Three Versus 4 Daily Exchanges and Residual Kidney Function Decline in Incident CAPD Patients: A Randomized Controlled Trial

Effects of initial peritoneal dialysis prescription on clinical outcomes in Japanese peritoneal dialysis patients: a cohort study

Effects of the initial peritoneal dialysis (PD) prescription on clinical outcomes are unknown in Japan. We conducted a cohort study using data from Peritoneal Dialysis Outcomes and Practice Patterns Study. The patients were divided into two groups by the volume of the initial PD prescription (≤ 4 L/day or > 4 L/day). Cause-specific Cox proportional hazards survival models were used to model the association between different PD prescriptions and the clinical outcomes. The outcomes included transfer to HD, mortality, the composite of mortality and transfer to HD, peritonitis, hospitalization, and the patient-reported outcomes (PROs). Of the 342 patients, 98 were prescribed ≤ 4 L/day, and 244 were prescribed > 4 L/day. Patients prescribed ≤ 4 L/day were older with a lower percentage being male, had more cardiovascular and cerebrovascular disease but lower diabetes prevalence, were more likely to be receiving CAPD, used more assisted PD, and had lower BMI and mean serum creatinine levels. There were no significant differences between groups in terms of transfer to HD, mortality, transfer to HD or mortality, hospitalization, incidence of peritonitis, and PROs. Patients with initial PD prescriptions of ≤ 4 L/day compared to > 4 L/day had similar clinical outcomes. This practice may provide health economic benefits in Japan.

Clinical guideline on adequacy and prescription of peritoneal dialysis

In recent years, the meaning of adequacy in peritoneal dialysis has changed. We have witnessed a transition from an exclusive achievement of specific objectives -namely solute clearances and ultrafiltration- to a more holistic approach more focused to on the quality of life of these patients. The purpose of this document is to provide recommendations, updated and oriented to social and health environment, for the adequacy and prescription of peritoneal dialysis. The document has been divided into three main sections: adequacy, residual kidney function and prescription of continuous ambulatory peritoneal dialysis and automated peritoneal dialysis. Recently, a guide on the same topic has been published by a Committee of Experts of the International Society of Peritoneal Dialysis (ISPD 2020). In consideration of the contributions of the group of experts and the quasi-simultaneity of the two projects, references are made to this guide in the relevant sections. We have used a systematic methodology (GRADE), which specifies the level of evidence and the strength of the proposed suggestions and recommendations, facilitating future updates of the document.

A Randomized Controlled Trial Comparing Automated Peritoneal Dialysis and Hemodialysis for Urgent-Start Dialysis in ESRD

Introduction

Peritoneal dialysis (PD) shows promise for urgent-start dialysis in end-stage renal disease (ESRD), with automated PD (APD) having advantages. However, there is limited multicenter randomized controlled trial (RCT) evidence comparing APD with temporary hemodialysis (HD) for this indication in China.

Methods

This multicenter RCT enrolled 116 patients with ESRD requiring urgent dialysis from 11 hospitals, randomized to APD or HD. Patients underwent a 2-week treatment with APD or HD via a temporary central venous catheter (CVC), followed by a maintenance PD. Outcomes were assessed over 12 months during 8 visits. The primary outcome was dialysis-related complications.

Results

The 1-year incidence of dialysis-related complications was significantly lower in the APD group than in the HD group (25.9% vs. 56.9%, P = 0.001). No significant differences were found between the groups in terms of PD catheter survival rates (P = 0.388), peritonitis-free survival rates (P = 0.335), and patient survival rates (P = 0.329). In terms of health economics, the total direct medical cost of the initial hospitalization for patients with ESRD was significantly lower in the APD group (27,008.39 CNY) than in the HD group (42,597.54 CNY) (P = 0.001), whereas the duration of the first hospital stay showed no significant difference (P = 0.424).

Conclusion

For patients with ESRD needing urgent initiation of dialysis, APD was associated with a lower incidence of dialysis-related complications and lower initial hospitalization costs compared with HD, with no significant differences in PD catheter survival rate, peritonitis-free survival rates, or patient survival rates. These findings can guide clinical decision-making for the optimal dialysis modality for patients requiring urgent dialysis initiation.

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.

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.

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.

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.

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 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.

Automated peritoneal dialysis as a cost-effective urgent-start dialysis option for ESRD patients: A prospective cohort study

BACKGROUND

Several studies have reported the feasibility of urgent-start peritoneal dialysis (PD) as an alternative to hemodialysis (HD) using a central venous catheter (CVC). However, the cost-effectiveness of automated peritoneal dialysis (APD) as an urgent-start dialysis modality has not been directly evaluated, especially in China.

METHODS

We prospectively enrolled patients with end-stage renal disease (ESRD) who required urgent-start dialysis at a single center from March 2019 to November 2020. Patients were grouped according to their urgent-start dialysis modality (APD and HD). Urgent-start dialysis conducted until 14 days after PD catheter insertion. Then, PD was maintained. Each patient was followed until July 2021 or death or loss to follow-up. The primary outcome was the incidence of short-term dialysis-related complications. The secondary outcome was the cost and duration of the initial hospitalization. Technique survival, peritonitis-free or bacteriamia-free survival and patient survival were also compared.

RESULTS

Sixty-eight patients were included in the study, of whom 36 (52.9%) patients were in APD group. Mean follow-up duration was 20.1 months. Compared with the HD group, the APD group had significantly fewer short-term dialysis-related complications. The cost of initial hospitalization was also significantly lower in APD patients. There was no significant difference between APD and HD patients with respect to duration of the initial hospitalization, technique survival rate, peritonitis-free or bacteriemia-free survival rate, and patient survival rate.

CONCLUSION

Among ESRD patients with an urgent need for dialysis, APD as urgent-start dialysis modality, compared with HD using a CVC, resulted in fewer short-term dialysis-related complications and lower 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.

The estimation of protein equivalents of total nitrogen in Chinese CAPD patients: an explanatory study

Objective

The protein equivalent of total nitrogen appearance (PNA) formula, based on the urea nitrogen appearance (UNA), is popularly used by stable continuous ambulatory peritoneal dialysis (CAPD) patients to estimate dietary daily protein intake (DPI). However, we found that the estimated DPI was higher than that directly evaluated from the dietary records of most of our CAPD patients. Therefore, in the present study, we tried to determine possible bias in PNA estimation by UNA with a nitrogen balance study of our CAPD patients.

Methods

Thirty-one CAPD patients with stable clinical conditions were included. Their 3-day dietary records were reviewed by a dedicated dietitian to calculate their energy, protein, and nitrogen intake (NI). The nitrogen removal (NR) from urine and dialysate was measured by the Kjeldahl technique. Then, we calculated the proportion of urea nitrogen appearance (UNA) in total nitrogen appearance (TNA) and analyzed the possible factors that could affect this proportion.

Results

Among these patients, 17 males and 14 females, the mean age was 64.19 ± 12.42, and the dialysate drainage volume was 6700 (2540) ml/day. The percentage of UNA in TNA was 63.22 ± 6.66%. Compared with the other classic nitrogen balance studies in the CAPD population, the protein nitrogen and other nonurea nitrogen losses in this study were all lower. Based on these 31 nitrogen balance studies, we proposed a pair of new equations to estimate PNA by UNA. (1) PNA = 9.3 + 7.73 UNA; (2) PNA = PNPNA + TPL = 6.7 + 7.28 UNA + TPL.

Conclusion

Our study suggested that the PNA formula generated from previous European studies overestimated DPI in our CAPD patients.

The history of peritoneal dialysis in China: past, present and future trends

Peritoneal dialysis (PD) was introduced in China more than 60 years ago and has grown continuously since then. Now China leads the first of the world in number of patients on PD. In this manuscript a brief review of the history of peritoneal dialysis in China is presented; this includes a description of pioneers and their important contributions, discussion of peritoneal dialysate, the technique of the use of Tenckhoff catheter, the use of continuous ambulatory peritoneal dialysis (CAPD) and dialysis registration. Current ongoing PD research activities among Chinese PD academicians are also discussed. Finally, we present four areas of future focus: 1) the promotion of PD in rural areas where PD use is still very limited due to the lack of PD awareness and education; 2) PD quality management and continuous quality improvement (CQI) program particularly focusing on PD adequacy and patient rehabilitation; 3) development and enforcement of national standards on PD management; 4) multi-center studies to compare the benefits of PD and hemodialysis (HD) that should include survival, rehabilitation and cost-effectiveness.

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.

Outcome measures for technique survival reported in peritoneal dialysis: A systematic review

BACKGROUND

Peritoneal dialysis (PD) technique survival is an important outcome for patients, caregivers and health professionals, however, the definition and measures used for technique survival vary. We aimed to assess the scope and consistency of definitions and measures used for technique survival in studies of patients receiving PD.

METHOD

MEDLINE, EMBASE and CENTRAL databases were searched for randomised controlled studies (RCTs) conducted in patients receiving PD reporting technique survival as an outcome between database inception and December 2019. The definition and measures used were extracted and independently assessed by two reviewers.

RESULTS

We included 25 RCTs with a total of 3645 participants (41-371 per trial) and follow up ranging from 6 weeks to 4 years. Terminology used included 'technique survival' (10 studies), 'transfer to haemodialysis (HD)' (8 studies) and 'technique failure' (7 studies) with 17 different definitions. In seven studies, it was unclear whether the definition included transfer to HD, death or transplantation and eight studies reported 'transfer to HD' without further definition regarding duration or other events. Of those remaining, five studies included death in their definition of a technique event, whereas death was censored in the other five. The duration of HD necessary to qualify as an event was reported in only four (16%) studies. Of the 14 studies reporting causes of an event, all used a different list of causes.

CONCLUSION

There is substantial heterogeneity in how PD technique survival is defined and measured, likely contributing to considerable variability in reported rates. Standardised measures for reporting technique survival in PD studies are required to improve comparability.

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.

Prescribing high-quality peritoneal dialysis: The role of preserving residual kidney function

Maintenance of residual kidney function (RKF) is independently associated with increased survival in patients with end-stage renal disease. Presence of RKF is also associated with improved volume status, better nutritional status, reduced erythropoietin requirement, and decreased rate of peritonitis in patients on peritoneal dialysis (PD). Thus, the preservation of RKF is an important therapeutic end point in the management of patients on PD. Measurement of RKF in PD patients should be based on the mean of 24-h urinary creatinine and urea clearances, and ideally, this should be done quarterly. Compared to those started on hemodialysis, patients initiated on PD appear to have slower decline in RKF. The choice of PD modality should be based on patient preference, as there is no clear evidence to date showing one modality is superior than the other in preserving RKF. Peritoneal dialysates with neutral pH and low glucose degradation products seem to have a favorable effect on RKF. An angiotensin-converting enzyme inhibitor or angiotensin receptor blocker should be used whenever possible to preserve RKF and reduce cardiac mortality. Both loop diuretics and icodextrin can be utilized to maintain fluid balance in PD patients. However, caution should be taken to avoid volume depletion which could accelerate RKF decline. Short-term use of aminoglycosides does not have a detrimental impact on RKF, but prolonged use (>3 weeks) should be avoided to minimize the risk of ototoxicity. Lastly, potential nephrotoxic agents such as intravenous contrast should be used judiciously.

Incremental peritoneal dialysis

Incremental peritoneal dialysis (PD) has been variably defined. It involves taking advantage of the residual renal function that is usually present at initiation of dialysis to initially prescribe less onerous lower doses of PD while still achieving individualized clearance goals. We propose that incremental PD be defined as a strategy, rather than a particular regime, in which: (1) less than standard “full-dose” PD is initially prescribed in recognition of the value of residual renal function; (2) peritoneal clearance is initially less than the individualized clearance goal but the combination of peritoneal plus renal clearance achieves or exceeds that goal clearance; and (3) there is a clear intention to increase dose of PD as renal clearance declines and/or symptoms appear.

Incremental PD by its nature lessens the workload of dialysis for those doing PD, reduces cost and exposure of the peritoneal membrane to glucose, and may lessen mechanical symptoms. Evidence that incremental PD improves clinical outcomes compared to the use of full-dose PD is lacking but one randomized controlled trial, multiple observational studies, and a systematic review all suggest that outcomes are at least as good. Given that incremental PD costs less and is inherently less onerous, it is reasonable, pending larger randomized trials, to adopt this strategy.

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.

What PD Research in China Tells Us

Peritoneal dialysis (PD) was introduced in China later than in most Western countries, and PD research activity was quite limited until the 1990s. However, in the 2000s, and even more so during the last decade, there has been an unsurpassed increase in the number of PD patients, paralleled by a substantial increase in PD research activity reflected by an increasing number of PD papers from China. In this brief review, we describe some of the factors that may explain the dramatic developments in PD research in mainland China, such as the focus on basic research using scientific approaches that subsequently could be applied also in clinical studies. Another important factor was the growing interactions with international PD research centers in Hong Kong and in Western countries. Thanks to strong support from Chinese national and regional funding sources, a growing number of young Chinese researchers went to key international PD centers to learn about novel advanced research techniques. This paved the way for long-lasting, productive collaborations with benefits also for the foreign host institutions. Finally, we present some current research projects, including basic research that may contribute to the understanding of mechanisms behind complications such as peritonitis, and clinical projects aiming at improving PD management guidelines and better understanding of the potential of PD in China. Because of the size of the PD population, now the largest in the world, and the increasing number, and quality, of researchers in the PD field, PD research in China is destined to be a major contributor to advancements in PD in the near future.

Single Daily Icodextrin Exchange as Initial and Solitary Therapy

Background

Incremental dialysis utilizes gradually increasing dialysis doses in response to declines in residual kidney function, and it is the preferred renal replacement therapy for patients who have just transitioned to end-stage renal disease (ESRD). Incremental peritoneal dialysis (PD) may impose fewer restrictions on patients’ lifestyle, help attenuate lifetime peritoneal and systemic exposure to glucose and its degradation products, and minimize connections that could compromise the sterile fluid path. In this study, we utilized a 3-pore kinetic model to assess fluid and solute removal during single daily icodextrin treatments for patients with varying glomerular filtration rates (GFR).

Methods

Single icodextrin exchanges of 8 to 16 hours using 2- and 2.5-L bag volumes were simulated for different patient transport types (i.e., high to low) to predict daily peritoneal ultrafiltration (UF), daily peritoneal sodium removal, and weekly total (peritoneal + residual kidney) Kt/V (Kt/VTotal) for patients with residual renal GFRs ranging from 0 to 15 mL/min/1.73 m2.

Results

Daily peritoneal UF varied from 359 to 607 mL, and daily peritoneal Na removal varied from 52 to 87 mEq depending on length of icodextrin exchange and bag volume. Both were effectively independent of patient transport type. All but very large patients (total body water [TBW] > 60 L) were predicted to achieve adequate dialysis (Kt/VTot al ≥ 1.7) with a GFR of 10 mL/min/1.73 m2, and small patients (TBW: 30 L) were predicted to achieve adequate dialysis with a GFR of 6 mL/min/1.73 m2.

Conclusions

A single daily icodextrin exchange can be tailored to augment urea, UF, and Na removal in patients with sufficient residual kidney function (RKF). A solitary icodextrin exchange may therefore be reasonable initial therapy for some incident ESRD patients.