Peritoneal dialysis tailored to pediatric needs

End-stage kidney disease in infancy: an educational review

An increasing number of infants with end-stage kidney disease (ESKD) are surviving and receiving renal replacement therapy (RRT). Unique clinical issues specific to this age group of patients influence their short- and long-term outcomes. This review summarizes current epidemiology, clinical characteristics, ethical dilemmas, management concerns, and outcomes of infants requiring chronic dialysis therapy. Optimal care during infancy requires a multidisciplinary team working closely with the patient's family. Nutritional management, infection prevention, and attention to cardiovascular status are important treatment targets. Although mortality rates remain higher among infants on dialysis compared to older pediatric dialysis patients, outcomes have improved over time. Most importantly, infants who subsequently receive a kidney transplant are now experiencing graft survival rates that are comparable to older pediatric patients.

Peritoneal dialysis catheter outcomes in infants initiating peritoneal dialysis for end-stage renal disease

Background

End-stage renal disease (ESRD) although rare among infants presents many management challenges. We sought to evaluate factors associated with PD catheter failure among infants initiated on chronic PD.

Methods

A retrospective chart review of all children under two years of age who had PD catheters placed for initiation of chronic PD from 2002 to 2015. Data was extracted for catheter related events occurring within 12 months of catheter placement. Cox and Poisson regression models were used to delineate factors associated catheter complications.

Results

Twenty-five infants with median age 18 days had PD catheters placed for chronic dialysis. Common complications included leakage around the exit site (31%), blockage (26%), migration or malposition (23%), catheter-related infections (18%), and other complications (2%). Predictors of initial PD catheter failure were age less than one month at catheter placement (hazard ratio (HR) 7.77, 95% CI, 1.70–35.39, p = 0.008), use of catheter within three days of placement (HR 5.67, 95% CI, 1.39–23.10, p = 0.015) and presence of a hernia (HR 8.64, 95% CI, 1.19–62.36, p = 0.033). In an adjusted Poisson regression model, PD catheter use within three days of placement was the only predictor of any catheter complication over the12 months of follow up.

Conclusions

Use of PD catheters within three days of placement was associated with catheter failure. We recommend that when possible, catheters should be allowed to heal for at least three days prior to use to reduce risk of complications and improve catheter survival.

Peritoneal Dialysis in Austere Environments: An Emergent Approach to Renal Failure Management

Peritoneal dialysis (PD) is a means of renal replacement therapy (RRT) that can be performed in remote settings with limited resources, including regions that lack electrical power. PD is a mainstay of end-stage renal disease (ESRD) therapy worldwide, and the ease of initiation and maintenance has enabled it to flourish in both resource-limited and resource-abundant settings. In natural disaster scenarios, military conflicts, and other austere areas, PD may be the only available life-saving measure for acute kidney injury (AKI) or ESRD. PD in austere environments is not without challenges, including catheter placement, availability of dialysate, and medical complications related to the procedure itself. However, when hemodialysis is unavailable, PD can be performed using generally available medical supplies including sterile tubing and intravenous fluids. Amidst the ever-increasing global burden of ESRD and AKI, the ability to perform PD is essential for many medical facilities.

Genomic reprograming analysis of the Mesothelial to Mesenchymal Transition identifies biomarkers in peritoneal dialysis patients

Peritoneal dialysis (PD) is an effective renal replacement therapy, but a significant proportion of patients suffer PD-related complications, which limit the treatment duration. Mesothelial-to-mesenchymal transition (MMT) contributes to the PD-related peritoneal dysfunction. We analyzed the genetic reprograming of MMT to identify new biomarkers that may be tested in PD-patients. Microarray analysis revealed a partial overlapping between MMT induced in vitro and ex vivo in effluent-derived mesothelial cells, and that MMT is mainly a repression process being higher the number of genes that are down-regulated than those that are induced. Cellular morphology and number of altered genes showed that MMT ex vivo could be subdivided into two stages: early/epithelioid and advanced/non-epithelioid. RT-PCR array analysis demonstrated that a number of genes differentially expressed in effluent-derived non-epithelioid cells also showed significant differential expression when comparing standard versus low-GDP PD fluids. Thrombospondin-1 (TSP1), collagen-13 (COL13), vascular endothelial growth factor A (VEGFA), and gremlin-1 (GREM1) were measured in PD effluents, and except GREM1, showed significant differences between early and advanced stages of MMT, and their expression was associated with a high peritoneal transport status. The results establish a proof of concept about the feasibility of measuring MMT-associated secreted protein levels as potential biomarkers in PD.

Impact of fill volume on ultrafiltration with icodextrin in children on chronic peritoneal dialysis

BACKGROUND

Icodextrin is a solution of glucose polymers developed to provide sustained ultrafiltration over an extended dwell. Our aim was to determine whether or not fill volume with icodextrin contributes to the ability to achieve ultrafiltration in children.

METHODS

The charts of all children on chronic peritoneal dialysis between January 2000 and July 2014 were screened for the use of an icodextrin day dwell. Data were extracted from the electronic chart and the HomeChoice™ Pro card and corrected for body surface area (BSA).

RESULTS

Fifty children had an icodextrin day dwell. A linear correlation was found between the daytime fill volume and net ultrafiltration (p < 0.001). More ultrafiltration was achieved with a fill volume above 550 ml/m(2) BSA (107 ± 75 ml/m(2) BSA) than with smaller fill volumes (-8 ± 99 ml; p = 0.004). Ultrafiltration was achieved in 88 % of children with a fill volume above 550 ml/m(2) BSA versus only 44 % of patients with a smaller fill volume (p = 0.001). Icodextrin was well tolerated.

CONCLUSIONS

Our observations reveal that the larger the fill volume the higher the likelihood of achieving ultrafiltration with icodextrin and suggest that a minimum day dwell volume of 550 ml/m(2) BSA seems to facilitate ultrafiltration in children. To our knowledge this is the largest study addressing ultrafiltration with icodextrin in children.

[Peritoneal dialysis adequacy in pediatrics. From the peritoneal equilibration test to the aquaporins]

An evaluation of the characteristics of peritoneal solute and water transport is essential to assess the suitability of prescribing dialysis in patients suffering from chronic renal disease. There are currently a series of models to perform this evaluation. The peritoneal equilibration test (PET) evaluates the peritoneal transport capacity, classifying the patients into four transport categories: high, high-average, low-average, and low. The short PET enables the same evaluation to be made in only 2hours, and has been validated in paediatric patients. On the other hand, the MiniPET provides additional information by evaluating the free water transport capacity by the ultra-small pores, and the Accelerated Peritoneal Examination Time (APEX) evaluates the time when the glucose and urea equilibration curves cross, and has been proposed as the optimum dwell time to achieve adequate ultrafiltration. An analysis is presented on the current information on these diagnostic methods as regards free water transport via aquaporins, which could be an important tool in optimising solute and water transport in patients on chronic peritoneal dialysis, particularly as regards the cardiovascular prognosis.

Optimizing peritoneal dialysis prescription for volume control: the importance of varying dwell time and dwell volume

Not only adequate uremic toxin removal but also volume control is essential in peritoneal dialysis (PD) to improve patient outcome. Modification of dwell time impacts on both ultrafiltration (UF) and purification. A short dwell favors UF but preferentially removes small solutes such as urea. A long dwell favors uremic toxin removal but also peritoneal fluid reabsorption due to the time-dependent loss of the crystalloid osmotic gradient. In particular, the long daytime dwell in automated PD may result in significant water and sodium reabsorption, and in such cases icodextrin should be considered. Increasing dwell volume favors the removal of solutes such as sodium due to the increased volume of diffusion and the recruitment of peritoneal surface area. A very large fill volume with too high an intraperitoneal pressure (IPP) may, however, result in back-filtration and thus reduced UF and sodium clearance. Based on these principles and the individual transport and pressure kinetics obtained from peritoneal equilibration tests and IPP measurements, we suggest combining short dwells with a low fill volume to favor UF with long dwells and a large fill volume to favor solute removal. Results from a recent randomized cross-over trial and earlier observational data in children support this concept: the absolute UF and UF relative to the administered glucose increased and solute removal and blood pressure improved.

Mesenchymal Conversion of Mesothelial Cells Is a Key Event in the Pathophysiology of the Peritoneum during Peritoneal Dialysis

Peritoneal dialysis (PD) is a therapeutic option for the treatment of end-stage renal disease and is based on the use of the peritoneum as a semipermeable membrane for the exchange of toxic solutes and water. Long-term exposure of the peritoneal membrane to hyperosmotic PD fluids causes inflammation, loss of the mesothelial cells monolayer, fibrosis, vasculopathy, and angiogenesis, which may lead to peritoneal functional decline. Peritonitis may further exacerbate the injury of the peritoneal membrane. In parallel with these peritoneal alterations, mesothelial cells undergo an epithelial to mesenchymal transition (EMT), which has been associated with peritoneal deterioration. Factors contributing to the bioincompatibility of classical PD fluids include the high content of glucose/glucose degradation products (GDPs) and their acidic pH. New generation low-GDPs-neutral pH fluids have improved biocompatibility resulting in better preservation of the peritoneum. However, standard glucose-based fluids are still needed, as biocompatible solutions are expensive for many potential users. An alternative approach to preserve the peritoneal membrane, complementary to the efforts to improve fluid biocompatibility, is the use of pharmacological agents protecting the mesothelium. This paper provides a comprehensive review of recent advances that point to the EMT of mesothelial cells as a potential therapeutic target to preserve membrane function.

Risk factors for morbidity and mortality in pediatric patients with peritoneal dialysis catheters

PURPOSE

As peritoneal dialysis (PD) is the preferred long-term dialysis modality in the pediatric population, we sought to identify risk factors for mortality and reoperation.

METHODS

A retrospective review of patients undergoing PD catheter insertions at a single center from 1994-2009 was performed. The following variables were evaluated: age (<1 year), comorbidities, omentectomy, concomitant gastrostomy, and laparoscopic technique. Multivariable Cox regressions analyses were used to evaluate patient survival and reoperation-free survival of PD catheters.

RESULTS

207 patients with a median age of 10 years underwent PD insertion. Mortality was 7% with a median follow up of 72 months. Reoperation for malfunction and infection was required in 49% of patients with a median PD catheter survival of 11 months. Reoperation for hernias occurred in 14% of patients. Multivariate Cox regressions analyses identified age <1 year, lack of omentectomy, concomitant gastrostomy, and prematurity as variables significantly associated with higher rates of mortality or reoperation.

CONCLUSIONS

In this large study of pediatric patients undergoing PD, higher complication rates were noted in infants less than one year of age. Concomitant gastrostomy was associated with a higher rate of reoperation for infection. Failure to perform omentectomy was associated with a higher rate of catheter failure.

Impact of global economic disparities on practices and outcomes of chronic peritoneal dialysis in children: insights from the International Pediatric Peritoneal Dialysis Network Registry

BACKGROUND, OBJECTIVES, AND METHODS: The number of patients on chronic peritoneal dialysis (CPD) is increasing rapidly on a global scale. We analyzed the International Pediatric Peritoneal Dialysis Network (IPPN) registry, a global database active in 33 countries spanning a wide range in gross national income (GNI), to identify the impact of economic conditions on CPD practices and outcomes in children and adolescents.

RESULTS

We observed close associations of GNI with the fraction of very young patients on dialysis, the presence and number of comorbidities, the prevalence of patients with unexplained causes of end-stage kidney disease, and the rate of culture-negative peritonitis. The prevalence of automated PD increased with GNI, but was 46% even in the lowest GNI stratum. The GNI stratum also affected the use of biocompatible peritoneal dialysis fluids, enteral tube feeding, calcium-free phosphate binders, active vitamin D analogs, and erythropoiesis-stimulating agents (ESAs). Patient mortality was strongly affected by GNI (hazard ratio per $10 000: 3.3; 95% confidence interval: 2.0 to 5.5) independently of young patient age and the number of comorbidities present. Patients from low-income countries tended to die more often from infections unrelated to CPD (5 of 9 vs 15 of 61, p = 0.1). The GNI was also a strong independent predictor of standardized height (p < 0.0001), adding to the impact of congenital renal disease, anuria, age at PD start, and dialysis vintage. Patients from the lower economic strata (GNI < $18 000) had higher serum parathyroid hormone (PTH) and lower serum calcium, and achieved lower hemoglobin concentrations. No impact of GNI was observed with regard to CPD technique survival or peritonitis incidence.

CONCLUSIONS

We conclude that CPD is practiced successfully, albeit with major regional variation related to economic differences, in children around the globe. The variations encompass the acceptance of very young patients and those with associated comorbidities to chronic dialysis programs, the use of automated PD and expensive drugs, and the diagnostic management of peritonitis. These variations in practice related to economic difference do not appear to affect PD technique survival; however, economic conditions seem to affect mortality on dialysis and standardized height, a marker of global child morbidity.