Effect of icodextrin on volume status, blood pressure and echocardiographic parameters: a randomized study

The impact of icodextrin on the outcomes of incident peritoneal dialysis patients

OBJECTIVE

The aim of the study is to investigate the effects of icodextrin on the risks of death, technique failure and the first episode of peritonitis in peritoneal dialysis (PD) patients.

METHODS

From medical records of a medical center in Taiwan, a total of 725 newly diagnosed end-stage kidney disease patients receiving PD for at least 90 days from January 1, 2007 to December 31, 2018 were identified. These patients were grouped as 190 icodextrin users and 535 non-users. Users were defined as utilization of icodextrin for ≥ 50% of their PD duration. The use of icodextrin was considered a time-varying exposure in the Cox proportional hazard model. The risks of death, technique failure and the first episode of peritonitis were compared between two cohorts by the end of 2018.

RESULTS

Compared to the non-users, the icodextrin users had significant lower risks of mortality (6.5 vs.7.2 per 100 person-years; adjusted HR = 0.62, 95% CI = 0.42-0.91) and technique failure (12.7 vs. 15.2 per 100 person-years; adjusted HR = 0.61, 95% CI = 0.47-0.81), and the first peritonitis episode (5.0 vs. 17.0 per 100 person-years; adjusted HR = 0.22, 95% CI = 0.14-0.35). The risk of peritonitis reduced further in icodextrin users with diabetes and with cardiovascular disease.

CONCLUSION

Icodextrin was associated with lower risks of mortality, technique failure, and the first episode of peritonitis.

Why should we use a low sodium dialysis solution for peritoneal dialysis?

Overhydration is highly prevalent in patients on peritoneal dialysis (PD), with inappropriately high sodium load supposedly playing a central role in the pathophysiology of the conditions. Recent studies have revealed the novel role of the interstitium as a buffer system for sodium ions, and it has been reported that patients on dialysis, including PD, present increased levels of sodium in the interstitium, such as in subcutaneous tissue and muscle. Hence, therapy for correction of overhydration should target the excess extracellular volume and the excess sodium storage in the interstitium. The ultrafiltrate obtained using the currently available PD solutions is hypo- to isonatric as compared to serum, which is disadvantageous for prompt and efficient sodium removal from the body in patients with overhydration. In contrast, use of low sodium PD solutions is characterised by iso- to hypernatric ultrafiltrate, which may beneficial for reducing sodium storage in the interstitium. Trials of low sodium PD solutions have reported possible clinical merits, for example, decreased blood pressure, reduced dryness of mouth and decreased body water content as assessed using bioimpedance methods. Given these observations and the high prevalence of overhydration in current PD populations, it makes medical sense that low sodium solutions be positioned as the new standard solution in the future. However, for medical safety, that is, to avoid hyponatremia and excessive decreases in blood pressure, further studies are needed to establish the appropriate compositions and applications of low sodium solutions.

A randomized clinical trial to evaluate the effects of icodextrin on left ventricular mass index in peritoneal dialysis

Left ventricular hypertrophy is a risk factor for cardiovascular mortality in patients on peritoneal dialysis (PD). Because icodextrin has a greater ultrafiltration power compared with glucose-based solutions for long dwell, it could improve left ventricular mass by reducing fluid overload. This was a randomized clinical trial that included patients on PD recruited from 2 teaching hospitals, in Sao Paulo—Brazil. Patients were allocated to the control glucose group (GLU) or the intervention icodextrin (ICO) group. Clinical and cardiac magnetic resonance image (MRI) parameters were evaluated at baseline and 6 months after randomization. The primary outcome was the change in left ventricular mass adjusted by surface area (ΔLVMI), measured by cardiac MRI. A total of 22 patients completed the study (GLU, N = 12 and ICO, N = 10). Baseline characteristics such as age, sex, underlying disease, and time on dialysis were similar in both groups. At baseline, 17 patients (77.3%) presented with left ventricular hypertrophy with no difference between groups (p = 0.748). According to the total body water (TBW)/extracellular water (ECW) ratio, 36.8% and 80% of patients from GLU and ICO groups, respectively, were considered hypervolemic (p = 0.044). During follow-up, ΔLVMI was 3.9 g/m (− 10.7, 2.2) in GLU and 5.2 (− 26.8, 16.8) in ICO group (p = 0.651). ΔLVMI correlated with change in brain natriuretic peptide (r = 0.566, p = 0.044), which remained significant in a multiple regression analysis. The use of the icodextrin-based solution in prevalent patients on PD compared with a glucose-based solution was not able to improve LMV. A larger randomized trial with a longer follow-up period may be needed to show changes in LVM in this patient population.

Trial registration: this study has been registered at ReBEC (Registro Brasileiro de Ensaios Clinicos) under the identification #RBR-2mzhmj2, available at: https://ensaiosclinicos.gov.br/pesquisador.

International Icodextrin Use and Association with Peritoneal Membrane Function, Fluid Removal, Patient and Technique Survival

BACKGROUND

Icodextrin has been shown in randomized controlled trials to benefit fluid management in peritoneal dialysis (PD). We describe international icodextrin prescription practices and their relationship to clinical outcomes.

METHODS

We analyzed data from the prospective, international PDOPPS, from Australia/New Zealand, Canada, Japan, the United Kingdom, and the United States. Membrane function and 24-hour ultrafiltration according to icodextrin and glucose prescription was determined at baseline. Using an instrumental variable approach, Cox regression, stratified by country, was used to determine any association of icodextrin use to death and permanent transfer to hemodialysis (HDT), adjusted for demographics, comorbidities, serum albumin, urine volume, transplant waitlist status, PD modality, center size, and study phase.

RESULTS

Icodextrin was prescribed in 1986 (35%) of 5617 patients, >43% of patients in all countries, except in the United States, where it was only used in 17% and associated with a far greater use of hypertonic glucose. Patients on icodextrin had more coronary artery disease and diabetes, longer dialysis vintage, lower residual kidney function, faster peritoneal solute transfer rates, and lower ultrafiltration capacity. Prescriptions with or without icodextrin achieved equivalent ultrafiltration (median 750 ml/d [interquartile range 300-1345 ml/d] versus 765 ml/d [251-1345 ml/d]). Icodextrin use was not associated with mortality (HR=1.03; 95% CI, 0.72 to 1.48) or HDT (HR 1.2; 95% CI, 0.92 to 1.57).

CONCLUSIONS

There are large national and center differences in icodextrin prescription, with the United States using significantly less. Icodextrin was associated with hypertonic glucose avoidance but equivalent ultrafiltration, which may affect any potential survival advantage or HDT.

Peritoneal-Membrane Characteristics and Hypervolemia Management in Peritoneal Dialysis: A Randomized Control Trial

Excessive bodily-fluid retention is the major cause of hypertension and congestive heart failure in patients with end-stage renal disease. Compared to hemodialysis, peritoneal dialysis (PD) uses the abdominal peritoneum as a semipermeable dialysis membrane, providing continuous therapy as natural kidneys, and having fewer hemodynamic changes. One major challenge of PD treatment is to determine the dry weight, especially considering that the speed of small solutes and fluid across the peritoneal membrane varies among individuals; considerable between-patient variability is expected in both solute transportation and ultrafiltration capacity. This study explores the influence of peritoneal-membrane characteristics in the hydration status in patients on PD. A randomized control trial compares the bioimpedance-assessed dry weight with clinical judgment alone. A high peritoneal membrane D/P ratio was associated with the extracellular/total body water ratio, dialysate protein loss, and poor nutritional status in patients on PD. After a six-month intervention, patients with monthly bioimpedance analysis (BIA) assistance had better fluid (−1.2 ± 0.4 vs. 0.1 ± 0.4 kg, p = 0.014) and blood-pressure (124.7 ± 2.7 vs. 136.8 ± 2.8 mmHg, p < 0.001) control; however, hydration status and blood pressure returned to the baseline after we prolonged BIA assistance to a 3-month interval. The dry-weight reduction process had no negative effect on residual renal function or peritoneal-membrane function. We concluded that peritoneal-membrane characteristics affect fluid and nutritional status in patients on PD, and BIA is a helpful objective technique for fluid assessment for PD.

Traduction des Recommandations de l'ISPD pour l'évaluation du dysfonctionnement de la membrane péritonéale chez l'adulte

Informations concernant cette traductionDans le cadre d’un accord de partenariat entre l’ISPD et le RDPLF, le RDPLF est le traducteur français officiel des recommandations de l’ISPD. La traduction ne donne lieu à aucune compensation financière de la part de chaque société et le RDPLF s’est engagé à traduire fidèlement le texte original sous la responsabilité de deux néphrologues connus pour leur expertise dans le domaine. Avant publication le texte a été soumis à l’accord de l’ISPD. La traduction est disponible sur le site de l’ISPD et dans le Bulletin de la Dialyse à Domicile.Le texte est, comme l’original, libremement téléchargeable sous licence copyright CC By 4.0https://creativecommons.org/licenses/by/4.0/Cette traduction est destinée à aider les professionnels de la communauté francophone à prendre connaissance des recommandations de l’ISPD dans leur langue maternelle. Toute référence dans un article doit se faire au texte original en accès libre :Peritoneal Dialysis International https://doi.org/10.1177/0896860820982218 Dans les articles rédigés pour des revues françaises, conserver la référence à la version originale anglaise ci dessus, mais ajouter «version française  https://doi.org/10.25796/bdd.v4i3.62673"»TraducteursDr Christian Verger, néphrologue, président du RDPLFRDPLF, 30 rue Sere Depoin, 95300 Pontoise – FranceProfesseur Max Dratwa, néphrologueHôpital Universitaire Brugmann – Bruxelles – Belgique

ISPD recommendations for the evaluation of peritoneal membrane dysfunction in adults: Classification, measurement, interpretation and rationale for intervention

Lay summary

Peritoneal dialysis (PD) uses the peritoneal membrane for dialysis. The peritoneal membrane is a thin layer of tissue that lines the abdomen. The lining is used as a filter to help remove extra fluid and poisonous waste from the blood. Everybody is unique. What is normal for one person’s membrane may be very different from another person’s. The kidney care team wants to provide each person with the best dialysis prescription for them and to do this they must evaluate the person’s peritoneal lining. Sometimes dialysis treatment itself can cause the membrane to change after some years. This means more assessments (evaluations) will be needed to determine whether the person’s peritoneal membrane has changed. Changes in the membrane may require changes to the dialysis prescription. This is needed to achieve the best dialysis outcomes. A key tool for these assessments is the peritoneal equilibration test (PET). It is a simple, standardized and reproducible tool. This tool is used to measure the peritoneal function soon after the start of dialysis. The goal is to understand how well the peritoneal membrane works at the start of dialysis. Later on in treatment, the PET helps to monitor changes in peritoneal function. If there are changes between assessments causing problems, the PET data may explain the cause of the dysfunction. This may be used to change the dialysis prescription to achieve the best outcomes. The most common problem with the peritoneal membrane occurs when fluid is not removed as well as it should be. This happens when toxins (poisons) in the blood cross the membrane more quickly than they should. This is referred to as a fast peritoneal solute transfer rate (PSTR). Since more efficient fluid removal is associated with better outcomes, developing a personal PD prescription based on the person’s PSTR is critically important. A less common problem happens when the membrane fails to work properly (also called membrane dysfunction) because the peritoneal membrane is less efficient, either at the start of treatment or developing after some years. If membrane dysfunction gets worse over time, then this is associated with progressive damage, scarring and thickening of the membrane. This problem can be identified through another change of the PET. It is called reduced ‘sodium dip’. Membrane dysfunction of this type is more difficult to treat and has many implications for the individual. If the damage is major, the person may need to stop PD. They would need to begin haemodialysis treatment (also spelled hemodialysis). This is a very important and emotional decision for individuals with kidney failure. Any decision that involves stopping PD therapy or transitioning to haemodialysis therapy should be made jointly between the clinical team, the person on dialysis and a caregiver, if requested. Although evidence is lacking about how often tests should be performed to determine peritoneal function, it seems reasonable to repeat them whenever there is difficulty in removing the amount of fluid necessary for maintaining the health and well-being of the individual. Whether routine evaluation of membrane function is associated with better outcomes has not been studied. Further research is needed to answer this important question as national policies in many parts of the world and the COVID-19 has placed a greater emphasis and new incentives encouraging the greater adoption of home dialysis therapies, especially PD. For Chinese and Spanish Translation of the Lay Summary, see Online Supplement Appendix 1.

Key recommendations

Guideline 1:

A pathophysiological taxonomy: A pathophysiological classification of membrane dysfunction, which provides mechanistic links to functional characteristics, should be used when prescribing individualized dialysis or when planning modality transfer (e.g. to automated peritoneal dialysis (PD) or haemodialysis) in the context of shared and informed decision-making with the person on PD, taking individual circumstances and treatment goals into account. (practice point)

Guideline 2a:

Identification of fast peritoneal solute transfer rate (PSTR): It is recommended that the PSTR is determined from a 4-h peritoneal equilibration test (PET), using either 2.5%/2.27% or 4.25%/3.86% dextrose/glucose concentration and creatinine as the index solute. (practice point) This should be done early in the course dialysis treatment (between 6 weeks and 12 weeks) (GRADE 1A) and subsequently when clinically indicated. (practice point)

Guideline 2b:

Clinical implications and mitigation of fast solute transfer: A faster PSTR is associated with lower survival on PD. (GRADE 1A) This risk is in part due to the lower ultrafiltration (UF) and increased net fluid reabsorption that occurs when the PSTR is above the average value. The resulting lower net UF can be avoided by shortening glucose-based exchanges, using a polyglucose solution (icodextrin), and/or prescribing higher glucose concentrations. (GRADE 1A) Compared to glucose, use of icodextrin can translate into improved fluid status and fewer episodes of fluid overload. (GRADE 1A) Use of automated PD and icodextrin may mitigate the mortality risk associated with fast PSTR. (practice point)

Guideline 3:

Recognizing low UF capacity: This is easy to measure and a valuable screening test. Insufficient UF should be suspected when either (a) the net UF from a 4-h PET is <400 ml (3.86% glucose/4.25% dextrose) or <100 ml (2.27% glucose /2.5% dextrose), (GRADE 1B) and/or (b) the daily UF is insufficient to maintain adequate fluid status. (practice point) Besides membrane dysfunction, low UF capacity can also result from mechanical problems, leaks or increased fluid absorption across the peritoneal membrane not explained by fast PSTR.

Guideline 4a:

Diagnosing intrinsic membrane dysfunction (manifesting as low osmotic conductance to glucose) as a cause of UF insufficiency: When insufficient UF is suspected, the 4-h PET should be supplemented by measurement of the sodium dip at 1 h using a 3.86% glucose/4.25% dextrose exchange for diagnostic purposes. A sodium dip ≤5 mmol/L and/or a sodium sieving ratio ≤0.03 at 1 h indicates UF insufficiency. (GRADE 2B)

Guideline 4b:

Clinical implications of intrinsic membrane dysfunction (de novo or acquired): in the absence of residual kidney function, this is likely to necessitate the use of hypertonic glucose exchanges and possible transfer to haemodialysis. Acquired membrane injury, especially in the context of prolonged time on treatment, should prompt discussions about the risk of encapsulating peritoneal sclerosis. (practice point)

Guideline 5:

Additional membrane function tests: measures of peritoneal protein loss, intraperitoneal pressure and more complex tests that estimate osmotic conductance and ‘lymphatic’ reabsorption are not recommended for routine clinical practice but remain valuable research methods. (practice point)

Guideline 6:

Socioeconomic considerations: When resource constraints prevent the use of routine tests, consideration of membrane function should still be part of the clinical management and may be inferred from the daily UF in response to the prescription. (practice point)

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

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

Comparison of clinical effects between icodextrin and glucose solutions on outcomes of peritoneal dialysis: systematic review and meta-analysis of randomized controlled trials

Background

Icodextrin enhances peritoneal filtration for patients on peritoneal dialysis (PD). However, clinically important outcomes have not yet been analyzed using authentic, objective statistical methods. The present systematic review aimed to determine the risks and benefits of icodextrin compared with a glucose-based solution with respect to clinically important and patient-centered outcomes.

Methods

We systematically investigated only randomized controlled trials (RCTs) by adopting the Cochrane Database of Systematic Review (2014) and searched the CENTRAL, MEDLINE, and EMBASE databases for eligible studies reported in the literature. The quality of the evidence was assessed using the GRADE approach.

Results

We finally evaluated important outcomes in 13 RCTs. Icodextrin significantly decreased the number of reported episodes of uncontrolled fluid overload in four RCTs that involved 236 patients (relative risk [RR], 0.31; 95% confidence interval [CI], 0.12 to 0.82; moderate certainty evidence). However, the inclusion of icodextrin for peritoneal ultrafiltration did not significantly differ in six RCTs involving 252 patients (mean difference [MD], 186.76 mL; 95% CI, − 47.08 to 420.59; low certainty evidence). Regarding other clinically important outcomes, all-cause mortality in 10 RCTs involving 1106 patients (RR, 0.75; 95% CI, 0.33 to 1.71; low certainty evidence) and technical survival in five RCTs involving 470 patients (RR, 0.57; 95%CI, 0.29 to 1.12; low certainty evidence) were not significant. Urine volume in four RCTs involving 136 patients, residual renal function in five RCTs involving 181 patients and peritoneal function measured as the ratio of solute concentration in dialysate and plasma (D/P ratio) in two RCTs involving 105 patients were not specifically affected by icodextrin, and the results for adverse events were similar between icodextrin and glucose PD solutions.

Conclusion

Icodextrin could relieve uncontrolled fluid overload without adding risk. However, a significant effect on clinically relevant outcomes such as technical survival and overall patient survival was not suggested. More trials are required to increase the statistical power and to verify the value of icodextrin in clinical practice.

Trial registration

PROSPERO, CRD42018104360

Methodology of Assessment of Fluid Status and Ultrafiltration Problems

Loss of sodium and water excretion with disruption of volume homeostasis is a crucial abnormality of end-stage renal failure. Fluid management is a fundamental function of dialysis therapy, but studies show frequent occult fluid overload, hypertension, and cardiac dysfunction in peritoneal dialysis. A rigorous approach to fluid management in PD can achieve excellent fluid, hypertension, and cardiovascular results in clinical practice. The present article explores the reasons for fluid overload and poor ultrafiltration in peritoneal dialysis patients and discusses optimal assessment and management of these problems.

Could Solutions Low in Glucose Degradation Products Preserve Residual Renal Function in Incident Peritoneal Dialysis Patients? A 1-Year Multicenter Prospective Randomized Controlled Trial (Balnet Study)

⋄ Objectives

In vitro studies of peritoneal dialysis (PD) solutions demonstrated that a lactate-buffered fluid with neutral pH and low glucose degradation products (LF) has better biocompatibility than a conventional acidic lactate-buffered fluid (CF). However, few clinical trials have evaluated the long-term benefit of the biocompatible solution on residual renal function (RRF). To compare LF with CF, we performed a prospective, randomized study with patients starting PD.

⋄ Patients and Methods

After 1-month run-in period, 91 new PD patients were randomized for 12 months of treatment with either LF (Balance: Fresenius Medical Care, Bad Homburg, Germany; n = 48) or CF (Stay•Safe: Fresenius; n = 43). We measured RRF, acid–base balance, peritoneal equilibration test, and adequacy of dialysis every 6 months after the run-in period.

⋄ Results

After 12 months of treatment, the residual glomerular filtration rate (GFR) in patients using LF tended to be higher than that of patients on CF ( p = 0.057 by repeated-measures analysis of variance). We observed a significant difference in the changes of residual GFR between the two groups ( p = 0.009), a difference that was especially marked in the subgroup whose baseline residual GFR was more than 2 mL/min/1.73 m2. In addition, serum total CO2 levels were higher ( p = 0.001) and serum anion gap was lower ( p = 0.019) in the LF group. We observed no differences between groups for Kt/V, C-reactive protein, or normalized protein equivalent of nitrogen appearance.

⋄ Conclusions

In incident PD patients with significant residual GFR, LF may better preserve RRF over a 12-month treatment period. Additionally, pH-neutral PD fluid may improve acid–base balance as compared with CF.

Can we Overcome the Predestined Poor Survival of Diabetic Patients? Perspectives from Pre- and Post-Dialysis

Although the survival of diabetic peritoneal dialysis (PD) patients has improved, it is still much worse than the survival of nondiabetic patients. Diabetes has its own risks for cardiovascular disease (CVD), such as increased levels of advanced glycation end-products, carbonyl and oxidative stress, and low-grade inflammation. An independent, graded association has been observed between a reduced glomerular filtration rate and the risk of CVD events in chronic kidney disease (CKD). Both CKD and diabetes synergistically lead to a high risk of CVD. It seems that the poor survival of diabetic PD patients is predestined at the initiation of dialysis because of multiple pre-existing risk factors and comorbid diseases, particularly CVD.

Recently, several trials were successful in improving the survival of patients with diabetic CKD. Tight control of glucose, blood pressure management using angiotensin converting-enzyme inhibitors or angiotensin II receptor blockers, and use of statins, antioxidants, or peroxisome proliferator-activated receptor gamma agonists may improve the survival of diabetic PD patients. However, simple correction of a single CVD risk factor is not likely to be effective. New PD solutions such as those low in glucose degradation products or those with icodextrin may also be effective in reducing the risk of CVD in diabetic PD patients. Therefore, multifactorial interventions—including diet control, early referral, and choice of an optimal PD solution—may improve the survival of diabetic PD patients.

Controlling Inflammation in Peritoneal Dialysis: The Role of PD-Related Factors as Potential Intervention Targets

Cardiovascular (CV) disease is the main cause of death in peritoneal dialysis (PD) patients, but the mechanisms mediating the increased CV risk observed in this group of patients are still largely unknown, which limits the perspective on effective therapeutic strategies. Patients on PD are already exposed to a number of traditional risk factors from the start of their chronic kidney disease (CKD), because many of those risk factors are common to CV disease and CKD alike. As renal dysfunction progresses, CKD-related risk factors are introduced, changing the profile of both the CV disease and the markers of risk. In this phase, which usually starts when glomerular filtration rate falls below 60 mL/min, the list of risk factors is expanded to include disturbances of mineral metabolism, anemia, fluid overload, uremic toxicity, and increased signs of oxidative stress and inflammation. Although many of the risk factors linked to CV burden are not related to the dialytic procedure, additional harm is introduced after the initiation of PD—with, for example, the presence of chronic infections and factors related to PD fluids, particularly reabsorption of glucose. In the present article, we review the impact of the novel risk factors introduced with the initiation of PD therapy, and we propose potential therapeutic strategies (which remain to be tested) for reducing CV mortality in this group of patients.

Uncertainties in BP management in dialysis patients

Hypertension in dialysis patients is extremely common. In this article, we review the current evidence for blood pressure (BP) goals in hemodialysis patients, and consider the effectiveness of interventions by which BP may be lowered, including manipulation of dietary and dialysate sodium; optimization of extracellular water; prolongation of dialysis time; and antihypertensive medication. Although two meta-analyses suggest lowering BP using antihypertensive drugs might be beneficial in reducing cardiovascular events and mortality, there are insufficient rigorously designed trials in hypertensive hemodialysis populations to determine preferred antihypertensive drug classes. We suggest aiming for predialysis systolic BP between 130 and 159 mm Hg, while at the same time acknowledge the significant limitations of the data upon which it is based. We conclude by summarizing current knowledge as regards management of hypertension in the peritoneal dialysis population and make recommendations for future research in this field.

Improving Salt Balance in Peritoneal Dialysis Patients

Volume homeostasis is an important predictor of outcome in peritoneal dialysis. Because volume retention is driven by salt retention, maintenance of salt balance should be a concern to all nephrologists. An important factor in this is dietary salt restriction. This has long been neglected in peritoneal dialysis patients, where it was considered that the continuous nature of the therapy and residual renal function would be sufficient to remove any extra salt load. In patients with preserved renal function, diuresis and salt excretion can be enhanced by the application of high doses of loop diuretics. This practice seems not to have an impact on the further deterioration of renal function. Peritoneal salt removal can be enhanced using polyglucose. Also, the use of low sodium-containing dialysate can be efficient. These solutions are, however, not commercially available, and they need higher concentrations of glucose to obtain an efficient osmolarity. It should always be considered that, due to sodium sieving over the ultrasmall pores, fluid and salt removal are not always concordant.

Influence of Icodextrin on Plasma and Dialysate Levels of N∊-(Carboxymethyl)Lysine and N∊-(Carboxyethyl)Lysine

Rationale

Standard peritoneal glucose solutions may induce the formation of advanced glycation end products (AGEs). Preliminary data suggest that AGE formation may be less with the use of polyglucose solutions (icodextrin). Therefore, we investigated whether the use of icodextrin for the long dwell would result in a reduction in plasma and dialysate levels of the AGE products N∊-(carboxymethyl) lysine (CML) and N∊-(carboxyethyl)lysine (CEL).

Patients and Methods

40 patients were randomized to treatment with standard glucose solutions (1.36%) and icodextrin for the long dwell during a 4-month study period; 32 patients completed the study. CML was assessed by stable isotope dilution/tandem mass spectrometry.

Results

CML levels in plasma increased significantly in patients treated with icodextrin (0.146 ± 0.056 at start vs 0.188 ± 0.069 μmol/mmol Lys at the end of the study, p < 0.0001) but did not change in the control group (0.183 ± 0.090 vs 0.188 ± 0.085 μmol/mmol Lys). The same held true for CML levels in dialysate (0.28 ± 0.09 at start vs 0.33 ± 0.11 μmol/mmol Lys at the end of the study, p < 0.025). No change was observed in patients treated with the control solutions (0.31 ± 0.11 at start vs 0.31 ± 0.07 μmol/mmol Lys).

Conclusion

Contrary to the hypothesis, plasma and dialysate levels of CML increased in patients treated using icodextrin for the long dwell.

Relationship of Demographic, Dietary, and Clinical Factors to the Hydration Status of Patients on Peritoneal Dialysis

Objectives

To establish which clinical factors are associated with an increased proportion of extracellular fluid (ECF) in peritoneal dialysis (PD) patients.

Design

A single-center, cross-sectional analysis of 68 stable PD patients.

Method

Bioelectrical impedance measurements (RJL, single frequency; RJL Systems, Clinton, Michigan, USA) of resistance and reactance were used to determine the proportion of ECF comprising total body water (TBW) in 68 stable PD patients attending for routine clearance and membrane studies. All patients underwent detailed dietetic, adequacy, and membrane function tests. Blood pressure and antihypertensive requirements were also documented.

Results

Significant gender differences in body composition were observed, such that women had lower absolute TBW and fat-free mass per kilogram body weight, but proportionately more ECF for a given TBW, mean ECF:TBW 0.5 ± 0.03 versus 0.44 ± 0.05, p < 0.005. In view of this, patients were split into two groups, defined as “over-” or “normally” hydrated, either by using the single discriminator (median ECF:TBW = 0.47) for the whole population, which resulted in groups distorted by gender, or by using different discriminators according to gender (women: 0.49, men 0.45). In both analyses, overhydrated patients were older, had significantly lower plasma albumin, less total fluid removal per kilogram body weight, and higher peritoneal solute transport. When split by a single discriminator, the overhydrated patients had lower sodium removal and significantly less intracellular fluid volume due to an excess of women in this group who also had less residual function and had been on dialysis longer. Using gender-specific discrimination, overhydrated patients were heavier due to expansion of the ECF volume: 20 ± 4.1 L versus 16 ± 3.3 L, p < 0.001. Stepwise multivariate analysis found age ( p = 0.001), albumin ( p = 0.009), and fluid losses per kilogram body weight ( p = 0.025) to be independent predictors of gender-adjusted hydration status. Sodium intake did not vary according to hydration status.

Conclusion

Gender influences the assessment of hydration status of PD patients when employing bioimpedance, such that women tend to have more ECF. Taking this into account, age, albumin, and achieved fluid removal appear to be independently associated with hydration status, whereas peritoneal solute transport is not. Advice on dietary sodium should take account of hydration status and achievable losses.

Chronic Inflammation in Peritoneal Dialysis: The Search for the Holy Grail?

Mortality and morbidity in chronic kidney disease (CKD) patients are unacceptably high. The annual mortality rate due to cardiovascular disease (CVD) is approximately 9%, which, for the middle-aged person, is at least 10- to 20-fold higher than for the general population. Classic risk factors for CVD are highly prevalent in CKD patients, but they cannot fully account for the excessive rate of CVD in this population. Instead, it has become increasingly clear that nontraditional risk factors, such as systemic inflammation, may play a key role in the development of atherosclerosis. It is well established that inflammatory markers are very powerful predictors of high CVD morbidity and mortality not only in the general population, but particularly in CKD patients. Signs of a sustained low-grade inflammation, such as increased levels of C-reactive protein (CRP), are present in the majority of stage 5 CKD patients, even in patients in clinically stable condition, and they are also commonly observed after the initiation of dialysis therapy. Dialysis therapy — hemodialysis as well as peritoneal dialysis (PD) — may itself contribute to systemic inflammation. Local intraperitoneal inflammation can also occur in patients treated with PD. These local effects may result in a low-grade inflammation, caused by the bioincompatibility of conventional glucose-based dialysis fluids, to intense inflammation associated with peritonitis. Given these circumstances, it is reasonable to hypothesize that strategies aiming to reduce inflammation are potentially important and novel, and could serve to reduce CVD, thereby lowering morbidity and mortality in patients with CKD. In this review we provide information supporting the hypothesis that systemic inflammation is tightly linked to the most common complications of CKD patients, in particular those on PD, and that local inflammation in PD may contribute to various related complications. The aims of this review are to discuss the reasons that make inflammation an attractive target for intervention in CKD, the particular aspects of the inflammation–CVD axis during PD treatment that are likely involved, and possible means for the detection and management of chronic inflammation in PD patients.

Blood Pressure, Volume, and Sodium Control in an Automated Peritoneal Dialysis Population

Objectives

To examine the control of blood pressure and volume, and the role of sodium removal in a single, large, contemporary, automated peritoneal dialysis (APD) population where icodextrin is used liberally and there is a policy to avoid long duration glucose-based daytime dwells.

Design

Observational cross-sectional study.

Setting

A university hospital.

Patients

56 APD patients, with a mean duration on peritoneal dialysis of 1.9 years; 50% were prescribed icodextrin.

Main Outcome Measures

Blood pressure, extracellular water volume (ECW)-to-intracellular water volume (ICW) ratio, and total (peritoneal and urinary) sodium removal.

Results

Sodium Removal: Mean total sodium removal, while low at 102.9 ± 64.6 mmol/day, showed a wide range, with 41% having a sodium removal of >120 mmol/day. Total sodium removal correlated with total body water, ECW, and ICW ( p < 0.001, p < 0.001, p < 0.025, respectively), as well as with height and weight ( p < 0.06, p < 0.01 respectively). On multivariate analysis, only ultra-filtration volume and urine volume were significantly associated with total sodium removal ( r2 = 0.67, p < 0.0001 for both). There was also a correlation between sodium removal and urea nitrogen appearance ( r2 = 0.31, p < 0.001), with urea nitrogen appearance in turn being closely correlated with ICW ( p < 0.001). Volume Status: The ECW/ICW ratio was 0.88 ± 0.17, which was not significantly different to that found in hemodialysis patients without clinical evidence of fluid overload, either predialysis (0.96 ± 0.16) or postdialysis (0.92 ± 0.16); p = 0.07 and 0.36 respectively. Blood Pressure: Mean ± standard deviation systolic blood pressure (BP) was 111.9 ± 18.2 mmHg and diastolic BP was 63.3 ± 11.9 mmHg, with only 4 (7%) patients having a systolic BP > 140 mmHg and 1 (2%) having a diastolic BP > 80 mmHg. Median number of antihypertensives was 1 per day. Blood pressure control and ECW/ICW ratio were similar in those with sodium removal >120 mmol/day compared to those with sodium removal ≤120 mmol/day ( p = 0.39 for SBP, p = 0.70 for diastolic B P, p = 0.24 for ECW/ICW).

Conclusions

We have shown that good blood pressure and volume control is achievable in a large contemporary APD population with liberal use of icodextrin and avoidance of long daytime glucose-based dwells. Neither low nor high sodium removal was associated with more frequent hypertension or volume expansion.

Article Commentary: Application of Bioelectrical Impedance to Clinical Assessment of Body Composition in Peritoneal Dialysis

Patients on peritoneal dialysis (PD) develop complex changes in body composition. These changes reflect hydration, nutrition, and body fat, all important elements reflecting patient well-being and efficacy of therapy that should be assessed and monitored as guides to patient management. They are all notoriously difficult to accurately measure in clinical practice and simultaneous abnormalities may obscure detection, as in the malnourished fluid-overloaded patient where body weight is misleadingly stable. Malnutrition is a serious complication in PD that carries an adverse prognosis. Assessment of hydration in PD is important in determining “dry weight” to allow adjustment of dialysis prescription to optimize fluid balance. A number of techniques have been investigated to measure body composition in clinical practice. Of these, bioelectrical impedance analysis (BIA) has attracted most interest and seems to be of greatest promise. Cases illustrating different aspects of the use of BIA in PD patients are described, and the background, possible uses, and limitations of BIA in PD patients are discussed. To be of clinical value, BIA must be used to distinguish between extracellular water (which reflects hydration) and body cell mass, or intracellular water (which declines in wasting and malnutrition). The high precision of BIA is ideally suited to detecting changes in body composition and its main role may be in longitudinal monitoring. However, inaccuracy of absolute measurements and variability of normal values in the general population make precise diagnosis of the degree of normality of body composition in an individual subject a more difficult task for body composition analysis.

Serum BNP Concentration and Left Ventricular Mass in CAPD and Automated Peritoneal Dialysis Patients

Objective

To compare ultrafiltration under continuous ambulatory peritoneal dialysis (CAPD) and automated PD (APD), disclosing potential effects on serum B-type natriuretic peptide (BNP) levels and echocardiographic findings.

Patients and Methods

This cross-sectional clinical study included 32 patients on CAPD and 30 patients on APD without clinical evidence of heart failure or hemodynamically significant valvular heart disease. Peritoneal equilibration tests, BNP levels, and echocardiographic measurements were performed in each subject. BNP measurements were also performed in 24 healthy control subjects.

Results

Patients on APD had lower ultrafiltration and higher values of BNP and left ventricular mass index (LVMI) compared with patients on CAPD (respectively: 775 ± 160 vs 850 ± 265 mL, p = 0.01; 253.23 ± 81.64 vs 109.42 ± 25.63 pg/mL, p = 0.001; 185.12 ± 63.50 vs 129.30 ± 40.95 g/m2, p = 0.001). This occurred despite higher mean dialysate glucose concentrations and far more extensive use of icodextrin in the APD group.

Conclusion

Treatment with APD is associated with higher plasma BNP levels and LVMI compared to CAPD. This may be the result of chronic fluid retention caused by lower ultra-filtration in APD patients.

Use of Icodextrin during Nocturnal Automated Peritoneal Dialysis Allows Sustained Ultrafiltration While Reducing the Peritoneal Glucose Load: A Randomized Crossover Study

Background

Optimization of ultrafiltration and preservation of the peritoneal membrane are desirable objectives in peritoneal dialysis (PD) patients. Mixtures of glucose-and non-glucose-based solutions may help to meet both targets simultaneously.

Aim

To analyze the effects, in terms of ultrafiltration and peritoneal glucose load, of including icodextrin-based dialysate in the nocturnal schedule of patients undergoing automated PD (APD).

Method

Following a randomized crossover design, 17 APD patients underwent two 10-day study periods under identical prescription (including amino acid-based solution for the night schedule), except for the substitution of 2 L glucose-based dialysate in the nocturnal mixture (control) by a similar amount of icodextrin-based dialysate (icodextrin phase) in one period. Dependent variables included ultra-filtration, sodium removal, peritoneal glucose load, and residual renal function. We measured serum and urine levels of icodextrin metabolites at the end of each phase.

Results

Ultrafiltration was marginally higher during the icodextrin phase (median 815 vs 763 mL/day, p = 0.07), while peritoneal sodium removal was similar in both phases (74 vs 71 mmol/L/day). Peritoneal glucose load (median 67.5 vs 104.0 g/day, p < 0.005) and absorption (14.0 vs 35.6 g/day, p < 0.005) were lower during the icodextrin phase. Diuresis was also modestly lower during the icodextrin phase (500 vs 600 mL/day, p < 0.05). Serum levels of icodextrin metabolites were moderately higher in the icodextrin phase ( p < 0.005) in patients both on and off diurnal icodextrin.

Conclusion

Inclusion of amino acid- and icodextrin-based solutions in the nocturnal schedule of APD patients may allow sustained ultrafiltration and sodium removal while significantly reducing the peritoneal glucose load in these patients.

The Potential Cardiovascular Benefits of Low-Glucose Degradation Product, Biocompatible Peritoneal Dialysis Fluids: A Review of the Literature

Cardiovascular mortality in the end-stage renal disease (ESRD) population remains the leading cause of death. Targeting traditional cardiovascular risk factors has proven unsuccessful in this patient population, and therefore attention has turned to risk factors related to chronic kidney disease (CKD). The toxicity of high-glucose peritoneal dialysis (PD) solutions has been well documented. The breakdown of glucose into glucose degradation products (GDP) and advanced glycation end-products (AGE) has the ability to alter cell viability and cause premature apoptosis and is strongly correlated with interstitial fibrosis and microvascular sclerosis. Biocompatible solutions have been introduced to combat the hostile milieu to which PD patients are exposed.

Given the considerable cardiovascular burden for PD patients, little is known about the cardiovascular impact the new biocompatible solutions may have. This review analyzes the existing literature regarding the mechanisms through which low-GDP solutions may modulate cardiovascular risk. Interventions using low-GDP solutions have provided encouraging changes in structural cardiovascular measures such as left ventricular mass (LVM), although metabolic changes from reduced GDP and AGE exposure yield inconclusive results on vascular remodelling. It is thought that the local effects of reduced glucose exposure may improve membrane integrity and therefore fluid status. Further research in the form of a robust randomized controlled trial should be carried out to assess the true extent of the cardiovascular benefits these biocompatible solutions may hold.

Icodextrin Versus Glucose Solutions for the Once-Daily Long Dwell in Peritoneal Dialysis: An Enriched Systematic Review and Meta-analysis of Randomized Controlled Trials

RATIONALE & OBJECTIVE

The efficacy and safety of icodextrin versus glucose-only peritoneal dialysis (PD) regimens is unclear. The aim of this study was to compare once-daily long-dwell icodextrin versus glucose among patients with kidney failure undergoing PD.

STUDY DESIGN

Systematic review of randomized controlled trials (RCTs), enriched with unpublished data from investigator-initiated and industry-sponsored studies.

SETTING & STUDY POPULATIONS

Individuals with kidney failure receiving regular PD treatment enrolled in clinical trials of dialysate composition.

SELECTION CRITERIA FOR STUDIES

Medline, Embase, CENTRAL, Ichushi Web, 10 Chinese databases, clinical trials registries, conference proceedings, and citation lists from inception to November 2018. Further data were obtained from principal investigators and industry clinical study reports.

DATA EXTRACTION

2 independent reviewers selected studies and extracted data using a prespecified extraction instrument.

ANALYTIC APPROACH

Qualitative synthesis of demographics, measurement scales, and outcomes. Quantitative synthesis with Mantel-Haenszel risk ratios (RRs), Peto odds ratios (ORs), or (standardized) mean differences (MDs). Risk of bias of included studies at the outcome level was assessed using the Cochrane risk-of-bias tool for RCTs.

RESULTS

19 RCTs that enrolled 1,693 participants were meta-analyzed. Ultrafiltration was improved with icodextrin (medium-term MD, 208.92 [95% CI, 99.69-318.14] mL/24h; high certainty of evidence), reflected also by fewer episodes of fluid overload (RR, 0.43 [95% CI, 0.24-0.78]; high certainty). Icodextrin-containing PD probably decreased mortality risk compared to glucose-only PD (Peto OR, 0.49 [95% CI, 0.24-1.00]; moderate certainty). Despite evidence of lower peritoneal glucose absorption with icodextrin-containing PD (medium-term MD, -40.84 [95% CI, -48.09 to-33.59] g/long dwell; high certainty), this did not directly translate to changes in fasting plasma glucose (-0.50 [95% CI, -1.19 to 0.18] mmol/L; low certainty) and hemoglobin A_1c levels (-0.14% [95% CI, -0.34% to 0.05%]; high certainty). Safety outcomes and residual kidney function were similar in both groups; health-related quality-of-life and pain scores were inconclusive.

LIMITATIONS

Trial quality was variable. The follow-up period was heterogeneous, with a paucity of assessments over the long term. Mortality results are based on just 32 events and were not corroborated using time-to-event analysis of individual patient data.

CONCLUSIONS

Icodextrin for once-daily long-dwell PD has clinical benefit for some patients, including those not meeting ultrafiltration targets and at risk for fluid overload. Future research into patient-centered outcomes and cost-effectiveness associated with icodextrin is needed.

Sodium toxicity in peritoneal dialysis: mechanisms and "solutions"

The major trials in peritoneal dialysis (PD) have demonstrated that increasing peritoneal clearance of small solutes is not associated with any advantage on survival, whereas sodium and fluid overload heralds higher risk of death and technique failure. On the other hand, higher sodium and fluid overload due to loss of residual kidney function (RKF) and higher transport membrane is associated with poor patient and technique survival. Recent experimental studies also show that, independently from fluid overload, sodium accumulation in the peritoneal interstitium exerts direct inflammatory and angiogenetic stimuli, with consequent structural and functional changes of peritoneum, while in patients with Chronic Kidney Disease sodium stored in interstitial skin acts as independent determinant of left ventricular hypertrophy. Noteworthy, this tissue pool of sodium is modifiable being removed by dialysis. Therefore, novel PD strategies to optimize sodium removal, including the use of bimodal and/or low-sodium solutions, are actively tested. Nonetheless, a holistic approach aimed at preserving peritoneal function and the kidney may represent the key of therapy success in the hard task of preserving adequate sodium balance in PD patients. In this review, we describe the available evidence on sodium toxicity in PD, either related or unrelated to fluid overload, and we also discuss about possible "solutions" to preserve or restore sodium balance in PD patients.

Factors associated with systolic hypertension in peritoneal dialysis patients

Background

Hypertension is common in peritoneal dialysis (PD) patients and associated with adverse outcomes. Besides solute clearance, PD convective clearance is used to control extracellular water (ECW) volume and sodium balance. Previous studies have reported on hypertension in PD patients treated with continuous ambulatory peritoneal dialysis (CAPD) using hypertonic glucose dialysates. However, increasing numbers of PD patients are now treated with automated peritoneal dialysis (APD) and icodextrin dialysates. As such, we wished to explore factors associated with systolic blood pressure (SBP) in a modern cohort to identify targets to improve blood pressure control in PD patients.

Methods

We retrospectively reviewed the results from PD patients attending for peritoneal membrane assessment who had corresponding bioimpedance ECW and brain natriuretic peptide (NT-proBNP) measurements.

Results

We studied 510 PD patients: 317 (72.2%) male, 216 (42.4%) diabetics, median age 59 (47–72) years, and 51% treated by APD with a day-time icodextrin exchange. Mean systolic blood pressure (SBP) was 140 ± 24.8 mmHg. SBP was independently associated with 4-hour dialysate to plasma creatinine ratio (β = 29.5 (95% confidence limits 11.4–47.5, p = 0.001), N-terminal brain natriuretic peptide [β = 11.9 (7.2–16.7), p < 0.001], and daily urine sodium excretion [β = 1.7 (1.0–2.3), p < 0.001].

Conclusion

In the era of APD cyclers and icodextrin, SBP is associated with increased NT-proBNP, a marker of ECW expansion, and faster peritoneal transport, a risk factor for a positive sodium balance, and increased urinary sodium suggestive of higher dietary sodium intake. Patients should be encouraged to restrict sodium intake and PD prescriptions targeted to control ECW to improve SBP control.

Assessment and Management of Hypertension among Patients on Peritoneal Dialysis

Approximately 7%-10% of patients with ESKD worldwide undergo peritoneal dialysis (PD) as kidney replacement therapy. The continuous nature of this dialytic modality and the absence of acute shifts in pressure and volume parameters is an important differentiation between PD and in-center hemodialysis. However, the burden of hypertension and prognostic association of BP with mortality follow comparable patterns in both modalities. Although management of hypertension uses similar therapeutic principles, long-term preservation of residual diuresis and longevity of peritoneal membrane function require particular attention in the prescription of the appropriate dialysis regimen among those on PD. Dietary sodium restriction, appropriate use of icodextrin, and limited exposure of peritoneal membrane to bioincompatible solutions, as well as adaptation of the PD regimen to the peritoneal transport characteristics, are first-line therapeutic strategies to achieve adequate volume control with a potential long-term benefit on technique survival. Antihypertensive drug therapy is a second-line therapeutic approach, used when BP remains unresponsive to the above volume management strategies. In this article, we review the available evidence on epidemiology, diagnosis, and treatment of hypertension among patients on PD and discuss similarities and differences between PD and in-center hemodialysis. We conclude with a call for randomized trials aiming to elucidate several areas of uncertainty in management of hypertension in the PD population.

Clinical Studies of Interventions to Mitigate Cardiovascular Risk in Peritoneal Dialysis Patients

Cardiovascular disease (CVD) is highly prevalent in the peritoneal dialysis (PD) population, affecting up to 60% of cohorts. CVD is the primary cause of death in up to 40% of PD patients in Australia, New Zealand, and the United States. Cardiovascular mortality rates are reported to be approximately 14 per 100 patient-years, which are 10- to 20-fold greater than those of age- and sex-matched controls. The excess risk of CVD is related to a combination of traditional risk factors (such as hypertension, dyslipidemia, obesity, smoking, sedentary lifestyle, and insulin resistance), nontraditional (kidney disease-related) risk factors (such as anemia, chronic volume overload, inflammation, malnutrition, hyperuricemia, and mineral and bone disorder), and PD-specific risk factors (such as dialysis solutions, glycation end products, hypokalemia, residual kidney function, and ultrafiltration failure). Interventions targeting these factors may mitigate cardiovascular risk, although high-level clinical evidence is lacking. This review summarizes the evidence relating to cardiovascular interventions targeting modifiable CVD risk factors in PD patients, as well as highlighting the key recommendations of the International Society for Peritoneal Dialysis Cardiovascular and Metabolic Guidelines.

Icodextrin is associated with a lower risk of atrial fibrillation in peritoneal dialysis patients

AIM

Dialysis patients with atrial fibrillation (AF) are at 1.72-fold increased mortality risk. This study investigated whether peritoneal dialysis (PD) patients using icodextrin were at a reduced risk of AF.

METHODS

From the Taiwan National Health Insurance database, we identified 4040 icodextrin users and 3517 non-users among 7557 patients newly diagnosed with end-stage renal disease undergoing PD from 2005 to 2011. The incidence of AF was compared between PD patients with and without icodextrin treatment by the end of 2011, with the hazard ratio (HR) of AF measured using Cox proportional hazards regression models.

RESULTS

The incidence of AF was 50% lower in icodextrin users than in non-users (2.14 vs 4.24 per 1000 person-years) with an adjusted HR of 0.49 (95% confidence interval (CI) = 0.28-0.85). The protective effect was greater for PD patients with diabetes (adjusted HR = 0.39, 95% CI = 0.17-0.86) than those without diabetes (adjusted HR = 0.57, 95% CI = 0.28-1.18). The beneficial effect of icodextrin treatment remained after controlling for the competing risk of deaths, with an adjusted sub-HR of 0.35 (95% CI = 0.16-0.75) for those with diabetes and 0.50 (95% CI = 0.26-0.99) for those without diabetes.

CONCLUSION

The use of icodextrin solution is associated with a lower risk of new-onset AF in PD patients. The protective effectiveness was greater for those with diabetes.

Biocompatible dialysis fluids for peritoneal dialysis

BACKGROUND

Biocompatible peritoneal dialysis (PD) solutions, including neutral pH, low glucose degradation product (GDP) solutions and icodextrin, have previously been shown to favourably influence some patient-level outcomes, albeit based on generally sub-optimal quality studies. Several additional randomised controlled trials (RCT) evaluating biocompatible solutions in PD patients have been published recently. This is an update of a review first published in 2014.

OBJECTIVES

This review aimed to look at the benefits and harms of biocompatible PD solutions in comparison to standard PD solutions in patients receiving PD.

SEARCH METHODS

The Cochrane Kidney and Transplant Specialised Register was searched up to 12 February 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All RCTs and quasi-RCTs in adults and children comparing the effects of biocompatible PD solutions (neutral pH, lactate-buffered, low GDP; neutral pH, bicarbonate(± lactate)-buffered, low GDP; glucose polymer (icodextrin)) in PD were included. Studies of amino acid-based solutions were excluded.

DATA COLLECTION AND ANALYSIS

Two authors extracted data on study quality and outcomes. Summary effect estimates were obtained using a random-effects model, and results were expressed as risk ratios and 95% confidence intervals (CI) for categorical variables, and mean differences (MD) or standardised mean differences (SMD) and 95% CI for continuous variables.

MAIN RESULTS

This review update included 42 eligible studies (3262 participants), including six new studies (543 participants). Overall, 29 studies (1971 participants) compared neutral pH, low GDP PD solution with conventional PD solution, and 13 studies (1291 participants) compared icodextrin with conventional PD solution. Risk of bias was assessed as high for sequence generation in three studies, allocation concealment in three studies, attrition bias in 21 studies, and selective outcome reporting bias in 16 studies.Neutral pH, low GDP versus conventional glucose PD solutionUse of neutral pH, low GDP PD solutions improved residual renal function (RRF) preservation (15 studies, 835 participants: SMD 0.19, 95% CI 0.05 to 0.33; high certainty evidence). This approximated to a mean difference in glomerular filtration rate of 0.54 mL/min/1.73 m² (95% CI 0.14 to 0.93). Better preservation of RRF was evident at all follow-up durations with progressively greater preservation observed with increasing follow up duration. Neutral pH, low GDP PD solution use also improved residual urine volume preservation (11 studies, 791 participants: MD 114.37 mL/day, 95% CI 47.09 to 181.65; high certainty evidence). In low certainty evidence, neutral pH, low GDP solutions may make little or no difference to 4-hour peritoneal ultrafiltration (9 studies, 414 participants: SMD -0.42, 95% CI -0.74 to -0.10) which approximated to a mean difference in peritoneal ultrafiltration of 69.72 mL (16.60 to 122.00 mL) lower, and may increase dialysate:plasma creatinine ratio (10 studies, 746 participants: MD 0.01, 95% CI 0.00 to 0.03), technique failure or death compared with conventional PD solutions. It is uncertain whether neutral pH, low GDP PD solution use led to any differences in peritonitis occurrence, hospitalisation, adverse events (6 studies, 519 participants) or inflow pain (1 study, 58 participants: RR 0.51, 95% CI 0.24 to 1.08).Glucose polymer (icodextrin) versus conventional glucose PD solutionIn moderate certainty evidence, icodextrin probably reduced episodes of uncontrolled fluid overload (2 studies, 100 participants: RR 0.30, 95% CI 0.15 to 0.59) and augmented peritoneal ultrafiltration (4 studies, 102 participants: MD 448.54 mL/d, 95% CI 289.28 to 607.80) without compromising RRF (4 studies, 114 participants: SMD 0.12, 95% CI -0.26 to 0.49; low certainty evidence) which approximated to a mean creatinine clearance of 0.30 mL/min/1.73m² higher (0.65 lower to 1.23 higher) or urine output (3 studies, 69 participants: MD -88.88 mL/d, 95% CI -356.88 to 179.12; low certainty evidence). It is uncertain whether icodextrin use led to any differences in adverse events (5 studies, 816 participants) technique failure or death.

AUTHORS' CONCLUSIONS

This updated review strengthens evidence that neutral pH, low GDP PD solution improves RRF and urine volume preservation with high certainty. These effects may be related to increased peritoneal solute transport and reduced peritoneal ultrafiltration, although the evidence for these outcomes is of low certainty due to significant heterogeneity and suboptimal methodological quality. Icodextrin prescription increased peritoneal ultrafiltration and mitigated uncontrolled fluid overload with moderate certainty. The effects of either neutral pH, low GDP solution or icodextrin on peritonitis, technique survival and patient survival remain uncertain and require further high quality, adequately powered RCTs.

Asymptomatic fluid overload predicts survival and cardiovascular event in incident Chinese peritoneal dialysis patients

Background

Fluid overload is common among asymptomatic peritoneal dialysis (PD) patients. We aim to determine the prevalence and prognostic significance of fluid overload, as measured by bioimpedance spectroscopy, in asymptomatic incident PD patients.

Methods

We performed a single-center study on 311 incident PD patients. Volume status was represented by the volume of overhydration (OH), OH/extracellular water (ECW) ratio, ECW/total body water (TBW) ratio, and ECW to intracellular water (ICW) ratio (E:I ratio). Patient survival, technique survival and cardiovascular event-free survival were determined.

Results

The median period of follow up was 27.3 months. Fluid overload was present in 272 patients (87.5%) when defined as OH volume over 1.1L. All hydration parameters significantly correlated with Charlson Comorbidity Index, and inversely with total Kt/V, and serum albumin. Multivariate cause-specific Cox analysis showed that volume status independently predicted patient survival; every 0.1 unit increase in E:I ratio was associated with 24.5% increase in all-cause mortality (adjusted cause-specific hazard ratio [ACSHR] 1.245, p = 0.002). Hydration status was also an independent predictor of cardiovascular event-free survival after excluding hospital admission for congestive heart failure; each 0.1 unit increase in E:I ratio was associated with 18.7% decrease in cardiovascular event-free survival (ACSHR 1.187, p = 0.011). In contrast, hydration parameters were not associated with technique survival.

Conclusions

Fluid overload is common in asymptomatic incident PD patients and is a strong predictor of patient survival and cardiovascular event. The impact of bioimpedance spectroscopy-guided fluid management on the outcome of PD patients deserves further study.

Longitudinal analysis of cardiac structure and function in incident-automated peritoneal dialysis: comparison between icodextrin solution and glucose-based solution

Background

This study aimed to evaluate the longitudinal changes in cardiac structure and function in incident-automated peritoneal dialysis (APD) patients.

Methods

We conducted a 2-year prospective, randomized, open-label, parallel-group study to compare the efficacy of icodextrin solution versus glucose-based solution. Echocardiography was performed at baseline, 1 and 2 years. Echocardiographic parameters over 2 years were evaluated for each group, using the Friedman test. Generalized linear regression analysis was used to test the associations between baseline clinical variables and echocardiographic changes, and a multivariate model was used to analyze cardiac function between the two groups.

Results

A total of 43 APD patients were enrolled in the beginning of this study. Twenty patients in the icodextrin group (ICO) and 18 patients in the glucose group (GLU) completed the study. In left ventricular (LV) systolic function measurements, ejection fraction (EF) increased significantly in the GLU group. Measurements of LV diastolic function and septal early mitral annulus velocity (EMV) increased significantly from baseline to 24-months in the ICO group (5.43–5.51 ms). The GLU group showed a significant decrease in peak early diastolic velocity (EDV) (70.67–68.25 cm/s), but a significant increase in septal EMV (5.94–7.57 ms) from baseline to 24-months. No significant association was found between the baseline clinical variables and echocardiographic changes within 24 months in the generalized linear regression analysis. Multivariate models were used to investigate changes in the four primary endpoints, namely, myocardial performance index (MPI), left ventricular ejection fraction (LVEF), deceleration time (DT), and E/e′ ratio. These primary endpoints show no significant association with the baseline values in both the ICO and GLU groups.

Conclusion

The present study demonstrates that long-dwell icodextrin solution can maintain reasonable cardiac structure and function in incident-APD patients.

Trial registration

ISRCTN14931270 (retrospectively registered on 23/03/2018).

Icodextrin reduces the risk of congestive heart failure in peritoneal dialysis patients

PURPOSE

Icodextrin can enhance ultrafiltration and consequently improve fluid balance and can control blood pressure and reduce left ventricular mass for peritoneal dialysis (PD) patients. This study investigated whether icodextrin use could reduce the risk of congestive heart failure (CHF) for PD patients.

METHODS

From the Taiwan National Health Insurance database, we identified 5462 newly diagnosed end-stage renal disease patients undergoing PD from 2005 to 2010. Incidence rates and hazard ratio of CHF were estimated for patients with and without icodextrin treatment by the end of 2011.

RESULTS

Among PD patients, icodextrin users had an overall 26% lower incidence of CHF than non-users (13.7 vs 18.6 per 1000 person-years). Relatively, the adjusted hazard ratio was 0.67 (95% CI = 0.52-0.87) for users compared with non-users. Among PD patients with diabetes, the incident CHF in icodextrin users was 37.5% lower than that in non-users (17.8 vs 28.5 per 1000 person-years). Among PD patients without diabetes, the incident CHF in icodextrin users was 30.4% lower than that in non-users (11.0 vs 15.8 per 1000 person-years).

CONCLUSIONS

Icodextrin solution could reduce the risk of new-onset CHF, particularly effective when diabetic PD patients use it.

Does Routine Bioimpedance-Guided Fluid Management Provide Additional Benefit to Non-Anuric Peritoneal Dialysis Patients? Results from COMPASS Clinical Trial

INTRODUCTION

In peritoneal dialysis (PD) patients, volume overload is related to cardiac dysfunction and mortality, while intravascular volume depletion is associated with a rapid decline in the residual renal function (RRF). This study sought to determine the clinical usefulness of bioimpedance spectroscopy (BIS)-guided fluid management for preserving RRF and cardiac function in PD patients.

SUBJECTS AND METHODS

This is a multicenter, prospective, open-label study that was conducted over a 1-year period (NCT01887262). Non-anuric (urine volume > 500 mL/day) subjects on PD were enrolled. Subjects in the control group received fluid management based on the clinical information alone. Those in the BIS group received BIS-guided fluid management along with clinical information.

RESULTS

The subjects (N = 137, mean age 51.3 ± 12.8 years, 54% male) were randomly assigned to the BIS group (n = 67) or to the control group (n = 70). There were no significant differences between the 2 groups with regard to age, sex ratio, cause of kidney failure, duration of PD, baseline comorbidity, RRF, PD method, or peritoneal transport type. At baseline, the 2 groups were not different in terms of RRF (glomerular filtration rate [GFR], 5.1 ± 2.9 vs 5.5 ± 3.7 mL/min/1.73 m²). After follow-up, changes in the GFR between the 2 groups were not different (-1.5 ± 2.4 vs -1.3 ± 2.6 mL/min/1.73 m², p = 0.593). Over the 1-year study period, both groups maintained stability of various fluid status parameters. Between the 2 groups, there were no differences in the net change of various fluid status parameters such as overhydration (OH) and extracellular water/total body water (ECW/TBW). A net change in ECW over 1 year was slightly but significantly higher in the control group (net increase, 0.57 ± 1.27 vs 0.05 ± 1.63 L, p = 0.047). However, this difference was not translated into an improvement in RRF in the BIS group. There were no differences in echocardiographic parameters or arterial stiffness at the end of follow-up.

CONCLUSION

Routine BIS-guided fluid management in non-anuric PD patients did not provide additional benefit in volume control, RRF preservation, or cardiovascular (CV) parameters. However, our study cannot be generalized to the whole PD population. Further research is warranted in order to investigate the subpopulation of PD patients who may benefit from routine BIS-guided fluid management.

Low GDP Solution and Glucose-Sparing Strategies for Peritoneal Dialysis

Long-term exposure to a high glucose concentration in conventional peritoneal dialysis (PD) solution has a number of direct and indirect (via glucose degradation products [GDP]) detrimental effects on the peritoneal membrane, as well as systemic metabolism. Glucose- or GDP-sparing strategies often are hypothesized to confer clinical benefits to PD patients. Icodextrin (glucose polymer) solution improves peritoneal ultrafiltration and reduces the risk of fluid overload, but these beneficial effects are probably the result of better fluid removal rather than being glucose sparing. Although frequently used for glucose sparing, the role of amino acid-based solution in this regard has not been tested thoroughly. When glucose-free solutions are used in a combination regimen, published studies showed that glycemic control was improved significantly in diabetic PD patients, and there probably are beneficial effects on peritoneal function. However, the long-term effects of glucose-free solutions, used either alone or as a combination regimen, require further studies. On the other hand, neutral pH-low GDP fluids have been shown convincingly to preserve residual renal function and urine volume. The cost effectiveness of these solutions supports the regular use of neutral pH-low GDP solutions. Nevertheless, further studies are required to determine whether neutral pH-low GDP solutions exert beneficial effects on patient-level outcomes, such as peritonitis, technique survival, and patient survival.

Renal Association Clinical Practice Guideline on peritoneal dialysis in adults and children

These guidelines cover all aspects of the care of patients who are treated with peritoneal dialysis. This includes equipment and resources, preparation for peritoneal dialysis, and adequacy of dialysis (both in terms of removing waste products and fluid), preventing and treating infections. There is also a section on diagnosis and treatment of encapsulating peritoneal sclerosis, a rare but serious complication of peritoneal dialysis where fibrotic (scar) tissue forms around the intestine. The guidelines include recommendations for infants and children, for whom peritoneal dialysis is recommended over haemodialysis.Immediately after the introduction there is a statement of all the recommendations. These recommendations are written in a language that we think should be understandable by many patients, relatives, carers and other interested people. Consequently we have not reworded or restated them in this lay summary. They are graded 1 or 2 depending on the strength of the recommendation by the authors, and A-D depending on the quality of the evidence that the recommendation is based on.