Peritoneal Dialysis System Research Articles

Desenvolvimento e avaliação da esterilidade de sistema de diálise peritoneal pediátrico fechado

To develop an easy-handling totally closed pediatric peritoneal dialysis system and assess the sterility assurance level. From February to December 2008 was designed and developed a closed-system pediatric peritoneal dialysis at the Bioengineering Division of Braile Biomédica Indústria, Comércio e Representações S/A. Twenty systems were manufactured and submitted to sterility assurance level testing, and were divided into Group A (10)--using the sterility test--and B (10)--ethylene oxide gas penetration. In Group A, the sterility test was negative for bacteria and fungi proliferation within 14 days in all systems. In Group B, the gas penetration test showed that there was gas penetration in all points assessed. It was possible to develop a new easy-handling closed-system pediatric peritoneal dialysis and ensure its sterility.

Pneumoperitoneum Complicating Peritoneal Dialysis Catheter

A 55-year-old male presented with progressively worsening nausea over a one-year period. It began when he started peritoneal dialysis for end-stage renal disease. His nausea progressed to the point that he could not tolerate oral intake. He also had difficulty with exchanges, but the exchange fluid was clear. He denied any fever, chills, abdominal pain, change in bowel movements, hematochezia, or hematemesis. The physical exam was unremarkable except for mild discomfort in the right lower quadrant. The peritoneal dialysis catheter was intact and appeared to be clean. The laboratory exam showed a normal white cell count and a negative peritoneal fluid culture. A KUB showed a large amount of free intra-peritoneal air. Further questioning of the patient revealed improper use of the peritoneal dialysis system as a cause of the pneumoperitoneum. The prevalence and clinical significance of pneumoperitoneum in peritoneal dialysis (PD) patients is not defined fully in the current literature. Some reports suggested that, unlike in nonPD patients, it rarely is caused by gastrointestinal perforation. 1 Intestinal perforation can be ruled out by rapid clinical improvement with standard therapy, growth of Staphylococcus epidermidis in the peritoneal effluent culture, reduction of pneumoperitoneum after correction of the technical fault, and in contrast to the Gram-negatives and/or anaerobes usually found during bowel perforation. 2-3

The Vicenza Wearable Artificial Kidney for Peritoneal Dialysis (ViWAK PD)

Background: The study describes the structure and operational characteristics of a new wearable system for continuous ambulatory peritoneal dialysis (CAPD) for chronic kidney disease patients. Methods: We designed a wearable system consisting of: (1) a double lumen peritoneal catheter; (2) a dialysate outflow line; (3) a miniaturized rotary pump; (4) a circuit for dialysate regeneration featuring a waterproof container with 4 cartridges in parallel with a mixture of activated carbon and polystyrenic resins; (5) a filter for deaeration and microbiological safety; (6) a dialysate inflow line, and (7) a handheld computer as a remote control. The system has been tested circulating 12 liters of exhausted PD solution through the experimental adsorption unit at a rate of 20 ml/min. Creatinine, β₂-microglobulin (β₂-MG) and angiogenin were measured before and after the adsorption unit at baseline, and after 4 and 10 h of use. Results: The cartridges containing polystyrenic resin completely removed β₂-MG and angiogenin from the fluid batch. Those with the activated carbon removed completely urea and creatinine. The final result was 11.2 liters of net solute clearance. The system is designed to be used as follows: The peritoneal cavity is loaded in the morning with 2 liters of fresh PD solution. After 2 h, when dialysate/plasma equilibration at approximately 50% has occurred, recirculation is activated for 10 h at a rate of 20 ml/min. After this period, recirculation stops and glucose is optionally added to the peritoneal cavity to achieve ultrafiltration if needed. After 2 h the fluid is drained and a 2-liter icodextrin exchange is performed overnight to achieve further ultrafiltration. The clearance provided by the minicycler is further increased by the 2-liter exchange and the overnight exchange. Therefore, the system operates 24 h/day and provides creatinine and β₂-MG clearance in the range of 15–16 liters/day, corresponding to a weekly clearance of 100–110 liters. The patient reduces the number of exchanges compared to CAPD and uses less fluid than in automated peritoneal dialysis (APD). Furthermore, the handheld computer allows for prescription and assessment of the therapy providing information on cartridge saturation, flow and pressure conditions and offering the possibility of remote wireless control of operations. Some problems still remain to be solved in the present configuration including the addition of an injection system for glucose and bicarbonate when needed, a system to reduce fibrin delivery to the sorbent and finally a more complex mixture of sorbents to make sure a complete removal of small molecules including urea is achieved. Conclusion: The wearable PD system may become a possible alternative to APD or CAPD reducing the time dedicated to perform exchanges and improving peritoneal dialysis adequacy and patient’s rehabilitation.

Development of a computer-aided diagnosis system for continuous peritoneal dialysis: An availability of the simultaneous numerical optimization technique for kinetic parameters in the peritoneal dialysis model

We developed a novel diagnostic system for continuous peritoneal dialysis, which evaluates the peritoneal permeability and hydraulic conductance (peritoneal function) by applying the kinetic model and a clinical test with minimum nursing time. Kinetic parameters for the peritoneal function were determined by the simultaneous numerical optimization techniques (SNOT). Furthermore dialysis outcome and ultrafiltration volume were estimated and predicted by using the kinetic model with a set of optimal kinetic parameters, which were in agreement with measured data ( r 2 > 0.82 ) . The clinical implementation of the SNOT is very useful to explore the better prescriptions for each patient's clinical condition.

Improvement of Peritoneal Ultrafiltration with Peritoneal Dialysis Solution Buffered with Bicarbonate/Lactate Mixture

In computer simulations, according to the three-pore model of peritoneal transport, neutralization of conventional acidic peritoneal dialysis fluids is predicted to produce an improved ultrafiLtration (UF). However, in a previous study, a two-compartment peritoneal dialysis system with a minimum of glucose degradation products (GDP), PD-Bio, having a pH of 6.3 and being conventionalLy lactate buffered, did not produce an increased UF. We tested a newly formulated, glucose-based, GDP-reduced solution, denoted "N" for "neutral," containing a mixture of lactate (30 mmol/L) and bicarbonate (10 mmol/L) as buffer system, and having a pH of 7.2. This new formulation was compared with Gambrosol trio (GT) (identical in composition to PD-Bio, but delivered in a three-compartment system; both by Gambro Lundia AB, Lund, Sweden) in an open, prospective controlled study of 13 patients. Each of the 13 patients used GT for 14 days, followed by 14 days of N. All bags were weighed on a digital scale before instillation and after drainage to assess the UF in each dwell (and during 24 hours). Glucose concentration in each bag was noted. In the morning and night dwells, dialysis fluid glucose concentration was standardized to 2.5%. Body weight was measured every morning (empty abdomen). In the middle of each 14-day period, a 4-hour standardized ("study day") dwell was performed, using 125I-albumin (RISA) as volume marker, during which blood and dialysate samples were taken repeatedly and anaLyzed for RISA, creatinine, urea, phosphate, glucose, standard bicarbonate, lactate, and pH. The permeability surface area product (PS) for small solutes (and A0/deltaX; "area parameter") was calculated. Clearance (Cl) of RISA to plasma (P) (C-->P), "direct lymphatic absorption," and total Cl of RISA out of the peritoneal cavity (Cl(out)) were also determined. The 13 patients using N, compared to GT, displayed an increased daily UF, the difference being 233 mL (p < 0.05). The pH values of N were higher during the first 90 minutes of the 4-hour dwell compared to the pH values of GT. Neither the small solute PS values nor RISA determined UF, nor did body weight differ significantly between the GT and the N periods. A new bicarbonate/lactate-buffered solution, N, with neutral pH (of 7.2) and low in GDP seems to produce an improved UF compared to a lactate-buffered solution with a pH of 6.3, equally low in GDP, partly in agreement with our earlier predictions. A dialysis solution with a neutral pH combined with a reduced lactate concentration, partially replaced by bicarbonate, evidently increases UF, conceivably by causing less peritoneal vasodilatation than solutions buffered by lactate or high concentrations of bicarbonate alone.

Possible Shock Leads to Recall of Peritoneal Dialysis System

Possible Shock Leads to Recall of Peritoneal Dialysis System

Management of Refractory Ascites by Using a Peritoneal Dialysis System with Extracorporeal Ultrafiltration by Hemodialysis Dialyzer

The treatment of refractory ascites remains a challenge in cirrhosis with ascites and end-stage renal disease (ESRD). Successful experiences with continuous ambulatory peritoneal dialysis (CAPD) for treatment of ESRD patients with ascites secondary to liver cirrhosis have been reported, but the CAPD modality has the drawback of protein loss and was observed to cause patients to become severely malnourished. We devised a CAPD method for treatment of ascites without protein loss. We use a peritoneal dialysis (PD) system to drain ascitic fluid and to reinject concentrated ascites into the abdomen after extracorporeal ultrafiltration of the ascitic fluid using a hemodialysis dialyzer and pump. Here, we report our experience with 2 cirrhotic patients with ascites treated by this method. Ascites are collected by gravity through a Y transfer set into a 3-L plastic bag for intravenous hyperalimentation. The ascitic fluid drained is removed by a pump at a rate of 200 mL/min (AK-90: Gambro Lundia, Lund, Sweden) and passed through a hollow-fiber dialyzer with triacetate membrane (FB-210G: Nipro, Osaka, Japan). Heparin (5,000 U) is infused into the inflow line at the start of the session only. At the end of treatment, about 500 mL concentrated ascitic fluid is returned to the peritoneal cavity by gravity through the Y transfer set. Case 1: A 77-year-old female was referred to us because of massive ascites from hepatic cirrhosis associated with hepatitis B infection and renal insufficiency. Abdominal paracentesis was required once weekly for recurrence of massive ascites. As a result, the patient was obliged to stay in the bed almost all day, and her nutritional condition deteriorated because of poor appetite and respiratory compromise. Using the Y transfer set, we commenced using our method, and performed it thrice or twice weekly. After 9 months of treatment, the patient's body weight was being maintained at 52 kg, and her serum albumin level had risen from 2.4 g/dL to 3.4 g/dL without albumin administration. Case 2: A 61-year-old male with diabetes from the age of 51 was diagnosed with hepatitis C at age 53. At age 60, his renal function deteriorated, requiring hemodialysis (HD). After 3 months, abdominal distention was noted, and HD was frequently complicated by low blood pressure, large weight gains between HD treatments, and interruption of HD sessions. Albumin administration was required to treat the low blood pressure. Ascites was poorly controlled using HD, and tense ascites developed, requiring repeated paracentesis for comfort. At first during application of our method, ascitic fluid volume was 6 L per thrice-weekly HD session. After 5 months, ascitic fluid volume had diminished to about 2 - 3 L per HD session, and we decreased the frequency of our method to once weekly. Protein levels in the ascitic fluid were 6 g/dL at the start of treatment and decreased to 2 - 3 g/dL after 6 months. Hemodynamic instability during HD was reduced. We conclude that management of refractory ascites by using a PD system with extracorporeal ultrafiltration by an HD dialyzer is useful. The technique compensates for the drawbacks of PD management of ESRD patients with ascites, although further experience with the technique is necessary.

Continuous Flow Peritoneal Dialysis: Assessment of Fluid and Solute Removal in a High-Flow Model of “Fresh Dialysate Single Pass”

♦ Background Growing concern over the limited capacity of the peritoneal dialysis (PD) system has revived interest in continuous flow peritoneal dialysis (CFPD), a modality in which continuous circulation of PD fluid is maintained at a high flow rate using two separate catheters or one dual-lumen catheter. The CFPD regimen contrasts the “inflow/outflow” regimen, which requires specific times devoted to filling and draining the peritoneum via a single-lumen catheter. Historical data established CFPD capabilities in providing higher solute clearance and ultrafiltration rate (UFR) using either an open loop system with a single pass of fresh PD fluid, or various external purifications of the spent dialysate. ♦ Objective To compare, in patients with various peritoneal transport patterns, fluid and solute removal achieved during a standardized program of CFPD versus two control schedules: nightly intermittent peritoneal dialysis (NIPD) and nightly tidal peritoneal dialysis (NTPD). This study focused on small solute clearances and UFR using only isotonic PD solution (Dianeal PD1 1.36%; Baxter Healthcare, Castlebar, Ireland). The model of fresh dialysate, single pass, was used to optimize solute gradients and to characterize the impact of a continuous flow regimen on peritoneal transport characteristics. ♦ Methods In a crossover trial, 4-hour CFPD sessions were performed at a fixed dialysate flow rate (100 mL/minute) in 5 patients being treated with automated PD. A hemofiltration monitor (BM25; Baxter Healthcare, Brussels, Belgium) was adapted to the CFPD technique. The peritoneal cavity was filled through a temporary second catheter and simultaneously drained using the permanent peritoneal access. Fluid and solute removal were compared to data obtained from a control period based on 8-hour sessions of NIPD or NTPD using 13 L of isotonic dialysate. ♦ Results High-flow CFPD enhanced the diffusive transport coefficient compared with the alternative flow regimen in patients ranging from low to high transporters. Weekly creatinine clearance increased from 36.9 L (22.3 – 49.6 L) and 37.3 L (27.5 – 45.0 L) with NIPD and NTPD respectively, to 74.9 L (42.3–107.5 L) with CFPD. Mean UFR was 2.44 mL/min with CFPD versus 0.92 and 0.89 mL/min with NIPD and NTPD respectively. The mass transfer area coefficient (MTAC) of creatinine with CFPD was 2.5-fold that obtained from the peritoneal equilibration test data. ♦ Conclusion Our results confirm that CFPD is highly effective in increasing fluid and solute removal. Furthermore, consistent with historical data, our findings indicate that the enhanced solute transfer is not due only to steeper solute gradients, but also depends on increased MTAC in a wide range of peritoneum transport characteristics.

History and development of the access for peritoneal dialysis.

One of the most important components of the peritoneal dialysis system is a permanent and trouble-free access to the peritoneal cavity. Although in the development of peritoneal access various ideas have been tried, nowadays only catheters penetrating the abdominal integument are in use. Unfortunately, none of the currently used catheters is trouble free; poor dialysate drainage, pericatheter leaks, exit site and tunnel infections, and recurrent peritonitis episodes are frequently encountered. Therefore, there is an incessant search for new technological solutions, including new shapes of intraperitoneal and intramural catheter segments and new catheter materials are tried. This chapter will present a brief history of peritoneal catheter development and describe the designs of the most commonly used catheters.

In Vitro Superiority of Dual-Chambered Peritoneal Dialysis Solution with Possible Clinical Benefits

should reflect this fact.Their design should consider the real use of PDFs.Conventional PDFs are known to disturb perito-neal membrane cell function not only as a consequenceof their acidic pH in combination with their high lac-tate concentration, but also as a result of their highconcentrations of glucose and glucose degradationproducts (GDPs), which lead to the formation of ad-vanced glycation end-products (AGEs) in the perito-neal membrane.New PD solutions are produced in dual-chamberedbags. Application of a dual-chambered continuousambulatory peritoneal dialysis (CAPD) system leadsto decreased GDP formation during heat sterilizationof glucose owing to a low pH (2.8 – 3.2) in the glu-cose-containing chamber. Thus it may be concludedthat dual-chambered PDFs, as compared with con-ventional acidic lactate-buffered PDFs, display a re-duced protein glycation potential. In addition, themixing of the two fluids before use results in a morephysiologic solution with a neutral pH, which alsocontributes to the improved biocompatibility and clini-cal comfort of these new PDFs.This review describes cell studies of acute andchronic exposure to GDPs, as well as

Factors affecting hemodialysis and peritoneal dialysis efficiency.

Hemodialysis and peritoneal dialysis are two blood purification techniques that use similar operating systems. The hemodialysis system is based on three components (blood, membrane, and dialysate). The peritoneal dialysis system is based on the same components that can, however, be less manipulated and adjusted. In hemodialysis the blood flow is the main determinant of small solute removal thanks to a prevalently diffusive mechanism. Convection is also used to transport larger solutes across the membrane, but this mechanism relies on the high permeability coefficient of the membrane and high transmembrane pressure leading to high ultrafiltration rates. The membrane can therefore influence the performance of the techniques as far as solute removal and ultrafiltration are concerned. Finally, diffusion is facilitated by an improved distribution of dialysate flow in the dialysate compartment. This can be achieved with a special dialysate pathway configuration based on space yarns or micronodulation of the fibers. In peritoneal dialysis, blood flow and membrane characteristics can be less manipulated or almost not at all. The only variables are dialysate volume, flow, dwell time, and composition. Thanks to modification in these aspects of the dialysate, peritoneal dialysis techniques with different clearances and ultrafiltration rates can be accomplished.

Staphylococcal Peritonitis in Continuous Ambulatory Peritoneal Dialysis: Colonization With Identical Strains at Exit Site, Nose, and Hands

To evaluate the relationship of nasal or skin Staphylococcus carrier status with identical strains and the development of staphylococcal peritonitis, 59 consecutive peritonitis episodes in patients using a twin-bag system for continuous ambulatory peritoneal dialysis from a single dialysis center were prospectively studied. Dialysate samples and exit-site, nose, and nail swabs from patients and their dialysis partners were obtained on the same day for culture. When bacteria belonging to the same species of the Staphylococcus genus were isolated from dialysate and at least one extraperitoneal anatomic site, pulsed-field gel electrophoresis typing was performed. The bacterial strains isolated from catheter exit site, nose, or nails of each patient and his or her dialysis partner were classified as identical or different. Twenty-seven of the 59 peritonitis episodes (46%) were caused by staphylococci. Nineteen of these 27 patients carried the same Staphylococcus species causing the peritonitis episode at the exit site, nose, or nails, but only 17 patients (63%) carried an identical strain. Four of 5 dialysis partners carried the same Staphylococcus species causing the peritonitis episode at nose or nails, but the strain was identical for only 3 dialysis partners (60%). Four patients and 1 dialysis partner carried unrelated strains of the Staphylococcus species causing the peritonitis episode. The most frequently colonized site with strains identical to that causing the peritonitis episode was the catheter exit site, followed by nose and nails. This finding may be clinically relevant because eradication of Staphylococcus aureus colonizing the catheter exit site may be more important and have a greater likelihood of success than maneuvers directed to more distant locations.

Importance of Product Design on Effective Bacterial Removal by Fluid Convection in Y Set and Twinbag Systems

The goal of this study was to quantitatively compare in vitro the ability of four commercially available peritoneal dialysis solution system designs to prevent the infusion of the most common accidental touch and airborne bacterial contaminant, Staphylococcus epidermidis, into the peritoneum using a total system evaluation approach. This approach took into consideration the number of system openings to the environment during an exchange combined with each system’s convective flushing characteristics. A Y set and a Twinbag system utilizing either an antimicrobial cap or a snap disconnect design for disconnection at the end of the solution exchange procedure were selected for study. The lowest peritoneal bacterial recovery count was seen with the antimicrobial cap system Twinbag, being significantly lower than any of the other systems tested (p < 0.0001). The highest bacterial recovery count occurred in the snap disconnect Y system, being significantly higher than any of the other products tested (p < 0.0001). Both the antimicrobial cap systems permitted infusion of fewer bacteria than the snap disconnect systems, despite being inoculated with larger numbers of bacteria to account for a potential additional opening of the system, during the disconnect procedure. This evaluation emphasizes the importance of fluid path flow design in the overall safety performance of peritoneal dialysis systems.

Treatment of peritonitis complicating continuous ambulatory peritoneal dialysis: an Asian perspective

Summary: Geographically, socially, economically and culturally, Asia differs from the United States of America and Europe. These differences may affect the delivery of different continuous ambulatory peritoneal dialysis (CAPD) systems, the incidence and nature of CAPD peritonitis and its treatment. From a recent survey, it has been shown that the use of more expensive disconnect systems has yet to gain popularity in many Asian countries due to its increased cost, but may now be justified in the light of recent cost‐effective studies done in the region. In order to compare the incidence, microbiological profile and treatment strategy of CAPD peritonitis among Asian–Pacific countries, a survey was conducted among renal units of the Asian–Pacific Society members collecting retrospective data from 1 July, 1994 to 30 June, 1995. In this ‘cross country’ analysis, no correlation was found between peritonitis rate and the percentage use of disconnect systems. This observation highlights the difficulties in extrapolating data from one unit (e.g. in the United States of America) to another (e.g. in Asia) in order to decide if one CAPD system is more cost‐effective than the other. Also observed was a relatively high incidence of culture negativity and gram negative culture positivity rates among some Asian–Pacific countries. These findings imply that primary treatment for CAPD peritonitis in these countries should involve the use of a single broad spectrum antibiotic or two antibiotics with gram positive and negative coverage. the median pseudomonas peritonitis rate of 12% means that antibiotics with anti‐pseudomonas activity should also be used. the use of oral vs intraperitoneal (i.p.) drug treatment for established CAPD peritonitis has considerable attraction in Asia because of its reduced cost and ease of administration especially in countries with poor transport arrangement between home and the treatment centre and inadequate home social support. the fluoroquinolones have been extensively studied most in the region and achieve cure rates comparable to conventional i.p. regimens. However, with long‐term use, progressive development of bacterial resistance has been observed and this would ultimately limit their effectiveness. the introduction of oral fluconazole has not reduced the chance of catheter removal but is recommended for the treatment of fungal (especially candida) peritonitis in Asia as it is relatively safe, cheap and simple to use. Oral nystatin given with each antibiotic prescription is also effective in reducing the incidence of candida peritonitis and is inexpensive. Peritonitis secondary to Mycobacterium tuberculosis is more often observed in Asia because the latter is endemic in the region. In contrast to previous recommendations, we have shown from a much larger experience that catheter removal is not mandatory for the cure of this condition and this approach is compatible with long‐term preservation of peritoneal function.

Peritonitis in an urban peritoneal dialysis program: An analysis of infecting pathogens

We have previously found that race, level of education, and peritoneal dialysis system are factors that significantly and independently influence peritonitis rates in our patient population. We now extend these observations by assessing the pathogens responsible for peritonitis in these subgroups. Between January 1, 1981, and May 15, 1993, 248 peritoneal dialysis patients underwent dialysis at our facility. The rate of peritonitis by pathogen was determined in these patients using the fixed effects Poisson model. Total peritonitis rates in black patients (1.89 episodes/patient-year) were significantly greater compared with white patients (1.11 episodes/patient-year; P < 0.0001). Increased infection rates in black patients were significant for Staphylococcus epidermidis, Staphylococcus aureus, and gram-negative pathogens. The level of education had a negative correlation with peritonitis rates (≤ 8 years, 2.00 episodes/patient-year; 9 to 12 years, 1.64 episodes/patient-year; and ≥ 13 years, 1.24 episodes/ patient-year) with patients having ≥ 13 years of education at the start of dialysis demonstrating a significantly lower total peritonitis rate compared with patients with 9 to 12 years ( P = 0.001) or ≤8 years ( P < 0.001) of education. This was accounted for by a significant decrease in infection rates for S epidermidis, polymicrobial, and gram-negative organisms. Finally, patients on automated peritoneal dialysis had significantly lower total peritonitis rates (0.59 episodes/patient-year) compared with patients on either a connect (2.11 episodes/patient-year) or disconnect (1.46 episodes/patient-year) system. A significant decrease in infection rates for every category of pathogen except fungal infections was found in patients on automated peritoneal dialysis in comparison to the other two systems. Overall, significant differences in S epidermidis infection rates was the single most important factor accounting for the differences in peritonitis rates observed between the various subgroups of patients evaluated. This is best demonstrated in the evaluation of the peritoneal dialysis systems in which S epidermidis infection rates were only 0.20 episodes/patient-year for automated peritoneal dialysis and 0.55 episodes/patient-year for the disconnect system compared with 0.85 episodes/patient-year for the connect system. Since S epidermidis infections generally are attributed to touch contamination, identifying patients at greatest risk allows the potential for intervention with closer supervision, adjustments in the peritoneal dialysis training/education approach, or a change in the peritoneal dialysis system.

Estimating increases in outpatient dialysis costs resulting from scientific and technological advancement.

The Medicare program's base payment rate for outpatient dialysis services has never been adjusted for the effects of inflation, productivity changes, or scientific and technological advancement on the costs of treating patients with end-stage renal disease. In recognition of this, Congress asked the Prospective Payment Assessment Commission to annually recommend an adjustment to Medicare's base payment rate to dialysis facilities. One component of this adjustment addresses the cost-increasing effects of technological change--the scientific and technological advances (S&TA) component. The S&TA component is intended to encourage dialysis facilities to adopt technologies that, when applied appropriately, enhance the quality of patient care, even though they may also increase costs. We found the appropriate increase to the composite payment rate for Medicare outpatient dialysis services in fiscal year 1995 to vary from 0.18% to 2.18%. These estimates depend on whether one accounts for the lack of previous adjustments to the composite rate. Mathematically, the S&TA adjustment also depends on whether one considers the likelihood of missing some dialysis sessions because of illness or hospitalization. The S&TA estimates also allow for differences in the incremental costs of technological change that are based on the varying advice of experts in the dialysis industry. The major contributors to the cost of technological change in dialysis services are the use of twin-bag disconnect peritoneal dialysis systems, automated peritoneal dialysis cyclers, and the new generation of hemodialysis machines currently on the market. Factors beyond the control of dialysis facility personnel that influence the cost of patient care should be considered when payment rates are set, and those rates should be updated as market conditions change. The S&TA adjustment is one example of how the composite rate payment system for outpatient dialysis services can be modified to provide appropriate incentives for producing high-quality care efficiently.

In Vitro and in Vivo Efficacy of a New Connector Device for Continuous Ambulatory Peritoneal Dialysis

The purpose of this study was to evaluate the in vitro and in vivo efficacy of a new connection system for continuous ambulatory peritoneal dialysis (CAPD), called the T-set. With this system the patient wears a 27-cm extension line filled with Amuchina during the dwell time; the bag is made of a fill container linked to a drainage tube with a Y-shaped set. For bag exchange, only one connection is needed and this is subsequently flushed with the entire drainage volume. The in vitro efficacy of the system was tested with 20 sets filled with 10 mL of Amuchina and inoculated in the distal lumen with 2.1 x 10(3) colony-forming units (cfu) of S. aureus. After an incubation of 4-6 hours at 35-37 degrees C, three dialysate samples per set were collected, respectively, at the beginning of drainage and filling. All 120 samples were negative, whereas two control sets, filled with a phosphate-buffered saline, had positive drainage samples, and at least one positive infusion sample, indicating the efficacy of Amuchina in sterilizing the system under conditions simulating touch contamination. To evaluate the in vivo efficacy, safety, and acceptability of the T-system, a prospective randomized controlled trial was performed in seven centers: a control group (CG) of 56 patients (follow-up: 952.3 months, mean +/- SD: 17.0 +/- 7.8) was treated with a long branch (21 patients) or short branch (35 patients) Y-set and a test group (TG) of 66 patients (follow-up:898.1 months, mean +/- SD: 13.6 +/- 7.8) with the T-set.(ABSTRACT TRUNCATED AT 250 WORDS)

Issues of Biocompatibility for the Continuous Ambulatory Peritoneal Dialysis System

Issues of Biocompatibility for the Continuous Ambulatory Peritoneal Dialysis System

1 alpha-Hydroxycholecalciferol adsorption to peritoneal dialysis bags: influence of time, glucose concentration, temperature, and albumin.

The present study examines the adsorptive phenomenon of 1 alpha-hydroxycholecalciferol (1 alpha-OHD3) to peritoneal dialysis bags. One minute after injection of 1 alpha-OHD3 into the dialysis bags, a significant adsorption to the bags was observed in experiments where albumin was not added. A higher temperature (37 degrees versus 23 degrees C) in bags containing 13.6 mg glucose/ml resulted in less adsorption (P < 0.05). Adding albumin to bags at 37 degrees C with a glucose concentration of 13.6 mg/ml, reduced the adsorptive phenomenon significantly (P < 0.01). Bags tested at 37 degrees C with a glucose concentration of 38.6 mg/ml resulted in a significantly higher 1 alpha-OHD3 adsorption than bags containing 13.6 mg glucose/ml (P < 0.01). It is concluded that adsorption of 1 alpha-OHD3 to dialysis bags is affected by time, albumin, temperature and glucose concentrations. Substantial amounts of 1 alpha-OHD3 is retained by the peritoneal dialysis system when albumin is not added.

A Review of Staphylococcu S aureus Exit-Site and Tunnel Infections in Peritoneal Dialysis Patients

Staphylococcus aureus peritoneal exit-site and tunnel infections are a source of considerable morbidity for peritoneal dialysis patients. These infections are difficult to resolve, can lead to peritonitis, and often require removal of the peritoneal catheter. Staphylococcal nasal carriage is the major risk factor for S aureus exit-site infections and peritonitis episodes. In the future, the identification of patients who are S aureus nasal carriers and then treatment of the carriage state with rifampin may prove to be a means of decreasing infection rates. The best treatment for S aureus exit-site and tunnel infections has not been established. Treatment regimens in general use include oral antibiotics or intraperitoneal vancomycin. The optimal length of therapy is also unclear. Since the development of the disconnect peritoneal dialysis system, S aureus, rather than the Staphylococcus epidermidis, is the leading cause of peritonitis. To further decrease peritonitis rates, attention must now be directed at catheter-related peritonitis episodes, with S aureus the most common cause of such episodes. Controlled, prospective studies designed to investigate methods of preventing and treating S aureus exit-site infections in peritoneal dialysis patients are needed.