II. NKF-K/DOQI Clinical Practice Guidelines for Peritoneal Dialysis Adequacy: update 2000

The relationship between changes in peritoneal permeability with CA-125 and HIF-1α

BACKGROUND

Peritoneal fibrosis (PF) is a major, persistent complication of prolonged peritoneal dialysis that eventually leads to peritoneal ultrafiltration failure and termination of peritoneal dialysis. Prolonged exposure to high glucose concentrations, degradation products, uremic toxins, and episodes of peritonitis can cause some changes in the peritoneal membrane, resulting in intraperitoneal inflammation and PF, leading to failure of ultrafiltration and dialysis. CA-125 can be used as a biomarker of peritoneal mesothelial cell count in the peritoneal dialysate and for monitoring cell count in PD patients. Hypoxia-inducible factor 1-alpha (HIF-1α) has been reported to cause PF, but has not been reported to be associated with changes in peritoneal structure. We hypothesized that peritoneal adequacy can be followed using HIF-1α and CA-125 values. In the present study, therefore, we investigated the relationship between HIF-1α and CA-125 levels and parietal membrane permeability changes in PD patients.

METHODS

Forty-five patients were included in the study. Peritoneal permeability was constant in 20 of these, while peritoneal permeability increased in 11 and decreased in 14. The HIF-1α value from the blood samples of the patients and the CA-125 measurement from the peritoneal fluids were measured. The relationship between peritoneal variability and CA-125 and HIF levels after follow-up was investigated.

RESULTS

We compared serum HIF-1α and peritoneal fluid CA-125 levels in the three groups receiving peritoneal dialysis treatment. HIF-1α levels increased with peritoneal permeability changes, while CA-125 levels decreased. In patients with high to low permeability changes, HIF-1α levels were higher compared to those with stable or low to high changes, which was statistically significant. Conversely, CA-125 levels significantly decreased in patients whose peritoneal permeability changed from high to low, compared to the other two groups.

CONCLUSION

Changes in peritoneal structure can be followed with biomarkers. It has been shown that CA-125 and HIF-1α levels can guide the changes in the peritoneal membrane. This can be useful in the monitoring of peritoneal dialysis.

Residual Kidney Function in Hemodialysis: Its Importance and Contribution to Improved Patient Outcomes

Individuals afflicted with advanced kidney dysfunction who require dialysis for medical management exhibit different degrees of native kidney function, called residual kidney function (RKF), ranging from nil to appreciable levels. The primary focus of this manuscript is to delve into the concept of RKF, a pivotal yet under-represented topic in nephrology. To begin, we unpack the definition and intrinsic nature of RKF. We then juxtapose the efficiency of RKF against that of hemodialysis in preserving homeostatic equilibrium and facilitating physiological functions. Given the complex interplay of RKF and overall patient health, we shed light on the extent of its influence on patient outcomes, particularly in those living with advanced kidney dysfunction and on dialysis. This manuscript subsequently presents methodologies and measures to assess RKF, concluding with the potential benefits of targeted interventions aimed at preserving RKF.

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.

Correlation of Serum Asprosin Levels With Normalized Protein Catabolic Rate in Patients Receiving Peritoneal Dialysis Treatment

Background Peritoneal dialysis patients are malnourished due to loss of protein in the dialysate and inadequate dialysis, although they take additional calories every day during treatment. Many parameters are used to assess nutritional status, with normalized protein catabolic rate (nPCR) being one of the most common. Asprosin, a novel adipokine secreted by adipose tissue, peaks during fasting and induces hepatic glucose release through the activation of the G-protein-cAMP-PKA pathway, which has been indicated to have a curative effect on chronic inflammation. In this study, we aimed to investigate the relationship between asprosin levels and nutritional parameters in patients receiving peritoneal dialysis treatment as well as to investigate the applicability of more practical tests. Methodology A total of 70 peritoneal dialysis patients, 35 female (59%) and 24 male (41%), were included in the study. The mean age of the patients was 53 ± 14 years (range = 18-80 years), and the median peritoneal dialysis duration was 31.5 months (range = 20-56.2 months). The most common etiologic cause was hypertension (37%). Patients over 18 years of age who had been receiving peritoneal dialysis treatment for at least 24 months were included in the study. The correlation between patients' nPCR levels and serum asprosin, body mass index, and lipids was evaluated. Results The correlation between the level of nPCR and the serum asprosin level, body mass index, and lipids was evaluated. Patients with nPCR <0.815 were considered malnourished, and factors affecting malnutrition were determined by univariate analysis. Among the factors affecting malnutrition according to univariate analysis, those with p-value <0.05 were analyzed by multivariate analysis. Low asprosin level was one of the independent factors affecting malnutrition in patients (Exp(B) = 0.944, 95% confidence interval (CI) = 0.896-0.994). Other independent factors affecting malnutrition were Kt/V (Exp(B) = 0.018, 95% CI = 0.001-0.550) and residual renal function (Exp(B) = -0.004, 95% CI = 0.993-0.999). Conclusions There is a need for more accessible tests and reliable parameters to evaluate dialysis and nutritional deficiency in peritoneal dialysis patients. One possible hormone that could serve as a guide is asprosin.

Fibrosis of Peritoneal Membrane, Molecular Indicators of Aging and Frailty Unveil Vulnerable Patients in Long-Term Peritoneal Dialysis

Peritoneal membrane status, clinical data and aging-related molecules were investigated as predictors of long-term peritoneal dialysis (PD) outcomes. A 5-year prospective study was conducted with the following endpoints: (a) PD failure and time until PD failure, (b) major cardiovascular event (MACE) and time until MACE. A total of 58 incident patients with peritoneal biopsy at study baseline were included. Peritoneal membrane histomorphology and aging-related indicators were assessed before the start of PD and investigated as predictors of study endpoints. Fibrosis of the peritoneal membrane was associated with MACE occurrence and earlier MACE, but not with the patient or membrane survival. Serum α-Klotho bellow 742 pg/mL was related to the submesothelial thickness of the peritoneal membrane. This cutoff stratified the patients according to the risk of MACE and time until MACE. Uremic levels of galectin-3 were associated with PD failure and time until PD failure. This work unveils peritoneal membrane fibrosis as a window to the vulnerability of the cardiovascular system, whose mechanisms and links to biological aging need to be better investigated. Galectin-3 and α-Klotho are putative tools to tailor patient management in this home-based renal replacement therapy.

High intraperitoneal interleukin-6 levels predict ultrafiltration (UF) insufficiency in peritoneal dialysis patients: A prospective cohort study

Introduction

UF insufficiency is a major limitation in PD efficiency and sustainability. Our study object to investigate the efficacy of intraperitoneal inflammation marker, IL-6 level as a predictor of UF insufficiency in continuous ambulatory peritoneal dialysis (CAPD) patients.

Methods

Stable prevalent CAPD patients were enrolled in this prospective study. IL-6 concentration in the overnight effluent was determined and expressed as the IL-6 appearance rate (IL-6 AR). Patients were divided into two groups according to the median of IL-6 AR and prospectively followed up until death, transfer to permanent HD, recovery of renal function, kidney transplantation, transfer to other centers, lost to follow-up or to the end of study (January 31, 2021). Factors associated with UF capacity as well as dialysate IL-6 AR were assessed by multivariable linear regression. Cox proportional hazards model was used to examine the association between dialysate IL-6 AR and UF insufficiency.

Results

A total of 291 PD patients were enrolled, including 148 males (51%) with a mean age of 56.6 ± 14.1 years and a median PD duration of 33.4 (12.7-57.5) months. No correlation was found between dialysate IL-6 AR and UF capacity at baseline. PD duration was found positively correlated with baseline dialysate IL-6 AR, while 24h urine volume was negatively correlated with baseline dialysate IL-6 AR (P < 0.05). By the end of study, UF insufficiency was observed in 56 (19.2%) patients. Patients in the high IL-6 AR group showed a significantly inferior UF insufficiency-free survival when compared with their counterparts in the low IL-6 AR group (P = 0.001). In the multivariate Cox regression analysis, after adjusting for DM, previous peritonitis episode and 24h urine volume, higher baseline dialysate IL-6 AR (HR 3.639, 95% CI 1.776-7.456, P = 0.002) were associated with an increased risk of UF insufficiency. The area under the ROC curve (AUC) for baseline IL-6 AR to predict UF insufficiency was 0.663 (95% CI, 0.580-0.746; P < 0.001).

Conclusion

Our study suggested that the dialysate IL-6 AR could be a potential predictor of UF insufficiency in patients undergoing PD.

Abnormal Calcium Metabolism Mediated Increased Risk of Cardiovascular Events Estimated by High Ankle-Brachial Index in Patients on Peritoneal Dialysis

Cardiovascular disease (CVD) is the leading cause of death in peritoneal dialysis (PD) patients. But the relationship between regular PD and the risk of major adverse cardiovascular events (MACE) remains controversial. The possible risk factors are not fully elucidated. This study aims to investigate the possible factors affecting the risk of MACE estimated by high ankle-brachial index (ABI) in PD patients. A total of 243 patients were enrolled and divided into chronic kidney diseases (CKD) stage 1, non-dialyzed CKD stages 2–5, and PD groups. The prevalence of high ABI, indicating increased MACE, was elevated with CKD progression but not further increased in PD patients. Systolic blood pressure was closely correlated with high ABI in non-dialyzed CKD patients (β = 0.059, P = 0.001). But in PD patients, serum calcium had a crucial effect on high ABI (β = −9.853, P < 0.001). Additionally, PD patients with high ABI tended to dialyze inadequately (Kt/V <1.7) compared to those with normal ABI (29.0 vs. 13.3%, P = 0.031). Further mediation analysis revealed that ~86.2% of the relationship between Kt/V and high ABI was mediated by serum calcium in PD patients (mediation effect = 86.2%, ab = −0.220, 95% CI: −0.381 to −0.059, P = 0.008), especially in those starting PD before 55 years of age and with normal body mass index. This present study indicated that improvement of PD adequacy by maintaining calcium balance might be a promising method to reduce the risk of MACE estimated by high ABI for PD patients.

Current clinical practice in adapted automated peritoneal dialysis (aAPD)-A prospective, non-interventional study

Adapted automated peritoneal dialysis (aAPD), comprising a sequence of dwells with different durations and fill volumes, has been shown to enhance both ultrafiltration and solute clearance compared to standard peritoneal dialysis with constant time and volume dwells. The aim of this non-interventional study was to describe the different prescription patterns used in aAPD in clinical practice and to observe outcomes characterizing volume status, dialysis efficiency, and residual renal function over 1 year. Prevalent and incident, adult aAPD patients were recruited during routine clinic visits, and aAPD prescription, volume status, residual renal function and laboratory data were documented at baseline and every quarter thereafter for 1 year. Treatments were prescribed according to the nephrologist's medical judgement in accordance with each center's clinical routine. Of 180 recruited patients, 160 were analyzed. 27 different aAPD prescription patterns were identified. 79 patients (49.4%) received 2 small, short dwells followed by 3 long, large dwells. During follow-up, volume status changed only marginally, with visit mean values ranging between 1.59 (95% confidence interval: 1.19; 1.99) and 1.97 (1.33; 2.61) L. Urine output and creatinine clearance decreased significantly, accompanied by reductions in ultrafiltration and Kt/V. 25 patients (15.6%) received a renal transplant and 15 (9.4%) were changed to hemodialysis. Options for individualization offered by aAPD are actually used in practice for optimized treatment. Changes observed in renal function and dialysis efficiency measures reflect the natural course of chronic kidney disease. No safety events were observed during the study period.

Management of Kidney Failure in Patients with Diabetes Mellitus: What Are the Best Options?

Diabetic kidney disease (DKD) is the most frequent cause of kidney failure (KF). There are large variations in the incidence rates of kidney replacement therapy (KRT). Late referral to nephrology services has been associated with an increased risk of adverse outcomes. In many countries, when patients reach severely reduced glomerular filtration rate (GFR), they are managed by multidisciplinary teams led by nephrologists. In these clinics, efforts will continue to halt chronic kidney disease (CKD) progression and to prevent cardiovascular mortality and morbidity. In patients with diabetes and severely reduced GFR and KF, treating hyperglycemia is a challenge, since some drugs are contraindicated and most of them require dose adjustments. Even more, a decision-making process will help in deciding whether the patient would prefer comprehensive conservative care or KRT. On many occasions, this decision will be conditioned by diabetes mellitus itself. Effective education should cover the necessary information for the patient and family to answer these questions: 1. Should I go for KRT or not? 2. If the answer is KRT, dialysis and/or transplantation? 3. Dialysis at home or in center? 4. If dialysis at home, peritoneal dialysis or home hemodialysis? 5. If transplantation is desired, discuss the options of whether the donation would be from a living or deceased donor. This review addresses the determinant factors with an impact on DKD, aiming to shed light on the specific needs that arise in the management and recommendations on how to achieve a comprehensive approach to the diabetic patient with chronic kidney disease.

Development and validation of a novel score to predict dialysis inadequacy in continuous ambulatory peritoneal dialysis patients

Objective

Adequate dialysis is of great importance for continuous ambulatory peritoneal dialysis (CAPD) patients. This study aimed to develop and validate an easily applicable quantitative dialysis adequacy risk scoring system in CAPD patients based on laboratory parameters from a single blood draw.

Methods

A total of 634 CAPD patients from four study centers were enrolled in this study (345 and 289 patients in development and validation groups, respectively). A risk score model for inadequate dialysis was developed based on multivariate regression analysis, which was validated by the area under the receiver operator curve and calibrated by a calibration curve.

Results

Seven independent predictors for inadequate dialysis were identified in the development group (male sex, hypoalbuminemia, anemia, being overweight, hyperuricemia, estimated glomerular filtration rate <4.7 mL/min/1.73 m², and serum creatinine >800 μmol/L). A risk prediction score model was established and validated in the development and validation groups. Further analysis indicated that this model is suitable for CAPD patients with a wide range of clinical manifestations.

Conclusion

An easily applicable novel risk scoring system was established to detect inadequate dialysis in CAPD patients.

Normalized Protein Catabolic Rate Is a Superior Nutritional Marker Associated With Dialysis Adequacy in Continuous Ambulatory Peritoneal Dialysis Patients

Introduction: Current knowledge of the relationship between normalized protein catabolic rate (nPCR) and dialysis adequacy is limited. Our study aimed to explore the potential relationship between nPCR and dialysis adequacy.

Methods: In this cross-sectional study, we analyzed the association of nPCR with peritoneal dialysis adequacy in 266 continuous ambulatory peritoneal dialysis (CAPD) patients (mean age 48.6 ± 13.1 years; 50.8% male). The patients were divided into two groups: a dialysis inadequacy group (total weekly Kt/V urea < 1.70) and a dialysis adequacy group (total weekly Kt/V urea≥1.70). We then analyzed the correlation between dialysis adequacy and the patients' primary cause of end-stage renal disease, nutritional and inflammatory markers, and biochemical parameters. Multivariable logistic regression analysis was also used to identify risk factors for inadequate dialysis.

Results: We observed a significantly higher level of nPCR (0.98 ± 0.22 vs. 0.79 ± 0.18 g/kg/day, p < 0.001) in the dialysis adequacy group, whereas we observed no significant differences among other nutritional markers such as albumin, prealbumin, and transferrin. Correlation analyses revealed that dialysis adequacy was positively associated with residual glomerular filtration rate (rGFR), hemoglobin, serum calcium, and body mass index (BMI), while dialysis adequacy was negatively associated with leak-protein, uric acid, high-sensitivity C-reactive protein, interleukin-6, and serum phosphorus. Furthermore, a logistic regression analysis revealed that gender (male), nPCR <0.815 g/kg/day, higher weight, and rGFR <2.43 mL/min/1.73 m² were independent risk factors for inadequate dialysis.

Conclusion: Nutritional status is closely associated with dialysis adequacy. Among common nutritional markers, nPCR may be superior for predicting CAPD dialysis adequacy. Gender (male), nPCR <0.815 g/kg/day, higher weight, and rGFR <2.43 mL/min/1.73 m² are independent risk factors for dialysis inadequacy in CAPD patients.

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.

Association of Tubular Solute Clearance with Symptom Burden in Incident Peritoneal Dialysis

BACKGROUND AND OBJECTIVES

Residual kidney function is important to the health and wellbeing of patients with ESKD. We tested whether the kidney clearances of proximal tubular secretory solutes are associated with burden of uremic and heart failure symptoms among patients on peritoneal dialysis with residual kidney function.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We enrolled 29 patients on incident peritoneal dialysis with residual urine output >250 ml daily. We used targeted liquid chromatography-mass spectrometry to quantify plasma, 24-hour urine, and peritoneal dialysate concentrations of ten tubular secretory solutes. We calculated the kidney and peritoneal dialysis clearances of each secretory solute, creatinine, and urea, and we estimated a composite kidney and peritoneal secretion score. We assessed for uremic symptoms using the Dialysis Symptom Index and heart failure-related symptoms using the Kansas City Cardiomyopathy Questionnaire. We used linear regression to determine associations of composite secretory solute clearances and GFR_urea+Cr with Dialysis Symptom Index symptom score and Kansas City Cardiomyopathy Questionnaire summary score.

RESULTS

Mean residual kidney clearances of creatinine and urea were 8±5 and 9±6 ml/min per 1.73 m², respectively, and mean GFR_urea+Cr was 8±5 ml/min per 1.73 m². The residual kidney clearances of most secretory solutes were considerably higher than creatinine and urea clearance, and also, they were higher than their respective peritoneal dialysis clearances. After adjustments for age and sex, each SD higher composite kidney secretion score was associated with an 11-point lower Dialysis Symptom Index score (95% confidence interval, -20 to -1; P=0.03) and a 12-point higher Kansas City Cardiomyopathy Questionnaire score (95% confidence interval, 0.5- to 23-point higher score; P=0.04). Composite peritoneal dialysis secretion score was not associated with either symptom assessment.

CONCLUSIONS

Residual kidney clearances of secretory solutes are higher than peritoneal dialysis clearances. Kidney clearances of secretory solutes are associated with patient-reported uremic and heart failure-related symptoms.

Changes in Peritoneal Dialysis Practices in Canada 1996 – 1999

← Objective

Over the past decade, clinical studies and clinical practice guidelines have suggested the use of higher small solute clearance targets for patients on peritoneal dialysis (PD). This study asks whether these recommendations have translated into changes in clinical prescription of PD.

← Study Design

Data were collected annually from 1996 to 1999 on all prevalent dialysis patients in 24 Canadian centers, accounting for approximately 40% of the Canadian chronic dialysis population. Approximately a third of these patients were on PD. Full details of each patient's prescription were recorded, with particular attention to dwell volumes and frequency of exchanges for continuous ambulatory PD (CAPD) and to total treatment volumes and day dwells for automated PD (APD). The most recent Kt/V and creatinine clearance values available were recorded for each patient and the overall results for each year were compared to present treatment recommendations.

← Setting

24 university- and community-based hospitals.

← Results

From 1996 to 1999, the use of APD, relative to CAPD, grew from 14% to 28% of all PD patients. Among CAPD patients, the proportion using dwell volumes greater than 2 L rose from 14% to 32%, and the proportion doing more than 4 dwells per day rose from 16% to 28%. The mean daily volume of prescribed fluid for CAPD patients increased from 8.3 to 9.1 L. As a result, the proportion of patients achieving a weekly Kt/V above 2.0 rose from 54% to 72%, and those receiving a Kt/V less than 1.7 fell from 22% to 10%. For creatinine clearance, those exceeding 60 L per week rose from 63% to 73%. For APD, the mean treatment volume rose from 11.8 L in 1996 to plateau at about 13.4 L in 1998 and 1999. However, the proportion of patients receiving more than 1 day dwell grew from 31% in 1998 to 40% in 1999, and the proportion that were “day dry” fell from 25% to 17%. For APD, the proportion of patients with a Kt/V above 2.0 rose from 67% to 77%, and with a creatinine clearance above 60 L, from 62% to 70%. The proportion with no recent clearance value recorded fell during the course of the study, from 45% to 27%.

← Conclusion

There was a marked change in PD prescription practices in Canada during the second half of the 1990s. This occurred in response to clinical studies and publication of guidelines. There is room for further improvement, especially with respect to the proportion of patients that did not have regular clearance measurements made.

Impact of Peritoneal Dialysis Dose Guidelines on Clinical Outcomes

The objective was to review the rationale for the Kidney Disease Outcomes Quality Initiative (K/DOQI) recommendations for adequacy of peritoneal dialysis and to evaluate the impact of these recommendations on clinical practice and patient survival. The K/DOQI recommendations were based on large observational studies; the target weekly Kt/V value of 2.0 assumed equivalence of peritoneal and renal clearances. This assumption is no longer considered correct. The impact on clinical practice was evaluated by an examination of temporal trends before and after publication of the guidelines in 1997. In the United States and The Netherlands, there had been a trend toward increased delivered total Kt/V prior to 1997, and there was no acceleration in this trend after 1997. Two randomized clinical trials have implemented these guidelines with increased peritoneal Kt/V (or creatinine clearance) used to achieve the K/DOQI target in the intervention group. This was not associated with improved survival, compared to a lower Kt/V, in either of the randomized clinical trials. Among the explanations for the failure to improve outcome are potential adverse effects of increasing the dialysis dose. These include increased intraperitoneal pressure associated with increased exchange volume, failure to increase clearance of middle molecules, and increased exposure to glucose. Strategies that increase peritoneal clearance without exposure to these potential adverse effects include more-frequent exchanges rather than increased exchange volume, and decreased exposure to glucose and glucose degradation products. Pending such studies, current K/DOQI guidelines should be updated in a timely manner.

Timely Initiation of Dialysis — Single-Exchange Experience in 39 Patients Starting Peritoneal Dialysis

♦ Objective

To establish the effectiveness and patient acceptability of initiating peritoneal dialysis (PD) according to published guidelines.

♦ Setting

A university teaching hospital and a neighboring district general hospital.

♦ Design

Nonrandomized prospective pilot study.

♦ Patients

39 patients with a Kt/V > 2.0 attending predialysis clinics at both hospitals agreed to participate in this study.

♦ Methods

Patients were started on a single exchange of dialysate overnight. Dialysis adequacy was monitored at least every 2 months and incremental increases in dialysis were used to maintain combined urinary and dialysis Kt/V above 2.0. Routine laboratory parameters and complications of dialysis were monitored during the follow-up period.

♦ Results

The mean weekly Kt/V at initiation of dialysis was 2.09. Median actuarial survival on a single exchange before requiring incremental dialysis was 297 days. At the end of the study period, all patients were still alive: 8 remained on 1 exchange, 18 were on more than 1 exchange, 8 had switched to hemodialysis, and 5 had received renal transplants. During the 12 665 patient-days on single-exchange dialysis, there were 14 hospital admissions of 12 patients. This resulted in a mean of 1.64 hospital days per patient–year for the whole group. During the follow-up period there were 2 episodes of bacterial peritonitis, 3 pleural leaks, 1 patent processus vaginalis, and 1 inguinal hernia that required surgical intervention. The use single daily icodextrin exchanges was associated with a 46% incidence of culture-negative peritonitis.

♦ Conclusions

This pilot study has shown that a timely start of dialysis with a single overnight PD exchange is acceptable to patients. Incremental dialysis as residual renal function falls is easily managed and patients also find this acceptable. Complication and hospitalization rates were low. The presence of residual renal function often allows complications to be managed without the need for hemodialysis. The use of icodextrin as a single-exchange dialysate is associated with sterile peritonitis in a significant proportion of cases.

Suitable Dialytic Indicators for Pediatric Peritoneal Dialysis Patients: The Alternative to Creatinine Clearance

← Objective

Owing to the discord between body weight and body surface area (BSA), creatinine clearance (CCr) is predisposed to be small in pediatric patients on peritoneal dialysis (PD). Alternatively, Kt/V creatinine (Kt/V creat), which is normalized to total body water (TBW) rather than BSA, could be a better dialytic indicator. In this study, the efficiency of dialysis and the nutritional status of pediatric patients on chronic PD were examined, and the utility of dialytic indicators was evaluated.

← Patients and Methods

49 patients under 20 years old, in stable condition, and on PD were analyzed. Weekly total Kt/V of urea (Kt/V urea), CCr, Kt/V creat, and normalized protein equivalent of nitrogen appearance (nPNA) were measured for all patients and for patients under 6 years old. The target value was 2.0/week for Kt/V urea and 60 L/week/1.73 m2 for CCr, as recommended by the Kidney Disease Outcomes Quality Initiative guidelines. The target value for Kt/V creat was set as 1.52/week, using a male model with a height of 170 cm and a body weight of 65 kg.

← Results

The mean values of delivered Kt/V urea, CCr, Kt/V creat, and nPNA (and proportion of patients that achieved each target value) for all patients were 2.25 ± 0.57/week (67.4%), 53.8 ± 19.3 L/week/1.73 2m (26.5%), 1.83 ± 0.73/week (65.3%), and 1.11 ± 0.42 g/day, respectively. The values for patients under 6 years old were 2.38± 0.26/week (90.0%), 45.9 ± 12.8 L/week/1.73 2m (10.0%), 1.94 ± 0.51/week (90.0%), and 1.52 ± 0.67 g/day, respectively. Stepwise multiple regression analyses revealed that the relationship between CCr and Kt/V urea was affected by the patient's age.

← Conclusions

Our pediatric patients achieved the recommended target value of Kt/V urea. At the same time, the nPNA results reflected the patient's status well. However, CCr appeared to be inappropriate as an indicator for patients under 6 years old. Kt/V creat is suggested to be a better dialytic indicator for these patients.

The Initiating Dialysis Early and Late (Ideal) Study: Study Rationale and Design

Objectives

The primary objective of the IDEAL study is to determine whether the timing of dialysis initiation has an effect on survival in subjects with end-stage renal disease (ESRD). The secondary objectives are to determine the impact of “early start” versus “late start” dialysis on nutritional and cardiac morbidity, quality of life, and economic cost.

Design

Prospective multicenter randomized controlled trial. Patients are randomized to commence dialysis at a glomerular filtration rate (by Cockcroft–Gault) of either 10 – 14 mL/minute/1.73 m2 (“early start”) or 5 – 7 mL/min/1.73 m2 (“late start”), with stratification for dialysis modality (hemodialysis vs peritoneal dialysis), study center, and the presence or not of diabetes mellitus.

Setting

Dialysis units throughout Australia and New Zealand.

Patients

Patients with ESRD commencing chronic dialysis therapy.

Outcome Measures

Three years from randomization, all-cause mortality, morbidity, and economic impact; structural and functional cardiac status, nutritional state, and quality of life will be assessed.

Results

To date, 388 patients of a minimum 800 patients have been entered and randomized into the study. Current recruitment rates suggest sufficient patients will be enrolled by December 2004 and follow-up completed by December 2007.

Conclusions

The IDEAL study will provide evidence for the optimal time to commence dialysis.

Efficient Monthly Subcutaneous Administration of Darbepoetin in Stable CAPD Patients

Background

Although subcutaneous administration of recombinant human erythropoietin (rHuEPO) in continuous ambulatory peritoneal dialysis (CAPD) patients is a widely accepted recommendation, the lowest possible frequency of an efficient dosing regimen remains controversial. Darbepoetin alpha, a new erythropoiesis-stimulating protein with a threefold longer serum half-life compared with rHuEPO, has greater in vivo potency and can be administered less frequently to obtain the same biological response. This study assessed the efficacy of darbepoetin administered once monthly in the treatment of anemia in CAPD patients.

Patients and Methods

In this single-center, prospective cohort study, 11 stable CAPD patients (5 males, 6 females; mean age 68.8 ± 14.1 years; mean duration on peritoneal dialysis 31.6 ± 13 months) maintained average hemoglobin and hematocrit levels of 12.09 ± 1.29 g/dL and 37.29% ± 3.58%, respectively, while receiving a mean weekly maintenance dose of epoetin alfa of 129 IU/kg. These same patients were assigned to receive the equivalent weekly darbepoetin dose once monthly for 24 consecutive weeks. Hematological response, iron status (transferrin saturation, serum ferritin levels), C-reactive protein (CRP), and the patients’ biochemical profiles were evaluated monthly.

Results

During the monthly administration of darbepoetin, mean serum levels of Hb and Hct were 12.17 ± 1.28 g/dL and 37.1% ± 1.19% respectively. No statistically significant difference was apparent between the previous and monthly dosing values (12.09 ± 1.29 vs 12.17 ± 1.28 g/dL, p = 0.769, and 37.29% ± 3.58% vs 37.1% ± 1.19%, p = 0.752). Transferrin saturation levels as well as serum ferritin levels also remained unchanged (30.4% ± 8.6% vs 30.1% ± 9.4%, NS, and 556 ± 212 vs 621 ± 234 ng/mL, respectively, NS).

Conclusion

These results indicate that darbepoetin alfa can be effectively given subcutaneously at monthly intervals for the treatment of anemia in stable CAPD patients. However, more studies are needed to validate the long-term efficacy of this monthly subcutaneous administration.

Is Growth a Valid Outcome Measure of Dialysis Clearance in Children Undergoing Peritoneal Dialysis?

♦ Objective

Our study evaluated growth as a clinical outcome measure of peritoneal dialysis (PD) adequacy in children with end-stage renal disease (ESRD).

♦ Design

This retrospective single-center study was carried out in our tertiary-care medical center.

♦ Patients

The study enrolled 24 patients who initiated dialysis after January 1, 1995, and who had been on dialysis for a minimum of 1 year.

♦ Results

The weekly mean total [PD + residual renal function (RRF)] creatinine clearance (CCr) and Kt/Vurea were 70.3 ± 18 L per 1.73 m2 and 3.45 ± 0.73, respectively. Of the 24 patients, 12 (50%) were anuric. The mean height standard deviation score (SDS) changed to –1.78 at the end of 1 year from –1.58 at baseline. Catch-up growth (positive Δ height SDS) was observed in 9 patients (37%), 7 of whom (78%) had residual renal function (RRF). In contrast, only 5 of 15 patients (33%) with a negative ΔSDS for height had RRF ( p < 0.025). The mean height SDS in patients with RRF improved to –1.64 from –1.78; in patients without RRF, it worsened to –1.90 from –1.37 ( p = 0.01). While the weekly total Kt/Vurea in patients with RRF (3.53) was similar to that in patients without RRF (3.37, p = 0.6), only the native Kt/Vurea had a significant (but weak) positive correlation with Δheight SDS ( r 2 = 0.17, p = 0.04). In contrast, the total weekly CCr was significantly higher ( p = 0.001) in patients with RRF (81.1 L/1.73 m2) as compared with those without RRF (59.5 L/1.73 m2). However, only the native CCr—and not the dialysis CCr—had a significant (but weak) positive correlation with Δheight SDS ( r 2 = 0.17, p = 0.04).

♦ Conclusions

These preliminary data provide evidence for a correlation between solute clearance and growth, with RRF exerting a significant influence on that outcome. The Kt/Vurea data also appear to contradict the presumed equivalence of PD and native clearance in children with ESRD.

Peritoneal Dialysis Adequacy in Asia—Is Higher Better?

Sufficient data are available to support the contention that renal and peritoneal clearances are not equivalent, and that loss of residual renal function (RRF) cannot be completely compensated by an increase in the exchange volume or frequency of peritoneal dialysis. When RRF is minimal (for example, renal Kt/V is 0.1 – 0.3), increasing the peritoneal Kt/V beyond the “conventional” value recommended by the Dialysis Outcomes Quality Initiative yields little additional clinical benefit. The cut-off peritoneal ( not total) Kt/V is possibly 1.6 – 1.7. However, delivery of peritoneal small-solute clearance below that cut-off level has a major detrimental effect on clinical outcome in CAPD patients with little RRF. Measures to preserve RRF therefore become an important goal in the treatment of CAPD patients. In short, with regard to RRF (renal Kt/V), higher is always better, and we should always try to preserve it. For peritoneal Kt/V, higher is better only up to a certain limit. The importance of aspects of adequate dialysis other than small-solute removal—especially fluid removal, blood pressure control, nutrition, acid–base balance, mineral metabolism, and anemia and lipid control—cannot be sufficiently emphasized.

Patient Characteristics Associated with Defects of the Peritoneal Cavity Boundary

Background

Conflicting literature exist regarding the patient characteristics that may confer an increased risk for anatomic complications of the peritoneal cavity boundaries.

Methods

We collected data from 75 randomly selected units in the United States and Canada, representing a total of 1864 peritoneal dialysis (PD) patients.

Results

200 of these patients experienced a total of 217 anatomic complications between July 2000 and June 2001; 16 patients had more than 1 complication. Hernias comprised 60.4% of all complications: 24.9% inguinal, 18.9% umbilical, 13.8% ventral, 2.3% femoral, and 0.5% intrathoracic. Other complications included pericatheter or subcutaneous leak (25.3%), hydrothorax (6.0%), and miscellaneous (8.3%). Peritoneal dialysis modalities in use at the time of complication were automated PD (52.3%), continuous ambulatory PD (38.6%), and nocturnal intermittent PD (9.1%). The overall incidence of hernias was 7%.

Conclusions

Logistic regression analysis found no association between hernias and age, body surface area, PD modality, volume of dialysate, time of largest dwell (day/upright vs night/recumbent), or type of catheter used. Cystic disease conferred a 2.5-fold increase in risk for anatomic complications ( p < 0.001); female gender conferred an 80% reduction in risk ( p < 0.0001), and Kt/V ≥2.0 conferred a 52% reduction in risk ( p < 0.05) for hernia.

The Impact of Social Support on the Survival of Chinese Peritoneal Dialysis Patients

Background

Social support is an independent risk factor for mortality among new hemodialysis patients. We evaluated the effect of social support on the outcome of Chinese peritoneal dialysis (PD) patients.

Methods

We studied 167 prevalent PD patients. They completed the Medical Outcomes Study Social Support Survey, Chinese Version (MOS-SSS-C) questionnaire. Patients were followed for 1 year. Outcome measures included change in nutritional status, hospitalization, and technique and actuarial patient survival.

Results

Actuarial survival was 57.1%, 72.7%, 85.3%, and 88.6% for MOS-SSS-C total score quartiles I, II, III, and IV, respectively (log rank test, p = 0.037). Technique survival was 57.1%, 81.9%, 91.9%, and 91.4% (log rank test, p = 0.0044). By multivariate analysis with the Cox proportional hazard model to adjust for confounders, every 1 point increase in MOS-SSS-C total score was associated with a 0.6% [95% confidence interval (CI) 0.2% – 0.9%, p = 0.003] reduction in the risk of death and a 0.5% (95%CI 0.1% – 1.0%, p = 0.037) reduction in the risk of technique failure. The MOS-SSS-C score had no significant effect on change in nutritional or dialysis adequacy indices, hospitalization, or number of peritonitis episodes in 1 year.

Conclusion

The degree of social support is an important predictor of actuarial and technique survival in Chinese PD patients. Measures to enhance social support may represent an easily achievable means of improving the clinical outcome of PD patients.

Impact of Nutritional Status on Peritonitis in CAPD Patients

Objective

To determine the impact of nutritional status on peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD) in a developing country.

Methods

56 patients with end-stage renal disease on CAPD were randomly selected for this study. These patients were assessed for nutritional status and peritonitis episodes. Nutritional parameters were assessed by anthropometry, diet, body mass index (BMI), Nutritional Risk Index (NRI), serum albumin level, and Subjective Global Assessment (SGA). Based on SGA, patients were categorized into either group 1 (malnutrition, n = 31) or group 2 (normal nutritional status, n = 25). Peritonitis was considered the primary outcome and was compared between the two groups.

Results

Demographic profiles, Kt/V, creatinine clearance, and mean follow-up of the two groups were similar. Number of peritonitis episodes was significantly higher in patients with malnutrition (25/31) compared to patients with normal nutritional status (4/25) ( p = 0.001). Mean peritonitis rate per patient per year was also significantly higher in patients with malnutrition (0.99 ± 1.07) compared to patients with normal nutritional status (0.18 ± 0.42) ( p = 0.007). On univariate analysis, malnutrition based on SGA ( p = 0.009), NRI ( p = 0.02), serum albumin level ( p = 0.005), and calorie intake ( p = 0.006) was a significant predictor of peritonitis. On multivariate Cox regression analysis, only SGA ( p = 0.001, odds ratio 0.08, 95% confidence interval 0.02 – 0.36) was found to be a significant predictor of peritonitis. On general linear model, the observed power of prediction of peritonitis was 0.96 based on SGA. On Kaplan–Meier survival analysis, peritonitis-free survival in patients with normal nutrition (42 months) was significantly higher compared to patients with malnutrition (21 months) based on SGA (log rank p = 0.003).

Conclusion

We conclude that peritonitis rate is high in patients with malnutrition and that malnutrition indices, especially SGA, can predict the peritonitis rate in CAPD patients.

Variability in Case Mix and Peritoneal Dialysis Selection in Fifty-Nine French Districts

In France, the use of peritoneal dialysis (PD) as the first-choice treatment varies greatly between districts, as it is already known to do between countries. Baseline clinical factors associated with choice of first modality were analyzed in 10815 new end-stage renal disease patients in 59 districts. To describe practices at the district level, we used an agglomerative hierarchical classification, with proximity defined by a likelihood-ratio test that compared multivariate logistic regressions of the following factors: age, gender, diabetes, congestive heart failure, severe behavioral disorders, mobility, and employment. To propose a typology, each cluster of districts was described by a multivariate logistic regression. While populations starting PD in France, as elsewhere, are more likely to be young or employed, they are also more likely to be elderly or have congestive heart failure or severe behavioral disorders. Overall, 14% of patients start with PD, but this rate varies significantly across districts, from 0% to 45%. A specific combination of factors was associated with the first-choice modality in each group of districts. This study highlights the lack of consensual medical criteria for this choice and the likelihood that nonmedical factors may explain the observed differences. The high variability suggests that PD can be used in almost all clinical conditions. Accordingly, patient preference should play a more important role in the decision-making process.

Differences in predicting glucose absorption from peritoneal dialysate compared to measured absorption in peritoneal dialysis patients treated by continuous ambulatory peritoneal dialysis and ambulatory peritoneal dialysis cyclers

Background and aims:

Glucose-containing peritoneal dialysates are used to generate an osmotic gradient for the convective removal of water and sodium. Predictive equations were developed to estimate glucose absorption without having to formally measure changes in dialysate glucose. In view of the changes in peritoneal dialysis prescriptions over time, we compared predicted and measured glucose absorption.

Subjects/methods:

We measured peritoneal glucose losses when peritoneal dialysis patients attended their first assessment of peritoneal membrane function, and compared this to glucose exposure and Kidney Disease Outcomes Quality Initiative, Grodstein and Bodnar predictive equations.

Results:

We studied 689 patients; 329 (56.9%) males, 53 (37.1%) diabetics, with mean age 57.1 ± 16.2 years, with 186 treated by automated peritoneal dialysis cyclers and 377 by automated peritoneal dialysis with a daytime icodextrin exchange and 126 by continuous ambulatory peritoneal dialysis. Using Bland -Altman analysis, all equations demonstrated systematic bias overestimating glucose absorption with increasing glucose absorption. For continuous ambulatory peritoneal dialysis patients, the Kidney Disease Outcomes Quality Initiative formula underestimated glucose absorption (bias 188 (−39 to 437) mmol/day, as did Grodstein (bias 37.9 (−105 to 29) mmol/day, whereas mean bias for Bodnar was −29 (−130 to 180)). There was systematic overestimation for all equations for both automated peritoneal dialysis with and without a daytime exchange, with increasing bias with greater glucose absorption.

Conclusion:

Although formally measuring peritoneal glucose absorption is time consuming and requires patient co-operation, current predictive equations overestimate glucose absorption and do not provide accurate estimations of glucose absorption particularly for automated peritoneal dialysis patients.

Volume management as a key dimension of a high-quality PD prescription

BACKGROUND

Appropriate volume control is one of the key goals in a peritoneal dialysis (PD) prescription. As such it is an important component of the International Society of Peritoneal Dialysis (ISPD) guideline for "High-quality PD prescription" necessitating a review of the literature on volume management. The workgroup recognized the importance of including within its scope measures of volume status and blood pressure in prescribing high-quality PD therapy.

METHODS

A Medline and PubMed search for publications addressing volume status and its management in PD since the publication of the 2015 ISPD Adult Cardiovascular and Metabolic Guidelines, from October 2014 through to July 2019, was conducted.

RESULTS

There were no randomized controlled trials on blood pressure intervention and six randomized trials of bioimpedance-guided volume management. Generally, all studies were of small sample size, short duration, and used surrogate markers as primary outcomes. As a consequence, only "practice points" were drawn. High-quality goal-directed PD prescription should aim to achieve and maintain clinical euvolemia taking residual kidney function and its preservation into account, so that both fluid removal from peritoneal ultrafiltration and urine output are considered and residual kidney function is not compromised. Blood pressure should be included as a key objective parameter in assessing the quality of PD prescription but there is currently no evidence for a specific target in PD. Clinical examination remains the keystone of routine clinical care.

CONCLUSIONS

High-quality goal-directed PD prescription should include volume management as one of the key dimensions.

International comparison of peritoneal dialysis prescriptions from the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS)

Background:

We describe peritoneal dialysis (PD) prescription variations among Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) participants on continuous ambulatory PD (CAPD) and automated PD (APD; n = 4657) from Australia/New Zealand (A/NZ), Canada, Japan, Thailand, United Kingdom (UK), and United States (US).

Results:

CAPD was more commonly used in Thailand and Japan, while APD predominated over CAPD in A/NZ, Canada, the US, and the UK. Total prescribed PD volume normalized to the surface area was the highest in Thailand and the lowest in Japan (for both APD and CAPD) and the UK (for CAPD). PD patients from Thailand had the lowest residual urine volume and residual renal urea clearance, yet achieved the highest dialysis urea clearance. Japanese patients had the lowest dialysis urea clearances for both APD and CAPD. Despite having similar urine volumes to patients in A/NZ, Canada, Japan, and the UK, US CAPD and APD patients used 2.5% and 3.86% glucose PD solutions more frequently, whereas fewer than 25% of these patients used icodextrin. Over half of the patients in A/NZ, Canada, the UK, and Japan used icodextrin, whereas it was hardly used in Thailand. Japan and Thailand were more likely to use 1.5% glucose solutions for their PD prescription.

Conclusions:

There are considerable international variations in PD modality use and prescription patterns that translate into important differences in achieved dialysis clearances. Ongoing recruitment of additional PDOPPS participants and accrual of follow-up time will allow us to test the associations between specific PD prescription regimens and clinical and patient-reported outcomes.

Facility size and mortality in hospital-based and freestanding haemodialysis units: A nationwide retrospective cohort study

AIM

Existing studies on the association between haemodialysis facility size/volume and patient survival are mostly limited to freestanding dialysis units in the United States. This study in Taiwan explored the facility size - mortality association in both hospital-based and freestanding haemodialysis (HD) units.

METHODS

In this nationwide population-based retrospective cohort study, we used the Taiwan National Health Insurance Research Database to include patients who began maintenance (HD) between 2008 and 2012. Facility size was categorized according to the number of stations in the HD unit. The 5 years mortality rate was analyzed using a frailty model for Cox regression. The patients in hospital-based and freestanding HD units were examined separately.

RESULTS

Among the 39 506 patients, 24 597 (62.3%) and 14 909 (37.7%) patients received HD in hospital-based and freestanding facilities, respectively. After the 4th month of dialysis initiation, the 5 years survival rates of patients in hospital-based and freestanding HD units were 50.7% and 52.3%, respectively. When patient and other facility characteristics were adjusted, patients in the smallest facility category (1-15 stations) showed the highest mortality risk (hazard ratio, 1.36; 95% confidence interval, 1.11-1.67) among all the patients treated in hospital-based units. The patients treated in freestanding units with 1-15, 16-30 and 31-45 stations showed 31%, 33% and 36%, respectively, higher mortality risks than those of patients treated in units with more than 45 stations.

CONCLUSION

A small facility size was associated with an increased mortality risk in HD patients, and the threshold size was higher in freestanding units.

Comparison of Methods Study between a Photonic Crystal Biosensor and Certified ELISA to Measure Biomarkers of Iron Deficiency in Chronic Kidney Disease Patients

The total analytical error of a photonic crystal (PC) biosensor in the determination of ferritin and soluble transferrin receptor (sTfR) as biomarkers of iron deficiency anemia in chronic kidney disease (CKD) patients was evaluated against certified ELISAs. Antigens were extracted from sera of CKD patients using functionalized iron-oxide nanoparticles (fAb-IONs) followed by magnetic separation. Immuno-complexes were recognized by complementary detection Ab affixed to the PC biosensor surface, and their signals were followed using the BIND instrument. Quantification was conducted against actual protein standards. Total calculated error (TEcalc) was estimated based on systematic (SE) and random error (RE) and compared against total allowed error (TEa) based on established quality specifications. Both detection platforms showed adequate linearity, specificity, and sensitivity for biomarkers. Means, SD, and CV were similar between biomarkers for both detection platforms. Compared to ELISA, inherent imprecision was higher on the PC biosensor for ferritin, but not for sTfR. High SE or RE in the PC biosensor when measuring either biomarker resulted in TEcalc higher than the TEa. This did not influence the diagnostic ability of the PC biosensor to discriminate CKD patients with low iron stores. The performance of the PC biosensor is similar to certified ELISAs; however, optimization is required to reduce TEcalc.

Clinical Relevance of Intraperitoneal Pressure in Peritoneal Dialysis Patients

Introduction

Intraperitoneal pressure (IPP) in peritoneal dialysis (PD) increases in sitting and upright positions and is related to some individual characteristics. Adverse effects can appear with IPP > 20 cm H2O. Few studies about peritoneal transport or abdominal wall problems have directly measured IPP. We measured IPP in our prevalent PD patients to identify the clinical factors related to its variability and its possible association with peritoneal transport and abdominal wall complications.

Methods

We performed a retrospective, observational study of our stable PD patients. Intraperitoneal pressure was measured using the Durand's method in supine, sitting, and upright position.

Results

Forty-nine patients were included, 70% males, mean age 61.1 ± 15 years, body mass index (BMI) 27.9 ± 5.2 kg/m2. The mean of supine IPP was 18.0 ± 4.4 cm H2O. Intraperitoneal pressure in sitting and upright positions were similar and higher than in supine. Supine IPP showed a positive correlation with BMI ( p < 0.0005) and comorbidity ( p < 0.05). A multivariate linear regression analysis showed that BMI and comorbidity ( p < 0.005) had a positive correlation with IPP; time on PD and daily total ultrafiltration (UF) (p < 0.005) showed a negative correlation. Patients with an IPP ≥ 20 cm H2O had more hernias (35% vs 17%) and leakages (21% vs 8%) without statistical significance.

Conclusion

Our supine IPPs were higher than others published in adults. Intraperitoneal pressure has an individual value associated with body size. Greater IPP was correlated with lower daily total UF and more hernias and leakages. The measurement of IPP is a simple technique and can help with PD prescription, especially in obese patients.

Factors affecting responsiveness to hepatitis B immunization in dialysis patients

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are widespread health problems all over the world and have high morbidity and mortality. Hemodialysis patients are more frequently exposed to these viruses as they have poor immune system and frequently undergo parenteral interventions. The vaccination against HBV prevents infection and it has been recommended for the prevention of HBV infection in all susceptible dialysis patients. This study aimed to determine the seroprevalence of HBV and HCV infections and analyzed the factors affecting inadequate response to HBV vaccine in dialysis patients.

METHODS

The data for 584 dialysis patients that were followed up at seven dialysis centers were analyzed. The patients received four doses of 40 μg recombinant hepatitis B vaccine at 0, 1, 2, and 6 months and were tested for anti-HBs titer after one month of completion of vaccination. If patients showed a titer of anti-HBs <10 IU/mL, an additional 40 μg in four vaccine doses was administered immediately and they were retested for the anti-HBs following the same schedule. The patients were divided into two groups: responders and non-responders.

RESULTS

HBsAg and anti-HCV seroprevalence was 3.4% and 10.3%, respectively. After vaccination schedule, 264 (83.5%) patients had antibody response to HBV vaccine and 52 (16.5%) had no response. Hepatitis B vaccine unresponsiveness is more common in the patients with hepatitis C positivity (p = 0.011), BMI >30 (p = 0.019), over the age of 65 years (p = 0.009), and duration of dialysis treatment >5 years (p = 0.001). There was no statistically significant difference between gender, causes of renal disease, erythropoietin treatment, and the type of dialysis.

CONCLUSION

Hepatitis C infection, obesity, being elderly, and having long hemodialysis period reduced the hepatitis B vaccination response in hemodialysis patients.

A Simulation Model to Estimate the Cost and Effectiveness of Alternative Dialysis Initiation Strategies

Background. Patients with end-stage renal disease (ESRD) require dialysis to maintain survival. The optimal timing of dialysis initiation in terms of cost-effectiveness has not been established.

Methods . We developed a simulation model of individuals progressing towards ESRD and requiring dialysis. It can be used to analyze dialysis strategies and scenarios. It was embedded in an optimization frame worked to derive improved strategies.

Results. Actual (historical) and simulated survival curves and hospitalization rates were virtually indistinguishable. The model overestimated transplantation costs (10%) but it was related to confounding by Medicare coverage. To assess the model's robustness, we examined several dialysis strategies while input parameters were perturbed. Under all 38 scenarios, relative rankings remained unchanged. An improved policy for a hypothetical patient was derived using an optimization algorithm.

Conclusion. The model produces reliable results and is robust. It enables the cost-effetiveness analysis of dialysis strategies.

Associations of pulmonary function with serum biomarkers and dialysis adequacy in patients undergoing peritoneal dialysis

BACKGROUND

As lung impairment is an indicator of increased morbidity and mortality in patients receiving continuous ambulatory peritoneal dialysis (CAPD), the risk factors associated with impaired lung function are of great significance. The aim of this study is to elucidate the effects of inflammatory biomarkers and dialysis adequacy on pulmonary function, in CAPD patients.

METHODS

101 patients undergoing CAPD, 30 CKD5 patients and 30 healthy subjects were enrolled. Spirometry and serum biomarkers were evaluated in each subject. Pulmonary function was compared among patients and control groups. Pearson analysis was used to analyze the correlation between serum biomarkers, dialysis adequacy and pulmonary function.

RESULTS

Lower vital capacity, maximal voluntary ventilation (MVV), forced vital capacity (FVC), peak expiratory flow (PEF), maximal mid-expiratory flow rate (MMEF), and diffusing capacity of the lung for carbon monoxide (DLCO) were observed in the CAPD group (all P < 0.05) when compared with control subjects. DLCO % was negatively correlated with CRP (r = -0.349, P = 0.007) and positively correlated with albumin (r = 0.401, P = 0.002). Total Kt/V was associated positively with MMEF % (r = 0.316, P = 0.019), and MVV % (r = 0.362, P = 0.007). nPNA was positively correlated with FVC % (r = 0.295, P = 0.049) and MMEF % (r = 0.381, P = 0.010).

CONCLUSION

The results suggest that lung function decline was directly related to higher CRP level, hypoalbuminemia, and dialysis inadequacy. These findings provide the evidence that inflammation and dialysis adequacy play a role in predicting outcomes of CAPD patients with pulmonary impairment.

Circulating bacterial-derived DNA fragment level is a strong predictor of cardiovascular disease in peritoneal dialysis patients

BACKGROUND

Circulating bacterial DNA fragment is related to systemic inflammatory state in peritoneal dialysis (PD) patients. We hypothesize that plasma bacterial DNA level predicts cardiovascular events in new PD patients.

METHODS

We measured plasma bacterial DNA level in 191 new PD patients, who were then followed for at least a year for the development of cardiovascular event, hospitalization, and patient survival.

RESULTS

The average age was 59.3 ± 11.8 years; plasma bacterial DNA level 34.9 ± 1.5 cycles; average follow up 23.2 ± 9.7 months. At 24 months, the event-free survival was 86.1%, 69.8%, 55.4% and 30.8% for plasma bacterial DNA level quartiles I, II, III and IV, respectively (p < 0.0001). After adjusting for confounders, plasma bacterial DNA level, baseline residual renal function and malnutrition-inflammation score were independent predictors of composite cardiovascular end-point; each doubling in plasma bacterial DNA level confers a 26.9% (95% confidence interval, 13.0 - 42.5%) excess in risk. Plasma bacterial DNA also correlated with the number of hospital admission (r = -0.379, p < 0.0001) and duration of hospitalization for cardiovascular reasons (r = -0.386, p < 0.0001). Plasma bacterial DNA level did not correlate with baseline arterial pulse wave velocity (PWV), but with the change in carotid-radial PWV in one year (r = -0.238, p = 0.005).

CONCLUSIONS

Circulating bacterial DNA fragment level is a strong predictor of cardiovascular event, need of hospitalization, as well as the progressive change in arterial stiffness in new PD patients.

Trends in the Timing and Clinical Context of Maintenance Dialysis Initiation

Whether secular trends in eGFR at dialysis initiation reflect changes in clinical presentation over time is unknown. We reviewed the medical records of a random sample of patients who initiated maintenance dialysis in the Department of Veterans Affairs (VA) in fiscal years 2000-2009 (n=1691) to characterize trends in clinical presentation in relation to eGFR at initiation. Between fiscal years 2000-2004 and 2005-2009, mean eGFR at initiation increased from 9.8±5.8 to 11.0±5.5 ml/min per 1.73 m(2) (P<0.001), the percentage of patients with an eGFR of 10-15 ml/min per 1.73 m(2) increased from 23.4% to 29.9% (P=0.002), and the percentage of patients with an eGFR>15 ml/min per 1.73 m(2) increased from 12.1% to 16.3% (P=0.01). The proportion of patients who were acutely ill at the time of initiation and the proportion of patients for whom the decision to initiate dialysis was based only on level of kidney function did not change over time. Frequencies of documented clinical signs and/or symptoms were similar during both time periods. The adjusted odds of initiating dialysis at an eGFR of 10-15 or >15 ml/min per 1.73 m(2) (versus <10 ml/min per 1.73 m(2)) during the later versus earlier time period were 1.43 (95% confidence interval [95% CI], 1.13 to 1.81) and 1.46 (95% CI, 1.09 to 1.97), respectively. In conclusion, trends in eGFR at dialysis initiation at VA medical centers do not seem to reflect changes in the clinical context in which dialysis is initiated.

Evaluating the benefits of home-based peritoneal dialysis

Peritoneal dialysis (PD) is an effective renal replacement strategy for patients suffering from end-stage renal disease. PD offers patient survival comparable to or better than in-center hemodialysis while preserving residual kidney function, empowering patient autonomy, and reducing financial burden to payors. The majority of patients suffering from kidney failure are eligible for PD. In patients with cardiorenal syndrome and uncontrolled fluid status, PD is of particular benefit, decreasing hospitalization rates and duration. This review discusses the benefits of chronic PD, performed by the patient or a caregiver at home. Recognition of the benefits of PD is a cornerstone in stimulating the use of this treatment strategy.