Continuous Flow Peritoneal Dialysis Research Articles

#3022 Rationale and design of the CORDIAL first-in-human clinical trial: a system for sorbent-assisted continuous flow peritoneal dialysis

Abstract Background and Aims Peritoneal dialysis has important disadvantages, including low plasma clearance and a limited technique survival. A new device for sorbent-assisted continuous flow peritoneal dialysis has been designed (Wearable Artificial KIDney, WEAKID) that is based on continuous recirculation (rapid cycling) of peritoneal dialysate via a single-lumen peritoneal catheter with regeneration of dialysate using sorbents. Anticipated benefits are a better plasma clearance a higher mass transfer area coefficient with continuous flow of dialysate and enhanced diffusion due to a higher time-averaged plasma-dialysate concentration gradient with sorbent-based dialysate regeneration, and a prolonged technique survival thanks to lower peritonitis risk (less (dis)connections) and a lower glucose exposure. Method This is a first-in-human, prospective, open-label, non-randomized, single-arm, multicenter study, that will be performed at the University Medical Center Utrecht (Utrecht, The Netherlands), Università degli studi di Modena e Reggio Emilia (Italy), and Instituto de Investigación Hospital Universitario La Paz, Servicio Madrileño de Salud (Spain). We aim to include 12 stable, adult PD patients. In the first week, blood, urine, and dialysate samples will be collected over three separate days to assess the efficacy of the patient's standard PD schedule. The WEAKID system will then be tested in a clinical setting on 6 days over a period of 2 weeks (three consecutive days per week). During the first week, participants will be treated with WEAKID without sorbents for 4h (first day) or 8h (second and third day). The second week, treatment will consist of WEAKID with sorbents for 4h (first day) or 8h (second and third day). This way, exposure to new components of the system is incremental and the effectiveness of continuous recirculation of dialysate and that the added effect of sorbent-based dialysate regeneration can be analyzed separately. Outcomes The primary aim of this first-in-human clinical trial is to evaluate the (short term) clinical safety and performance of WEAKID treatment in a clinical setting. The primary safety objective will be assessed by describing and examining the incidence of: Key secondary objectives include an evaluation of efficacy in terms of plasma clearance, ultrafiltration, net base release, and patient tolerance. Planning Inclusion of the first patient is expected in January 2024, the final inclusion is expected to take place in November 2024.

#2978 Formative usability test of a novel device for peritoneal dialysis (WEAKID)

Abstract Background and Aims Chronic kidney disease is a growing problem worldwide with a growing number of patients requiring kidney replacement therapy. In recent years we have developed a novel device for peritoneal dialysis (PD), the WEarable Artificial KIDney (WEAKID); composed of a wearable device connected to a dialysate reservoir. WEAKID uses both sorbent technology and continuous flow PD to improve dialysis efficacy. Formative usability testing aids to the identification of design issues that may interfere with a device's safe and effective use and thus may influence decisions made in the design process. Here, we present the results of an international, multicentre, formative usability study of WEAKID among nurses and patients. Method This study used a mixed-methods design and was conducted in hospitals in Italy (Modena University Hospital), Spain (La Paz University Hospital, Madrid), and the Netherlands (University Medical Center Utrecht) between November 2021 and December 2022. An individual, formative usability testing session was conducted with each participant (nurse or patient) under the conditions of simulated use. Participants were asked to perform basic operational procedures (i.e. turning the device on/off, input of dialysis settings, handling an alarm) with the device according to a usability task list. Their performance was observed and use errors (i.e., something that a participant does or fails to do that results in an unexpected or unintended outcome) were noted. Furthermore, participants were asked for feedback, both verbally and by means of completing the system usability scale (SUS), reflecting perceived usability on a scale from 0 (worst) to 100 (best). Results We included 14 participants (n = 6 nurses, n = 8 patients) in three participating centres. All nurses were female and had a median experience with PD of 20.5 years (range 0.5-32). Patients were generally highly educated (n = 5, 63%). In total, 22 use errors occurred, 10 in nurses and 12 in patients. These use errors included factors not related to the device, e.g. not taking appropriate hygiene measures. In particular, use errors occurred during the priming/connection of catheter and handling the alarm. Participants’ feedback mainly concerned the small screen (and thus font) size, user interface (e.g. lack of colour-coded soft buttons), and (short) length of the patient line. The mean SUS score was 70 (range 57.5–85) for nurses, and 71.9 (range 55–87.5) for patients. Conclusion Despite the slightly above-average perceived usability of the device's current design stage, participants made a lot of suggestions for improvements, and usability must be improved to make the device ready for market introduction.

Gravity-assisted continuous flow peritoneal dialysis technique use in acute kidney injury in children: a randomized, crossover clinical trial.

Our previously demonstrated continuous flow peritoneal dialysis (CFPD) technique in children with acute kidney injury (AKI), although effective, was manpower heavy and expensive due to the high-volume pumps required. The aim of this study was to develop and test a novel gravity-driven CFPD technique in children using readily available, inexpensive equipment and to compare this technique to conventional PD. After development and initial in vitro testing, a randomised crossover clinical trial was conducted in 15 children with AKI requiring dialysis. Patients received both conventional PD and CFPD sequentially, in random order. Primary outcomes were measures of feasibility, clearance and ultrafiltration (UF). Secondary outcomes were complications and mass transfer coefficients (MTC). Paired t-tests were used to compare PD and CFPD outcomes. Median (range) age and weight of participants were 6.0 (0.2-14) months and 5.8 (2.3-14.0) kg, respectively. The CFPD system was easily and rapidly assembled. There were no serious adverse events attributed to CFPD. Mean ± SD UF was significantly higher on CFPD compared to conventional PD (4.3 ± 3.15 ml/kg/h vs. 1.04 ± 1.72 ml/kg/h; p < 0.001). Clearances for urea, creatinine and phosphate for children on CFPD were 9.9 ± 3.10 ml/min/1.73m2, 7.9 ± 3.3 ml/min/1.73m2 and 5.5 ± 1.5 ml/min/1.73m2 compared to conventional PD with values of 4.3 ± 1.68 ml/min/1.73m2, 3.57 ± 1.3 ml/min/1.73m2 and 2.53 ± 0.85 ml/min/1.73m2, respectively (all p < 0.001). Gravity-assisted CFPD appears to be a feasible and effective way to augment ultrafiltration and clearances in children with AKI. It can be assembled from readily available non-expensive equipment. A higher resolution version of the Graphical abstract is available as Supplementary information.

ISPD guidelines for peritoneal dialysis in acute kidney injury: 2020 Update (paediatrics).

1.1 Peritoneal dialysis is a suitable renal replacement therapy modality for treatment of acute kidney injury in children. (1C)2. Access and fluid delivery for acute PD in children.2.1 We recommend a Tenckhoff catheter inserted by a surgeon in the operating theatre as the optimal choice for PD access. (1B) (optimal)2.2 Insertion of a PD catheter with an insertion kit and using Seldinger technique is an acceptable alternative. (1C) (optimal)2.3 Interventional radiological placement of PD catheters combining ultrasound and fluoroscopy is an acceptable alternative. (1D) (optimal)2.4 Rigid catheters placed using a stylet should only be used when soft Seldinger catheters are not available, with the duration of use limited to <3 days to minimize the risk of complications. (1C) (minimum standard)2.5 Improvised PD catheters should only be used when no standard PD access is available. (practice point) (minimum standard)2.6 We recommend the use of prophylactic antibiotics prior to PD catheter insertion. (1B) (optimal)2.7 A closed delivery system with a Y connection should be used. (1A) (optimal) A system utilizing buretrols to measure fill and drainage volumes should be used when performing manual PD in small children. (practice point) (optimal)2.8 In resource limited settings, an open system with spiking of bags may be used; however, this should be designed to limit the number of potential sites for contamination and ensure precise measurement of fill and drainage volumes. (practice point) (minimum standard)2.9 Automated peritoneal dialysis is suitable for the management of paediatric AKI, except in neonates for whom fill volumes are too small for currently available machines. (1D)3. Peritoneal dialysis solutions for acute PD in children3.1 The composition of the acute peritoneal dialysis solution should include dextrose in a concentration designed to achieve the target ultrafiltration. (practice point)3.2 Once potassium levels in the serum fall below 4 mmol/l, potassium should be added to dialysate using sterile technique. (practice point) (optimal) If no facilities exist to measure the serum potassium, consideration should be given for the empiric addition of potassium to the dialysis solution after 12 h of continuous PD to achieve a dialysate concentration of 3-4 mmol/l. (practice point) (minimum standard)3.3 Serum concentrations of electrolytes should be measured 12 hourly for the first 24 h and daily once stable. (practice point) (optimal) In resource poor settings, sodium and potassium should be measured daily, if practical. (practice point) (minimum standard)3.4 In the setting of hepatic dysfunction, hemodynamic instability and persistent/worsening metabolic acidosis, it is preferable to use bicarbonate containing solutions. (1D) (optimal) Where these solutions are not available, the use of lactate containing solutions is an alternative. (2D) (minimum standard)3.5 Commercially prepared dialysis solutions should be used. (1C) (optimal) However, where resources do not permit this, locally prepared fluids may be used with careful observation of sterile preparation procedures and patient outcomes (e.g. rate of peritonitis). (1C) (minimum standard)4. Prescription of acute PD in paediatric patients4.1 The initial fill volume should be limited to 10-20 ml/kg to minimize the risk of dialysate leakage; a gradual increase in the volume to approximately 30-40 ml/kg (800-1100 ml/m2) may occur as tolerated by the patient. (practice point)4.2 The initial exchange duration, including inflow, dwell and drain times, should generally be every 60-90 min; gradual prolongation of the dwell time can occur as fluid and solute removal targets are achieved. In neonates and small infants, the cycle duration may need to be reduced to achieve adequate ultrafiltration. (practice point)4.3 Close monitoring of total fluid intake and output is mandatory with a goal to achieve and maintain normotension and euvolemia. (1B)4.4 Acute PD should be continuous throughout the full 24-h period for the initial 1-3 days of therapy. (1C)4.5 Close monitoring of drug dosages and levels, where available, should be conducted when providing acute PD. (practice point)5. Continuous flow peritoneal dialysis (CFPD)5.1 Continuous flow peritoneal dialysis can be considered as a PD treatment option when an increase in solute clearance and ultrafiltration is desired but cannot be achieved with standard acute PD. Therapy with this technique should be considered experimental since experience with the therapy is limited. (practice point) 5.2 Continuous flow peritoneal dialysis can be considered for dialysis therapy in children with AKI when the use of only very small fill volumes is preferred (e.g. children with high ventilator pressures). (practice point).

Renal replacement therapies for infants and children in the ICU.

Pediatric acute kidney injury (AKI) in critically ill patients is associated with increased morbidity and mortality. Emerging data support that the incidence of pediatric AKI in the ICU is rising. For children with severe AKI, renal replacement therapy (RRT) can provide a lifesaving supportive therapy. The optimal timing to deliver and modality by which to deliver RRT remain a point of discussion within pediatric (and adult) literature. This review discusses the use of RRT for pediatric patients in the ICU. We discuss the most recent evidence-based methods for RRT with a focus on continuous RRT. The feasibility of dialyzing the smallest infants and more medically complex children in the ICU is dependent on the advancements in dialysis access and circuit technology. At present, data indicate that upward of 27% of children in the ICU develop AKI and 6% require RRT. Newer dialysis modalities including prolonged intermittent hemodialysis and continuous flow peritoneal dialysis as well as newer dialysis technologies such as the smaller volume circuits (e.g., Cardio-Renal Pediatric Dialysis Emergency Machine, Newcastle Infant Dialysis and Ultrafiltration System) have made the provision of dialysis safer and more effective for pediatric patients of a variety of sizes. Renal replacement in the ICU requires a multidisciplinary team approach that is facilitated by a pediatric nephrologist in conjunction with intensivists and skilled nursing staff. Although mortality rates for children on dialysis remain high, outcomes are improving with the support of the multidisciplinary team and dialysis technology advancements.

Computer Simulations of Continuous Flow Peritoneal Dialysis Using the 3-Pore Model—a First Experience

Computer Simulations of Continuous Flow Peritoneal Dialysis Using the 3-Pore Model—a First Experience

Computer Simulations of Continuous Flow Peritoneal Dialysis Using the 3-Pore Model-A First Experience.

Background:Continuous flow peritoneal dialysis (CFPD) is performed using a continuous flux of dialysis fluid via double or dual-lumen PD catheters, allowing a higher dialysate flow rate (DFR) than conventional treatments. While small clinical studies have revealed greatly improved clearances using CFPD, the inability to predict ultrafiltration (UF) may confer a risk of potentially harmful overfill. Here we performed physiological studies of CFPD in silico using the extended 3-pore model.Method:A 9-h CFPD session was simulated for: slow (dialysate to plasma creatinine [D/P crea] < 0.6), fast (D/P crea > 0.8) and average (0.6 ≤ D/P crea ≤ 0.8) transporters using 1.36%, 2.27%, or 3.86% glucose solutions. To avoid overfill, we applied a practical equation, based on the principle of mass-balance, to predict the UF rate during CFPD treatment.Results:Increasing DFR > 100 mL/min evoked substantial increments in small- and middle-molecule clearances, being 2 - 5 times higher compared with a 4-h continuous ambulatory PD (CAPD) exchange, with improvements typically being smaller for average and slow transporters. Improved UF rates, exceeding 10 mL/min, were achieved for all transport types. The β2-microglobulin clearance was strongly dependent on the UF rate and increased between 60% and 130% as a function of DFR. Lastly, we tested novel intermittent-continuous regimes as an alternative strategy to prevent overfill, being effective for 1.36% and 2.27%, but not for 3.86% glucose.Conclusion:While we find substantial increments in solute and water clearance with CFPD, previous studies have shown similar improvements using high-volume tidal automated PD (APD). Lastly, the current in silico results need confirmation by studies in vivo.

WEAKID - Clinical validation of miniature wearable dialysis machine - H2020

The project aims to validate a miniature wearable dialysis machine in a clinical setting and to prepare the system for CE-marking. Wearable dialysis allows renal patients to dialyze conveniently and continuously at home or at work, independently from a fixed water supply, up to 24 hrs/day. Such a continuous treatment mimics healthy kidneys and is twice as effective as current dialysis techniques, hereby offering health benefits, quality of life (fitness, mobility) while reducing medical costs (less medication, dialysis at home lowers costs). The miniature wearable dialysis system is based on continuous flow peritoneal dialysis with a fluidic access to the abdomen. The peritoneal dialysate is continuously circulated and refreshed by means of a small and wearable sorption unit that removes toxins from the dialysate. The technology has been demonstrated in preclinial research. In order to demonstrate the clinical efficacy and safety of the system an early feasibility first-in-human trial (phase 0) and a pilot crossover trial (phase 1) will be performed in peritoneal dialysis (PD) patients. The phase 0 study will involve a selected group of 12 stable PD patients in a clinical setting for 5 consecutive days. Upon successful functionality and safety analysis of the phase 0 trial, the clinical validation is continued in a crossover study to test the hypotheses that the system (1) improves blood purification, (2) results in adequate ultrafiltration and (3) does not show important safety/biocompatibility problems. Hereto 30 stable PD patients will be randomised to receive either with the wearable system in the first month and conventional PD in the second month or vice versa. The clinical trials will be performed by three European medical centres specialised in dialysis treatment.

PERITONEAL DIALYSIS IN TREATMENT FOR PATIENTS WITH ACUTE KIDNEY INJURY

This article is a review of the literature. Peritoneal dialysis (PD) was the first method of dialysis renal replacement therapy (DRRT), used for the treatment of patients with acute kidney injury (AKI). PD is able to correct metabolic, electrolyte, acid-alkali disorders and hypervolemia in patients with AKI. Continuous equilibration PD and continuous flow PD can provide of dialysis dose compared with extracorporeal methods of DRRT. However, PD is considered less effective than hemodialysis. In this regard, PD has used in patients with AKI, especially those who are hemodynamically unstable or at risk of bleeding because of severe coagulation abnormalities, in infants and children with AKI, and in patients with circulatory failure.

Development of a wearable bioartificial kidney using the Bioartificial Renal Epithelial Cell System (BRECS).

Cell therapy for the treatment of renal failure in the acute setting has proved successful, with therapeutic impact, yet development of a sustainable, portable bioartificial kidney for treatment of chronic renal failure has yet to be realized. Challenges in maintaining an anticoagulated blood circuit, the typical platform for solute clearance and support of the biological components, have posed a major hurdle in advancement of this technology. This group has developed a Bioartificial Renal Epithelial Cell System (BRECS) capable of differentiated renal cell function while sustained by body fluids other than blood. To evaluate this device for potential use in end-stage renal disease, a large animal model was established that exploits peritoneal dialysis fluid for support of the biological device and delivery of cell therapy while providing uraemic control. Anephric sheep received a continuous flow peritoneal dialysis (CFPD) circuit that included a BRECS. Sheep were treated with BRECS containing 1×108 renal epithelial cells or acellular sham devices for up to 7days. The BRECS cell viability and activity were maintained with extracorporeal peritoneal fluid circulation. A systemic immunological effect of BRECS therapy was observed as cell-treated sheep retained neutrophil oxidative activity better than sham-treated animals. This model demonstrates that use of the BRECS within a CFPD circuit embodies a feasible approach to a sustainable and effective wearable bioartificial kidney. Copyright © 2016 John Wiley & Sons, Ltd.

Continuous flow peritoneal dialysis in a paediatric intensive care unit

Continuous flow peritoneal dialysis in a paediatric intensive care unit

Continuous flow peritoneal dialysis (CFPD) improves ultrafiltration in children with acute kidney injury on conventional PD using a 4.25 % dextrose solution

Criticism against the use of acute peritoneal dialysis (PD) has been its low clearance and low ultrafiltration (UF) volumes compared to extracorporeal techniques. The aim of our study was to determine whether continuous flow peritoneal dialysis (CFPD) would improve UF in children with acute kidney injury (AKI) in cases where UF on conventional PD was inadequate using 4.25% glucose concentrations. Five infants were prospectively studied. All had AKI with fluid overload. The median age of the patients was 6 (range 0.43-9) months; the median weight was 6.5 (range 2.7-8.4) kg. Each patient served as his or her own control, undergoing both CFPD and conventional PD. CFPD was performed with two bedside-placed catheters using a 2.5% glucose concentration. After initial filling, a dialysate flow rate of 100ml/min/1.73m(2) was maintained with an adapted continuous venovenous haemofiltration machine. The UF flow rate was set at 2.5ml/min/1.73m(2) and adapted as necessary. UF and clearance rates were measured for both PD and CFPD. The median UF rate achieved was 1.7 (range 0.01-5.30) mg/kg/h with conventional PD versus 6.7 (range 2.17-15.7) mg/kg/h with CFPD (p = 0.042). The clearances of urea and creatinine were 6.89(range 4.50-7.55) and 7.46 (range 4.79-10.50)mL/min/1.73m(2), respectively, with conventional PD and 19 (17.0-30.0) and 41 (standard deviation17.4, range 12.0-52.0) mL/min/1.73m(2), respectively, with CFPD (both p = 0.043). Continuous flow peritoneal dialysis improves UF in fluid overloaded infants who are not achieving adequate UF on conventional PD.

A neonate with severe oligo-anuric renal failure during multi-organ failure survived with prolonged renal replacement therapy.

Sir, Here, we report a neonate with severe oligo-anuric renal failure during multi-organ failure who survived with prolonged renal replacement therapy. A female neonate, born at a gestational age of 39 weeks and 3 days, weighing 2780 gram, presented cyanosis on Day 15. She developed anuria and respiratory arrest, requiring mechanical ventilation. Blood pressure was 39/24 mmHg. She was diagnosed as having interrupted aortic arch, requiring surgery (Figure 1). Serum creatinine increased from 0.34 to 1.26 mg/dL. Continuous-flow peritoneal dialysis (PD), using two catheters for dialysate infusion and drainage simultaneously, was started. She had septicemia, which was controlled with antibiotics. After surgery, chylous effusion occurred in the thorax, resulting in pleural effusion and edema. At ∼2 months, she passed small volumes of urine output with renal and dialytic clearances of 0.98 and 11.45 mL/min/1.73 m2, respectively. Ligation of the thoracic duct was performed at 2.5 months. Overfluid status continued till 3 months, requiring PD and mechanical ventilation. Fig. 1. Course of the illness in the neonate. Cdial, dialytic clearance; Cr, creatinine; Crenal, renal clearance; Inf, influenza A virus infection; PN, peritonitis; RS, respiratory syncytial virus infection; RV, rotavirus infection; UV, urine volume. Because of frequent vomiting, she was fed with an intestinal tube at 4.5 months, resulting in severe diarrhea for 1 month. She remained anuric at 5 months despite decreased serum creatinine (1.36 mg/dL) due to malnutrition. Renal clearance was 1.68 mL/min/1.73 m2 at 6 months when urine output was redetected. She had episodes of peritonitis and virus infections, resulting in pleural effusion, requiring antibiotics, supportive therapy and PD. Renal clearance increased to 8.44 mL/min/1.73 m2 at 8 months. Urine output increased with serum creatinine of 0.81–1.2 mg/dL and renal clearance of 10.4 mL/min/1.73 m2 at 10 months, representing almost 50% of total clearance. Dialysis was stopped 1 year after surgery. Her growth and development are normal with glomerular filtration rate of 24.7 mL/min/1.73 m2. Prolonged oligo-anuria correlates with the final outcome [1]. Renal function recovered after 6–14 months of oliguria in two children with hemolytic uremic syndrome (HUS), in whom plasma infusion prolonged acute renal failure (ARF) [2], and after 23 days of oliguria in an infant with HUS, at the age of 23 weeks [3]. Younger age is another poor prognostic factor of ARF [4]. Neonates have a decreased number and function of nephron, resulting in severe renal insult and poor outcome [5]. ARF occurs in 8% of neonates in the intensive care unit, and its mortality rate is 48% [4], depending on the underlying disease and prognostic factors, including respiratory support, hypotension, cardiac disorders, surgery, oliguria/anuria, need for vasopressor drugs or dialysis, sepsis or multi-organ failure [1]. Despite these factors, the renal function of our patient returned to an extent that allowed cessation of dialysis after many months although PD might have been stopped late. Our patient still has significant chronic kidney disease and will require renal replacement therapy again in the future. Our observation suggests that neonates with severe oligo-anuric renal failure during multi-organ failure may survive with prolonged renal replacement therapy.

Peritoneal Dialysis in Acute Kidney Injury: Lessons Learned and Applied

Peritoneal dialysis (PD) is a simple, safe, gentle, and efficient renal replacement therapy (RRT) method. It is able to correct acute kidney injury (AKI)-induced metabolic, electrolytic, and acid-base disorders and volume overload both in and out the intensive care unit setting. Some PD modalities, such as high-volume PD and continuous flow PD, can provide RRT doses and efficiency comparable to extracorporeal blood purification methods. PD is particularly suitable for children, patients with refractory heart failure or hemodynamically instable, conditions where systemic anticoagulation should be avoided, patients with difficulty for vascular access and hypo- and hyperthermia conditions. In the following manuscript, PD technical aspects and the possible advantages and limitations of this RRT method will be discussed, and the more recent literature on clinical experience with PD for treatment of AKI will be reviewed.

Continuous Flow Peritoneal Dialysis

Acute renal failure can be treated with different dialysis modalities, depending on patient characteristics and hospital resources. Peritoneal dialysis (PD) can be first choice in situations like hypotension, disturbed coagulation, or difficult venous access. The main disadvantage of PD is the relatively limited efficacy. The aim of this study was to investigate whether continuous flow peritoneal dialysis (CFPD) is a more effective treatment than conventional PD in acute renal failure. A pilot study was performed at The Red Cross University Hospital in Cape Town in six patients. Patients were treated with both CFPD and conventional PD for 8 to 16 hours. CFPD was performed with two bedside-placed catheters. After initial filling, dialysate flow rate (100 ml/1.73 m2 per minute) was maintained with an adapted continuous venovenous hemofiltration machine. Ultrafiltration flow rate was set at 2.5 ml/1.73 m2 per minute. Mean ultrafiltration was 0.20 ml/1.73 m2 per minute with conventional PD versus 1.8 ml/1.73 m2 per minute with CFPD. Mean clearances of urea and creatinine were 5.0 and 7.6 ml/1.73 m2 per minute with conventional PD versus 15.0 and 28.8 ml/1.73 m2 per minute with CFPD, respectively. No complications occurred. In this first report of CFPD in six pediatric patients with acute renal failure, CFPD was on average three to five times more effective for urea and creatinine clearance and ultrafiltration than conventional PD, without any complications observed. CFPD has the ability to improve therapy for acute renal failure.

Flow-through peritoneal dialysis in neonatal enema-induced hyperphosphatemia

Fleet enemas are hypertonic solutions with an osmotic action and a high concentration of phosphate. When retained in the human body they have a great toxic potential, causing severe hydro-electrolyte disorders in children, especially in newborns. We report the case of a previously healthy 8-day-old newborn who needed neonatal intensive care treatment after the inadvertent administration of an osmotically active hypertonic phosphate enema. Taking into account that phosphate removal by peritoneal dialysis (PD) strongly depends on total dialysate turnover, we chose continuous flow PD (CFPD) as the treatment option, with a successful outcome. Clinical experience with this dialytic modality is limited to a few case reports in pediatric and adult patients. To the best of our knowledge, we report here the first description of CFPD in the setting of acute phosphate nephropathy in the neonatal period. The modality of PD described here has potential as an alternative management option as it is a highly efficient, methodologically simple, and low-cost method without any need for sophisticated equipment. Physicians and parents should be aware of the adverse effects of a hypertonic phosphate enema and should never use these medications in infants and newborns.

Future technologies and techniques in peritoneal dialysis-opportunities and challenges ahead.

In the last 5 years, we have started to witness the emergence of new technologies and techniques that offer the potential for improved patient outcomes but which often still lack clinical demonstration and/or confirmation in well-designed, multicentre studies. These include biocompatible solutions, glucose sparing regimens, low-sodium solutions, bimodal solution formulations and continuous flow peritoneal dialysis (CFPD). This review discusses the potential benefits ascribable to each of these technologies and an analysis of the challenges that have to be surmounted before anyone of these candidate technologies can be declared as established. The demonstration of either hard clinical endpoints or validated surrogate endpoints is very feasible in terms of sample size requirements for some outcome measures, such as preservation of RRF, but will be much more challenging for other endpoints such as preservation of UF capacity.

Advances in the Technology of Automated, Tidal, and Continuous Flow Peritoneal Dialysis

Automated peritoneal dialysis (APD) has undergone substantial growth in recent years because of an increased demand for higher doses of peritoneal dialysis (PD) treatment and a need to improve quality of life for patients. The evolution of this treatment is closely linked with the development of new automatic machines and with recent advances in prescription and monitoring of PD treatment. In the present article, we describe the characteristics of the new generation of APD cyclers with particular regard to adequacy targets and safety. There is renewed interest in continuous-flow peritoneal dialysis (CFPD), because of a belief that new peritoneal access technologies will make the success of this modality a possibility. In the CFPD technique, a certain amount of fluid is constantly present in the abdomen, and constant inflow and outflow are maintained without interruption thanks to paired indwelling catheters. The PD solution is used either in a single pass or in a recirculation loop with a regeneration systems (sorbent cartridge or dialyzer).

The role of tidal peritoneal dialysis in modern practice: A European perspective

Tidal peritoneal dialysis (TPD) has been introduced to optimize adequacy of peritoneal dialysis (PD). Early studies reported similar or even better small solute clearances with TPD than those achieved with continuous ambulatory peritoneal dialysis or continuous cyclic peritoneal dialysis. However, in many studies treatment volumes were much higher during TPD compared with other PD modalities. Based on current evidence, TPD provides no advantage of increased small solute clearances, middle molecule clearances, or peritoneal ultrafiltration as compared to non-tidal automated peritoneal dialysis (APD) when dialysate flow is kept constant. However, TPD reduces drainage pain and nightly alarms during cycler treatment. Tidal volume should be kept as high as possible in these patients, especially in those with low average peritoneal transport rates. Based on theoretical considerations and little evidence, TPD could provide better clearances than conventional APD when a very high dialysate flow (>or=5 l/h) is used. Such dialysate flow rates are not routinely prescribed in home APD patients. However, they may be interesting for in-center PD patients. One randomized crossover trial reported higher small solute clearances with TPD compared to non-tidal APD in patients with acute renal failure. TPD is also the preferred treatment modality in patients with ascites as it allows a controlled outflow of fluid from the peritoneal cavity. Newer treatment modalities, for example, continuous flow PD, may be interesting alternatives in an effort to increase efficacy of PD in the future. However, because such treatment regimens are expensive and elaborate they have not been established for routine use until now.

The “Ronco” Catheter for Continuous Flow Peritoneal Dialysis

To perform CFPD, a two way access must be available in order to allow continuous inflow and outflow of the solution. This is most likely achieved with a double lumen peritoneal catheter. To design a double lumen catheter does not necessarily mean to increase the size of the tube or to increase the discomfort of the patient. However, the real challenge is to find a design in which minimal re-circulation is experienced. The two tips of the catheter must be positioned such that a maximal exposure of the peritoneal surface to the fluid is guaranteed during one single passage of the fluid from one lumen to another. Double lumen catheters with one short branch and another long of straight and of spiral shape were originally designed. Ash and coworkers have designed a catheter with a t-shape configuration in order to distantiate to the maximum the tips of the two lumens. Recently we have designed a novel catheter for CFPD equipped with a thin walled silicone diffuser used to gently diffuse the inflow dialysate into the peritoneum. The holes on the round tapered diffuser are positioned to allow dialysate to perpendicularly exit 360 degrees from the diffuser. The diffuser design and hole locations disperse the high-flow dialysate fluid at 360 degrees, reducing trauma to the peritoneal walls and allowing the dialysate to mix into the peritoneum. The dispersed fluid infused into the peritoneal cavity is then drained through the second lumen whose tip is placed into the lower Douglas cavity. The new catheter with diffuser is also equipped with a special removable hub that allows for easy creation of the subcutaneous tunnel without increasing the size of the skin exit site. The results so far achieved seems to offer advantages in terms of high flows, minimal pressure regimes and negligible recirculation.