randomised in a 1:1 ratio and controlled through usual clinical practice, with a low intervention level and non-commercial. It includes 152 patients older than 18 years with chronic renal disease stage 5 and start HD as RRT, with an RRF of ≥4ml/min/1.73m², measured by renal clearance of urea (KrU). The intervention group includes 76 patients who will start with one session of HD per week (progressive HD). The control group includes 76 patients who will start with three sessions per week (conventional HD). The primary purpose is assessing the survival rate, while the secondary purposes are the morbidity rate (hospital admissions), the clinical parameters, the quality of life and the efficiency.

DISCUSSION

This study will enable us to know, with the highest level of scientific evidence, the number of sessions a patient should receive when starting the HD treatment, depending on his/her RRF.

TRIAL REGISTRATION

Registered at the U.S. National Institutes of Health, ClinicalTrials.gov under the number NCT03239808.

Conventional dialysis in the elderly: How lenient should our guidelines be?

There has been a dramatic, worldwide expansion in life expectancy across the last century. This has resulted in a progressively more elderly and comorbid population. It is increasingly recognized that healthcare in this group needs to move to the concept of "adding life to years". Recognition and assessment of frailty is vital in changing our approach in elderly patients. Current guidelines in dialysis have a limited evidence base across all age groups, but particularly the elderly and serve them poorly. Moreover, the burden of guidelines for each comorbidity of the multimorbid patient is increasing and can be conflicting. Finally, there is increasing evidence relating to the harm associated with the delivery of conventional dialysis. In dialysis patients, frailty is the overwhelming determinant in relation to patient-specific outcomes rather than modality of treatment; therefore, the focus should be on promoting quality of life. We need to focus on new priorities of care when we design guidelines "for people not diseases". Patient-centered goal-directed therapy, arising from shared decision making between physician and patient, should allow adaption of the dialysis regime to maximize opportunities while minimizing treatment-related morbidity and concentrating on alleviating symptoms.

Measuring residual renal function for hemodialysis adequacy: Is there an easier option?

Most patients starting hemodialysis (HD) have residual renal function. As such, there has been increased interest in starting patients with less frequent and shorter dialysis session times. However, for this incremental approach to be successful, patients require regular monitoring of residual renal function, so that as residual renal function declines, the amount of HD is appropriately increased. Currently most dialysis centers rely on interdialytic urine collections. However, many patients find these inconvenient and there may be marked intrapatient variability due to compliance issues. Thus, alternative markers of residual renal function are required for routine clinical practice. Currently three middle sized molecules; cystatin C, β2 microglobulin, and βtrace protein have been investigated as potential endogenous markers of glomerular filtration. Although none is ideal, combinations of these markers have been proposed to provide a more accurate estimation of glomerular clearance, and in particular cut offs for minimal residual renal function. However, in patients with low levels of residual renal function it remains unclear as to whether the benefits of residual renal function equally apply to glomerular filtration or tubular function.

Intradialytic hypotension

PURPOSE OF REVIEW

This review focuses on recent advances in our understanding of intradialytic hypotension (IDH) and measures that may reduce its frequency.

RECENT FINDINGS

The frequency and severity of IDH predict the risk for adverse clinical outcomes. The highest mortality risks associated with IDH were observed when the intradialytic systolic blood pressure (SBP) nadirs were <90 and <100 mmHg and the predialysis SBP were ≤159 mmHg or ≥160 mmHg, respectively. Interdialytic weight gain (IDWG) ≥3 kg occurs more frequently among patients with IDH. Prolonged and possibly more frequent dialysis, use of biofeedback devices, dialysate cooling and limiting sodium loading are useful measures to reduce the frequency of IDH.

SUMMARY

Frequent IDH is associated with high IDWGs and a poor prognosis. Studies on prolonged dialysis, biofeedback devices and cooled dialysate have yielded promising results. Intradialytic relative blood volume monitoring devices have been investigated in preventing IDH but results are mixed. Administration of a sodium/hydrogen exchange isoform 3 inhibitor increases stool sodium but has not been shown to decrease IDWG. IDH continues to be a significant dialysis complication deserving of further investigation.

Pathogenesis and treatment of ANCA-associated vasculitis-a role for complement

The antineutrophil cytoplasm autoantibody (ANCA)-associated vasculitides (AAV), although rare in childhood, can have devastating effects on affected organs, especially the kidney. In this review we present an update on the pathogenesis and treatment of ANCA vasculitis, with a particular emphasis on the role of the alternative pathway of complement. The rationale and evidence for the current treatment strategies are summarized. Targeting the activation of neutrophils by the anaphylatoxin C5a may serve as an additional therapeutic strategy, however the results of clinical studies are awaited.

Plasma Beta-Trace Protein as a Marker of Residual Renal Function: The Effect of Different Hemodialysis Modalities and Intra-Individual Variability over Time

BACKGROUND/AIMS

Beta-trace protein (BTP) is a low-molecular-weight molecule, which may be used to assess residual renal function (RRF) in dialysis patients. Here we evaluated the influence of hemodialysis (HD) and hemodiafiltration (HDF) on plasma BTP, and analyzed the inter- and intra-individual variability of plasma BTP over time in HD and peritoneal dialysis (PD) patients.

METHODS

In 12 prevalent HD patients, the effect of a single session of low-flux HD, high-flux HD and HDF on plasma BTP was studied. Blood samples were taken at baseline, after 120 and 240 minutes, and at the start of the next dialysis session. In 13 HD patients and 10 PD patients, inter- and intra-individual variability over three months was studied (monthly and weekly, respectively). Plasma BTP was measured using a nephelometric method.

RESULTS

No significant decrease in plasma BTP was seen following a session of low-flux HD. Both high-flux HD and HDF resulted in a significant decrease immediately after dialysis (22% and 61% median decrease, respectively). A significant reduction of the molecule persisted only in HDF and a significant decrease (-15%) was still found immediately before the start of the next dialysis session. In both HD and PD patients, the reproducibility over time was excellent with intra-class correlation coefficient of 0.96 (0.93-0.99) and 0.92 (0.86-0.99) respectively. In a small cohort of PD patients, fair agreement existed between mGFR (average of renal urea and creatinine clearance from a 24 hours urine collection) and the BTP-based GFR estimation.

CONCLUSION

BTP is a stable marker and a promising tool for RRF estimations in PD and HD patients. In patients receiving HDF, plasma levels of BTP should be interpreted with caution.

Feasibility of Incremental 2-Times Weekly Hemodialysis in Incident Patients With Residual Kidney Function

INTRODUCTION

We hypothesized that at least half of incident hemodialysis (HD) patients on 3-times weekly dialysis could safely start on an incremental, 2-times weekly HD schedule if residual kidney function (RKF) had been considered.

METHODS

RKF is assessed in all our HD patients. This single-center, retrospective cohort study of incident adult HD patients, who survived ≥6 months on a 3-times weekly HD regimen and had a timed urine collection within 3 months of starting HD, assessed each patient's theoretical ability to achieve adequate urea clearance, ultrafiltration rate, and hemodynamic stability if on 2-times weekly HD.

RESULTS

Of the 410 patients in the cohort, we found that 112 (27%) could have optimally and 107 (26%) could have been appropriately considered for 2-times weekly incremental HD. In general, diuretics were underutilized in >50% of subjects who had adequate RKF urea clearance. The optimal 2-times weekly patients had better potassium and phosphorus control. The correlation coefficient of calculated residual kidney urea clearance with 24-hour urine volume and with kinetic model residual kidney clearance was 0.68 and 0.99, respectively.

DISCUSSION

More than 50% of incident HD patients with RKF have adequate kidney urea clearance to be considered for 2-times weekly HD. When additionally ultrafiltration volume and blood pressure stability are taken into account, more than one-fourth of the total cohort could optimally start HD in an incremental fashion.

The ESRD Quality Incentive Program-Can We Bridge the Chasm?

The ESRD Quality Incentive Program (QIP) is the first mandatory federal pay for performance program launched on January 1, 2012. The QIP is tied to the ESRD prospective payment system and mandated by the Medicare Improvements for Patients and Providers Act of 2008, which directed the Centers for Medicare and Medicaid Services to expand the payment bundle for renal dialysis services and legislated that payment be tied to quality measures. The QIP links 2% of the payment that a dialysis facility receives for Medicare patients on dialysis to the facility's performance on quality of care measures. Quality measures are evaluated annually for inclusion on the basis of importance, validity, and performance gap. Other quality assessment programs overlap with the QIP; all have substantial effects on provision of care as clinicians, patients, regulators, and dialysis organizations scramble to keep up with the frequent release of wide-ranging regulations. In this review, we provide an overview of quality assessment and quality measures, focusing on the ESRD QIP, its effect on care, and its potential future directions. We conclude that a patient-centered, individualized, and parsimonious approach to quality assessment needs to be maintained to allow the nephrology community to further bridge the quality chasm in dialysis care.

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.