Diagnostic Accuracy of MMP-8 and IL-6-Based Point-of-Care Testing to Detect Peritoneal Dialysis-Related Peritonitis: A Single-Center Experience

BACKGROUND

Peritoneal dialysis-related peritonitis (PDRP) is the most common complication of peritoneal dialysis (PD), which can lead to poor outcomes if not diagnosed and treated early. We aimed to investigate the diagnostic accuracy of MMP-8 and IL-6-based point-of-care tests (POCTs) in diagnosing PDRP in PD patients.

METHODS

This retrospective chart review study was conducted at a comprehensive kidney center in Qatar. It involved all adult PD patients who underwent PDRP from July 2018 to October 2019 and for whom MMP-8 and IL-6-based POCTs were used to diagnose presumptive peritonitis. Measures of diagnostic accuracy were computed. Peritoneal fluid effluent analysis was the reference standard.

RESULTS

We included 120 patients (68 [56.7%] females, ages 55.6 ± 15.6 years, treatment duration 39.5 ± 30.4 months [range: 5-142 months]). In this population, MMP-8 and IL-6-based POCTs yielded 100% in all dimensions of diagnostic accuracy (sensitivity, specificity, positive and negative predictive values).

CONCLUSIONS

MMP-8 and IL-6-based POCTs might be helpful in the early detection of PDRP. This monocentric observation requires further confirmation in a prospective multicentric setting.

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.

Factors influencing renal replacement therapy modality choice from the nephrologist's perspective

BACKGROUND

Peritoneal dialysis (PD) offers quality of life and empowerment for persons with end-stage kidney disease (ESKD). Nevertheless, the prevalence of PD is low in Belgium and Europe in general. Reimbursement, patient mix and late referral have been quoted as underlying reasons. However, to date no one-size-fits-all solution increasing uptake of PD has been successfully implemented. We aimed to understand the nephrologist's perspective, beliefs, and experiences on dialysis modality selection and to clarify underlying process-level and intrinsic motivations steering final decisions.

METHODS

Using purposeful sampling, Belgian nephrologists (non-/academic, geographical spread, age, gender) were selected. We conducted semi-structured interviews, and audiotapes were transcribed verbatim. Meaningful units were grouped into (sub-)themes, and a conceptual framework was developed using grounded theory according to Charmaz as guidance.

RESULTS

Twenty-nine nephrologists were interviewed. We identified four themes: Trust and belief (in PD as a technique; own expertise, knowledge and team; in behavior of patient, family practitioner), feeling of control (paternalism; insecurity; prejudice), vision of care and approach (shared decision making; troubleshooting attitude; flexibility and creativity; complacency), and organizational issues (predialysis; access; financial; and assisted PD).

CONCLUSIONS

Based on these interviews, it is apparent that next to already identified singular issues such as late referral, predialysis education, patient mix and financial incentives, more intrinsic factors also impact uptake of home-based therapies. These factors intertwine and relate both to process-level topics and to attitudes and culture of the nephrologists within the team.

Transitions in an integrated model of renal replacement therapy in a regional health system

INTRODUCTION AND OBJECTIVES

The choice of renal replacement therapy (RRT) is an important decision that determines the quality of life and survival. Most patients change from one RRT modality to another to adapt RRT to clinical and psychosocial needs. This has been called «integrated model of RRT» that implies new questions about the best sequence of techniques.

MATERIAL AND METHODS

The study describes the impact of transitions between RRT modalities on survival using the Madrid Registry of Renal Patients (2008-2018). This study used the proportional hazards models and competitive risk models to perform an intention-to-treat (ITT), according to their 1st RRT modality and as-treated (AT) analysis, that consider also their 1st transition.

RESULTS

A total of 8971 patients started RRT during this period in Madrid (6.6 Million population): 7207 (80.3%) on hemodialysis (HD), 1401 (15.6%) on peritoneal dialysis (PD) and 363 (4.2%) received a pre-emptive kidney transplantation (KT). Incident HD-patients were older (HD group 65.3 years (SD 15.3) vs PD group 58.1 years (SD 14.8) vs KTX group 52 years (SD 17.2); p < 0.001) and had more comorbidities. They presented higher mortality (HD group 40.9% vs PD group 22.8% vs KTX group 8.3%, p < 0.001) and less access to a transplant (HD group 30.4% vs PD group 51.6%; p < 0.001). Transitions between dialysis techniques define different groups of patients with different clinical outcomes. Those who change from HD to PD do it earlier (HD → PD: 0.7 years (SD 1.1) vs PD → HD: 1.5 years (SD 1.4) p < 0.001), are younger (HD → PD: 53.5 years (SD 16.7) vs PD → HD: 61.6 years (SD 14.6); p < 0.001), presented less mortality (HD → PD: 24.5% vs PD → HD: 32.0%; p < 0.001) and higher access to a transplant (HD → PD: 49.4% vs PD → HD: 31.7%; p < 0.001). Survival analysis by competitive risks is essential for integrated RRT models, especially in groups such as PD patients, where 51.6% of the patients were considered as lost follow-up (received a KTX after during the first 2.5 years on PD). In this analysis, survival of patients who change from one technique to another, is more similar to the destination modality than the origin one.

CONCLUSION

Our data suggest that transitions between RRT-techniques describes different patients, who associate different risks, and could be analyzed in an integrated manner to define improvement actions. This approach should be incorporated into the analysis and reports of renal registries.

Transitions in an integrated model of renal replacement therapy in a regional health system

INTRODUCTION AND OBJECTIVES

The choice of renal replacement therapy (RRT) is an important decision that determines the quality of life and survival. Most patients change from one RRT modality to another to adapt RRT to clinical and psychosocial needs. This has been called «integrated model of RRT» that implies new questions about the best sequence of techniques.

MATERIAL AND METHODS

The study describes the impact of transitions between RRT modalities on survival using the Madrid Registry of Renal Patients (2008-2018). This study used the proportional hazards models and competitive risk models to perform an intention-to-treat (ITT), according to their 1st RRT modality and as-treated (AT) analysis, that consider also their 1st transition.

RESULTS

A total of 8971 patients started RRT during this period in Madrid (6.6 Million population): 7207 (80.3%) on hemodialysis (HD), 1401 (15.6%) on peritoneal dialysis (PD) and 363 (4.2%) received a pre-emptive kidney transplantation (KTX). Incident HD-patients were older (HD group 65.3 years (SD 15.3) vs PD group 58.1 years (SD 14.8) vs KTX group 52 years (SD 17.2); p<0.001) and had more comorbidities. They presented higher mortality (HD group 40.9% vs PD group 22.8% vs 8.3% KTX group, p<0.001) and less access to a transplant (HD group 30.4% vs DP group 51.6%; p<0.001). Transitions between dialysis techniques define different groups of patients with different clinical outcomes. Those who change from HD to PD do it earlier (HD→PD: 0.7 years (SD 1.1) vs PD→HD: 1.5 years (SD 1.4) p<0.001), are younger (HD→PD: 53.5 years (SD 16.7) vs PD→HD: 61.6 years (SD 14.6); p<0.001), presented less mortality (HD→PD: 24.5% vs PD→HD: 32.0%; p<0.001) and higher access to a transplant (HD→PD: 49.4% vs PD→HD: 31.7%; p<0.001). Survival analysis by competitive risks is essential for integrated RRT models, especially in groups such as PD patients, where 51.6% of the patients were considered as lost follow-up (received a KTX after during the first 2.5 years on PD). In this analysis, survival of patients who change from one technique to another, is more similar to the destination modality than the origin one.

CONCLUSION

Our data suggest that transitions between RRT-techniques describes different patients, who associate different risks, and could be analyzed in an integrated manner to define improvement actions. This approach should be incorporated into the analysis and reports of renal registries.

Barriers and opportunities to increase PD incidence and prevalence: Lessons from a European Survey

INTRODUCTION

Peritoneal dialysis (PD) remains underutilised and unplanned start of dialysis further diminishes the likelihood of patients starting on PD, although outcomes are equal to haemodialysis (HD).

METHODS

A survey was sent to members of EuroPD and regional societies presenting a case vignette of a 48-year-old woman not previously known to the nephrology department and who arrives at the emergency department with established end-stage kidney disease (unplanned start), asking which dialysis modality would most likely be chosen at their respective centre. We assessed associations between the modality choices for this case vignette and centre characteristics and PD-related practices.

RESULTS

Of 575 respondents, 32.8%, 32.2% and 35.0% indicated they would start unplanned PD, unplanned HD or unplanned HD with intention to educate patient on PD later, respectively. Likelihood for unplanned start of PD was only associated with quality of structure of the pre-dialysis program. Structure of pre-dialysis education program, PD program in general, likelihood to provide education on PD to unplanned starters, good collaboration with the PD access team and taking initiatives to enhance home-based therapies increased the likelihood unplanned patients would end up on PD.

CONCLUSIONS

Well-structured pre-dialysis education on PD as a modality, good connections to dedicated PD catheter placement teams and additional initiatives to enhance home-based therapies are key to grow PD programs. Centres motivated to grow their PD programs seem to find solutions to do so.

Peritoneal dialysis patient selection from a comorbidity perspective

Despite many medical and socioeconomic advantages, peritoneal dialysis (PD) is an underutilized dialysis modality that in most countries is used by only 5%-20% of dialysis patients, while the vast majority are treated with in-center hemodialysis. Several factors may explain this paradox, such as lack of experience and infrastructure for training and monitoring of PD patients, organizational issues, overcapacity of hemodialysis facilities, and lack of economic incentives for dialysis centers to use PD instead of HD. In addition, medical conditions that are perceived (rightly or wrongly) as contraindications to PD represent barriers for the use of PD because of their purported potential negative impact on clinical outcomes in patients starting PD. While there are few absolute contraindications to PD, high age, comorbidities such as diabetes mellitus, obesity, polycystic kidney disease, heart failure, and previous history of abdominal surgery and renal allograft failure, may be seen (rightly or wrongly) as relative contraindications and thus barriers to initiation of PD. In this brief review, we discuss how the presence of these conditions may influence the strategy of selecting patients for PD, focusing on measures that can be taken to overcome potential problems.

Outcomes after transfer from hemodialysis to peritoneal dialysis vs peritoneal dialysis as initial therapy: A systematic review and meta-analysis

Outcomes of patients who are transferred to peritoneal dialysis (PD) after an initial phase of hemodialysis (HD) compared to patients initiating dialysis with PD is controversial. We performed a systematic literature to assess evidence. Primary outcome was overall survival (OS), while secondary outcomes were technique failure, mortality and peritonitis. Meta-analysis indicated that PD initial group had significantly better OS as compared to HD to PD group. Pooled analysis demonstrated a significantly higher probability of technique failure in the HD to PD group as compared to PD initial group. Mortality rate in HD to PD group was significantly higher but there was no statistically significant difference in peritonitis rates between the two groups. On meta-regression analysis, transfer from HD to PD due to vascular access problems was associated with significantly reduced probability of OS. Our study indicates that patients transferred from HD to PD after at least 3 months of HD therapy may have reduced OS as compared to patients initiating dialysis with PD. Our findings lend some support to PD first policy and the need for heightened vigilance among the switched patients to monitor for adverse events.

Monitoring of Long-Term Peritoneal Membrane Function

Objective

Peritoneal membrane function influences dialysis prescription and clinical outcome and may change with time on treatment. Increasingly sophisticated tools, ranging from the peritoneal equilibration test (PET) to the standard permeability analysis (SPA) and personal dialysis capacity (PDC) test, are available to the clinician and clinical researcher. These tests allow assessment of a number of aspects of membrane function, including solute transport rates, ultrafiltration capacity, effective reabsorption, transcellular water transport, and permeability to macromolecules. In considering which tests are of greatest value in monitoring long-term membrane function, two criteria were set: those that result in clinically relevant interpatient differences in achieved ultrafiltration or solute clearances, and those that change with time in treatment.

Study Selection

Clinical validation studies of the PET, SPA, and PDC tests. Studies reporting membrane function using these methods in either long-term (5 years) peritoneal dialysis patients or longitudinal observations (> 2 years).

Data Extraction

Directly from published data. Additional, previously unpublished analysis of data from the Stoke PD Study.

Results

Solute transport is the most important parameter. In addition to predicting patient and technique survival at baseline, there is strong evidence that it can increase with time on treatment. Whereas patients with initially high solute transport drop out early from treatment, those with low transport remain longer on treatment, although, over 5 years, a proportion develop increasing transport rates. Ultrafiltration capacity, while being a composite measure of membrane function, is a useful guide for the clinician. Using the PET (2.27% glucose), a net ultrafiltration capacity of < 200 mL is associated with a 50% chance of achieving less than 1 L daily ultrafiltration at the expense of 1.8 hypertonic (3.86%) exchanges in anuric patients. Using a SPA (3.86% glucose), a net ultrafiltration capacity of < 400 mL indicates ultrafiltration failure. While there is circumstantial evidence that, with time on peritoneal dialysis, loss of transcellular water transport might contribute to ultrafiltration failure, none of the current tests is able to demonstrate this unequivocally. Of the other membrane parameters, evidence that interpatient differences are clinically relevant (permeability to macro-molecules), or that they change significantly with time on treatment (effective reabsorption), is lacking.

Conclusion

A strong case can be made for the regular assessment by clinicians of solute transport and ultrafiltration capacity, a task made simple to achieve using any of the three tools available.

Reformulating the Integrated Care Concept for the New Millennium

The concept of integrated care advocates a planned approach to predialysis care. Its components include timely referral to a renal care team, timely preparation for dialysis, and timely initiation of dialysis, with peritoneal dialysis (PD) as the initial therapy for suitable patients. This initial therapy may then be followed by timely transfer to hemodialysis (HD) when residual renal function declines or when other PD-related problems occur.

We argue that at least three problems exist with the integrated care approach as it is currently being articulated. They are ( 1 ) an under emphasis on slowing the rate of progression of chronic kidney disease, aggressive management of cardiovascular risk factors and other comorbidities, and pre-emptive live donor transplantation; ( 2 ) a lack of consideration of home HD as an alternate initial therapy; and ( 3 ) a lack of discussion about patient choice. We propose a modified version of integrated care that we believe will optimize modality distribution and patient outcomes, while reducing the relative costs per patient treated, compared to the current situation in most countries.

Peritoneal Dialysis: Better than, Equal to, or Worse than Hemodialysis? Data Worth Knowing before Choosing a Dialysis Modality

Technological advances such as those that allow the delivery of an adequate dialysis dose to a larger percentage of patients, minimization of peritoneal membrane damage with more biocompatible solutions, and lower peritonitis rates will undoubtedly improve retention of patients on peritoneal dialysis (PD) for longer periods. Currently, only 15% of the world dialysis population is managed by PD. Peritoneal dialysis has many advantages over hemodialysis, and if end-stage renal disease (ESRD) patients are fully informed about them, the proportion of patients who would prefer this treatment would rise to 25% – 30%. An integrated approach to the treatment of ESRD could start with PD in a large percentage of patients, especially those who will receive a kidney transplant within 2 – 3 years. With the present epidemic of ESRD, this approach could lead to a significant saving, relieve the pressure on dialysis units, and allow a larger number of ESRD patients to be treated.

Disturbed Appetite Patterns and Nutrient Intake in Peritoneal Dialysis Patients

Objective

Malnutrition is common among peritoneal dialysis (PD) patients. Reduced nutrient intake contributes to this. It has long been assumed that this reflects disturbed appetite. We set out to define the appetite profiles of a group of PD patients using a novel technique.

Design

Prospective, cross-sectional comparison of PD patients versus controls.

Setting

Teaching hospital dialysis unit.

Patients

39 PD patients and 42 healthy controls.

Intervention

Visual analog ratings were recorded at hourly intervals to generate daily profiles for hunger and fullness. Summary statistics were generated to compare the groups. Food intake was measured using 3-day dietary records.

Main Outcome Measures

Hunger and fullness profiles. Derived hunger and fullness scores.

Results

Controls demonstrated peaks of hunger before mealtimes, with fullness scores peaking after meals. The PD profiles had much reduced premeal hunger peaks. A postmeal reduction in hunger was evident, but the rest of the trace was flat. The PD fullness profile was also flatter than in the controls. Mean scores were similar despite the marked discrepancy in the profiles. The PD group had lower peak hunger and less diurnal variability in their hunger scores. They also demonstrated much less change in fullness rating around mealtimes, while the mean and peak fullness scores were little different. The reported nutrient intake was significantly lower for PD.

Conclusion

The data suggest that PD patients normalize their mean appetite perception at a lower level of nutrient intake than controls, suggesting that patient-reported appetite may be misleading in clinical practice. There is a loss of the usual daily variation for the PD group, which may contribute to their reduced food intake. The technique described here could be used to assess the impact of interventions upon the abnormal PD appetite profile.

How to Have a Successful Peritoneal Dialysis Program

The proportion of end-stage renal disease patients on continuous ambulatory peritoneal dialysis (CAPD) has increased by twofold in Hong Kong over last two decades, accounting for 80% of the entire dialysis population. Our encouraging outcome results—a 2-year actuarial patient survival of 83%, and a 2-year technique survival of 72.8%—further testify to the success of CAPD in our territory. A relatively constant successful outcome has been achieved despite an increasing prevalence of diabetes mellitus and an aging population. The present review postulates the reasons behind our success. Apart from reimbursement policy, technique-related factors, and center effects, inherent patient factors—including baseline survival advantage of Chinese patients, genetic difference, cardiovascular risk factors, and possibly lower dialysis volume requirement and compliance—are thought to be contributory. As for the future, more efforts are needed to further improve the technique survival rate and the nutritional status, psychosocial well-being, and rehabilitation of CAPD patients. Judicious assessment of peritoneal dialysis adequacy and preservation of residual renal function should be constantly exercised to tailor treatment to the needs of Chinese CAPD patients.

A Quarter of a Century of Adult Peritoneal Dialysis-Related Peritonitis at an Australian Medical Center

Background

Peritonitis remains one of the major complications of peritoneal dialysis (PD) and results in reduced technique survival and increased patient morbidity and mortality.

Methods

We prospectively recorded comprehensive data on all episodes of PD peritonitis over a 25-year period, including organisms isolated and antibiotic sensitivities. Data on 1588 PD patient-years with 2073 episodes of peritonitis were analyzed; 2089 organisms were isolated in 608 patients. Peritoneal dialysis technique and patient survival were also recorded.

Results

There was a significant decline over the years in the incidence of peritonitis, from 6.5 to 0.35 episodes/patient-year, with the decline in the post twin-bag era from 2.3 to 0.47 ( p < 0.001) due primarily to a decrease in gram-positive organisms. The most common isolates (68.9%) were gram-positive organisms; gram-negative organisms comprised 26.8% and fungi 4.1%. Coagulase-negative staphylococci were the most common pathogen isolated (35.3%). Culture-negative peritonitis was seen in 13.4% of episodes.

Conclusion

This is the largest series of PD peritonitis reported, demonstrating a dramatic reduction over a 25-year period and also detailing the changing trends of organisms isolated in association with improved technique and patient survival. Although rates have improved, peritonitis remains a major complication and further research needs to be done to improve both PD technique and patient survival.

Transition Between Different Renal Replacement Modalities: Gaps in Knowledge and Care-The Integrated Research Initiative

Patients with end-stage kidney disease (ESKD) have different options to replace the function of their failing kidneys. The "integrated care" model considers treatment pathways rather than individual renal replacement therapy (RRT) techniques. In such a paradigm, the optimal strategy to plan and enact transitions between the different modalities is very relevant, but so far, only limited data on transitions have been published. Perspectives of patients, caregivers, and health professionals on the process of transitioning are even less well documented. Available literature suggests that poor coordination causes significant morbidity and mortality.This review briefly provides the background, development, and scope of the INTErnational Group Research Assessing Transition Effects in Dialysis (INTEGRATED) initiative. We summarize the literature on the transition between different RRT modalities. Further, we present an international research plan to quantify the epidemiology and to assess the qualitative aspects of transition between different modalities.

Longer-Period Effects of Bicarbonate/Lactate-Buffered Neutral Peritoneal Dialysis Fluid in Patients Undergoing Peritoneal Dialysis

High concentrations of lactate are considered to contribute to impairment of the peritoneal membrane. We investigated the longer-period effects of bicarbonate/lactate-buffered neutral peritoneal dialysis fluid (PDF) in patients undergoing PD for about 2 years. Patients undergoing PD were changed from a lactate-buffered neutral PDF to a bicarbonate/lactate-buffered neutral PDF. We then investigated the patients' clinical outcomes and peritoneal membrane functions as well as the surrogate markers in the drained dialysate. Fourteen patients undergoing PD were enrolled. Peritonitis was observed in one patient. No other adverse events were observed. Peritoneal function did not change as the ultrafiltration volume decreased. Fibrin degradation products and vascular endothelial growth factor in the drained dialysate decreased while the interleukin level increased. These results suggest that bicarbonate/lactate-buffered neutral PDF may have beneficial effects in terms of peritoneal preservation and can be safely used in patients undergoing PD.

Using manual exchanges for an urgent-start peritoneal dialysis program

Background

Urgent-start peritoneal dialysis (USPD) was designed to avoid temporary hemodialysis initiation with a hemodialysis catheter. In these patients, PD is initiated within 2 weeks of catheter placement, but typically these prescriptions utilize automated peritoneal dialysis (APD) with a cycler. Manual exchanges have not been reported previously for USPD. We hypothesize that using multiple, low-volume manual exchanges, patients will have similar rates of peritonitis, exit-site infection (ESI), pericatheter leaks and discontinuation of PD in the first 3 months after initiation.

Methods

This retrospective study included patients who initiated PD in our unit from May 2014 until August 2016 using our USPD protocol. Patients with a body surface area <1.7 m² used 750 mL dwell volumes and those >1.7 m² used 1000 mL dwell volumes during the first 7 days. Dwell times were 2–2.5 h for two to three exchanges per day. After 7 days of successful therapy, the dwell volumes were doubled. All patients were maintained on furosemide 160 mg twice daily.

Results

There were 20 patients enrolled in our USPD program. Our rates of peritonitis, ESI, pericatheter leak and discontinuation of PD were 5%, 0%, 5% and 5%, respectively.

Conclusions

Manual exchange during USPD is a viable modality with similar results as APD. Using manual exchanges allows patients to be more ambulatory during the day when they are not dwelling, allows nurses to evaluate the amount of ultrafiltration and effluent characteristics and allows for training in manual exchanges as well.

Comparison of outcomes between emergent-start and planned-start peritoneal dialysis in incident ESRD patients: a prospective observational study

BACKGROUND

The clinical consequences of starting chronic peritoneal dialysis (PD) after emergent dialysis via a temporary hemodialysis (HD) catheter has rarely been evaluated within a full spectrum of treated end-stage renal disease (ESRD). We investigated the longer-term outcomes of patients undergoing emergent-start PD in comparison with that of other practices of PD or HD in a prospective cohort of new-onset ESRD.

METHODS

This was a 2-year prospective observational study. We enrolled 507 incident ESRD patients, among them 111 chose PD (43 planned-start, 68 emergent-start) and 396 chose HD (116 planned-start, 280 emergent-start) as the long-term dialysis modality. The logistic regression model was used to identify variables associated with emergent-start dialysis. The Kaplan-Meier survival analysis was used to determine patient survival and technique failure. The propensity score-adjusted Cox regression model was used to identify factors associated with patient outcomes.

RESULTS

During the 2-year follow-up, we observed 5 (4.5%) deaths, 15 (13.5%) death-censored technique failures (transfer to HD) and 3 (2.7%) renal transplantations occurring in the PD population. Lack of predialysis education, lower predialysis estimated glomerular filtration rate and serum albumin were predictors of being assigned to emergent dialysis initiation. The emergent starters of PD displayed similar risks of patient survival, technique failure and overall hospitalization, compared with the planned-start counterparts. By contrast, the concurrent planned-start and emergent-start HD patients with an arteriovenous fistula or graft were protected from early overall death and access infection-related mortality, compared with the emergent HD starters using a central venous catheter.

CONCLUSIONS

In late-referred chronic kidney disease patients who have initiated emergent dialysis via a temporary HD catheter, post-initiation PD can be a safe and effective long-term treatment option. Nevertheless, due to the potential complications and cost concerns, such practice of PD initiation would better be replaced with a planned-start mode by employing more effective predialysis therapeutic education and timely catheter placement.

Nano-sized carriers in gene therapy for peritoneal fibrosis in vivo

Peritoneal fibrosis is a crucial complication in patients receiving peritoneal dialysis. It is a major pathological feature of peritoneal membrane failure, which leads to withdrawal of peritoneal dialysis. No specific therapy has yet been established for the treatment of peritoneal fibrosis. However, gene therapy may be a viable option, and various nano-sized carriers, including viral and non-viral vectors, have been shown to enhance the delivery and efficacy of gene therapy for peritoneal fibrosis in vivo. This review focuses on the use of nano-sized carriers in gene therapy of peritoneal fibrosis in vivo.

Impact of break-in period on the short-term outcomes of patients started on peritoneal dialysis

OBJECTIVES

Peritoneal dialysis (PD) is one of the first-line modalities of renal replacement therapy in patients with end-stage renal disease. Guidelines recommended a break-in period of at least 2 weeks before full PD start. However, the optimal duration of the break-in period is still unclear. In the present study, we investigated the effect of various break-in periods on short-term outcomes in patients on PD. ♢

METHODS

All patients who underwent Tenckhoff catheter implantation and initiated PD in Renji Hospital, Shanghai Jiao Tong University School of Medicine, between 1 January 2001 and 31 December 2010 were included. Patients were grouped according to the duration of their break-in period: 7 days or less (BI ≤ 7), 8 - 14 days (BI8-14), and more than 14 days (BI>14). Kaplan-Meier curves and log-rank tests were used to compare short-term outcomes in the various groups. ♢

RESULTS

Our study enrolled 657 patients (44.5% men), of whom 344, 137, and 176 patients were in the respective break-in groups. Compared with BI>14 patients, BI ≤ 7 patients had a lower estimated glomerular filtration rate (5.34 ± 1.86 mL/min/1.73 m(2) vs 6.55 ± 1.71 mL/min/1.73 m(2), p < 0.001) and lower serum albumin (33.29 ± 5.36 g/L vs 36.64 ± 5.40 g/L, p < 0.001). The incidence of mechanical complications during the first 6 months was significantly higher in BI ≤ 7 patients than in BI>14 patients (8.4% vs 1.7%, p = 0.004). However, we observed no significant differences between the three groups with respect to the prevalence of catheter dysfunction requiring surgical intervention (p > 0.05). Logistic regression analysis showed that BI ≤ 7 [relative risk: 4.322; 95% confidence interval (CI): 1.278 to 14.608; p = 0.019] was an independent predictor of catheter dysfunction, but not of catheter dysfunction requiring surgical intervention (p > 0.05). Catheter dysfunction [hazard ratio (HR): 20.087; 95% CI: 7.326 to 55.074; p < 0.001] and peritonitis (HR: 4.533; 95% CI: 1.748 to 11.751; p = 0.002) were risk factors for technique failure during the first 6 months, but BI ≤ 7 was not correlated with technique failure. ♢

CONCLUSIONS

Patients starting PD with a break-in period of less than 1 week might experience a minor increased risk of mechanical complications, but no major effect on technique survival.

Comparison of plasma oxidative biomarkers and conformational modifications of hemoglobin in patients with diabetes on hemodialysis

BACKGROUND

Diabetes is associated with an increased generation of reactive oxygen species (ROS), which plays an important role in the development of oxidative stress and anemia.

OBJECTIVES

The main purpose of this study was to investigate whether patients with diabetes undergoing hemodialysis (HD) were susceptible to oxidative stress and whether resulting damages affect the structure of hemoglobin (Hb) and plasma proteins.

PATIENTS AND METHODS

Twenty patients with diabetes undergoing HD, 20 patients with diabetes and normal renal function, and 20 age- and sex-matched healthy subjects were included in this study. Methaemoglobin (Met-Hb), hemichrome and conformational changes of Hb were analyzed as oxidative markers in erythrocytes. Ferric reducing ability of plasma (FRAP) and protein carbonyl content (PCO) were determined as plasma oxidative biomarkers. Also triglyceride, cholesterol, albumin, blood urea nitrogen (BUN), creatinine, glucose and uric acid were assayed as biochemical parameters of plasma.

RESULTS

Patients with diabetes undergoing hemodialysis had significantly lower levels of PCO and albumin (P < 0.05), but significantly higher levels of FRAP, BUN, creatinine and uric acid (P < 0.05) as compared to patients with diabetes and normal renal function. Linear regression analysis showed significant negative correlations between PCO and FRAP (r = -0.53), oxy-Hb (r = -0.88) and Hb absorbance at 340 nm (r = -0.79), 420 nm (r = -0.85) and 577 nm (r = -0.68) in patients with diabetes undergoing hemodialysis. Also PCO was significantly and positively correlated with Hb absorbance at 275 nm (r = 0.63) and 560 nm (r = 0.61) which confirmed the oxidative damage to erythrocytes in control subjects.

CONCLUSIONS

Hemodialysis exacerbates oxidative stress and conformational changes of Hb in patients with diabetes on hemodialysis. The FRAP value can be used as a positive determinant, while PCO and Hb derivatives can be used as negative determinants of oxidative stress in patients with diabetes.

Age is not a contraindication to home-based dialysis - Quality-of-Life outcomes favour older patients on peritoneal dialysis regimes relative to younger patients

AIM

To compare Quality of Life, anxiety and depression between older (≥65 years) and younger (<65 years) patients across automated peritoneal dialysis and continuous ambulatory peritoneal dialysis.

BACKGROUND

There is a lack of studies as to whether the different peritoneal dialysis modalities confer similar outcomes in older and younger patients.

DESIGN

Cross-sectional.

METHODS

A total of 201 patients completed the Kidney Disease Quality of Life Short-Form, World Health Organization Quality of Life Instrument, Short Form and Hospital Anxiety and Depression Scale. Comorbidity and biochemical values were abstracted from medical records.

RESULTS

Older patients reported significantly better quality of life than younger patients in the Kidney Disease Quality of Life Short-Form effects of kidney disease and patient satisfaction and the World Health Organization Quality of Life Instrument overall Quality-of-Life/health despite worse clinical profile. Quality of life outcomes were comparable between automated peritoneal dialysis and continuous ambulatory peritoneal dialysis with the exception of the Kidney Disease Quality of Life Short-Form symptoms in favour of automated peritoneal dialysis. Levels of anxiety and depression were equivalent for older and younger patients across peritoneal dialysis modalities. The observed quality-of-life advantages for older patients persisted after case-mix adjustments and extended to more quality-of-life domains and depression and anxiety.

CONCLUSION

Our findings of superior quality of life in patients aged ≥ 65 support the expansion of peritoneal dialysis use in older patients. Patients across different age groups should be given non-biased information about both peritoneal dialysis modalities and individual preferences should be elicited and carefully considered by healthcare providers.

Optimization and evaluation of magnetic bead separation combined with matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS) for proteins profiling of peritoneal dialysis effluent

Peritoneal dialysis effluent (PDE) potentially carries an archive of peptides relevant to pathological processes in abdominal and surrounding tissues. Magnetic beads and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is one such approach that offers a unique tool for profiling of peptides, but this approach has not been used in the PDE analysis. In this study, we developed a strategy for screening PDE proteins <15 kDa and applied this technique to identify potential biomarkers for peritonitis. We examined four kinds of magnetic beads, including a carbon series (C3, C8), weak cation exchange (WCX) and immobilized metal-affinity chromatography (IMAC-Cu) beads. Samples processed with IMAC-Cu magnetic beads consistently showed more MS signals across all beads within the measured mass range. Moreover, there was no difference in the number and morphology of MS signals between concentrated and unconcentrated samples. The PDE peptidome pattern, based on a panel of 15 peaks, accurately recognized peritonitis PD patients from peritonitis-free patients with sensitivity of 90.5% and specificity of 94.7% respectively. Therefore, IMAC-Cu magnetic beads and unconcentrated samples can be used as a fast and cost-effective approach for sample preparation prior to more in-depth discovery of predictive biomarkers of disease in patients on dialysis.

Residual renal function in children treated with chronic peritoneal dialysis

Residual renal function (RRF) in patients with end-stage renal disease (ESRD) receiving renal replacement therapy is defined as the ability of native kidneys to eliminate water and uremic toxins. Preserved RRF improves survival and quality of life in adult ESRD patients treated with peritoneal dialysis. In children, RRF was shown not only to help preserve adequacy of renal replacement therapy but also to accelerate growth rate, improve nutrition and blood pressure control, reduce the risk of adverse myocardial changes, facilitate treatment of anemia and calcium-phosphorus balance abnormalities, and result in reduced serum and dialysate fluid levels of advanced glycation end-products. Factors contributing to RRF loss in children treated with peritoneal dialysis include the underlying renal disease such as hemolytic-uremic syndrome and hereditary nephropathy, small urine volume, severe proteinuria at the initiation of renal replacement therapy, and hypertension. Several approaches can be suggested to decrease the rate of RRF loss in pediatric patients treated with chronic peritoneal dialysis: potentially nephrotoxic drugs (e.g., aminoglycosides), episodes of hypotension, and uncontrolled hypertension should be avoided, urinary tract infections should be treated promptly, and loop diuretics may be used to increase salt and water excretion.

Dialysis adequacy in Chinese anuric peritoneal dialysis patients

PURPOSE

We aimed in this study to explore how lower-protein diet would affect dialysis adequacy in anuric peritoneal dialysis (PD) patients.

METHODS

Patients' demographic features were collected, namely age, gender, weight, height, underlying renal disease, and time on PD. Urea kinetic model was used to assess solute clearance. A consecutive 3-day dietary record was collected to evaluate dietary protein intake (DPI), and normalized protein nitrogen appearance (nPNA) was also calculated to reflect protein intake. Blood samples were collected to measure hemoglobin and biochemistry. Patient's nutritional status was assessed by biochemistry, handgrip strength, and subjective global assessment (SGA). Body fluid distribution was measured by body composition monitor.

RESULTS

Patients were 60.8 ± 14.92 years old, and the time on PD was 40.15 ± 22.90 months. Daily prescribed dialysis dose was 7,178 ± 1,326 mL. Kt/V was 1.6 ± 0.32. DPI was 0.8 ± 0.25 g/kg/day. nPNA was 0.9 ± 0.21 g/kg/day. Serum albumin was 39.42 ± 4.83 g/L. Prevalence of malnutrition (assessed by SGA) was 20.2 %. Serum phosphate and serum bicarbonate were 1.68 ± 0.47 and 27.16 ± 3.49 mmol/L, respectively. Systolic blood pressure and diastolic blood pressure were 123.4 ± 20.0 and 74.2 ± 12.6 mmHg, respectively. Patients with nPNA less than 0.6 had significantly lower serum albumin concentrations than the average, and patients with nPNA more than 1.2 g/kg/day had significantly higher levels of serum phosphate and serum urea than the average.

CONCLUSIONS

Our study suggested that anuric PD patients could achieve adequate dialysis even under lower solute clearance. And lower-protein diet contributed largely to adequate dialysis in these patients.

Comparing mortality of peritoneal and hemodialysis patients in the first 2 years of dialysis therapy: a marginal structural model analysis

BACKGROUND AND OBJECTIVES

There are conflicting research results about the survival differences between hemodialysis and peritoneal dialysis, especially during the first 2 years of dialysis treatment. Given the challenges of conducting randomized trials, differential rates of modality switch and transplantation, and time-varying confounding in cohort data during the first years of dialysis treatment, use of novel analytical techniques in observational cohorts can help examine the peritoneal dialysis versus hemodialysis survival discrepancy.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study examined a cohort of incident dialysis patients who initiated dialysis in DaVita dialysis facilities between July of 2001 and June of 2004 and were followed for 24 months. This study used the causal modeling technique of marginal structural models to examine the survival differences between peritoneal dialysis and hemodialysis over the first 24 months, accounting for modality change, differential transplantation rates, and detailed time-varying laboratory measurements.

RESULTS

On dialysis treatment day 90, there were 23,718 incident dialysis-22,360 hemodialysis and 1,358 peritoneal dialysis-patients. Incident peritoneal dialysis patients were younger, had fewer comorbidities, and were nine and three times more likely to switch dialysis modality and receive kidney transplantation over the 2-year period, respectively, compared with hemodialysis patients. In marginal structural models analyses, peritoneal dialysis was associated with persistently greater survival independent of the known confounders, including dialysis modality switch and transplant censorship (i.e., death hazard ratio of 0.52 [95% confidence limit 0.34-0.80]).

CONCLUSIONS

Peritoneal dialysis seems to be associated with 48% lower mortality than hemodialysis over the first 2 years of dialysis therapy independent of modality switches or differential transplantation rates.

Patient outcome in primary peritoneal dialysis patients versus those transferred from hemodialysis and transplantation

BACKGROUND

According to the concept of integrated care, renal transplantation, peritoneal dialysis (PD), and hemodialysis (HD) should be considered three complementary methods of renal replacement therapy. This study tried to evaluate patient outcomes in three different groups of PD patients, namely primary PD patients, those transferred to PD with failing kidney transplant, and those transferred to PD from HD.

METHOD

From January 1, 1995, to end of 2006 from 26 PD centers, 1,355 patients including demographic, clinical and laboratory data, which were monthly collected through questionnaires, were enrolled in the study. We compared patients' characteristics, factors affecting patient survival, and patient outcomes between primary PD patients (group 1, n = 1,067), patients transferred from transplantation (group 2, n = 43) and those transferred from HD (group 3, n = 245), which had been on HD for at least 3 months before switching to PD.

RESULTS

There was no difference in the proportion of patients with diabetes in the three groups. Overall, 238 patients (17.5%) were transferred to HD but there was no significant difference in PD technique survival on between the three groups. Death occurred in 256 (24%), 3 (7%) and 65 (26.5%) subjects in groups 1, 2 and 3, respectively. Most patients (81.5%) in group 2 underwent re-transplantation. The Kaplan-Meier survival rates were not different between the three groups. In the Cox multiple regression model, age, presence of diabetes and serum albumin level significantly influenced patient survival.

CONCLUSION

We concluded that PD could be considered safe for patients experiencing complications on HD, as well as for those with renal transplantation.

Time to move away from damage control strategy in hemodialysis vascular access management: a view from Saudi Arabia

For the last 40 years, most of the research and publications on hemodialysis access, has focused on the management of its complications e.g. thrombosis, infection, aneurysms. In other words, a damage control strategy. While this is undoubtedly an important part of access management, it is a deficient reactive strategy that does not enhance a better quality of life for patients or help reduce the burden on health care resources. To achieve these objectives, efforts should be directed at ways which provide a longer access life with fewer complications. Such an approach would save costs and reduce the suffering of the patient. In this paper we will focus on hemodialysis management in Saudi Arabia, describe the reasons for the current unsatisfactory situation, and highlight possible remedies.

Fluid flow stress affects peritoneal cell kinetics: possible pathogenesis of peritoneal fibrosis

BACKGROUND

Peritoneal fibrosis is an essential precursor condition to the development of encapsulating peritoneal sclerosis (EPS). This serious complication leads to a high mortality rate in peritoneal dialysis (PD) patients. Although several factors, including highly concentrated glucose in the dialysis solution, are believed to be potent agents for peritoneal fibrosis, the underlying mechanism remains unclear. During PD, the dialysis solution continuously generates fluid flow stress to the peritoneum under peristalsis and body motion. Fluid flow stress has been implicated as playing a critical role in the physiologic responses of many cell types. We therefore hypothesized that fluid flow stress may be involved in the pathogenesis of peritoneal fibrosis leading to EPS.

METHODS

To generate fluid flow stress, culture containers were placed on a rotatory shaker in a thermostatic chamber. In this system, the shaker rotated at a speed of 25 rpm with a radius of 1.5 cm. Mesothelial cells were cultured in low-glucose (1000 mg/L) or high-glucose (4500 mg/L) complete medium with and without flow stress.

RESULTS

Fluid flow stress promoted hyperplasia and epithelial-mesenchymal transition (EMT) of mesothelial cells independent of glucose concentration. Fluid flow stress inhibited expression of ERK (extracellular signal-regulated kinase) and p38 MAPK (mitogen-activated protein kinase) in mesothelial cells. Administration of ERK and p38 MAPK inhibitors replicated the stress-induced morphology of mesothelial cells.

CONCLUSIONS

The present data indicate that fluid flow stress promotes hyperplasia and EMT of mesothelial cells via the MAPK axis, suggesting that fluid flow stress may be involved in the pathogenesis of peritoneal fibrosis.

Peritoneal dialysis (PD) is a successful treatment after complete haemodialysis (HD) blood access failure complicated with superior vena cava syndrome (SVCS)

SVCS constitutes a serious clinical problem and often represents a definitive loss of vascular access for haemodialysis (HD). The patients must suffer numerous interventions in order to obtain a permanent vascular access for HD. Treatment of SVCS requires endovascular intervention or complex surgical revascularization. We present three patients with SVCS associated with central indwelling catheters for HD who were switched to peritoneal dialysis (PD) due to complete HD blood access failure, and discuss the evolution on PD.

Vascular Access Planning in Peritoneal Dialysis Patients

Peritoneal dialysis (PD) is a well-established renal replacement therapy for end-stage renal disease patients. Nonetheless, on an annual basis, at least 10% of patients shift from PD to hemodialysis for a variety of reasons. Thus the issue of vascular access creation needs to be addressed for this small but significant group of patients. Despite the relatively consistent number of dropouts, the creation of an arteriovenous fistula prior to transfer remains suboptimal, and variable from center to center. Literature for this specific area is poor and dated. Guidelines seem to suggest vascular access creation in high-risk failure patients, but they have no detailed criteria to select patients that would likely fail PD and therefore take advantage of a backup access. There is a need to better understand and predict patients that require conversion to hemodialysis to develop a plan that focuses on wellness and maximum quality of life in the lifecycle of PD patients. This review addresses the issue of vascular access planning in adult PD patients, presents the available literature on the topic and the current guidelines and recommendations, and describes a research agenda to guide decision making in clinical practice.

Oxidative Stress in Children on Peritoneal Dialysis

Objectives

Enhanced oxidative stress has been observed in dialysis and predialysis adult patients with chronic kidney disease (CKD), which resulted in increased mortality and morbidity within this population. Not much attention in the literature has been paid to nonenzymatic antioxidant defense in children with CKD on peritoneal dialysis (PD). The aim of the present study was to describe the plasma, erythrocyte, and dialysate concentrations of oxidized (GSSG) and reduced glutathione (GSH) and vitamins A, E, and C in a pediatric PD population.

Patients

10 children on PD and 27 age-matched healthy subjects were enrolled in the study.

Results

Erythrocyte and plasma GSH concentrations were lower in PD patients, erythrocyte concentration of GSSG remained unchanged, and plasma GSSG was significantly higher in children on PD. Children on PD exhibited decreased plasma concentrations of antioxidant vitamins compared to healthy subjects. Moreover, we documented loss of vitamins A, E, and C into ultrafiltrate.

Conclusion

Such low plasma levels of vitamins A, E, and C and simultaneously decreased activity of erythrocyte GSH may be responsible for the increased oxidative stress occurring in children with CKD on PD.

Governing therapy choices: power/knowledge in the treatment of progressive renal failure

This article outlines the struggle between the power of the health care professional and the rights of the individual to choose freely a modality of treatment. Nurses are instrumental in assisting patients in making the best decision for a therapy they will have to assume for the rest of their lives. In guiding patients' decision, nurses must take into account these unavoidable contingencies: changes in lifestyle, nutritional restrictions, level of acceptance, compliance issues, ease of training and availability of support/facilities. Ensuring that the patient makes an informed decision is therefore an ongoing challenge for nurses as they are taking part in a delicate balancing act between not directly influencing the patient's decision while making sure the patient is accurately informed.

Development of a computer-aided diagnosis system for a new modality of renal replacement therapy: an integrated approach combining both peritoneal dialysis and hemodialysis

The authors developed a computer-aided diagnosis system that includes a simple clinical test for the chronic renal disease patient who needs an integrated approach that combines both peritoneal dialysis and hemodialysis (PD-HD therapy). In this case study, the system simulated and estimated the dialysis outcome, the ultrafiltration volume and nutritional analysis by employing a pharmacokinetic model, and assessed the peritoneal permeable enhancement that can be a grave complication with peritoneal dialysis. This system requires only a minimum amount of nursing time and may be able to predict the optimal treatment schedule for PD-HD therapy and provide therapeutic monitoring in long-term peritoneal dialysis.

The importance of standardization of creatinine in the implementation of guidelines and recommendations for CKD: implications for CKD management programmes

BACKGROUND

In an attempt to reduce late referral and to improve the care of patients with chronic kidney disease (CKD), different organizations have issued guidelines on when to refer patients to the nephrologist. Most suggest referral of patients with a GFR below 60 ml/min/1.73 m2, and demand referral if the GFR is below 30 ml/min/1.73 m2. It is recommended to use the abbreviated MDRD equation to estimate GFR. This formula is, however, sensitive to the creatinine assay methodology. In addition, the impact of the implementation of such guidelines on the nephrology practice has never been evaluated. This study (i) identifies the true burden of CKD in a population and simulates the effects of a 100% implementation of the guidelines on the nephrology work load, and (ii) evaluates the validity of the estimated GFR using the abbreviated MDRD formula when routinely provided.

METHODS

Different laboratories (both hospital and private) in our region were asked to report on all the serum creatinine values performed during the first week of December 2004. If patients had more than one determination, only the lowest serum creatinine value was retained. Patients already known to a nephrology unit were not included. GFR was calculated using the abbreviated MDRD, using the serum creatinine as reported by these laboratories, or after correction to the MDRD-standard using different published equations.

RESULTS

20,108 patients, with a mean age of 53.4+/-16.2 years, 48% females, had at least one serum creatinine determination in the observation period. According to the K/DOQI CKD classification, 20.2, 1.6 and 0.8% of females and 13.3, 1.6 and 0.6% of males were in stage 3, 4 and 5, respectively, when the abbreviated MDRD formula was used with the serum creatinine value as reported by the laboratories. Important differences in classifications were obtained when the different correction formulae for creatinine were applied. According to the current recommendations, this would lead to a mandatory referral of 1650-2400 CKD stage 4 patients per 100 000 inhabitants and a suggested referral of another 4100-15 360 CKD stage 3 patients per 100,000 inhabitants to a nephrology unit.

CONCLUSION

Implementation of the current guidelines for referral of CKD patients to nephrologists would lead to an overload of the nephrology care capacities. Large differences in estimated GFRs with different corrections for serum creatinine are observed, resulting in important CKD classification differences. Standardization of serum creatinine assays is mandatory before guidelines, and especially the routine provision of the estimated GFR by the abbreviated MDRD formula, can be implemented in clinical practice.

Survival differences between peritoneal dialysis and hemodialysis among "large" ESRD patients in the United States

BACKGROUND

It has been hypothesized that peritoneal dialysis compared to hemodialysis may be less effective in large patients with end-stage renal disease (ESRD).

METHODS

We tested this hypothesis in a cohort of 134,728 new ESRD patients who were initiated on dialysis from May 1, 1995 to July 31, 1997 using data from United States Renal Data System (USRDS). Cox regression models evaluated the association of body mass index (BMI) in quintiles (8.8-20.9, 20.9-23.5, 23.5-26.1, 26.1-30.0, 30.0-75.2 kg/m(2)) with mortality over 2 years in peritoneal dialysis and hemodialysis patients separately, while time-dependent models evaluated the relative risk (RR) of death by modality for each BMI quintile.

RESULTS

For hemodialysis, the adjusted RR of death was greatest for patients with BMI <or = 20.9 (RR = 1.40, 95% CI 1.32-1.50 for diabetics and RR = 1.27, 95% CI 1.21-1.34 for nondiabetics) and lowest for patients with BMI >30.0 (RR = 0.97, 95% CI 0.96-0.99 for diabetic and RR = 0.97, 95% CI 0.95-0.98 for nondiabetic patients) compared with the referent (23.5-26.1; RR = 1.00). For peritoneal dialysis, the RR of death was also higher for patients with a BMI <20.9 (RR = 1.20, 95% CI 1.00-1.43 for diabetic and RR = 1.39, 95% CI 1.19-1.64 for nondiabetic patients) but no survival advantage was associated with higher BMI values. The RR of death (peritoneal dialysis/hemodialysis) for each BMI quintile was 0.99, 1.12, 1.26 (P < 0.01), 1.15 (P < 0.01), and 1.44 (P < 0.0001) for diabetic and were 1.07, 1.01, 0.96, 1.04, and 1.22 (P < 0.01) for nondiabetic patients, respectively.

CONCLUSION

We conclude that body size modifies the impact of dialysis modality on mortality risk among new ESRD patients in the United States. The selection of hemodialysis over peritoneal dialysis was associated with a survival advantage in patients with large body habitus.

The Euro-Balance Trial: The effect of a new biocompatible peritoneal dialysis fluid (balance) on the peritoneal membrane

BACKGROUND

Although peritoneal dialysis (PD) is a widely accepted form of renal replacement therapy (RRT), concerns remain regarding the bioincompatible nature of standard PD fluid. In order to evaluate whether a newly formulated fluid of neutral pH, and containing low levels of glucose degradation products (GDP), resulted in improved in vivo biocompatibility, it was compared in a clinical study to a standard PD fluid.

METHODS

In a multicenter, open, randomized, prospective study with a crossover design and parallel arms, a conventional, acidic, lactate-buffered fluid (SPDF) was compared with a pH neutral, lactate-buffered, low GDP fluid (balance). Overnight effluent was collected and assayed for cancer antigen 125 (CA125), hyaluronic acid (HA), procollagen peptide (PICP), vascular endothelial growth factor (VEGF), and tumor necrosis factor alpha (TNFalpha). Serum samples were assayed for circulating advanced glycosylation end products (AGE), N(epsilon)-(carboxymethyl)lysine (CML), and imidazolone. Clinical end points were residual renal function (RRF), adequacy of dialysis, ultrafiltration, and peritoneal membrane function. Eighty-six patients were randomized to either group I starting with SPDF for 12 weeks (Phase I), then switching to "balance" for 12 weeks (Phase II), or group II, which was treated vice versa. Seventy-one patients completed the study with data suitable for entry into the per protocol analysis. Effluent and serum samples, together with peritoneal function tests and adequacy measurements, were undertaken at study centers on three occasions during the study: after the four-week run-in period, after Phase I, and again after Phase II.

RESULTS

In patients treated with balance there were significantly higher effluent levels of CA125 and PICP in both arms of the study. Conversely, levels of HA were lower in patients exposed to balance, while there was no change in the levels of either VEGF or TNFalpha. Serum CML and imidazolone levels fell significantly in balance-treated patients. Renal urea and creatinine clearances were higher in both treatment arms after patients were exposed to balance. Urine volume was higher in patients exposed to balance. In contrast, peritoneal ultrafiltration was higher in patients on SPDF. When anuric patients were analyzed as a subgroup, there was no significant difference in peritoneal transport characteristics or in ultrafiltration on either fluid. There were no changes in peritonitis incidence on either solution.

CONCLUSION

This study indicates that the use of balance, a neutral pH, low GDP fluid, is accompanied by a significant improvement in effluent markers of peritoneal membrane integrity and significantly decreased circulating AGE levels. Clinical parameters suggest an improvement in residual renal function on balance, with an accompanying decrease in peritoneal ultrafiltration. It would appear that balance solution results in an improvement in local peritoneal homeostasis, as well as having a positive impact on systemic parameters, including circulating AGE and residual renal function.

Important differentiation of factors that predict outcome in peritoneal dialysis patients with different degrees of residual renal function

BACKGROUND

Residual renal function (RRF) is an important predictor of outcome in peritoneal dialysis (PD) patients. Whether results from survival studies in dialysis patients with RRF can also be extrapolated to anuric patients remains uncertain. In this observational study, we examined the characteristics of PD patients with a residual glomerular filtration rate (GFR) > or =1 ml/min per 1.73 m2 vs those with complete anuria and differentiated factors that predict outcome in the two groups of patients.

METHODS

Two hundred and forty-six continuous ambulatory peritoneal dialysis (CAPD) patients (39% being completely anuric) were recruited from a single regional dialysis centre. Assessments of haemodynamic, echocardiographic, nutritional and biochemical parameters and indices of dialysis adequacy were done at study baseline and were related to outcomes.

RESULTS

During the prospective follow-up of 30.8+/-13.8 (mean+/-SD) months, 28.0% of patients with residual GFR > or =1 ml/min per 1.73 m2 vs 50.5% of anuric patients had died (P = 0.005). The overall 2 year patient survival was 89.7 and 65.0% for patients with GFR > or =1 ml/min per 1.73 m2 and anuric patients, respectively (P = 0.0012). Compared with patients with GFR > or =1 ml/min per 1.73 m2, anuric patients were dialysed for longer (P<0.001), were more anaemic (P<0.005), and had higher calcium-phosphorus product (P<0.01), higher C-reactive protein (P<0.001), lower serum albumin (P<0.05), greater prevalence of malnutrition according to subjective global assessment (P<0.05) and more severe cardiac hypertrophy (P<0.001) at baseline. Using multivariable Cox regression analysis, serum albumin, left ventricular mass index and residual GFR were significant factors associated with mortality in patients with GFR > or =1 ml/min per 1.73 m2, while increasing age, atherosclerotic vascular disease and higher C-reactive protein were associated with greater mortality in anuric PD patients.

CONCLUSIONS

Our study demonstrates more adverse cardiovascular, inflammatory, nutritional and metabolic profiles as well as higher mortality in anuric PD patients. Furthermore, factors associated with mortality are also not equivalent for PD patients with and without RRF, suggesting that patients with and without RRF are qualitatively different.

Effects of an angiotensin II receptor blocker, valsartan, on residual renal function in patients on CAPD

BACKGROUND

Both residual renal function and blood pressure (BP) control contribute to patient survival in patients receiving continuous ambulatory peritoneal dialysis (CAPD). It is unknown whether antihypertensive drugs affect residual renal function in addition to BP reduction.

METHODS

We examined the effects of an angiotensin II receptor blocker, valsartan, on residual renal function and total clearance (renal and peritoneal) in 34 Japanese CAPD patients from 3 months to 2 years after the start of dialysis therapy. Patients were randomly assigned to valsartan (n = 18; age, 63.5 +/- 3.7 years; 11 men, 7 women) or a control group (n = 16; age, 63.5 +/- 3.3 years; 10 men, 6 women). Conventional antihypertensive treatment was continued in all patients to achieve the target BP in both groups of 130/80 mm Hg or less, measured at home.

RESULTS

BP reduction was similar in the valsartan and control groups. Valsartan significantly slowed the progressive decline in both residual renal function (3.2 +/- 0.3 to 4.3 +/- 0.7 mL/min/1.73 m2) and total clearance (42.1 +/- 3.2 to 48.3 +/- 4.8 L/wk/1.73 m2) by dialysis in CAPD patients compared with controls (5.9 +/- 0.5 to 2.8 +/- 0.4 mL/min/1.73 m2; 47.1 +/- 4.8 to 31.4 +/- 5.2 L/wk/1.73 m2).

CONCLUSION

This study shows that in patients with hypertension starting CAPD therapy, valsartan slows the decline in residual renal function and contributes to maintenance of weekly creatinine clearance and Kt/V (fraction per dialysis), which are the major factors contributing to the mortality and morbidity of CAPD patients. This effect appears to be mostly a result of maintaining residual renal function.

Icodextrin: a review of its use in peritoneal dialysis

Icodextrin (Extraneal) is a high molecular weight glucose polymer developed specifically for use as an alternative osmotic agent to dextrose during the once-daily long-dwell exchange in peritoneal dialysis (PD). Isosmotic 7.5% icodextrin solution induces transcapillary ultrafiltration (UF) by a mechanism resembling 'colloid' osmosis (unlike hyper-osmolar dextrose-based solutions, which induce UF by crystalline osmosis). In addition, absorption of icodextrin from the peritoneal cavity is relatively slow compared with that of dextrose; this results not only in UF of longer duration, but also a lower carbohydrate load compared with medium (2.5%) and strong (4.25%) dextrose exchanges. In randomised clinical trials of up to 2 years in duration, administration of icodextrin for the long (8- to 16-hour) overnight exchange in continuous ambulatory peritoneal dialysis (CAPD) or daytime exchange in automated peritoneal dialysis (APD) produced net UF which exceeded that with 1.5% and 2.5% dextrose solutions (thereby improving fluid balance), and was equivalent to that with 4.25% dextrose solution. Icodextrin also increased peritoneal clearances of creatinine and urea nitrogen compared with 2.5% dextrose solution. The increase in UF volume with icodextrin was enhanced in CAPD patients with high peritoneal membrane permeability (i.e. high and high-average transporters), maintained in the small number of patients followed-up for 2 years and sustained during episodes of peritonitis. Icodextrin reduced the percentage of patients with net negative UF in contrast to 1.5% and 2.5% dextrose and, in noncomparative studies, extended PD technique survival in patients who had failed dextrose-based dialysis. The use of icodextrin was also associated with some symptomatic improvements and health-related quality of life advantages, and no adverse effect on patient survival, compared with dextrose, although confirmation of these findings is ideally required in appropriately designed studies. The tolerability of icodextrin was generally similar to that of dextrose-based solutions in controlled clinical trials, although there was an approximate three-fold increase in the risk of new skin rash (5.5% vs 1.7%). However, reports of severe cutaneous hypersensitivity reactions remain rare; this possibility should not preclude the use of the polymer.

CONCLUSION

7.5% icodextrin solution offers the first feasible alternative to conventional dextrose solutions for the once-daily long-dwell exchange in PD. It is effective, generally well tolerated and appears to be most useful in situations of reduced or inadequate UF with dextrose, including in high and high-average transporters, during episodes of peritonitis and patients who have failed dextrose-based dialysis.

Personal dialysis capacity (PDC(TM)) test: a multicentre clinical study

BACKGROUND

The assessment of the peritoneal membrane capacity and physiology of the individual patient is becoming increasingly important. It allows the prescription of an individualized peritoneal dialysis (PD)-regimen, and the monitoring of peritoneal membrane function over time. The PDC(TM) program offers the possibility to evaluate the peritoneal membrane characteristics and to predict solute and water removal by simulation of different treatment regimens.

METHODS

This study evaluates the relevance of the PDC(TM) program when routinely used. The PDC(TM) data of 336 patients from nine different centres in Europe were evaluated.

RESULTS

The area parameter was 20 985+/-7578 cm/1.73 m(2) (mean+/-SD). The reabsorption of fluid after dissipation of glucose, Jv(AR), was 1.97+/-1.00 ml/min/1.73 m(2). The large pore fluid flux, Jv(L), was 0.11+/-0.07 ml/min/1.73 m(2). A multivariate model for prediction of serum albumin included dialysate protein loss, Jv(L), Jv(AR), nPCR, A(0)/deltaX, BMI and gender (R(2)=0.81, P<0.001). Total clearance fell with increasing PD duration (P<0.001). A negative relation between A(0)/deltaX and ultrafiltration (rho=-0.26, P<0.05), a positive relation between A(0)/deltaX and peritoneal creatinine clearance (rho=0.52, P<0.05) and urea clearance (rho=0.36, P<0.05), and a positive relation between measured peritoneal creatinine and urea clearance (rho=0.64, P<0.01) was observed.

CONCLUSIONS

In summary, the present study shows that the PDC(TM) program is a robust, accurate method to describe the peritoneal membrane transport characteristics. Analysis of PDC(TM) data of large groups of patients, especially if followed up over time, can give interesting information on the physiology of the peritoneal membrane and the impact of different parameters on it.

The role of APD in the improvement of outcomes in an ESRD program

We review the role of automated peritoneal dialysis (APD) in improving outcomes of an end-stage renal disease (ESRD) program. As the "integrated care approach" becomes accepted as the preferred strategy for treatment of ESRD patients, we looked for the potential place of APD in such an approach. APD has probably the same advantages as CAPD as a first-line renal replacement modality in suitable patients willing to perform PD. There is currently no hard evidence that residual renal function (RRF) should decline more rapidly in APD than in CAPD, at least if a dry abdomen during the day is avoided. The detection of peritonitis is probably more delayed in APD, but the frequency of peritonitis is lower, and there is no hard evidence pointing to a poorer outcome of peritonitis in APD as compared to CAPD. Quality of life is at least as good in APD, which is mostly related to the increased possibilities for adapting the exchange pattern to employment-related time frames. APD also has the potential to prolong technique success in patients failing CAPD rather than transferring them to hemodialysis. Nevertheless, APD remains more expensive and technically complicated, thereby missing the beauty of CAPD's simplicity. Therefore we believe that APD has its role in an integrated approach and that all patients should be informed of its potential. It would, however, not be correct to present APD as the preferred PD method for all patients, as it also has some drawbacks that make it less suitable for some categories of patients. In all cases, patients should have a free and informed choice.