Nutrition for the older adult - Current concepts. Report from an ESPEN symposium

BACKGROUND & AIMS

In view of the global demographic shift, a scientific symposium was organised by the European Society for Clinical Nutrition and Metabolism (ESPEN) to address nutrition-related challenges of the older population and provide an overview of the current state of knowledge.

METHODS

Eighteen nutrition-related issues of the ageing global society were presented by international experts during the symposium and summarised in this report.

RESULTS

Anorexia of ageing, dysphagia, malnutrition, frailty, sarcopenia, sarcopenic obesity, and the metabolic syndrome were highlighted as major nutrition-related geriatric syndromes. Great progress has been made in recent years through standardised definitions of some but not all syndromes. Regarding malnutrition, the GLIM approach has shown to be suitable also in older adults, justifying its continuous implementation. For anorexia of ageing, a consensus definition is still required. Intervention approaches should be integrated and person-centered with the aim of optimizing intrinsic capacity and maintaining functional capacity. Landmark studies like EFFORT and FINGER have impressively documented the potential of individualised and multifactorial interventions for functional and health benefits. Combining nutritional intervention with physical training seems particularly important whereas restrictive diets and drug treatment should generally be used with caution because of undesirable risks. Obesity management in older adults should take into account the risk of promoting sarcopenia.

CONCLUSIONS

In the future, even more individualised approaches like precision nutrition may enable better nutritional care. Meanwhile all stakeholders should focus on a better implementation of currently available strategies and work closely together to improve nutritional care for older adults.

Can one long peritoneal dwell with icodextrin replace two short dwells with glucose?

Background

Due to the slower dissipation of the osmotic gradient, icodextrin-based solutions, compared to glucose-based solutions, can improve water removal. We investigated scenarios where one icodextrin-based long dwell (Extraneal) replaced two glucose-based exchanges.

Methods

The three-pore model with icodextrin hydrolysis was used for numerical simulations of a single exchange to investigate the impact of different peritoneal dialysis schedules on fluid and solute removal in patients with different peritoneal solute transfer rates (PSTRs). We evaluated water removal (ultrafiltration, UF), absorbed mass of glucose (AbsGluc) and carbohydrates (AbsCHO, for glucose and glucose polymers), ultrafiltration efficiency (UFE = UF/AbsCHO) per exchange, and specified dwell time, and removed solute mass for sodium (ReNa), urea (ReU), and creatinine (ReCr) for a single peritoneal exchange with 7.5% icodextrin (Extraneal®) and glucose-based solutions (1.36% and 2.27%) and various dwell durations in patients with fast and average PSTRs.

Results

Introducing 7.5% icodextrin for the long dwell to replace one of three or four glucose-based exchanges per day leads to increased fluid and solute removal and higher UF efficiency for studied transport groups. Replacing two glucose-based exchanges with one icodextrin exchange provides higher or similar water removal and higher daily sodium removal but slightly lower daily removal of urea and creatinine, irrespective of the transport type present in the case of reference prescription with three and four daily exchanges.

Conclusion

One 7.5% icodextrin can replace two glucose solutions. Unlike glucose-based solutions, it resulted only in minor differences between PSTR groups in terms of water and solute removal with UFE remaining stable up to 16 h.

Integrated home dialysis model: facilitating home-to-home transition

Peritoneal dialysis (PD) and home hemodialysis (HHD) are the two home dialysis modalities offered to patients. They promote patient autonomy, enhance independence, and are generally associated with better quality of life compared to facility hemodialysis. PD offers some advantages (enhanced flexibility, ability to travel, preservation of residual kidney function, and vascular access sites) but few patients remain on PD indefinitely due to peritonitis and other complications. By contrast, HHD incurs longer and more intensive training combined with increased upfront health costs compared to PD, but is easier to sustain in the long term. As a result, the integrated home dialysis model was proposed to combine the advantages of both home-based dialysis modalities. In this paradigm, patients are encouraged to initiate dialysis on PD and transfer to HHD after PD termination. Available evidence demonstrates the feasibility and safety of this approach and some observational studies have shown that patients who undergo the PD-to-HHD transition have clinical outcomes comparable to patients who initiate dialysis directly on HHD. Nevertheless, the prevalence of PD-to-HHD transfers remains low, reflecting the multiple barriers that prevent the full uptake of home-to-home transitions, notably a lack of awareness about the model, home-care "burnout," clinical inertia after a transfer to facility HD, suboptimal integration of PD and HHD centers, and insufficient funding for home dialysis programs. In this review, we will examine the conceptual advantages and disadvantages of integrated home dialysis, present the evidence that underlies it, identify challenges that prevent its success and finally, propose solutions to increase its adoption.

Chronic kidney disease, dialysis and climate change

Chronic Kidney Disease is a serious public health problem and in clear relation to Climate Change and ecosystem maintenance. Renal health is particularly vulnerable to the impacts of climate change, and dialysis therapy (hemodialysis and PD) has a significant environmental footprint, conditioned by energy consumption and greenhouse gas production. In the last 50 years, people have changed ecosystems faster and more extensively than in any other period in human history. It is a consequence of ever-increasing demand for food, fresh water, fuel, industry, etc. and the result has been a substantial and largely irreversible loss of the diversity of life on Earth. Since 1979, human activities have caused the extinction of 60% of mammals, birds, fish and reptiles. There is an urgent need to adopt "Green Nephrology" measures by developing sustainable environmental solutions for the prevention and treatment of kidney diseases.

Personalized peritoneal dialysis prescription-beyond clinical or analytical values

Traditionally, dialysis adequacy has been assessed primarily by determining the clearance of a single small solute, urea. Nevertheless, it has become increasingly evident that numerous other factors play a crucial role in the overall well-being, outcomes and quality of life of dialysis patients. Consequently, in recent years, there has been a notable paradigm shift in guidelines and recommendations regarding dialysis adequacy. This shift represents a departure from a narrow focus only on the removal of specific toxins, embracing a more holistic, person-centered approach. This new perspective underscores the critical importance of improving the well-being of individuals undergoing dialysis while simultaneously minimizing the overall treatment burden. It is based on a double focus on both clinical outcomes and a comprehensive patient experience. To achieve this, a person-centered approach must be embraced when devising care strategies for each individual. This requires a close collaboration between the healthcare team and the patient, facilitating an in-depth understanding of the patient's unique goals, priorities and preferences while striving for the highest quality of care during treatment. The aim of this publication is to address the existing evidence on this all-encompassing approach to treatment care for patients undergoing peritoneal dialysis and provide a concise overview to promote a deeper understanding of this person-centered approach.

Delivering Person-Centered Peritoneal Dialysis

Peritoneal dialysis (PD) enables people to have a home-based therapy, permitting greater autonomy for individuals along with enhanced treatment satisfaction compared with in-center dialysis care. The burden of treatment on PD, however, remains considerable and underpins the need for person-centered care. This reflects the need to address the patient as a person with needs and preferences beyond just the medical perspective. Shared decision making is central to the recent International Society for Peritoneal Dialysis recommendations for prescribing PD, balancing the potential benefits of PD on patient well-being with the burden associated with treatment. This review considers the role of high-quality goal-directed prescribing, incremental dialysis, and remote patient monitoring in reducing the burden of dialysis, including an approach to implementing incremental PD. Although patient-related outcomes are important in assessing the response to treatment and, particularly life participation, the corollary of dialysis burden, there are no clear routes to the clinical implementation of patient-related outcome measures. Delivering person-centered care is dependent on treating people both as individuals and as equal partners in their care.

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.

Peritoneal Dialysis Care for People with Diabetes, Polycystic Kidney Disease, or Advanced Liver Disease

People treated with peritoneal dialysis (PD) often have complicating conditions that require careful management. Three such conditions are reviewed in this article-diabetes mellitus, polycystic kidney disease, and chronic liver disease. Each of these conditions requires an understanding of both its effect on the delivery of the PD and the effect of the PD on the condition itself. In diabetes, glucose absorption from the dialysate complicates metabolic control and affects salt and water management and patient outcome. There is particular benefit in clinical care being delivered through a multidisciplinary team that involves both kidney and diabetes experts. In relation to polycystic kidney disease, a key issue is the potential for increased intraperitoneal pressure due to the combined effect of the enlarged polycystic organs and the presence of the dialysis solution, and therefore, the PD prescription requires to be managed with a particular focus on limiting that pressure. For patients with liver disease, key issues include nutritional support because PD can add to protein losses already consequent on the liver disease itself. Considered approaches are required to manage ascites and reduce infection risk and the potential for hernias and leaks to develop. Mortality in this group is unfortunately high-however, PD may present a better management option than hemodialysis in many patients-particularly in those where the liver disease is complicated by low BP, clotting abnormalities, or troublesome ascites. Overall, the choice to use PD in patients with these complicating conditions should be based on shared decision making with the patient and their family members informed by high-quality information in which risks, benefits, and management strategies are clearly presented.

The Removal of Uremic Solutes by Peritoneal Dialysis

ABSTRACT

Peritoneal dialysis (PD) is now commonly prescribed to achieve target clearances for urea or creatinine. The International Society for Peritoneal Dialysis has proposed however that such targets should no longer be imposed. The Society's new guidelines suggest rather that the PD prescription should be adjusted to achieve well-being in individual patients. The relaxation of treatment targets could allow increased use of PD. Measurement of solute levels in patients receiving dialysis individualized to relieve uremic symptoms could also help us identify the solutes responsible for those symptoms and then devise new means to limit their accumulation. This possibility has prompted us to review the extent to which different uremic solutes are removed by PD.

Delivering Personalized, Goal-Directed Care to Older Patients Receiving Peritoneal Dialysis

Background

An aging population living with chronic kidney disease and progressing to kidney failure, subsequently receiving peritoneal dialysis (PD) is growing. A significant proportion of these patients are also living with multi-morbidities and some degree of frailty. Recent practice recommendations from the International Society of Peritoneal Dialysis advocate for high-quality, goal-directed PD prescription, and the Standardized Outcomes of Nephrology-PD initiative emphasized the need for an individualized, goal-based care approach in all patients receiving PD treatment. In older patients, this approach to PD care is even more important. A frailty screening assessment, followed by a comprehensive geriatric assessment (CGA) prior to PD initiation and when dictated by change in relevant circumstances is paramount in tailoring PD care and prescription according to the needs, life goals, as well as clinical status of older patients with kidney failure.

Summary

Our review aimed to summarize the different dimensions to be taken into account when delivering PD care to the older patient - from frailty screening and CGA in older patients receiving PD to employing a personalized, goal-directed PD prescription strategy, to preserving residual kidney function, optimizing blood pressure (BP) control, and managing anemia, to addressing symptom burden, to managing nutritional intake and promoting physical exercise, and to explore telehealth opportunities for the older PD population.

Key Messages

What matters most to older PD patients may not be simply extending survival, but more importantly, to be living comfortably on PD treatment with minimal symptom burden in a home environment and to minimize treatment complications.

Why are we Not Getting More Patients onto Peritoneal Dialysis? Observations From the United States with Global Implications

Peritoneal dialysis (PD) offers lifestyle advantages over in-center hemodialysis (HD) and is less costly. However, in the United States, less than 12% of end-stage kidney disease (ESKD) patients are maintained on this modality. In this brief review, we discuss some of the factors underlying the low prevalence of PD. These include inadequate patient education, a shortage of sufficiently well-trained medical and nursing personnel, absence of infrastructure to support urgent start PD, and lack of support for assisted PD, among other factors. Understanding and addressing these various issues may help increase the prevalence of PD in the United States and globally.

An update on absolute and relative indications for dialysis treatment modalities

Background

Choosing a dialysis modality is an important decision for people to make as their kidney failure progresses. In doing so, their options should be informed by any absolute or relative indications that may favour one modality over another.

Methods

In creating this update, we reviewed literature using a framework that considered first, high-level outcomes (survival and modality transition) from large registry data and cohort studies when considering optimal patient pathways; second, factors at a dialysis provider level that might affect relative indications; and third, specific patient-level factors. Both main types of dialysis modality, peritoneal (PD) and haemodialysis (HD), and their subtypes were considered.

Results

For most people starting dialysis, survival is independent of modality, including those with diabetes. Better survival is seen in those with less comorbidity starting with PD or home HD, reflecting continued improvements over recent decades that have been greater than improvements seen for centre HD. There are provider-level differences in the perceived relative indications for home dialysis that appear to reflect variability in experience, prejudice, enthusiasm, and support for patients and carers. Absolute contraindications are uncommon and, in most cases, where modality prejudice exists, e.g. obesity, Adult Polycystic Kidney Disease, and social factors, this is not supported by reported outcomes.

Conclusion

Absolute contraindications to a particular dialysis modality are rare. Relative indications for or against particular modalities should be considered but are rarely more important than patient preferences.

Association of Incremental peritoneal dialysis with residual kidney function decline in patients on peritoneal dialysis: The balANZ trial

BACKGROUND

Incremental peritoneal dialysis (PD), defined as less than Full-dose PD prescription, has several possible merits, including better preservation of residual kidney function (RKF), lower peritoneal glucose exposure and reduced risk of peritonitis. The aims of this study were to analyse the association of Incremental and Full-dose PD strategy with RKF and urine volume (UV) decline in patients commencing PD.

METHODS

Incident PD patients who participated in the balANZ randomised controlled trial (RCT) (2004-2010) and had at least one post-baseline RKF and UV measurement was included in this study. Patients receiving <56 L/week and ≥56 L/week of PD fluid at PD commencement were classified as Incremental and Full-dose PD, respectively. An alternative cut-point of 42 L/week was used in a sensitivity analysis. The primary and secondary outcomes were changes in measured RKF and daily UV, respectively.

RESULTS

The study included 154 patients (mean age 57.9 ± 14.1 years, 44% female, 34% diabetic, mean follow-up 19.5 ± 6.6 months). Incremental and Full-dose PD was commenced by 45 (29.2%) and 109 (70.8%) participants, respectively. RKF declined in the Incremental group from 7.9 ± 3.2 mL/min/1.73 m2 at baseline to 3.2 ± 2.9 mL/min/1.73 m2 at 24 months (p < 0.001), and in the Full-dose PD group from 7.3 ± 2.7 mL/min/1.73 m2 at baseline to 3.4 ± 2.8 mL/min/1.73 m2 at 24 months (p < 0.001). There was no difference in the slope of RKF decline between Incremental and Full-dose PD (p = 0.78). UV declined from 1.81 ± 0.73 L/day at baseline to 0.64 ± 0.63 L/day at 24 months in the Incremental PD group (p < 0.001) and from 1.38 ± 0.61 L/day to 0.71 ± 0.46 L/day in the Full-dose PD group (p < 0.001). There was no difference in the slope of UV decline between Incremental and Full-dose PD (p = 0.18).

CONCLUSIONS

Compared with Full-dose PD start, Incremental PD start is associated with similar declines in RKF and UV.

Multicentre registry analysis of incremental peritoneal dialysis incidence and associations with patient outcomes

BACKGROUND

Incremental peritoneal dialysis (PD) is increasingly advocated to reduce treatment burden and costs, with potential to better preserve residual kidney function. Global prevalence of incremental PD use is unknown and use in Australia and New Zealand has not been reported.

METHODS

Binational registry analysis including incident adult PD patients in Australia and New Zealand (2007-2017), examining incidence of and outcomes associated with incremental PD (first recorded PD exchange volume <42 L/week (incremental) vs. ≥42 L/week (standard)).

RESULTS

Incremental PD use significantly increased from 2.7% of all incident PD in 2007 to 11.1% in 2017 (mean increase 0.84%/year). Duration of incremental PD use was 1 year or less in 67% of cases. Male sex, Aboriginal and Torres Strait Islander (ATSI) or Māori ethnicities, age 45-59 years, medical comorbidities or treatment at a centre with low use of automated PD or icodextrin was associated with lower incidence of incremental PD use. Low body mass index and higher estimated glomerular filtration rate was associated with higher incidence. After accounting for patient and centre variables, commencing PD with an incremental prescription was associated with reduced peritonitis risk (adjusted hazard ratio 0.73, 95% confidence interval (CI) 0.61-0.86).When kidney transplantation and death were considered as competing risks, the association between incremental PD and peritonitis was not significant (sub-hazard ratio [SHR] 0.91, 95%CI 0.71-1.17, p = 0.5), however cumulative incidence of 30-day transfer to haemodialysis was lower in those receiving incremental PD (SHR 0.73, 95%CI 0.56-0.94, p = 0.01). There was no association between incremental PD and death.

CONCLUSIONS

Incremental PD use is increasing in Australia and New Zealand and is not associated with patient harm.

Use of incremental peritoneal dialysis: impact on clinical outcomes and quality of life measure

BACKGROUND

Incremental peritoneal dialysis (PD) can be defined as a PD prescription that is less than the standard, full dose prescription and is typically used for patients initiating PD with residual kidney function. It has been suggested that use of incremental peritoneal dialysis may help preserve residual kidney function and may offer better quality of life due to the lower treatment burden, however published evidence is limited. In this study we assessed the associations between incremental peritoneal dialysis use and both clinical outcomes and quality of life measures in a large cohort of incident peritoneal dialysis patients in the US.

METHODS

We considered adult patients initiating peritoneal dialysis between 31 July, 2015 and 31 May, 2019 within a single dialysis organization. Patients with body weight < 40 kg, amputation, or an estimated glomerular filtration rate > 20 mL/min during the first 4 weeks on peritoneal dialysis were excluded. Patients were assigned to exposure groups based on peritoneal dialysis prescription during dialysis weeks 5-8. Incremental peritoneal dialysis was defined by treatment frequency, number of exchanges/day, and exchange volume (for continuous ambulatory peritoneal dialysis patients) or by treatment frequency and presence/absence of last fill (for automated peritoneal dialysis patients). Analyses were performed separately for continuous ambulatory peritoneal dialysis and automated peritoneal dialysis. For each analysis, incremental peritoneal dialysis patients were propensity score matched to eligible full-dose peritoneal dialysis patients. Patients were followed for a maximum of 12 months until censoring for loss to follow-up or study end. Outcomes were compared using Poisson models (mortality, hospitalization, peritoneal dialysis discontinuation), linear mixed models (estimated glomerular filtration rate), and paired t tests (KDQOL domain scores).

RESULTS

Among continuous ambulatory peritoneal dialysis patients, compared to full-dose peritoneal dialysis, incremental peritoneal dialysis use was associated with better KDQOL scores on 3 domains: physical composite score (42.5 vs 37.7, p = 0.03), burden of kidney disease (60.2 vs 45.6, p = 0.003), effects of kidney disease (79.4 vs 72.3, p = 0.05). Hospitalization and mortality rates were numerically lower (0.77 vs 1.12 admits/pt-year, p = 0.09 and 5.0 vs 10.2 deaths/100 pt-years, p = 0.22), while no associations were found with estimated glomerular filtration rate or peritoneal dialysis discontinuation rate. Use of incremental peritoneal dialysis was not associated with any discernable effects on outcomes in automated peritoneal dialysis patients.

CONCLUSION

These results suggest that there may be benefits of using incremental PD in the context of continuous ambulatory peritoneal dialysis, particularly with respect to quality of life as a prescription strategy when initiating peritoneal dialysis. While no significant benefits of incremental peritoneal dialysis were detected among patients initiating automated peritoneal dialysis, no detrimental effects of using incremental schedules were observed for either peritoneal dialysis type.

Incremental peritoneal dialysis and survival outcomes: a propensity-matched cohort study

BACKGROUND

The advantages of an incremental dialysis start are not fully clear. We aimed to evaluate the association of incremental initiation of peritoneal dialysis with mortality.

METHODS

Incident peritoneal dialysis patients with a catheter placed at our hospital between 2008 and 2017 were included. All patients were followed up until December 31, 2019. Patients were categorized into different groups according to the initial daily dialysis exchanges, and were matched at a ratio of 1:2 with propensity score matching. Multiple variables including age, sex, residual kidney function, urine volume, hemoglobin, serum albumin and other important variables were included for the matching. Primary outcomes were all-cause and cardiovascular mortality.

RESULTS

A total of 1315 patients with a mean age of 45.9 years were enrolled. The mean glomerular filtration rate was 4.32 ml/min/1.73 m2 at start of dialysis. Two hundred eighty-five patients in the incremental group and 502 in the full dose group were matched for age, sex, residual kidney function, urine volume, hemoglobin, serum albumin and other important variables. Patient survival and cardiovascular event-free survival were similar between the two groups. However, during the first 6 years of peritoneal dialysis, patients in the incremental group had better survival (P = 0.011) and cardiovascular event-free survival (P = 0.044) than the full dose group, while such advantages disappeared when dialysis vintage became longer. Further analysis showed that the incremental group (vs full dose dialysis) had a 39% lower risk (95% CI 0.42-0.90, P = 0.012) of all-cause mortality and a 41% decreased risk (95% CI 0.35-0.99, P = 0.047) of cardiovascular mortality during the first 6 years of dialysis. Additionally, the cumulative hazard for anuria was significantly lower in the incremental group versus the full dose group (P = 0.006).

CONCLUSIONS

Our study shows a time-related survival advantage for incremental peritoneal dialysis patients, suggesting that an incremental regimen for starting peritoneal dialysis is feasible and is not associated with worse outcomes. Graphical Abstract presenting schematically the measurements of the solvation response function by processing the relevant streak camera images and the time-correlated photon counting (TCSPC) data and appropriately combining them together.

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.

Water implications in dialysis therapy, threats and opportunities to reduce water consumption: a call for the planet

Water is a dwindling natural resource, and potable water is wrongly considered an unlimited resource. Dialysis, particularly hemodialysis, is a water-hungry treatment that impacts the environment. The global annual water use of hemodialysis is approximately 265 million m3/yr. In this reference estimate, two-thirds of this water is represented by reverse osmosis reject water discharged into the drain. In this review, we would like to draw attention to the complexity and importance of water saving in hemodialysis. We propose that circular water management may comply with the "3R" concept: reduce (reduce dialysis need, reduce dialysate flow, and optimize reverse osmosis performance), reuse (reuse wastewater as potable water), and recycle (dialysis effluents for agriculture and aquaponic use). Awareness and sustainability should be integrated to create positive behaviors. Effective communication is crucial for water savings because local perspectives may lead to global opportunities. Besides the positive environmental impacts, planet-friendly alternatives may have significant financial returns. Innovative policies based on the transition from linear to circular water management may lead to a paradigm shift and establish a sustainable water management model. This review seeks to support policymakers in making informed decisions about water use, avoiding wasting, and finding solutions that may be planet friendly and patient friendly in dialysis, especially in hemodialysis treatments.

A Review of Residual Kidney Function in Peritoneal Dialysis Patients

Residual kidney function (RKF) has been associated with better survival, less morbidity, and improved quality of life in peritoneal dialysis (PD) patients. Since higher peritoneal clearance does not lead to better outcomes, more emphasis should be put on preserving kidney function. Many other benefits have been reported, including better volume and blood pressure control, better nutritional status, lower rates of PD peritonitis, preserved erythropoietin and vitamin D production, middle molecule clearance, lower Left Ventricular Hypertrophy, and better serum phosphate level. The most practical method of assessing RKF is the mean of 24-h urinary urea and creatinine clearance. Incremental PD prescription is an ideal option to supplement RKF in PD patients, which also offers more flexibility to the patient and, possibly, improved adherence. Angiotensin converting enzyme inhibitors and angiotensin receptor blockers should be used when possible in PD patients to preserve RKF. Loop diuretics are underutilized in PD patients despite providing an additional means of maintaining fluid balance and reducing the need for higher glucose-containing PD solutions. In this paper, we outline the importance of RKF in PD patients and the different strategies for its preservation.

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.

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.

The ABCs of personalized incremental dialysis start, Le Mans style

Thrice weekly hemodialysis (HD) is considered the standard of care for patients with end-stage chronic kidney disease (CKD) on extracorporeal renal replacement therapy. However, recent evidence has shown that up to one third of patients start dialysis with a residual kidney function that could allow a reduced frequency/dialysis dose. Interest towards HD schedules other than thrice weekly and the lessons learned from peritoneal dialysis, in addition to growing attention to patients' quality of life, have promoted renewed attention towards incremental HD (iHD). iHD comprises once and twice weekly schedules, makes it possible to soften the "dialysis shock" at the inception of therapy and is patient-friendly. Moreover, it might contribute to preserving residual kidney function longer. Nevertheless, iHD is performed differently in different settings and no guidelines exist on this subject. Taking advantage of the experience accrued with regard to the treatment of advanced CKD both in the outpatient clinic and in the dialysis unit in Le Mans, where two thirds of incident HD patients start in an incremental way, we aimed to present the practical aspects of iHD and discuss its advantages and drawbacks.

Urine volume as an estimator of residual renal clearance and urinary removal of solutes in patients undergoing peritoneal dialysis

In non-anuric patients undergoing peritoneal dialysis (PD), residual kidney function (RKF) is a main contributor to fluid and solute removal and an independent predictor of survival. We investigated if urine volume could be used to estimate renal clearances and removal of urea, creatinine, and phosphorus in PD patients. The observational, cross-sectional study included 93 non-anuric prevalent PD patients undergoing continuous ambulatory PD (CAPD; n = 34) or automated PD (APD; n = 59). Concentrations of urea, creatinine and phosphorus in serum and in 24-h collections of urine volume were measured to calculate weekly residual renal clearance (L/week) and removed solute mass (g/week). Median [interquartile range], 24-h urine output was 560 [330-950] mL and measured GFR (the mean of creatinine and urea clearances) was 3.24 [1.47-5.67] mL/min. For urea, creatinine and phosphorus, residual renal clearance was 20.60 [11.49-35.79], 43.02 [19.13-75.48] and 17.50 [8.34-33.58] L/week, respectively, with no significant differences between CAPD and APD. Urine volume correlated positively with removed solute masses (rho = 0.82, 0.67 and 0.74) and with weekly residual renal clearances (rho = 0.77, 0.62 and 0.72 for urea, creatinine, and phosphorus, respectively, all p < 0.001). Residual renal clearances and urinary mass removal rates for urea, creatinine, and phosphorus correlate strongly with 24-h urine volume suggesting that urine volume could serve as an estimator of typical values of residual solute removal indices in PD patients.

Incremental peritoneal dialysis after unplanned start initiation

Incremental peritoneal dialysis (PD) is characterized as less than a "standard dose" PD prescription. Compared to standard treatment, it has many potential advantages, including better preservation of residual renal function, a lower risk of peritonitis, and a decreased care delivery burden while reducing the environmental impact and economic cost. Unplanned PD can be defined when treatment starts up to 14 days after catheter insertion and is recognized as a safe and feasible clinical approach. In this perspective paper, we briefly discuss both strategies and share our experience and clinical routine in managing incremental PD after unplanned initiation.

The impact of multidisciplinary pre-dialysis care on the outcomes of incident peritoneal dialysis patients

Background

This study aims to evaluate the impact of multidisciplinary pre-dialysis care (MDPC) on the risks of peritonitis, technique failure and mortality in peritoneal dialysis (PD) patients.

Methods

Incident end-stage kidney disease patients who received peritoneal dialysis (PD) for more than 90 days were recruited in this study from 1 January 1, 2007 to December 31, 2018. Patients were classified into two groups, the MDPC group and the control group, that received the usual care by nephrologists. Risks of the first episode of peritonitis, technique failure and mortality were compared between the two groups.

Results

There were 126 patients under the usual care and 546 patients under the MDPC. Patients in the MDPC group initiated dialysis earlier than those in the non-MDPC group. There was no significant difference between these two groups in time to the first episode of peritonitis. Compared to the non-MDPC group, the MDPC group was at similar risks of technique failure (adjusted HR = 0.85, 95% CI = 0.64–1.15) and mortality (adjusted HR = 0.66, 95% CI = 0.42–1.02). Among patients with diabetes, the risk of mortality was significantly reduced in the MDPC group with an adjusted HR of 0.45 (95% CI = 0.25–0.80).

Conclusions

There was no significant difference in time to develop the first episode of peritonitis, and risks of technique failure and mortality between these two groups. Diabetic PD patients under MDPC had a lower risk of mortality than those under the usual care.

Cost Barriers to More Widespread Use of Peritoneal Dialysis in the United States

The United States Department of Health and Human Services launched the Advancing American Kidney Health Initiative in 2019, which included a goal of transforming dialysis care from an in-center to a largely home-based dialysis program. A substantial motivator for this transition is the potential to reduce costs of ESKD care with peritoneal dialysis. Studies demonstrating that peritoneal dialysis is less costly than in-center hemodialysis have often focused on the perspective of the payer, whereas less consideration has been given to the costs of those who are more directly involved in treatment decision making, including patients, caregivers, physicians, and dialysis facilities. We review comparisons of peritoneal dialysis and in-center hemodialysis costs, focusing on costs incurred by the people and organizations making decisions about dialysis modality, to highlight the financial barriers toward increased adoption of peritoneal dialysis. We specifically address misaligned economic incentives, underappreciated costs for key stakeholders involved in peritoneal dialysis delivery, differences in provider costs, and transition costs. We conclude by offering policy suggestions that include improving data collection to better understand costs in peritoneal dialysis, and sharing potential savings among all stakeholders, to incentivize a transition to peritoneal dialysis.

Peritoneal Dialysis for Potential Kidney Transplant Recipients: Pride or Prejudice?

Kidney transplantation (KT) is recognized as the gold-standard of treatment for patients with end-stage renal disease. Additionally, it has been demonstrated that receiving a pre-emptive KT ensures the best recipient and graft survivals. However, due to an overwhelming discrepancy between the organs available and the patients on the transplant waiting list, the vast majority of transplant candidates require prolonged periods of dialysis before being transplanted. For many years, peritoneal dialysis (PD) and hemodialysis (HD) have been considered competitive renal replacement therapies (RRT). This dualistic vision has recently been questioned by evidence suggesting that an individualized and flexible approach may be more appropriate. In fact, tailored and cleverly planned changes between different RRT modalities, according to the patient’s needs and characteristics, are often needed in order to achieve the best results. While home HD is still under scrutiny in this particular setting, current data seems to favor the use of PD over in-center HD in patients awaiting a KT. In this specific population, the demonstrated advantages of PD are superior quality of life, longer preservation of residual renal function, lower incidence of delayed graft function, better recipient survival, and reduced cost.

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.

Incremental peritoneal dialysis is a safe and feasible prescription in incident patients with preserved residual kidney function

BACKGROUND

Incremental peritoneal dialysis (PD) is recommended as a component of high-quality care by the international society for PD; however, its feasibility and clinical outcomes have not been widely reported. The aim of this study is to describe our experience with incremental PD.

METHODS

This was a retrospective cohort study of incident PD patients at Eastern Health between 2015 and 2019. Patients who stopped PD within 30 days were excluded. Incremental PD was defined in CAPD as using <8 L/day of exchange volume and in automated PD as dialysing without a last fill. Dialysis modality accorded with patient and physician preferences.

RESULTS

The 96 patients were included in this study; 54 with incremental PD. Compared to full-dose PD, incremental PD patients were more likely to be female, had less comorbid diabetes (28% vs. 52%) and higher residual kidney function (RKF) (Kt/V 2.0 ± 0.7 vs. 1.4 ± 0.7). Age, BMI and starting eGFR did not differ between groups. Incremental PD exposed patients to lower exchange volumes (4.4 ± 2.1 vs. 8.5 ± 1.1 L/day), glucose load (46 ± 41 g/day vs. 119 ± 46) and was associated with a longer peritonitis-free survival. PD technique survival, rates of peritonitis or hospitalization were comparable between groups. Predictors for longer incremental PD use included older age and higher starting eGFR.

CONCLUSIONS

Incremental PD is a feasible, goal-directed initial prescription in patients with RKF with comparable peritonitis rates and technique survival. Validation of this prescription in prospective studies is warranted.

Incremental peritoneal dialysis in incident end-stage kidney disease patients

BACKGROUND

This retrospective cohort study investigated the characteristics and outcomes of the end-stage kidney disease (ESKD) patients treated with incremental peritoneal dialysis (PD) at a large academic centre.

METHODS

ESKD patients initiating PD with a dialysate volume ≤6 L/day were analysed.

RESULTS

One hundred and seventy-five patients were included and were followed up for 352.6 patient-years. The baseline residual kidney function (RKF) was 8.3 ± 3.4 mL/min/1.73 m². The unadjusted 1- to 5-year patient survival rate was 89.6%, 80.4%, 65.4%, 62.7% and 48.8%, respectively, and the corresponding time on PD therapy rate was 95.1%, 89.1%, 89.1%, 82.4% and 77.6%. Greater initial PD dose (hazard ratio = 1.608, 95% confidence interval 1.089-2.375) was associated with death after adjusting for age, Charlson comorbidity index (CCI), haemodialysis prior to PD, assisted PD and baseline RKF, likely as a result of residual confounding. There was no association with PD discontinuation. The average peritonitis rate and hospitalisation rate were 0.122 and 0.645 episodes per patient-year, respectively. The dialysate volume increased from 4.5 (4.3-5.7) L/day to 8.0 (6.0-9.8) L/day at 5 years. Fifty-seven (32.6%) patients graduated to full-dose PD at a median time of 10.3 (6.2, 15.7) months. Male sex, greater body mass index and lower baseline serum albumin were risk factors for increasing PD dose to over 6 L/day within 1 year.

CONCLUSIONS

Incremental PD is a safe approach to initiate dialysis, and it offers satisfactory outcomes. Close monitoring, comprehensive evaluation of clinical responses and prompt adjustment of the prescription as needed play a crucial role in this patient-centred treatment.

Serum β2-microglobulin as a predictor of residual kidney function in peritoneal dialysis patients

BACKGROUND

While clinical guidelines recommend that residual kidney function (RKF) is measured in peritoneal dialysis (PD) patients, 24-h urine collection is cumbersome and prone to errors. We wished to determine whether an equation using serum β2-microglobulin (β2M) could prove of clinical benefit in estimating RKF and identifying patients who could start PD with incremental prescriptions.

METHODS

We measured serum β2M in consecutive PD outpatients recently starting dialysis with continuous ambulatory PD (CAPD) or automated PD (APD), attending a single tertiary hospital for their routine clinical visit. RKF was defined as the mean of 24-h urine clearances of creatinine and urea. An equation estimating RKF (eRKF) was generated based on serum β2M levels on a randomly selected modelling group.

RESULTS

We included 511 patients, of whom 351 in the modelling group and 150 in the validation group. Mean age was 58.7 ± 15.8, 307 (60.0%) were men and median RKF value was 4.5 (2.4-6.5) mL/min/1.73 m2. In the validation group, an equation based on β2M, creatinine, urea, age and gender showed minimal bias of - 0.1 mL/min/1.73 m2 to estimate RKF. Area under the receiving operator characteristic curve was 0.915 to detect RKF ≥ 2 mL/min/1.73 m2.

CONCLUSION

An equation based on serum β2M concentration would not be able to replace 24-h urine collection as the standard of care when an exact measurement of RKF is required. However, it could prove useful in identifying patients suitable for an incremental PD prescription and for monitoring RKF in individuals unable to reliably collect urine.

KDOQI US Commentary on the 2020 ISPD Practice Recommendations for Prescribing High-Quality Goal-Directed Peritoneal Dialysis

The recently published 2020 International Society for Peritoneal Dialysis (ISPD) practice recommendations regarding prescription of high-quality goal-directed peritoneal dialysis differ fundamentally from previous guidelines that focused on "adequacy" of dialysis. The new ISPD publication emphasizes the need for a person-centered approach with shared decision making between the individual performing peritoneal dialysis and the clinical care team while taking a broader view of the various issues faced by that individual. Cognizant of the lack of strong evidence for the recommendations made, they are labeled as "practice points" rather than being graded numerically. This commentary presents the views of a work group convened by the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) to assess these recommendations and assist clinical providers in the United States in interpreting and implementing them. This will require changes to the current clinical paradigm, including greater resource allocation to allow for enhanced services that provide a more holistic and person-centered assessment of the quality of dialysis delivered.

Peritoneal dialysis for acute kidney injury: Equations for dosing in pandemics, disasters, and beyond

BACKGROUND

Peritoneal dialysis (PD) is a viable option for renal replacement therapy in acute kidney injury (AKI), especially in challenging times during disasters and pandemics when resources are limited. While PD techniques are well described, there is uncertainty about how to determine the amount of PD to be prescribed toward a target dose. The aim of this study is to derive practical equations to assist with the prescription of PD for AKI.

METHODS

Using established physiological principles behind PD clearance and membrane transport, a primary determinant of dose delivery, equations were mathematically derived to estimate dialysate volume required to achieve a target dose of PD.

RESULTS

The main derivative equation is V_D = (1.2 × std-Kt/V × TBW)/(t_dwell + 4), where V_D is the total dialysate volume per day, std-Kt/V is the desired weekly dose, TBW is the total body water, and t_dwell is the dwell time. V_D can be expressed in terms of dwell volume, v_dwell, by V_D = (0.3 × std-Kt/V × TBW) - (6 × v_dwell). Two further equations were derived which directly describe the mathematical relationship between t_dwell and v_dwell. A calculator is included as an Online Supplementary Material.

CONCLUSIONS

The equations are intended as a practical tool to estimate solute clearances and guide prescription of continuous PD. The estimated dialysate volume required for any dose target can be calculated from cycle duration or dwell volume. However, the exact target dose of PD is uncertain and should be adjusted according to the clinical circumstances and response to treatment. The equations presented in this article facilitate the adjustment of PD prescription toward the targeted solute clearance.

Achieving dialysis adequacy: A global perspective

Dialysis adequacy is conventionally quantified as net urea clearance. Single pool (sp) Kt/V_urea remains the best studied measure of dialysis adequacy globally. Other measures such as fluid status control, anemia correction, and mineral metabolism are monitored variably. Increasing use of hemodiafiltration across Europe and many parts of Japan and Australia is predicated on studies showing better patient survival with middle molecule clearance. Apart from local clinical practice guidelines, the income level and public health policy of a country determine quality of dialysis services. Among developed nations, small solute clearance adequacy targets are achieved with high frequency. In the United States, dialysis adequacy target is met by focussing on high blood flow rates and large dialyzer size, sometimes at the cost of session time. In Japan, Australia, and Germany, session length is given importance. Dialysis adequacy reporting is restricted and inconsistent in developing nations. The Gulf Cooperation Council countries, Russia and Malaysia, respectively, are close to achieving dialysis adequacy target (spKt/V_urea ≥1.2) universally in their dialysis populations. Patient-reported outcomes are typically measured only in developed countries. Patient survival on dialysis, partly linked to dialysis adequacy, varies greatly around the world, with Japan having the best survival rates. Until the development of better markers of dialysis adequacy, universal consistency in reporting of conventional parameters with a focus on patient-reported measures should be endeavored.

The osmo-metabolic approach: a novel and tantalizing glucose-sparing strategy in peritoneal dialysis

Peritoneal dialysis (PD) is a viable but under-prescribed treatment for uremic patients. Concerns about its use include the bio-incompatibility of PD fluids, due to their potential for altering the functional and anatomical integrity of the peritoneal membrane. Many of these effects are thought to be due to the high glucose content of these solutions, with attendant issues of products generated during heat treatment of glucose-containing solutions. Moreover, excessive intraperitoneal absorption of glucose from the dialysate has many potential systemic metabolic effects. This article reviews the efforts to develop alternative PD solutions that obviate some of these side effects, through the replacement of part of their glucose content with other osmolytes which are at least as efficient in removing fluids as glucose, but less impactful on patient metabolism. In particular, we will summarize clinical studies on the use of alternative osmotic ingredients that are commercially available (icodextrin and amino acids) and preclinical studies on alternative solutions under development (taurine, polyglycerol, carnitine and xylitol). In addition to the expected benefit of a glucose-sparing approach, we describe an ‘osmo-metabolic’ approach in formulating novel PD solutions, in which there is the possibility of exploiting the pharmaco-metabolic properties of some of the osmolytes to attenuate the systemic side effects due to glucose. This approach has the potential to ameliorate pre-existing co-morbidities, including insulin resistance and type-2 diabetes, which have a high prevalence in the dialysis population, including in PD patients.

Foreign Perspective on Achieving a Successful Peritoneal Dialysis-First Program

Podcast

This article contains a podcast at https://www.asn-online.org/media/podcast/K360/2020_07_30_KID0000712019.mp3.

Person-centered peritoneal dialysis prescription and the role of shared decision-making

Person-centered care has become a dominant paradigm in modern health care. It needs to be applied to people with end-stage kidney disease considering the initiation of dialysis and to peritoneal dialysis (PD) prescription and care delivery. It is relevant to their decisions about goals of care, transplantation, palliative care, and discontinuation of dialysis. It is also relevant to decisions about how PD is delivered, including options such as incremental PD. Shared decision-making is the essence of this process and needs to become a standard principle of care. It requires engagement, education, and empowerment of patients. Patient-reported outcomes and patient-reported experience are also central to person-centered care in PD.