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In peritoneal dialysis (PD), ultrafiltration (UF) volume is the sum of solute-free- and solute-coupled-water removal, a dynamic process throughout the entire dwell exerted via aquaporin-1 (AQP1) and small pores, respectively. Determination of sodium sieving is used as a parameter for AQP1 function analysis, while coupled water removal is essential for adequate sodium and water balance and thus blood pressure control. The diffusive capacity of glucose via the small pores determines the dynamic crystalloid osmotic gradient. The osmotic conductance, i.e., milliliter of UF per gram of glucose absorbed, quantifies cooperation between small-pores and AQP1 channels. In continuous ambulatory peritoneal dialysis, with dwell times beyond glucose-induced sodium-sieving effects, approximate dialytic sodium removal (DSR) may be estimated from the UF volume (in average 100 mmol Na/L UF), while DSR is lower, with shorter cycle times, in automated PD (APD); therefore, effluent sodium concentrations should be measured. Applying dialysis mechanics, i.e., varying dwell time and dwell volume-as proposed in adapted APD to the PD prescription-may provide unmatched high DSR relative to UF volume, findings which are not sufficiently explained by the three-pore model of PD. Overall DSR should therefore be measured rather than estimated from UF volume., Author(s): Michel Fischbach [sup.1] , Ariane Zaloszyc [sup.1] , Betti Schaefer [sup.2] , Claus Peter Schmitt [sup.2] Author Affiliations: (1) 0000 0004 0593 6932grid.412201.4Service de Pédiatrie 1 CHU Hautepierre, Avenue [...]

Background Modern hemodialysis (HD) machines are able to measure ionic dialysance online and thereby continuously monitor Kt/V. The accuracy of measurement depends on the input of the correct urea distribution volume (V), available from anthropometric equations and body composition monitoring (BCM). The latter method, however, has not been validated in children. Methods We compared V determined by BCM to that calculated using four different anthropometric formulas (Morgenstern, Mellits and Cheek, Hume-Weyers and Watson equations) in 23 pediatric HD patients. We also compared online Kt/V using BCM-derived V with the Kt/V calculated from pre- and post-dialytic urea concentrations using the single-pool second-generation Daugirdas equation. Results The V calculated by the Morgenstern equation was similar to that derived by BCM, with a mean difference of -0.7 % (95 % limits of agreement -11.7 to 10.3 %). In contrast, the V calculated by the other equations was 5.4, 6.2 and 18 %, respectively higher than the BCM-derived V. The mean difference between Kt/V calculated using the Daugirdas equation and online Kt/V determination based on BCM-derived V data was 0.10 (95 % limits of agreement -0.50 to 0.70 %). Conclusions In our pediatric HD patients the V measured by BCM was in agreement with that calculated using the Morgenstern equation, which is the only equation which has been validated to date in children on dialysis. Online determination of Kt/V using a BCM-derived V largely agreed with that calculated by the Daugirdas equation. We therefore conclude that the former approach is suitable for frequent online assessment of dialytic small solute clearance., Author(s): Ariane Zaloszyc[sup.1] , Michel Fischbach[sup.1] , Betti Schaefer[sup.2] , Lorenz Uhlmann[sup.3] , Remi Salomon[sup.4] , Saoussen Krid[sup.4] , Claus Peter Schmitt[sup.2] Author Affiliations: (1) Nephrology Dialysis Transplantation Children's Unit, [...]

Background Pleural or pericardial effusions secondary to pleuro-peritoneal fistula (PPF) and pericardio-peritoneal fistula (PcPF) are rare but serious complications of peritoneal dialysis (PD). Methods We conducted a 10-year survey across all participating centres in the European Paediatric Dialysis Working Group to review the incidence, diagnostic techniques, therapeutic options and outcome of children on chronic PD with PPF and/or PcPF. Results Of 1506 children on PD there were ten cases (8 of PPF, 1 each of PcPF and PPF + PcPF), with a prevalence of 0.66 %. The median age at presentation was 1.5 [inter-quartile range (IQR) 0.4-2.4] years, and nine children were Conclusion In conclusion, PPF and PcPF are rare in children on chronic PD, but are associated with significant morbidity, requiring a change of dialysis modality in all cases. Risk factors for PPF development include age of, Author(s): Stephanie Dufek[sup.1] , Tuula Holtta[sup.2] , Michel Fischbach[sup.3] , Gema Ariceta[sup.4] , Augustina Jankauskiene[sup.5] , Rimante Cerkauskiene[sup.5] , Claus Peter Schmitt[sup.6] , Betti Schaefer[sup.6] , Christoph Aufricht[sup.7] , Elizabeth [...]

Background Few observations on apheresis in pediatric nephrology units have been published. Methods This retrospective study involved children [less than or equal to] 18 years undergoing plasma exchange (PE), immunoadsorption (IA), or double filtration plasmapheresis (DFPP) in 12 European pediatric nephrology units during 2012. Results Sixty-seven children underwent PE, ten IA, and three DFPP, for a total of 738 PE and 349IA/DFPP sessions; 67.2 % of PE and 69.2 % of IA/DFPP patients were treated for renal diseases, in particular focal segmental glomerulosclerosis (FSGS), hemolytic-uremic syndrome (HUS), and human leukocyte antigen (HLA) desensitization prior to renal transplantation; 20.9 % of PE and 23.1 % of IA/DFPP patients had neurological diseases. Membrane filtration was the most common technique, albumin the most frequently used substitution fluid, and heparin the preferred anticoagulant. PE achieved full disease remission in 25 patients (37.3 %), partial remission in 22 (32.8 %), and had no effect in 20 (29.9 %). The response to IA/ DFPP was complete in seven patients (53.8 %), partial in five (38.5 %), and absent in one (7.7 %). Minor adverse events occurred during 6.9 % of PE and 9.7 % of IA/DFPP sessions. Conclusions PE, IA, and DFPP are safe apheresis methods in children. Efficacy is high in pediatric patients with recurrent focal segmental glomerulosclerosis (FSGS), atypical hemolytic uremic syndrome (HUS), human leukocyte antigen (HLA) sensitization, and neurological autoimmune diseases. Keywords Pediatric apheresis * Therapeutic apheresis * Plasma exchange * Immunoadsorption * Double filtration plasmapheresis, Introduction Apheresis is a widely recognized therapeutic option in pediatric patients, even though the literature on the various forms of pediatric apheresis is mostly limited to single-center, retrospective studies [1-6]. [...]

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. Keywords Ultrafiltration * Sodium removal * PD prescription Dwell time * Dwell volume, Introduction During the last decade the definition of dialysis adequacy based on solute removal parameters, such as urea kinetics (Kt/V), has been questioned. Although this approach increased the urea dialysis [...]

Background Hypertension is frequent in chronic hemodialyzed patients and usually treated by reducing extracellular fluid. Probing dry weight only based on a clinical evaluation may be hazardous, especially in case of volume independent hypertension. Methods We performed a 1-year retrospective study in three pediatric centers to define the relation between blood pressure (BP) and hydration status, assessed by whole-body bioimpedance spectroscopy (BIS). We analyzed 463 concomitant measurements of BP, relative overhydration (rel.OH), and plasma sodium (Napl) in 23 children (mean age 13.9 ± 5.1 years). Results Pre-dialytic under-hydration (rel.OH+15 %) was assessed, however, the majority (73 %) showed normal BP. Patient-specific Napl setpoint could not be described. Mean dialysate sodium concentration was higher than mean Napl. Conclusions Hypertension is not always related to overhydration. Therefore, BIS should restrict the practice of 'probing dry weight' in hypertensive children. Moreover, sodium dialytic balance needs to be considered to improve BP management. Keywords Bioimpedance spectroscopy * Chronic hemodialysis * Dialysate sodium concentration * Hydration status * Hypertension, Introduction Cardiovascular morbidity and mortality is enhanced in chronic dialyzed patients, even in pediatric populations [1-8]. Therefore, optimized management of risk factors such as hypertension is crucial. The routine clinical [...]

The majority of children with acute, acute-onchronic, and progressive chronic liver failure require liver transplantation. Since organ availability is limited, extracorporeal liver support systems are increasingly applied to bridge the time until transplantation. At present, four different devices are available: the molecular adsorbent recirculating system (MARS), Prometheus dialysis, plasma exchange combined with hemodialysis (PE/HD), and single-pass albumin dialysis (SPAD). Randomized trials in adults have demonstrated efficient toxin removal, improved portal hypertension, hemodynamic stability, and improved hepatic encephalopathy compared with standard medical therapy. None of the liver support systems has yet been evaluated systematically in children. Knowledge of the specific indications and technical features of the different devices is essential if applied in children. MARS combines albumin dialysis with conventional hemodialysis and allows for efficient removal of water and protein-bound toxins without exogenous protein delivery and the associated infectious and allergic risks. It has successfully been applied in children with otherwise intractable cholestatic pruritus and with liver failure. The benefits, however, need to be balanced against the costs and the risk of volume and nitrogen overload if repeated plasma infusion is required. In cases of active bleeding, plasma exchange in combination with hemodialysis should be preferred. Keywords Molecular adsorbent recirculating system (MARS) dialysis * Liver failure * Extracorporeal liver support * Cholestatic pruritus * Children, Introduction Acute liver failure (ALF) is a rare but severe, and often life-threatening condition in children. The etiologies vary with age. In 40% of infants ALF is due to inborn [...]

Background Rituximab has proven effective in the treatment of complicated granulomatosis with polyangiitis (Wegener's, GPA). Two controlled trials in adults demonstrated beneficial effects of rituximab compared to cyclophosphamide in antineutrophil [...]

Background ABO-incompatible renal transplantation (ABOi-RTx) following preconditioning with immunoadsorption (IA) and rituximab is a promising approach to facilitate living-related RTx. However, clinical experience is limited in pediatric patients. Methods Three patients underwent living-related ABOi-RTx in our center. Preoperative IA was performed six, ten and 11 times in patient one, two and three, respectively, to achieve isoagglutinin titers of Results All three patients achieved normal renal function within 2-6 days post-RTx. Major postoperative bleeding occurred in two patients, with one requiring repeated blood transfusions and the other a surgical revision 4 h after RTx, despite local citrate anticoagulation use during the preoperative IA procedures in the latter patient. A pyelonephritis-associated increase of the isoagglutinin IgG/IgM titers to 1:64/1:128 led to a biopsy-proven acute humoral rejection in the third patient, which was treated successfully with plasma exchange and methylprednisolone pulses. The estimated glomerular filtration rate at 18, 8 and 23 months post-RTx was 96, 52 and 74 ml/min/1.73 m, respectively. Conclusions ABOi-RTx can successfully be performed in pediatric patients after preconditioning with quadruple immunosuppression, rituximab and IA. Caution is required regarding bleeding complications, which are most likely due to the unspecific binding of coagulation factors during repeated IA. Keywords ABO-incompatible kidney transplantation . Anticoagulation . Children . Immunoadsorption . Postoperative bleeding . Rituximab, Introduction ABO blood group antigens are expressed by the endothelium of solid organs, including the kidney; sensitization leads to hyperacute antibody-mediated allograft rejection. ABO-incompatibility (ABOi) has therefore been considered as [...]

Children with chronic kidney disease (CKD) suffer from inflammation and reactive metabolite-induced stress, which massively accelerates tissue and vascular aging. Peritoneal dialysis (PD) is the preferred dialysis mode in children, but currently used PD fluids contain far supraphysiological glucose concentrations for fluid and toxin removal and glucose degradation products (GDP). While the peritoneal membrane of children with CKD G5 exhibits only minor alterations, PD fluids trigger numerous molecular cascades resulting in major peritoneal membrane inflammation, hypervascularization, and fibrosis, with distinct molecular and morphological patterns depending on the GDP content of the PD fluid used. PD further aggravates systemic vascular disease. The systemic vascular aging process is particularly pronounced when PD fluids with high GDP concentrations are used. GDP induce endothelial junction disintegration, apoptosis, fibrosis, and intima thickening. This review gives an overview on the molecular mechanisms of peritoneal and vascular transformation and strategies to improve peritoneal and vascular health in patients on PD. [ABSTRACT FROM AUTHOR]

When prescribing hemodialysis in children, the clinician should first establish an adequate regimen, before seeking to optimize the treatment (Fischbach et al. 2005). A complete dialysis dose should consist of a urea dialysis dose and a determined convective volume. Intensified and more frequent dialysis regimens should not be considered exclusively as rescue therapy. Interestingly, a recent single-center study demonstrated that frequent on-line HDF provides an optimal dialysis prescription, both in terms of blood pressure control (and therefore avoidance of left ventricular hypertrophy), and catch-up growth, that is, no malnutrition or cachexia and less resistance to growth hormone. Nevertheless, this one-center experience would benefit from a prospective randomized study.