The standard peritoneal permeability analysis: A tool for the assessment of peritoneal permeability characteristics in CAPD patients (original) (raw)
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Kidney International, 2006
The peritoneal equilibration test (PET) with 3.86% glucose concentration (3.86%-PET) has been suggested to be more useful than the standard 2.27%-PET in peritoneal dialysis (PD), but no longitudinal data for 3.86%-PET are currently available. A total of 242 3.86%-PETs were performed in 95 incident PD patients, who underwent the first test during the first year of treatment and then once a year. The classical parameters of peritoneal transport, such as peritoneal ultrafiltration (UF), D/D 0 , and D/P Creat , were analyzed. In addition, the absolute dip of dialysate sodium concentration (DD Na), as an expression of sodium sieving, was studied. D/D 0 was stable, and a progressive decrease in UF was observed after the second PET, whereas D/P Creat firstly increased and then stabilized. DD Na was the only parameter showing a progressive decrease over time. On univariate analysis, D/D 0 and DD Na were found to be significantly associated with the risk of developing UF failure (risk ratio (RR) 0.987 (0.973-0.999), P ¼ 0.04, and RR 0.768 (0.624-0.933), P ¼ 0.007, respectively), but on multivariate analysis only DD Na showed an independent association with the risk of developing UF failure (RR 0.797 (0.649-0.965), P ¼ 0.020). UF, D/D 0 , and D/P Creat changed only in those patients developing UF failure, reflecting increased membrane permeability, whereas DD Na significantly decreased in all patients. The 3.86%-PET allows a more complete study of peritoneal membrane transport than the standard 2.27%-PET. DD Na shows a constant and significant reduction over time and is the only factor independently predicting the risk of developing UF failure in PD patients.
Comparison of peritoneal equilibration test with 2.27% and 3.86% glucose dialysis solution
PubMed, 2005
Background: The standard Peritoneal Equilibration Test (PET) uses a 2.27% glucose dialysis solution in peritoneal dialysis (PD). A more hypertonic solution (3.86%) has recently been proposed to obtain further information about ultrafiltration (UF). Aim: To compare results in terms of peritoneal solute transport (4h-dialysate-to-plasma ratio, 4h-D/P) between 2.27% and 3.86% PET. Design: 23 patients on PD were randomized to form two groups, A and B. A 2.27% dextrose 2-L exchange was used in group A, followed on the same day by a 3.86% dextrose 2-L exchange, both with a 4-hour dwell (2.27% and 3.86% PET); in group B, the same treatment was administered in reverse. 4h-D/P of urea, creatinine and sodium at time 0, 60, 120 and 240 minutes and net UF were calculated for each PET and compared. Results: No significant statistical differences were found for the usual peritoneal transport indexes, 4h-D/P of urea and creatinine, between 2.27% and 3.86% PET, which produced almost identical results. The creatinine 4h-D/P were 0.67+/-0.09 vs. 0.66+/-0.10 (p= NS) and the urea 4h-D/P 0.91+/-0.04 vs. 0.90+/-0.04 (p= NS). The sodium D/P was lower at all times during the 3.86% PET: D/P60= 0.92+/-0.05 vs. 0.88+/-0.03, D/P120= 0.91+/-0.02 vs. 0.87+/-0.03, D/P240= 0.92+/-0.02 vs. 0.88+/-0.04 (p< 0.0001). The net UF was 478 +/- 175 vs. 936 +/- 233 mL respectively (p< 0.0001). Conclusion: Our study suggests that a 3.86% PD solution could be used for PET instead of the 2.27% solution in order to assess peritoneal solute transport, as well as UF, while obtaining almost identical results as the 2.27% solution.
Peritoneal function and assessment of reference values using a 3.86% glucose solution
Peritoneal dialysis international : journal of the International Society for Peritoneal Dialysis
The most widely used peritoneal function test, the peritoneal equilibration test (PET), is performed with a 2.27% glucose solution. Recently, the International Society for Peritoneal Dialysis committee on ultrafiltration failure (UFF) advised performing the test with 3.86% glucose solution because it is more sensitive for detecting clinically significant UFF. Because no reference values for this test were available, we analyzed the results of standard peritoneal permeability analyses (SPAs) using 3.86% glucose. The tests were performed in our center on 154 clinically stable peritoneal dialysis (PD) patients that were free of peritonitis for at least 4 weeks. For the assessment of reference values, we used two approaches. In approach A, patients with UFF, defined as net ultrafiltration (UF) < 400 mL/4 hours, were excluded. In approach B, only patients within their first 2 years of PD treatment were included, regardless of net UF. Means and 95% confidence intervals (95% CI) were ca...
Peritoneal fluid transport in CAPD patients with different transport rates of small solutes
Peritoneal dialysis international: journal of the International Society for Peritoneal Dialysis
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 (K BD ) 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 K BD 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 K BD 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. Perit Dial Int 2004; 24:240-251 www.PDIConnect.com
Bosnian Journal of Basic Medical Sciences, 2010
e aim of this study was to analyze the importance of the peritoneal equilibration test (PET) in evaluation of the peritoneal membrane tranport status in patients treated with continuous ambulatory peritoneal dialysis (CAPD). e study included adult continuous ambulatory peritoneal dialysis (CAPD) patients, male and female, mean age ± , years with a prescription of four exchanges of litres (L) per day, who underwent peritoneal equilibration test (PET). Eleven of patients were diabetics. A modifi ed PET was performed during a hours dwell using , glucose dialysis solution. e dialysate/ plasma ratio of creatinine (D/P) at the end of the procedure, and the dialysate min/ initial dialysate ratio of glucose (D/D) were calculated and used as parametar of solute transport. With the test, chategorisation of patients was possible into high (H), high-average (HA), low average (LA), and low (L) transporters. In multivariate analysis age, gender, time on dialysis, comorbid diseases, diabetes mellitus (DM), serum albumin, were concidered as independent factors infl uencing the PET. Among patients (,) were classifi ed as H transpoters, () as HA, and (,) as LA. ere were no patients in low category. Creatinine D/P at hours was not diff erent DM and non-DM patients. ere were signifi cant diff erences in gender, comorbid disease, serum albumin, D/D glucose and volume drained in hours. e high transporter group had higher proporsion of man (p<,), higher proportion of patients with comorbid diseases, lower serum albumin concentration (p<,), lower D/D glucose (p<,), and lower drained volume (p<,). e PET was en easy, inexpensive, reliable test to assess peritoneal transport type and it also provided information about peritoneal clearance of solutes and ultrafi ltration. Peritoneal transport type classifi cation was recognized not only as aid for prescription, but also as a prognostic index.
Nephrology Dialysis Transplantation, 2013
In spite of many peritoneal tests proposed, there is still a need for a simple and reliable new approach for deriving detailed information about peritoneal membrane characteristics, especially those related to fluid transport. The sequential peritoneal equilibration test (sPET) that includes PET (glucose 2.27%, 4 h) followed by miniPET (glucose 3.86%, 1 h) was performed in 27 stable continuous ambulatory peritoneal dialysis patients. Ultrafiltration volumes, glucose absorption, ratio of concentration in dialysis fluid to concentration in plasma (D/P), sodium dip (Dip D/P Sodium), free water fraction (FWF60) and the ultrafiltration passing through small pores at 60 min (UFSP60), were calculated using clinical data. Peritoneal transport parameters were estimated using the three-pore model (3p model) and clinical data. Osmotic conductance for glucose was calculated from the parameters of the model. D/P creatinine correlated with diffusive mass transport parameters for all considered solutes, but not with fluid transport characteristics. Hydraulic permeability (L(p)S) correlated with net ultrafiltration from miniPET, UFSP60, FWF60 and sodium dip. The fraction of ultrasmall pores correlated with FWF60 and sodium dip. The sequential PET described and interpreted mechanisms of ultrafiltration and solute transport. Fluid transport parameters from the 3p model were independent of the PET D/P creatinine, but correlated with fluid transport characteristics from PET and miniPET.
Objective: The aim of this study was to analyze the correlation between the peritoneal equilibration test (PET) and the dialysis adequacy and transport test (DATT) for peritoneal transport type characterization, and the degree of patients' acceptance for each test. ♦ ♦ ♦ ♦ ♦ Design: Cross-sectional, observational multicenter study. ♦ ♦ ♦ ♦ ♦ Setting: Five referral (tertiary) dialysis centers of institutional practice. ♦ ♦ ♦ ♦ ♦ Patients: The study included 107 adult continuous ambulatory peritoneal dialysis (CAPD) patients with a prescription of four exchanges of 2 L per day, irrespective of age, gender, cause of end-stage renal disease, time on dialysis, nutritional status, or residual renal function. Patients on immunosuppressive therapy and those with cancer, hepatitis B, or HIV, and those having a peritonitis episode within the previous 30 days, or three or more episodes during the previous 12 months, were excluded. ♦ ♦ ♦ ♦ ♦ Main Measures: Peritoneal transport type as classified by creatinine and urea dialysis-to-plasma (D/P) ratios by PET and DATT. ♦ ♦ ♦ ♦ ♦ Results: Correlation coefficients between D/P ratios for creatinine and urea, obtained for the PET and the DATT, were 0.73 for D/P creatinine and 0.96 for D/P urea. Patients were classified into high, high-average, low-average, and low transport categories according to the mean and standard deviation of D/P creatinine values obtained from the PET at 4 hours. These values showed excellent concordance with those generated from the DATT data (κ κ κ κ κ = 0.82, 95% confidence interval 0.67 -0.93). Nineteen percent of patients showed discordance in their category when classified according to the PET versus the DATT. Patients' acceptance was better for the DATT than for the PET, as evaluated with a questionnaire. ♦ ♦ ♦ ♦ ♦ Conclusion: The DATT is an easy, inexpensive, and reliable test to assess peritoneal transport type, and it also provides information about peritoneal clearance of solutes and ultrafiltration. The DATT has better patient acceptance than the PET. Since the DATT has only been validated for patients on a fixed CAPD daily schedule of 4 × 2 L, the results should be confined only to patients receiving such a prescription.
Peritoneal Fluid Transport: Mechanisms, Pathways, Methods of Assessment
Archives of Medical Research, 2013
Fluid removal during peritoneal dialysis is controlled by many mutually dependent factors and therefore its analysis is more complex than that of the removal of small solutes used as markers of dialysis adequacy. Many new tests have been proposed to assess quantitatively different components of fluid transport (transcapillary ultrafiltration, peritoneal absorption, free water, etc.) and to estimate the factors that influence the rate of fluid transport (osmotic conductance). These tests provide detailed information about indices and parameters that describe fluid transport, especially those concerning the problem of the permanent loss of ultrafiltration capacity (ultrafiltration failure). Different theories and respective mathematical models of mechanisms and pathways of fluid transport are presently discussed and applied, and some fluid transport issues are still debated. Ó 2013 IMSS. Published by Elsevier Inc.
Peritoneal Membrane Evaluation in Routine Clinical Practice
Blood Purification, 2008
Background/Aims: Establishment of reference values for small solute transport, sodium sieving and effluent CA125 with 3.86% (4 h) peritoneal equilibration test (PET), and comparison with fast-fast PET with regard to small solute transport categories. Methods: Cross-sectional study; 69 prevalent patients. Sodium sieving corrected for sodium diffusion with a formula applicable to the PET. CA125 appearance rate (AR) was measured. Expected and observed 60 min D/ P creatinine were compared by Bland and Altman. Results: Means (95% CI): D/P creatinine 0.73 (0.70-0.76), MTAC creatinine 9.6 (8.4-10.9) ml/min, D/D 0 glucose 0.30 (0.28-0.31), corrected dip 0.17 (0.15-0.18), CA125 150 (125-176) U/min. Both corrected and uncorrected sodium sieving were informative. Peritoneal transport was faster at 60 min dwell. UFF patients presented very low corrected dip and CA125 AR. Conclusion: 3.86% (4 h) PET provided results similar to those from SPA. Correction for diffusion of sodium sieving is dispensable for simple clinical evaluations. D/P creatinine at 60 min overestimated small solute transport rate. Effluent CA125 was consistently lower in UFF patients.