scholarly journals Time Course of Peritoneal Function in Automated and Continuous Peritoneal Dialysis

2012 ◽  
Vol 32 (6) ◽  
pp. 605-611 ◽  
Author(s):  
Wieneke M. Michels ◽  
Marion Verduijn ◽  
Alena Parikova ◽  
Elisabeth W. Boeschoten ◽  
Dirk G. Struijk ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Repeated Measures ◽  
Time Course ◽  
Fluid Transport ◽  
Free Water ◽  
Transport Parameters ◽  
Lymphatic Absorption ◽  
Small Pore ◽  
Year 2000 ◽  
Over Time

♦ Background and ObjectivesIn automated peritoneal dialysis (APD), a patient's peritoneal membrane is more intensively exposed to fresh dialysate than it is in continuous ambulatory peritoneal dialysis (CAPD). Our aim was to study, in incident peritoneal dialysis (PD) patients, the influence of APD—compared with that of CAPD—on peritoneal transport over 4 years.♦ Design, Setting, Participants, and MeasurementsPatients were included if at least 2 annual standard permeability analyses (SPAs) performed with 3.86% glucose were available while the patient was using the same modality with which they had started PD (APD or CAPD). Patients were followed until their first modality switch. Differences in the pattern of SPA outcomes over time were tested using repeated-measures models adjusted for age, sex, comorbidity, primary kidney disease, and year of PD start.♦ ResultsThe 59 CAPD patients enrolled were older than the 47 APD patients enrolled (mean age: 58 ± 14 years vs 49 ± 14 years; p < 0.01), and they had started PD earlier (mean start year: 2000 vs 2002). Over time, no differences in solute ( p > 0.19) or fluid transport ( p > 0.13) were observed. Similarly, free water transport ( p = 0.43) and small-pore transport ( p = 0.31) were not different between the modalities. Over time, patients on APD showed a faster decline in effective lymphatic absorption rate (ELAR: p = 0.02) and in transcapillary ultrafiltration (TCUF: p = 0.07, adjusted p = 0.05). Further adjustment did not change the results.♦ ConclusionsCompared with patients starting on CAPD, those starting on APD experienced a faster decline in ELAR and TCUF. Other transport parameters were not different over time between the groups.

scholarly journals Analysis of Ultrafiltration Failure Diagnosed at the Initiation of Peritoneal Dialysis with the Help of Peritoneal Equilibration Tests with Complete Drainage at Sixty Minutes. A Longitudinal Study

2016 ◽  
Vol 36 (4) ◽  
pp. 442-447 ◽  
Author(s):  
Daniela Machado Lopes ◽  
Ana Rodríguez-Carmona ◽  
Teresa García Falcón ◽  
Andrés López Muñiz ◽  
Tamara Ferreiro Hermida ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Water Transport ◽  
Time Course ◽  
Free Water ◽  
Control Group ◽  
First Year ◽  
Study Group ◽  
Ultrafiltration Failure ◽  
Small Pore

BackgroundUltrafiltration failure (UFF) diagnosed at the initiation of peritoneal dialysis (PD) has been insufficiently characterized. In particular, few longitudinal studies have analyzed the time course of water transport in patients with this complication.ObjectiveTo investigate the time course of peritoneal water transport during the first year on PD in patients presenting UFF since the initiation of this therapy (study group).MethodProspective, observational, single-center design. We analyzed, at baseline and after 1 year of follow-up, peritoneal water transport in 19 patients incident on PD with UFF. We used incident patients without UFF as a control group. Water transport was characterized with the help of 3.86/4.25% dextrose-based peritoneal equilibration tests (PETs) with complete drainage at 60 minutes.ResultsThe study group revealed a disorder of water transport affecting both small-pore ultrafiltration (SPUF) ( p = 0.054 vs incident without UFF) and free water transport (FW T) ( p = 0.001). After 1 year of follow-up, FWT displayed a general increasing trend in the study group (mean variation 48.9 mL, 95% confidence interval [CI] 15.5, 82.2, p = 0.012), while the behavior of SPUF was less predictable (-4.8 mL, 95% CI -61.4, 71.1, p = 0.85). These changes were not observed in incident patients without UFF. Neither initial clinical characteristics, baseline PET-derived parameters, or suffering peritoneal infections during the first year predicted the time course of the capacity of UF in the study group. Recovery from incident UFF was apparently linked to improvement of SPUF.ConclusionsPatients with UFF at the start of PD suffer a disorder of peritoneal water transport affecting both FWT and SPUF. Free water transport increases systematically in these patients after 1 year of follow-up. The evolution of SPUF is less predictable, and improvement of this parameter marks reversibility of this complication.

scholarly journals The First Peritonitis Episode Alters the Natural Course of Peritoneal Membrane Characteristics in Peritoneal Dialysis Patients

2015 ◽  
Vol 35 (3) ◽  
pp. 324-332 ◽  
Author(s):  
Anouk T.N. van Diepen ◽  
Sadie van Esch ◽  
Dirk G. Struijk ◽  
Raymond T. Krediet
Keyword(s):  
Peritoneal Dialysis ◽  
Free Water ◽  
Glucose Absorption ◽  
Natural Course ◽  
Control Group ◽  
Peritoneal Membrane ◽  
Transport Parameters ◽  
Lymphatic Absorption ◽  
Peritoneal Transport ◽  
The Impact

ObjectiveLittle or no evidence is available on the impact of the first peritonitis episode on peritoneal transport characteristics. The objective of this study was to investigate the importance of the very first peritonitis episode and distinguish its effect from the natural course by comparison of peritoneal transport before and after infection.ParticipantsWe analyzed prospectively collected data from 541 incident peritoneal dialysis (PD) patients, aged > 18 years, between 1990 and 2010. Standard Peritoneal Permeability Analyses (SPA) within the year before and within the year after (but not within 30 days) the first peritonitis were compared. In a control group without peritonitis, SPAs within the first and second year of PD were compared.Main outcome measurementsSPA data included the mass transfer area coefficient of creatinine, glucose absorption and peritoneal clearances of β–2-microglobulin (b2m), albumin, IgG and α–2-macroglobulin (a2m). From these clearances, the restriction coefficient to macromolecules (RC) was calculated. Also, parameters of fluid transport were determined: transcapillary ultrafiltration rate (TCUFR), lymphatic absorption (ELAR), and free water transport. Crude and adjusted linear mixed models were used to compare the slopes of peritoneal transport parameters in the peritonitis group to the control group. Adjustments were made for age, sex and diabetes.ResultsOf 541 patients, 367 experienced a first peritonitis episode within a median time of 12 months after the start of PD. Of these, 92 peritonitis episodes were preceded and followed by a SPA within one year. Forty-five patients without peritonitis were included in the control group. Logistic reasons (peritonitis group: 48% vs control group: 83%) and switch to hemodialysis (peritonitis group: 22% vs control group: 3%) were the main causes of missing SPA data post-peritonitis and post-control. When comparing the slopes of peritoneal transport parameters in the peritonitis group and the control group, a first peritonitis episode was associated with faster small solute transport (glucose absorption, p = 0.03) and a concomitant lower TCUFR ( p = 0.03). In addition, a discreet decrease in macromolecular transport was seen in the peritonitis group: mean difference in post- and pre-peritonitis values: IgG: -8 μL/min ( p = 0.01), a2m: -4 μL/min ( p = 0.02), albumin: -10 μL/min (p = 0.04). Accordingly, the RC to macromolecules increased after peritonitis: 0.09, p = 0.04.ConclusionsThe very first peritonitis episode alters the natural course of peritoneal membrane characteristics. The most likely explanation might be that cured peritoneal infection later causes long-lasting alterations in peritoneal transport state.

scholarly journals Musculoskeletal Outcomes from Chronic High-Speed High-Impact Resistive Exercise

2019 ◽  
Vol 7 (1) ◽  
pp. 22-32 ◽  
Author(s):  
L. Chen ◽  
E.A. Selimovic ◽  
M. Daunis ◽  
T.A. Bayers T ◽  
L.J. Vargas ◽  
...  
Keyword(s):  
Repeated Measures ◽  
High Speed ◽  
Time Course ◽  
Exercise Intervention ◽  
Knee Extensor ◽  
Peak Torque ◽  
Resistive Exercise ◽  
Before And After ◽  
Independent Variable ◽  
Over Time

AbstractSubjects (n=13) did 30 workouts with their left leg on an Inertial Exercise Trainer (IET), while their right leg served as an untreated control. Before and after the 30 workouts, they underwent isokinetic strength tests (knee and ankle extensors of both legs) whose peak torque (PT), time to PT (TTPT), and rate of torque development (RTD) values were each analyzed with 2(leg)×2(time)×3(velocity) analysis of variances (ANOVAs), with repeated measures per independent variable. Peak force (PF) and total work (TW) data were measured from each IET workout, and they represent time course strength changes produced by our exercise intervention. PF and TW values for the three IET exercises that comprised each workout were each analyzed with one-way ANOVAs with time as the independent variable. Results included significant ankle and knee extensor PT increases, whereby the left leg achieved higher values at posttesting, but there were no significant TTPT changes and a time effect for ankle extensor RTD. Our data show that PF and TW each had significant increases over time, with the latter exhibiting greater gains over the 30-workout intervention. Our results imply that the IET yields strength gains over time comparable to standard resistive exercise hardware.

Peritoneal Fluid Transport in CAPD Patients with Different Transport Rates of Small Solutes

2004 ◽  
Vol 24 (3) ◽  
pp. 240-251 ◽  
Author(s):  
Danuta Sobiecka ◽  
Jacek Waniewski ◽  
Andrzej Weryński ◽  
Bengt Lindholm
Keyword(s):  
Peritoneal Dialysis ◽  
Solute Transport ◽  
Osmotic Pressure ◽  
Absorption Rate ◽  
Fluid Transport ◽  
Transport Coefficients ◽  
Dialysis Fluid ◽  
Transport Parameters ◽  
Ultrafiltration Rate ◽  
Small Solute

Background Continuous ambulatory peritoneal dialysis (CAPD) patients with high peritoneal solute transport rate often have inadequate peritoneal fluid transport. It is not known whether this inadequate fluid transport is due solely to a too rapid fall of osmotic pressure, or if the decreased effectiveness of fluid transport is also a contributing factor. Objective To analyze fluid transport parameters and the effectiveness of dialysis fluid osmotic pressure in the induction of fluid flow in CAPD patients with different small solute transport rates. Patients 44 CAPD patients were placed in low ( n = 6), low-average ( n = 13), high-average ( n = 19), and high ( n = 6) transport groups according to a modified peritoneal equilibration test (PET). Methods The study involved a 6-hour peritoneal dialysis dwell with 2 L 3.86% glucose dialysis fluid for each patient. Radioisotopically labeled serum albumin was added as a volume marker. The fluid transport parameters (osmotic conductance and fluid absorption rate) were estimated using three mathematical models of fluid transport: ( 1 ) Pyle model (model P), which describes ultrafiltration rate as an exponential function of time; ( 2 ) model OS, which is based on the linear relationship of ultrafiltration rate and overall osmolality gradient between dialysis fluid and blood; and ( 3 ) model G, which is based on the linear relationship between ultrafiltration rate and glucose concentration gradient between dialysis fluid and blood. Diffusive mass transport coefficients (KBD) for glucose, urea, creatinine, potassium, and sodium were estimated using the modified Babb–Randerson–Farrell model. Results The high transport group had significantly lower dialysate volume and glucose and osmolality gradients between dialysate and blood, but significantly higher KBD for small solutes compared with the other transport groups. Osmotic conductance, fluid absorption rate, and initial ultrafiltration rate did not differ among the transport groups for model OS and model P. Model G yielded unrealistic values of fluid transport parameters that differed from those estimated by models OS and P. The KBD values for small solutes were significantly different among the groups, and did not correlate with fluid transport parameters for model OS. Conclusion The difference in fluid transport between the different transport groups was due only to the differences in the rate of disappearance of the overall osmotic pressure of the dialysate, which was a combined result of the transport rate of glucose and other small solutes. Although the glucose gradient is the major factor influencing ultrafiltration rate, other solutes, such as urea, are also of importance. The counteractive effect of plasma small solutes on transcapillary ultrafiltration was found to be especially notable in low transport patients. Thus, glucose gradient alone should not be considered the only force that shapes the ultrafiltration profile during peritoneal dialysis. We did not find any correlations between diffusive mass transport coefficients for small solutes and fluid transport parameters such as osmotic conductance or fluid and volume marker absorption. We may thus conclude that the pathway(s) for fluid transport appears to be partly independent from the pathway(s) for small solute transport, which supports the hypothesis of different pore types for fluid and solute transport.

scholarly journals Measuring Peritoneal Absorption with the Prolonged Peritoneal Equilibration Test from 4 to 8 Hours Using Various Glucose Concentrations

2014 ◽  
Vol 34 (6) ◽  
pp. 605-611 ◽  
Author(s):  
Josep Teixidó–Planas ◽  
Maria Isabel Troya–Saborido ◽  
Guillermo Pedreira–Robles ◽  
Milagros Del-Rio–Lafuente ◽  
Ramon Romero–Gonzalez ◽  
...  
Keyword(s):  
Water Transport ◽  
Peritoneal Fluid ◽  
Glucose Solution ◽  
Free Water ◽  
Random Order ◽  
Practical Method ◽  
University Hospital ◽  
Transport Parameters ◽  
Peritoneal Equilibration Test ◽  
Small Pore

BackgroundPeritoneal fluid flows such as small-pore ultrafiltration and free water transport can now be calculated by means of the modified peritoneal equilibration test (PET). To calculate peritoneal fluid absorption, volume markers have been used, but that method is not easily applicable in clinical practice. Alternatively, absorption can be estimated using the personal dialysis capacity test. However, a method of measuring overall peritoneal absorption together with the PET is lacking. The aim of the present study was to assess whether overall peritoneal absorption was different when measured from the 4th to 8th hour in a prolonged PET using three different glucose solutions.MethodsThe study enrolled 32 stable peritoneal dialysis (PD) patients from a tertiary university hospital, who underwent three 8-hour prolonged PETs with 1.36%, 2.27%, and 3.86% glucose solution. The PETs were performed in random order over a period of less than 1 month. During the prolonged PET, the peritoneal volume was emptied and reinfused at 60 and 240 minutes and drained at 480 minutes. Peritoneal absorption was calculated as the volume difference between the 4th and the 8th hour.ResultsThe dialysate-to-plasma ratio (D/P) of urea, the D/P creatinine, and the mass transfer area coefficient (MTC) of creatinine at 240 minutes were not significantly different with the three glucose solutions. The end-to-initial (D/D0) glucose, MTC urea, and MTC glucose were significantly different. All water transport parameters were significantly different, except for the 4- to 8-hour absorption volumes and rates. The peritoneal absorption rates were, for 1.36% solution, 1.03 ± 0.58 mL/min [95% confidence interval (CI): 0.83 to 1.24 mL/min]; for 2.27% solution, 0.86 ± 0.71 mL/min (95% CI: 0.61 to 1.11 mL/min); and for 3.86% solution, 1.05 ± 0.78 mL/min (95% CI: 0.77 to 1.33 mL/min). Peritoneal absorption volumes and rates from the 4th to the 8th hour showed good correlations for the various solutions.ConclusionsUsing any glucose solution, the prolonged PET with voiding and reinfusion at the 4th hour could be a practical method for calculating overall peritoneal absorption from the 4th to the 8th hour in PD patients.

scholarly journals The contribution of free water transport and small pore transport to the total fluid removal in peritoneal dialysis

2005 ◽  
Vol 68 (4) ◽  
pp. 1849-1856 ◽  
Author(s):  
Alena Parikova ◽  
Watske Smit ◽  
Dirk G. Struijk ◽  
Machteld M. Zweers ◽  
Raymond T. Krediet
Keyword(s):  
Peritoneal Dialysis ◽  
Water Transport ◽  
Free Water ◽  
Fluid Removal ◽  
Small Pore ◽  
Total Fluid

Distributed modeling of osmotically driven fluid transport in peritoneal dialysis: theoretical and computational investigations

2009 ◽  
Vol 296 (6) ◽  
pp. H1960-H1968 ◽  
Author(s):  
Jacek Waniewski ◽  
Joanna Stachowska-Pietka ◽  
Michael F. Flessner
Keyword(s):  
Peritoneal Dialysis ◽  
Fluid Transport ◽  
Present Report ◽  
Capillary Wall ◽  
Distributed Model ◽  
Hydraulic Permeability ◽  
Transport Parameters ◽  
Distributed Modeling ◽  
Dialysis Solution ◽  
Osmotic Agent

Based on a distributed model of peritoneal transport, in the present report, a mathematical theory is presented to explain how the osmotic agent in the peritoneal dialysis solution that penetrates tissue induces osmotically driven flux out of the tissue. The relationships between phenomenological transport parameters (hydraulic permeability and reflection coefficient) and the respective specific transport parameters for the tissue and the capillary wall are separately described. Closed formulas for steady-state flux across the peritoneal surface and for hydrostatic pressure at the opposite surface are obtained using an approximate description of the concentration profile of the osmotic agent within the tissue by exponential function. A case of experimental study with mannitol as the osmotic agent in the rat abdominal wall is shown to be well described by our theory and computer simulations and to validate the applied approximations. Furthermore, clinical dialysis with glucose as the osmotic agent is analyzed, and the effective transport rates and parameters are derived from the description of the tissue and capillary wall.

scholarly journals Peritoneal Fluid and Solute Transport: Influence of Treatment Time, Peritoneal Dialysis Modality, and Peritonitis Incidence

2002 ◽  
Vol 13 (4) ◽  
pp. 1055-1060
Author(s):  
Andreas Fußhöller ◽  
Sandra zur Nieden ◽  
Bernd Grabensee ◽  
Jörg Plum
Keyword(s):  
Mass Transfer ◽  
Peritoneal Dialysis ◽  
Solute Transport ◽  
Peritoneal Fluid ◽  
Fluid Transport ◽  
Treatment Time ◽  
Lymphatic Absorption ◽  
Ultrafiltration Failure ◽  
Small Solute

ABSTRACT. The integrity of the peritoneal membrane in peritoneal dialysis (PD) is of major importance for adequate dialysis and fluid balance. However, alterations in peritoneal fluid transport, such as ultrafiltration failure, often develop during long-term PD. To investigate peritoneal solute and fluid transport and to analyze the influence of treatment time, peritonitis incidence, and PD modality (continuous ambulatory PD [CAPD] or automated PD [APD]), a cross-sectional study with an extended peritoneal transport test that used dextran 70 in 2 L of glucose was performed in 23 nonselected chronic PD patients. Compared were long-term (>40 mo) with short-term PD patients (<40 mo), CAPD with APD patients, and those with a peritonitis incidence of >0.25/yr to those with an incidence of <0.25/yr. Dialysate/plasma (D/P) ratio and mass transfer area coefficient of creatinine, lymphatic absorption rate (LAR), transcapillary ultrafiltration, and effective ultrafiltration were measured. Long-term PD patients had higher D/P ratio of creatinine (73.5 ± 2.3% versus 65.9 ± 2.2%; P < 0.01) and higher LAR (243 ± 69 ml/4 h versus 96 ± 31 ml/4 h; P < 0.03), both resulting in lower effective ultrafiltration (242 ± 35 ml/4 h versus 324 ± 30 ml/4 h; P < 0.05). D/P ratio (r = 0.66) and LAR (r = 0.67) were positively correlated to PD duration. Patients on APD compared with those on CAPD and patients with a history of peritonitis compared with those without did not differ in terms of D/P ratio, mass transfer area coefficient, LAR, transcapillary ultrafiltration, and effective ultrafiltration. Lower ultrafiltration after long-term PD is both the result of increased small solute transport and increased lymphatic absorption. APD or CAPD modality and peritonitis incidence do not have a significant influence on small solute transport or fluid kinetics.

The Difference in Causes of Early and Late Ultrafiltration Failure in Peritoneal Dialysis

2005 ◽  
Vol 25 (3_suppl) ◽  
pp. 41-45 ◽  
Author(s):  
Watske Smit ◽  
Alena Parikova ◽  
Dirk G. Struijk ◽  
Raymond T. Krediet
Keyword(s):  
Peritoneal Dialysis ◽  
Solute Transport ◽  
Major Complication ◽  
Transport Parameters ◽  
Short Term ◽  
Lymphatic Absorption ◽  
Equal Distribution ◽  
Long Term Treatment ◽  
Ultrafiltration Failure

♦ Objective Ultrafiltration failure (UFF) is a major complication of peritoneal dialysis. Although it seems associated with long-term treatment, it can also occur in recently started patients. To identify the causes of this complication in patients with early and late UFF we studied a group of 48 patients. Patients were classified as early if they had been treated for less than 2 years and as late if they had been treated for more than 4 years. ♦ Method The patients were studied using a standard peritoneal permeability analysis. They all had a net ultrafiltration of less than 400 mL after a 4-hour dwell with 3.86% glucose. As possible causes for UFF, the solute transport parameters dialysate-to-plasma ratio (D/P) and mass transfer area coefficient of creatinine were compared, as well as the effective lymphatic absorption rate (ELAR) and the maximum dip in D/P sodium as an assessment of osmotic conductance to glucose. ♦ Results 25 short-term patients were compared with 23 long-term patients. Both groups showed an equal distribution of high small solute transport rates as a cause of UFF. The chi-square test showed that a high ELAR was a more frequent cause in early UFF compared to late UFF. However, a decreased osmotic conductance to glucose was significantly more often observed in late UFF. Some patients showed more than one cause of the complication. ♦ Conclusion This study has shown that UFF in long-term patients is often caused by a decreased osmotic conductance to glucose, most likely caused by a dysfunction of peritoneal water channels in combination with increased peritoneal surface area. In short-term patients, aquaporin dysfunction is rare, but a high ELAR was a very important factor in the occurrence of UFF.

scholarly journals The Natural Time Course of Membrane Alterations during Peritoneal Dialysis is Partly Altered by Peritonitis

2016 ◽  
Vol 36 (4) ◽  
pp. 448-456 ◽  
Author(s):  
Sadie van Esch ◽  
Dirk G. Struijk ◽  
Raymond T. Krediet
Keyword(s):  
Peritoneal Dialysis ◽  
Time Course ◽  
Free Water ◽  
Natural Course ◽  
Ultrafiltration Rate ◽  
Pronounced Increase ◽  
Continuous Increase ◽  
Single Episode ◽  
Small Solute

Background The quality of the peritoneal membrane can deteriorate over time. Exposure to glucose-based dialysis solutions is the most likely culprit. Because peritonitis is a common complication of peritoneal dialysis (PD), distinguishing between the effect of glucose exposure and a possible additive effect of peritonitis is difficult. The aim of the present study was to compare the time-course of peritoneal transport characteristics in patients without a single episode of peritonitis—representing the natural course—and in patients who experienced 1 or more episodes of peritonitis during long-term follow-up. Methods This prospective, single-center cohort study enrolled incident adult PD patients who started PD during 1990–2010. A standard peritoneal permeability analysis was performed in the first year of PD treatment and was repeated every year. The results in patients without a single episode of peritonitis (“no-peritonitis group”) were compared with the results obtained in patients who experienced 1 or more peritonitis episodes (“peritonitis group”) during a follow-up of 4 years. Results The 124 patients analyzed included 54 in the no-peritonitis group and 70 in the peritonitis group. The time-course of small-solute transport was different in the groups, with the peritonitis group showing an earlier and more pronounced increase in the mass transfer area coefficient for creatinine ( p = 0.07) and in glucose absorption ( p = 0.048). In the no-peritonitis group, the net ultrafiltration rate (NUFR) and the transcapillary ultrafiltration rate (TCUFR) both showed a steep increase from the 1st to the 2nd year of PD that was absent in the peritonitis group. Both groups showed a decrease in the NUFR after year 3. A decrease in the TCUFR occurred only in the peritonitis group. That decrease was already present after the year 1 in patients with severe peritonitis. The time-course of free water transport showed a continuous increase in the patients without peritonitis, but a decrease in the patients who experienced peritonitis ( p < 0.01). No difference was observed in the time-course of the effective lymphatic absorption rate. The time-courses of immunoglobulin G and α2-macroglobulin clearances showed a decrease in both patient groups, with a concomitant increase of the restriction coefficient. Those changes were not evidently influenced by peritonitis. The two groups showed a similar decrease in the mesothelial cell mass marker cancer antigen 125 during follow-up. Conclusions On top of the natural course of peritoneal function, peritonitis episodes to some extent influence the time-course of small-solute and fluid transport—especially the transport of solute-free water. Those modifications increase the risk for overhydration.

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