The intact nephron hypothesis in reverse: an argument to support incremental dialysis

Five Things to Know About Incremental Peritoneal Dialysis

Incremental peritoneal dialysis (PD) offers patients newly starting dialysis less than the standard "full dose" of PD, reducing treatment burden and intrusiveness while minimizing symptoms of renal failure. Incremental PD is a cost-effective approach that has been associated with slower rates of decline in residual kidney function. This approach also produces less waste and in turn reduces environmental footprint compared to standard PD prescriptions. It also aligns with the International Society of Peritoneal Dialysis (ISPD) Practice Recommendations for high-quality, goal-oriented therapy. Awareness of incremental PD along with its advantages and limitations provides practitioners with the tools to provide more patient-centered dialysis prescriptions in appropriate populations.

Incremental peritoneal dialysis allows to reduce the time spent for dialysis, glucose exposure, economic cost, plastic waste and water consumption

BACKGROUND

Incremental peritoneal dialysis (incPD) as the initial PD strategy represents a convenient and resource-sparing approach, but its impact on patient, healthcare and environment has not been thoroughly evaluated.

METHODS

This study includes 147 patients who started incPD at our institution between 1st January, 2009 and 31st December, 2021. Adequacy measures, peritoneal permeability parameters, peritonitis episodes, hospitalizations and increase in CAPD dose prescriptions were recorded. The savings related to cost, patient glucose exposure, time needed to perform dialysis, plastic waste, and water usage were compared to full-dose PD treatment.

RESULTS

During the study follow-up 11.9% of the patients transitioned from incremental to full dose PD. Patient cumulative probability of remaining on PD at 12, 24, 36, 48 and 60 months was 87.6, 65.4, 46.1, 30.1 and 17.5%, respectively. The median transition time from 1 to 2 exchanges, from 2 to 3 and 3 to 4 exchanges were 5, 9 and 11.8 months, respectively. Compared to full dose PD, 1, 2, and 3 exchanges per day led to reduction in glucose exposure of 20.4, 14.8 or 8.3 kg/patient-year, free lifetime gain of 18.1, 13.1 or 7.4 day/patient-year, a decrease in cost of 8700, 6300 or 3540 €/patient-year, a reduction in plastic waste of 139.2, 100.8 or 56.6 kg/patient-year, and a decline in water use of 25,056, 18,144 or 10,196 L/patient-year.

CONCLUSIONS

In comparison with full-dose PD, incPD allows to reduce the time spent for managing dialysis, glucose exposure, economic cost, plastic waste, and water consumption.

Incremental Peritoneal Dialysis-Definition, Prescription, and Clinical Outcomes

ABSTRACT

Incremental peritoneal dialysis (IPD) is a strategy of RRT that is based on the prescription of a lower dose rather than the standard full dose of peritoneal dialysis (PD). The clearance goals are achieved through the combination of residual kidney function (RKF) and peritoneal clearance. The dialysis prescription should be increased as the RKF declines. IPD has been associated with clinical, economic, and environmental advantages. We emphasize possible better quality of life, fewer mechanical symptoms, lower costs, slight adverse metabolic effects, and less plastic waste and water consumption. The potential benefits for RKF preservation and the lower risk of peritonitis have also been discussed. There are some concerns regarding this strategy, such as inadequate clearance of uremic toxins and/or severe electrolyte disturbances due to undetected loss of RKF, lower clearance of medium-sized molecules (such as β-2-microglobulin) which mostly depends on the total PD dwell time, and patients' reluctance to dose adjustments. Current clinical evidence is based on moderate-quality to low-quality studies and suggests that the outcomes of IPD will be at least identical to those of full dose. This review aims to define IDP, discuss strategies for prescription, and review its advantages and disadvantages according to the current evidence.

On the importance of the interplay of residual renal function with clinical outcomes in end-stage kidney disease

Chronic kidney disease (CKD) is one of the most important public health concerns of the century, and is associated with high rates of morbidity, mortality and social costs. CKD evolving towards end-stage kidney disease (ESKD) is on the rise resulting in a greater number of patients requiring peritoneal dialysis (PD) and hemodialysis (HD). The aim of this manuscript is to review the current literature on the interplay of residual renal function (RRF) with clinical outcomes in ESKD. The persistence of RRF is one of the most important predictors of decreased morbidity, mortality, and better quality of life in both PD and HD patients. RRF contributes to the well-being of ESKD patients through various mechanisms including higher clearance of solutes, maintenance of fluid balance, removal of uremic toxins and control of electrolytes. Furthermore, RRF has beneficial effects on inflammation, anemia, malnutrition, diabetes mellitus, obesity, changes in the microbiota, and cardiac diseases. Several strategies have been proposed to preserve RRF, such as blockade of the renin-angiotensin-aldosterone system, better blood pressure control, incremental PD and HD. Several clinical trials investigating the issue of preservation of RRF are ongoing. They are needed to broaden our understanding of the interplay of RRF with clinical outcomes in ESKD.

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.

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.

Setting Up and Expanding a Home Dialysis Program: Is There a Recipe for Success?

Home dialysis modalities remain significantly underused in the United States despite similar overall survival in the modalities, and recent incentives to expand these modalities. Although the absolute number of patients using home modalities has grown, the proportion compared to in-center hemodialysis (ICHD) continues to remain quite low. Well known barriers to home dialysis utilization exist, and an organized and team-based approach is required to overcome these barriers. Herein, we describe our efforts at growing our home dialysis program at a large academic medical center, with the proportion of home dialysis patients growing from 12% to 21% over the past 9 years. We prioritized individualized education for patients and better training for physicians, with the help of existing resources, aimed at better utilization of home modalities; an example includes dedicated dialysis education classes taught twice monthly by an experienced nurse practitioner, as well as the utilization of the dialysis educator from a dialysis provider for inpatient education of patients with CKD. The nephrology fellowship curriculum was restructured with emphasis on home modalities, and participation in annual home dialysis conferences has been encouraged. For timely placement and troubleshooting of access for dialysis, we followed a complementary team approach using surgeons and interventional radiologists and nephrologists, driven by a standardized protocol developed at UAB, and comanaged by our access coordinators. A team-based approach, with emphasis on staff engagement and leadership opportunities for dialysis nurses as well as collaborative efforts from a team of clinical nephrologists and the dialysis provider helped maintain efficiency, kindle growth, and provide consistently high-quality clinical care in the home program. Lastly, efforts at reducing burden of disease such as decreased number of monthly visits as well as using innovative strategies, such as telenephrology and assisted PD and HHD, were instrumental in reducing attrition.

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.

How to set the stage for a full-fledged clinical trial testing 'incremental haemodialysis'

Most people who make the transition to maintenance haemodialysis (HD) therapy are treated with a fixed dose of thrice-weekly HD (3HD/week) regimen without consideration of their residual kidney function (RKF). The RKF provides an 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. Its preservation is instrumental to the prescription of incremental (1HD/week to 2HD/week) HD. The recently heightened interest in incremental HD has been hindered by the current limitations of the urea kinetic model (UKM), which tend to overestimate the needed dialysis dose in the presence of a substantial RKF. A recent paper by Casino and Basile suggested a variable target model (VTM), which gives more clinical weight to the RKF and allows less frequent HD treatments at lower RKF as opposed to the fixed target model, based on the wrong concept of the clinical equivalence between renal and dialysis clearance. A randomized controlled trial (RCT) enrolling incident patients and comparing incremental HD (prescribed according to the VTM) with the standard 3HD/week schedule and focused on hard outcomes, such as survival and health-related quality of life of patients, is urgently needed. The first step in designing such a study is to compute the 'adequacy lines' and the associated fitting equations necessary for the most appropriate allocation of the patients in the two arms and their correct and safe follow-up. In conclusion, the potentially important clinical and financial implications of the incremental HD render it highly promising and warrant RCTs. The UKM is the keystone for conducting such studies.

Incremental Peritoneal Dialysis May be Beneficial for Preserving Residual Renal Function Compared to Full-dose Peritoneal Dialysis

Maintaining residual renal function (RRF) is a crucial issue in peritoneal dialysis (PD). Incremental dialysis is the practice of initiating PD exchanges less than four times a day in consideration of RRF, and increasing dialysis dose in a step-wise manner as the RRF decreases. We aimed to compare the outcomes of incremental PD and full-dose PD in terms of RRF preservation and other outcomes. This was a single-center, observational study. Data were extracted retrospectively from a cohort of incident PD patients over 16 years old who started PD between 2007 and 2015 in the PD Unit of Seoul National University Hospital. We used inverse probability weighting (IPW) adjustment based on propensity scores to balance covariates between the incremental and full-dose PD groups. Multivariate, time-dependent Cox analyses were performed. Among 347 incident PD patients, 176 underwent incremental PD and 171 underwent conventional full-dose PD. After IPW adjustment, the incremental PD group exhibited a lower risk of developing anuria (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.43–0.88). Patient survival, technique survival, and peritonitis-free survival were all similar between these groups (P > 0.05 by log-rank test). Incremental PD was beneficial for preserving RRF and showed similar patient survival when compared to conventional full-dose PD.

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.

Incremental short daily home hemodialysis: a case series

Background

Patients starting dialysis often have substantial residual kidney function. Incremental hemodialysis provides a hemodialysis prescription that supplements patients’ residual kidney function while maintaining total (residual + dialysis) urea clearance (standard Kt/Vurea) targets. We describe our experience with incremental hemodialysis in patients using NxStage System One for home hemodialysis.

Case presentation

From 2011 to 2015, we initiated 5 incident hemodialysis patients on an incremental home hemodialysis regimen. The biochemical parameters of all patients remained stable on the incremental hemodialysis regimen and they consistently achieved standard Kt/Vurea targets. Of the two patients with follow-up >6 months, residual kidney function was preserved for ≥2 years. Importantly, the patients were able to transition to home hemodialysis without automatically requiring 5 sessions per week at the outset and gradually increased the number of treatments and/or dialysate volume as the residual kidney function declined.

Conclusions

An incremental home hemodialysis regimen can be safely prescribed and may improve acceptability of home hemodialysis. Reducing hemodialysis frequency by even one treatment per week can reduce the number of fistula or graft cannulations or catheter connections by >100 per year, an important consideration for patient well-being, access longevity, and access-related infections. The incremental hemodialysis approach, supported by national guidelines, can be considered for all home hemodialysis patients with residual kidney function.

Measured Glomerular Filtration Rate at Dialysis Initiation and Clinical Outcomes of Indian Peritoneal Dialysis Patients

The optimal time for dialysis initiation remains controversial. Studies have failed to show better outcomes with early initiation of hemodialysis; even a few had shown increased adverse outcomes including poorer survival. Few studies have examined the same in patients on peritoneal dialysis (PD). Measured glomerular filtration rate (mGFR) not creatinine-based estimated GFR is recommended as the measure of kidney function in end-stage renal disease (ESRD) patients. The objective of this observational study was to compare the outcomes of Indian patients initiated on PD with different residual renal function (RRF) as measured by 24-h urinary clearance method. A total of 352 incident patients starting on chronic ambulatory PD as the first modality of renal replacement therapy were followed prospectively. Patients were categorized into three groups as per mGFR at the initiation of PD (≤5, >5-10, and >10 ml/min/1.73 m2). Patient survival and technique survival were compared among the three groups. Patients with GFR of ≤5 ml/min/1.73 m2 (hazard ratio [HR] - 3.42, 95% confidence interval [CI] - 1.85-6.30, P = 0.000) and >5-10 ml/min/1.73 m2 (HR - 2.16, 95% CI - 1.26-3.71, P = 0.005) had higher risk of mortality as compared to those with GFR of >10 ml/min/1.73 m2. Each increment of 1 ml/min/1.73 m2 in baseline GFR was associated with 10% reduced risk of death (HR - 0.90, 95% CI - 0.85-0.96, P = 0.002). Technique survival was poor in those with an initial mGFR of ≤5 ml/min/1.73 m2 as compared to other categories. RRF at the initiation was also an important factor predicting nutritional status at 1 year of follow-up. To conclude, initiation of PD at a lower baseline mGFR is associated with poorer patient and technique survival in Indian ESRD patients.

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.

Kinetic Modeling of Incremental Ambulatory Peritoneal Dialysis Exchanges

Background

Incremental peritoneal dialysis (PD), the gradual introduction of dialysate exchanges at less than full-dose therapy, has been infrequently described in clinical reports. One concern with less than full-dose dialysis is whether urea clearance targets are achievable with an incremental regimen. In this report, we used a large database of PD patients, across all membrane transport types, and performed urea kinetic modeling determinations of possible incremental regimens for an individual membrane type.

Methods

Using a modified 3-pore model of peritoneal transport, various incremental manual continuous ambulatory PD (CAPD) exchanges employing glucose and/or icodextrin were evaluated. Peritoneal urea clearances from those simulations were added to residual kidney urea clearance for patients with various glomerular filtration rates (GFRs), and the total weekly urea clearance was then compared to the total weekly urea Kt/V target of 1.7. All 4 peritoneal membrane types were modeled. For each simulated prescription, net ultrafiltration and carbohydrate absorption were also calculated.

Results

Incremental CAPD regimens of 2 exchanges a day met adequacy targets if the GFR was 6 mL/min/1.73 m2 in all membrane types. For regimens employing 3 exchanges a day, Kt/V targets were achieved at GFR levels of 4 to 5 mL/min/1.73 m2 in high transporters to low transporters but higher tonicity 2.5% glucose solutions or icodextrin were required in some regimens.

Conclusions

This work demonstrates that with incremental CAPD regimens, urea kinetic targets are achievable in most new starts to PD with residual kidney function. Incremental PD may be a less intrusive, better accepted initial treatment regime and a cost-effective way to initiate chronic dialysis in the incident patient. The key role of intrinsic kidney function in incremental regimens is highlighted in this analysis and would warrant conscientious monitoring.

Changing Landscape for Peritoneal Dialysis: Optimizing Utilization

The future growth of peritoneal dialysis (PD) will be directly linked to the shift in US healthcare to a value-based payment model due to PD's lower yearly cost, early survival advantage over in-center hemodialysis, and improved quality of life for patients treating their kidney disease in the home. Under this model, nephrology practices will need an increased focus on managing the transition from chronic kidney disease to end-stage renal disease (ESRD), providing patient education with the aim of accomplishing modality selection and access placement ahead of dialysis initiation. Physicians must expand their knowledge base in home therapies and work toward increased technique survival through implementation of specific practice initiatives that highlight PD catheter placement success, preservation of residual renal function, consideration of incremental PD, and competence in urgent start PD. Avoidance of both early and late PD technique failures is also critical to PD program growth. Large dialysis organizations must continue to measure and improve quality metrics for PD, expand their focus beyond the sole provision of PD to holistic patient care, and initiate programs to reduce PD hospitalization rates and encourage physicians to consider the benefits of PD as an initial modality for appropriate patients. New and innovative strategies are needed to address the main reasons for PD technique failure, improve the connectivity of the patient in the home, leverage home biometric data to improve overall outcomes, and develop PD cycler devices that lower patient treatment burden and reduce both treatment fatigue and treatment-dependent complications.

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.

Observations of twice a week hemodialysis

Incremental hemodialysis may offer substantial clinical, patient-centered, and cost benefits. In the largest and most rigorous study to date, Mathew et al. show that incremental hemodialysis is associated with satisfactory survival in those with adequate residual renal function and reasonable general health. While encouraging, these findings are a call to action for a suitably powered randomized clinical trial, to generate definitive evidence of benefit with this approach and define optimal practice for "real-world" implementation.

Incremental Hemodialysis: How I Do It

Incremental hemodialysis (incrHD) is not widely used nor is it well understood. In addition, and perhaps with more impact, governmental regulations in the United States and their consequential influences on dialysis provider organizations have made the practice of incrHD more difficult than traditional thrice weekly in-center HD. IncrHD is critically dependent on the amount of residual kidney function (RKF) as well as the individualized goals of end-stage renal disease (ESRD) management. RKF has to be assessed frequently and dialysis adjusted accordingly. Home HD lends itself to an incremental approach more so than in-center HD. This may be due to more experience of the provider, more knowledge of the therapy by the patient and family, the availability of dialysis platforms conducive to incrHD, and/or that its less onerous regulation by the government. I have had a long and successful experience performing incremental dialysis (both peritoneal and hemodialysis) and share here my practice strategies and approaches for incrHD.

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.

Rate of Decline of Residual Kidney Function Before and After the Start of Peritoneal Dialysis

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BACKGROUND

There is a paucity of information on whether peritoneal dialysis (PD) slows the decline of residual kidney function (RKF) compared to the natural slope of RKF decline prior to dialysis start. Our aim was to analyze the RKF decline before and after initiating PD, and to determine the principal factors affecting this decline during the PD period. ♦

METHODS

We determined individual glomerular filtration rates (GFR) for approximately 12 months before and after PD in 77 new PD patients in a large academic medical center (2008 - 2012). The GFR was estimated by the Modification of Diet in Renal Disease (MDRD) equation in the predialysis period and by averaging 24-hour urine creatinine and urea clearances in the PD period. The rate of RKF decline was calculated using unadjusted linear regression analysis. Wilcoxon signed rank test was used to compare RKF decline before and after PD initiation. Multivariate linear regression was used to identify independent risk factors for RKF decline in the PD phase. ♦

RESULTS

A significantly slower mean rate of RKF decline was observed in the PD period compared with the predialysis period (-0.21 ± 0.30 vs -0.59 ± 0.55 mL/min/1.73 m(2)/month, p < 0.01). Higher baseline RKF, higher serum phosphate, and older age were independently associated with faster decline of RKF (all p < 0.01). ♦

CONCLUSIONS

In patients with advanced chronic kidney disease, initiating PD was associated with a slower rate of RKF decline compared to the rate in the predialysis period.