bluuebunny/crossref_metadata_2025_split huggingface dataset:
Urea Peritoneal Transfer Evaluated Using Plasma Water Urea Concentrations
Authors: Grzegorzewska Alicja E. 
Published: February 2020

Objective To quantify differences in evaluation of urea peritoneal transport parameters according to the expression of urea concentration in whole plasma and plasma water. Design Prospective study in which the dialysate samples for urea determinations were taken at short dwell times (2.5 45 minutes) during three consecutive exchanges of intermittent peritoneal dialysis (IPD). Blood samples were drawn at the beginning and at the end of the study period. Urea peritoneal transport parameters were calculated using urea concentration in whole plasma and plasma water. The results were then compared. Setting Peritoneal dialysis unit of a nephrology de partment. Patients Ten stable patients on IPD. Interventions Dialysateand blood sample collections.. Main Outcome Measures: Dialysate-to-plasma ratios (DIP), peritoneal clearances (Cp)’ and diffusive mass transport coefficients (KBD) of urea. Results At short dwell times, uncorrected (whole plasma) DIP and Cp of urea values were higher than the corrected (plasma water) values by 5.7% -5.9%. Uncorrected urea KBD’ calculated using the simplified two sample model of Garred et al., yielded an overestimation that significantly increased with prolongation of dwell (8.5±0.5% at 2.5 minutes vs 13.0±0.8% at 45 minutes). Urea KBD’ assessed by the linear regression model of Garred and Spencer, was 9.4±0.3% higher for uncorrected values. Conclusions The expression of urea concentration in whole plasma instead of plasma water overestimates urea peritoneal transfer parameters. The percent overestimation (y) of urea KBD’ calculated using the simplified model of Garred et al., can be predicted with the equation y = 0.131x+ 7.563, wherex is the dwell time (in minutes).
Weight Limitations for Weekly Urea Clearances Using Various Exchange Volumes in Continuous Ambulatory Peritoneal Dialysis
Authors: Nolph Karl D. , Jensen Richard A. , Khanna Ramesh , Twardowski Zbylut J. 
Published: February 2020

Objective To calculate the relationships of weekly KT/V urea to standard body weight with different exchange volumes (2, 2.5, or 3 L) for continuous ambulatory peritoneal dialysis (CAPD) in functionally a nephric patients and to display the results in graphic form. Design Theoretical calculations using previously measured 24-hour dialysate/plasma urea values in 77 CAPD patients and other defined components of weekly KT/V urea. Setting Measurements and calculations in theoretical patients doing standard CAPD with four daily exchanges. Patients Theoretical functionally anephric patients on standard CAPD as above. Interventions Theoretical calculations based on instillation of 2-, 2.5-, and 3-L exchange volumes. Main Outcome Measures Weekly urea clearances normalized to total body water (weekly KT/V urea). The values using different exchange volumes were related to standard body weight. Results Although a minimum recommended weekly KT/V urea target is arbitrary, the results illustrate the range of flexibility of CAPD relative to KT/V urea values with variations in exchange volume. The standard weights above which anephric patients on CAPD using four exchanges per day with 2-, 2.5-, and 3-L exchanges cannot reach a weekly KT/V urea target of 1.7, have been identified. The range of weekly KT/V urea levels possible with different exchange-volume programs has been graphically illustrated. Conclusions Weights above which a weekly KT/V urea of 1.7 cannot be reached in functionally anephric patients are 64, 77.6, and 91 kg for CAPD using 2-, 2.5-, and 3- L exchanges, respectively.
Icodextrin in Peritoneal Dialysis: Early Development and Clinical Use
Authors: Mistry Chandra D. , Gokal Ram 
Published: February 2020

Over the past decade we have explored the potential of a starch-derived glucose polymer (icodextrin) as a “colloid” osmotic agent and clinically adapted it to produce sustained ultrafiltration over long dwell exchanges. An optimal osmotic profile was defined using a series of glucose polymer formulations of varying molecular distribution. Initially, a readily available dextrin formulation (Caloreen) with a bimodal molecular weight profile was used. Five and 10% solutions containing this formulation [weight average MW (Mw) of 7000 dalton and number average MW (Mn) of 960 dalton were nearly twice as effective as 1.36% and 3.86% glucose solutions, but their effectiveness was limited by rapid absorption of fractions less than 12 glucose units. Further modification isolated a purified “high” MW fraction containing chain length greater than 12 glucose units with Mw of 16 823 dalton and Mn of 5304 dalton. A 5% solution containing this fraction, iso-osmolar to uremic plasma, provided calorie load half that of a 1.36% glucose, yet produced increased and sustained ultrafiltration for up to 12 hours by a mechanism resembling “colloid” osmosis. Only a fraction of glucose polymer load was absorbed via the lymphatic pathway, but its metabolism was incomplete, resulting in the accumulation of maltose. Although it was devoid of any detectable adverse effect in the short term, long-term concerns remained. In studies using a single daily overnight exchange of glucose polymer combined with three daytime exchanges of glucose over 5 days, 10 days, and 3 months, we have shown that a constant peritoneal clearance (3 mL/minute) ensures a steady-state level of maltose in the serum within 10 days, and this remains stable for up to 3 months without any adverse effects. The relative inertness of icodextrin has been the key factor in its success as the first “colloid” osmotic agent in clinical use. It is safe and effective, and the demonstration of steady-state levels of accumulated maltose and oligosaccharides without any adverse effects has been encouraging and provided further impetus to proceed with longer-term studies.
Cell Function, Viability, and Icodextrin
Authors: Topley Nicholas , Liberek Tomasz , Mistry Chandra , Coles Gerald A. , Williams John D. 
Published: February 2020

The bioincompatibility of conventional dialysis fluids is related primarily to the combination of low pH and high lactate concentrations. This results in the reduction of intracellular pH and a consequent inhibition of cell function. The use of high glucose concentrations to increase fluid osmolality adds to the cytotoxicity and has a further inhibitory effect on peritoneal cells. The clinical need for fluids that provide sustained ultrafiltration has led to a novel approach using a high molecular weight glucose polymer (icodextrin) to generate an ultrafiltration gradient in an iso-osmolar fluid. In the studies presented we have had the opportunity of examining, in the laboratory setting, the biocompatibility of such a fluid. As in previous studies with conventional fluids, pH per se has a profound effect on most modalities of cell function. In addition, there appearto be a few areas where problems can be ascribed to icodextrin itself. Furthermore, it is possible that Staph. epidermidis survives better in icodextrin than in conventional dialysate. Whether the benefits of sustained ultrafiltration outweigh the possible disadvantages outlined can only be judged when the results from ongoing clinical trials are available.
Peritoneal Fluid and Tracer Albumin Kinetics in the Rat. Effects of Increases in Intraperitoneal Hydrostatic Pressure
Authors: Zakaria EL Rasheid , Rippe Bengt 
Published: February 2020

Objectives To study the peritoneal fluid loss rate, the clearance (CI) of radioactive tracer albumin (RISA) eliminated from the peritoneal cavity (PC), as well as the peritoneal-to-plasma RISA clearance (CI -+ P) during acute peritoneal dialysis (PD) at large elevations in intraperitoneal hydrostatic pressure (IPP). Design Experimental study in anesthetized Wistar rats. Methods The intraperitoneal volume (IPV) was assessed using RISA dilution, correcting for the RISA CI from the PC. Volume recovery at termination of the dwells was obtained using graduated cylinders and preweighed gauze tissues. Measurements of CI and CI -+ P were obtained by repeated micro-sampling of dialysate and plasma, respectively. The IPP was continuously measured, and could be varied by external concentric abdominal compression using an inflatable cuff. On termination of the experiments, samples from tissues lining the PC were analyzed with respect to their content of RISA and edema, the latter being assessed from wet/dry weight ratios. Results At 2 mm Hg of IPP (control) the RISA CI was 27.1:1:2.0(:1:SE)μL.min-l, whereas CI→ Pwasonly 8.07:1:0.67 μL.min-l, at a total fluid loss rate of 10.1:1:5.4μL.min-1 for 1.36% Dianeal. At an IPP of 14 mm Hg, the CI increased to 55.3±4.1 μL.min -1 and the peritoneal fluid absorption rate was 34.4±5.6 μL.min -l, whereas CI -+ P was just moderately increased as compared to control (11.2:1:1.4 μL. min -I). Furthermore, a pleural effusion of 1.16:1:0.08 mL was detectable at elevated IPPs. The degree of edema formation in the anterior abdominal muscles (AAM) and the diaphragm (DIA) was largely insignificant during 150 min at 2 mm Hg of IPP, but increased markedly at 14 mm Hg, as did the RISA uptake to the AAM and DIA. The discrepancy between CI and CI -+ P was largely accounted for by tracer entrance into tissues lining the peritoneal cavity, mainly the AAM. Conclusions At a nearly unchanging capillary Starling equilibrium, the losses of fluid and of RISA from the PC were markedly elevated at increased IPPs. However, the RISA clearance to the plasma appeared to be only moderately altered at elevated IPP and represented only a minor fraction of the RISA clearance out of the PC. Tissues lining the PC apparently act as a variable ‘sink’ for intraperitoneal proteins and fluid during peritoneal dialysis (PD).
Analysis of Inflammatory Mediators and Peritoneal Permeability to Macromolecules Shortly before the Onset of Overt Peritonitis in Patients Treated with CAPD
Authors: Zemel Désirée , Betjes Michiel G.H. , Dinkla Chris , Struijk Dirk G. , Krediet Raymond T. 
Published: February 2020

Objective To investigate whether changes in peritoneal membrane characteristics and inflammatory mediators in dialysate precede the onset of overt infection during continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis. Design CAPD patients with a high peritonitis incidence stored every night bag at 4°C. Routinely, each bag was thrown away after two days. Only if patients developed peritonitis, all bags were delivered for study. Thus, two night bags immediately prior to the first peritonitis bag were available for analysis. A control study was done 14 days after recovery. Dialysate samples were measured for TNFα, IL-6, PGE2, 6-keto-PGF lα’ TxB2, and serum proteins. The clearance of β2-microglobulin was used as an indicator of the effective peritoneal surface area. The intrinsic peritoneal permeability was characterized by the restriction coefficient. Results Eight episodes occurred in 5 patients. The night dwells available prior to the first peritonitis effluent were drained maximally nine dwells and minimally one dwell before the first peritonitis bag. Dialysate leukocyte counts exceeded 100 × 106/L only on the day of manifest infection. However, bacterial cultures were already positive at least one day before overt infection in four episodes and in three of these cases two days before. No changes were observed prior to peritonitis for the clearance of β2-microglobulin or the restriction coefficient. In contrast to these permeability characteristics, the cytokines, TNFα and, though less significant, also IL-6, were increased in dialysate one day prior to overt infection, when compared to the values obtained at the control investigation. This was especially evident in effluents drained no longer than two dwells before the first peritonitis bag. Prostaglandin concentrations in dialysate were not different before the onset of manifest peritonitis from the values measured after recovery. Conclusion In this study, the increased effective peritoneal surface area and intrinsic peritoneal permeability during acute infection appeared to be preceded by elevations in the cytokines TNFα and, to a lesser extent, IL-6. These increments occurred only very shortly before the onset of clinical symptoms.
In Vitro Biocompatibility of a Heat -Sterilized, Low Toxic, and Less Acidic Fluid for Peritoneal Dialysis
Authors: Wieslander Anders P. , Deppisch Reinhold , Svensson Eva , Forsbäck Gunita , Speidel Rose , Rippe Bengt 
Published: February 2020

Objective The aim of this study was to investigate a peritoneal dialysis (PD) fluid (PD-Bio), produced with the intention of reducing the amount of glucose degradation products and to increase the final pH. The heat sterilization of the fluid was performed with the glucose separated from the electrolytes. After sterilization the two solutions were combined. Methods The in vitro biocompatibility of PD-Bio was measured as the inhibition of cell growth of a cultured fibroblast cell line and as the stimulated release of interleukin-1β from cultured human mononuclear cells. The glucose degradation products were measured as UV absorbance at 228 nm or 284 nm and the concentration of aldehydes was estimated with high-performance liquid chromatography and gas chromatography. Results Our results demonstrate that in comparison to conventional PD fluids the pH of PD-Bio was increased, to about 6.5. Due to less contaminating glucose degradation products in PD-Bio, basal cytotoxicity was significantly decreased for both 1.5% and 4% glucose-containing fluids, and the stimulated release of interleukin-1β was normalized compared to sterile filtered controls with the same pH. UV absorbance measured at 228 nm was decreased, whereas the absorbance at 284 nm was equal to that of a conventional fluid. In PD-Bio the concentrations of formaldehyde, acetaldehyde, methylglyoxal, and 2-furaldehyde were found to be below the detection limit, whereas glyoxal was present in the same and 5hydroxymethylfurfural (5-HMF) in higher concentrations than in conventionally produced PD fluid. Conclusions The results demonstrate that it is possible to improve biocompatibility of PD fluids by simply changing the way the fluid is produced.
Stability of Drug Additives to Peritoneal Dialysate
Authors: Bailie George R. , Kane Michael P. 
Published: February 2020

Objective The primary literature was reviewed to determine the stability of drug additives in peritoneal dialysis solutions. Data Sources A MEDLINE search and retrieval, covering the period 1981 to 1994, was undertaken to identify relevant original literature. Additional references were identified from citations within the original literature. Non-English literature was excluded unless an English abstract was provided. Study Selection Forty-nine studies were identified. Of these, 24 were directly related to drug stability, 13 were related to the clinical use of the drug additives but included no stability data, and 12 examined other, nonstability aspects of in vitroactivity of antibiotics, additives, or drug adsorption in peritoneal dialysis bags and tubing. Data Extraction Data included concentrations of drug additives and dialysate solutions, duration and temperatures of storage conditions, types of assay, and whether they were stability-indicating. Results Stability was defined as the duration of time that the drug concentration remained at 90% or more of the original concentration. Stability was examined under a large variety of conditions. Thirty-one drugs were identified from 20 manuscripts as single-drug additives. Most beta-Iactams were stable for 1 –2 weeks in a refrigerator and for several days at room temperature. Aminoglycosides were stable for 1 –2 days at room temperature. Glycopeptides were stable for several weeks refrigerated or at room temperature. Prolonged storage at room temperature resulted in instability of cefotaxime, ceftazidime, ceftriaxone, and miconazole. Eleven drugs were identified from seven manuscripts as drug combination studies and showed similar stability as single agents. Dialysate concentration appeared to have minimal effect on stability. Conclusions Drug additives in peritoneal dialysate, singly or combined, should be avoided unless data are available to support their stability. Additives should be made as close as possible to the time of the exchange. Alternatively, additives should be stored refrigerated, then warmed prior to use. The practice of preparing numerous bags at one time should be avoided. Finally, stability data do not indicate sterile integrity of the dialysate.
Peritoneal Dialysis Access: Prospective Randomized Comparison of the Swan Neck and Tenckhoffcatheters
Authors: Eklund Björn H. , Honkanen Eero O. , Kala Aino-Riitta , Kyllönen Lauri E. 
Published: February 2020

Objective To examine the impact of peritoneal catheter configuration on mechanical complications, catheter survival, probability of episodes of peritonitis, and probability of exit -site infections associated with the use of catheters for continuous ambulatory peritoneal dialysis (CAPD). Design Prospective randomized trial. Setting CAPD unit in one university hospital, serving a population of 1.2 million. Patients Forty consecutive patients requiring their first dialysis catheter for future CAPD were randomized to receive either a two-cuff permanently bent Swan neck catheter or a two-cuff straight Tenckhoff catheter. The skin exit was downward-directed in the Swan neck group and upward-directed in the Tenckhoff group. Results Dialysate leak, catheter migration, or tunnel infection did not occur in any of the patients. Three outer cuff extrusions needing cuff shaving occurred, all in the Tenckhoffgroup(p =0.1). No significant differences could be demonstrated in catheter survival at 2 years, probability of episodes of peritonitis, or probability of exit-site infections. Conclusion Catheter configuration did not influence the catheter-related mechanical or infectious complications, and equally good results were obtained with both catheter types studied.
Insertion of a Straight Peritoneal Catheter in an Arcuate Subcutaneous Tunnel by a Tunneler: Long Term Experience
Authors: Favazza Antonio , Petri Roberto , Montanaro Domenico , Boscutti Giuliano , Bresadola Fabrizio , Mioni Giuseppe 
Published: February 2020

Objective This study describes the results of the insertion of a straight Tenckhoff peritoneal catheter (PC) in an arcuate, caudally concave tunnel using a tunneler designed by the authors. It has a semicircular shape and a bending radius of 4.5 cm. Setting A hospital renal unit. Patients From June 1988 to February 1994, 112 straight Tenckhoff PCs, 62 with one deep cuff (single-cuff PC) and 50 with two cuffs (double-cuff PC), were inserted as first catheters in 112 patients (mean age 62±13 years), who underwent continuous ambulatory peritoneal dialysis (CAPD). The follow-up was 1099 months (mean 18±13 months)forsingle-cuff PC sand 1264 months (mean 25±15 months) for double-cuff PCs, respectively. Interventions After intraperitoneal placement of the PCs by median laparotomy, a 180° arc bend tunnel, with both external and peritoneal exits directed downwards, was created by means of the tunneler. Results The rate of exit-site infection (ESI) was 0.27 episodes/year (epis/year). The probability of remaining ESI-free was 76%, 60%, and 55% at 1, 2, and 3 years. The rate of tunnel infection (TI) was 0.046 epis/year. The incidence of the double-cuff PC-related ESI and TI tended to be lower than the incidence observed with the singlecuff PC. Episodes of peritonitis were 60 (0.30 epis/year), where 6 were subsequent to ESI and/or TI. Two PCs were lost due to ESI, 3 due to TI, and 11 due to peritonitis. Drainage failure, due to displacement of the PC caused by straightening, involved 3 PCs; 2 were lost. PC survival was 92%, 82%, and 74% at 1, 2 and 3 years, respectively. Conclusions By an easily used semicircular tunneler, the standard straight Tenckhoff PC can be stably positioned in an arcuate tunnel with both inner and outer exits directed downwards. This tunnel shape, as already suggested by some authors, appears to be an effective technical solution to reducing the PC-related complication rates.
Elevated Llpoprotein(A) and Fibrinogen Serum Levels Increase the Cardiovascular Risk in Continuous Ambulatory Peritoneal Dialysis Patients
Authors: Bartens Werner , Nauck Matthias , Schollmeyer Peter , Wanner Christoph 
Published: February 2020

Objective To analyze the relationship between lipoprotein(a) [Lp(a)] and fibrinogen as potential cardiovascular risk factors in patients on continuous ambulatory peritoneal dialysis (CAPD). Patients A total of 47 uremic patients receiving CAPD, 21 with coronary artery disease (CAD), 26 without CAD. Measurements Lp(a) levels were determined by an immunoradiometric assay. Since Lp(a) serum concentrations vary depending on the size, apoprotein(a) [apo(a)] isoforms were determined (Westernblot). Fibrinogen was quantified according to Clauss. Results The mean Lp(a) serum concentration was 43 ± 5 mg/dL (SEM) (median 33 mg/dL) in CAPD patients and 21 ± 2 mg/dL (8 mg/dL) in controls (p < 0.01). Patients with low molecular weight apo(a) isoforms exhibited substantially elevated Lp(a) levels when compared with patients with high molecular isoforms (p < 0.01). In addition, we found elevated fibrinogen levels in the CAPD patients (538 ± 61 mg/dL) compared with healthy controls (288 ± 46 mg/dL). Twenty-one CAPD patients (45%) were suffering from CAD. Patients with CAD had higher Lp(a) levels (54 ± 5 mg/dL vs 34 ± 4 mg/dL) as well as higher fibrinogen concentrations (628 ± 59 mg/dL vs 459 ± 46 mg/dL). Furthermore, a positive correlation between the fibrinogen levels and the Lp(a) serum concentration was observed (r = 0.45, p = 0.01). Conclusion We suggest that elevated Lp(a) levels are influenced by the allelic variation of the apo(a) isoform. In addition to the typical dyslipidemia found in CAPD patients, high levels of Lp(a) and fibrinogen may contribute to the elevated risk of coronary artery disease and other cardiovascular complications.
Fusarium Peritonitis in a Child on Peritoneal Dialysis: Case Report and Review of the Literature
Authors: Flynn Joseph T. , Meislich Debrah , Kaiser Bruce A. , Polinsky Martin S. , Baluarte H. Jorge 
Published: February 2020

Objective To review various aspects of the management of peritonitis due to Fusarium, a soil mold which infrequently causes infections in humans. Data Sources A case of Fusarium peritonitis in a child on chronic peritoneal dialysis (PD) is presented. The child developed Fusarium peritonitis 2 weeks after an episode of bacterial peritonitis. His Tenckhoff catheter was removed, and he was maintained on hemodialysis while receiving intravenous amphotericin. Following 2 weeks of treatment with amphotericin, he was successfully returned to PD. A literature review of all previously reported cases of Fusarium peritonitis was then conducted to determine features common to infections caused by Fusarium. Emphasis was also placed on unique characteristics of the organism that may affect patient management, as well as patient characteristics that may increase the risk for infection by Fusarium. Results Fusarium may cause infection inimmuno suppressed individuals, such as cancer patients or patients on chronic PD. The organism has a propensity to attach to foreign bodies such as intravascular and intraperitoneal catheters. Therefore, successful treatment of infections caused by Fusarium may require catheter removal in addition to systemic antifungal therapy. Conclusions This report presents the first known case of Fusarium peritonitis in a child. In view of the difficulties posed by this unusual organism, optimal therapy of Fusarium peritonitis should consist of immediate catheter removal and treatment with systemic antifungal drugs.