scholarly journals Multicenter clinical validation of an on-line monitor of dialysis adequacy.

1996 ◽  
Vol 7 (3) ◽  
pp. 464-471
Author(s):  
T A Depner ◽  
P R Keshaviah ◽  
J P Ebben ◽  
P F Emerson ◽  
A J Collins ◽  
...  
Keyword(s):  
Solute Concentration ◽  
Dialysis Dose ◽  
Dialysis Adequacy ◽  
Automated Method ◽  
Baxter Healthcare ◽  
Significant Difference ◽  
Urea Kinetics ◽  
Nitrogen Concentrations ◽  
On Line ◽  
Paired Analysis

Quantitation of hemodialysis by measuring changes in blood solute concentration requires careful timing when taking the postdialysis blood sample to avoid errors from postdialysis rebound and from recirculation of blood through the access device. It also requires complex mathematical interpretation to account for solute disequilibrium in the patient. To circumvent these problems, hemodialysis can be quantified and its adequacy assessed by direct measurement of the urea removed in the dialysate. Because total dialysate collection is impractical, an automated method was developed for measuring dialysate urea-nitrogen concentrations at frequent intervals during treatment. A multicenter clinical trial of the dialysate monitoring device, the Biostat 1000 (Baxter Healthcare Corporation, McGaw Park, IL) was conducted to validate the measurements of urea removed, the delivered dialysis dose (Kt/V), and net protein catabolism (PCR). The results were compared with a total dialysate collection in each patient. During 29 dialyses in 29 patients from three centers, the paired analysis of urea removed, as estimated by the dialysate monitor compared with the total dialysate collection, showed no significant difference (14.7 +/- 4.7 g versus 14.8 +/- 5.1 g). Similarly, measurements of Kt/V and PCR showed no significant difference (1.30 +/- 0.18 versus 1.28 +/- 0.19, respectively, for Kt/V and 42.3 +/- 15.7 g/day versus 52.2 +/- 17.4 g/day for PCR). When blood-side measurements during the same dialyses were analyzed with a single-compartment, variable-volume model of urea kinetics, Kt/V was consistently overestimated (1.49 +/- 0.29/dialysis, P < 0.001), most likely because of failure to consider urea disequilibrium. Because urea disequilibrium is difficult to quantitate during each treatment, dialysate measurements have obvious advantages. The dialysate monitor eliminated errors from dialysate bacterial contamination, simplified dialysate measurements, and proved to be a reliable method for quantifying and assuring dialysis adequacy.

Dialysis dose and nutrition assessment by optical on-line dialysis adequacy monitor

2009 ◽  
Vol 72 (10) ◽  
pp. 303-311 ◽  
Author(s):  
M. Luman ◽  
J. Jerotskaja ◽  
K. Lauri ◽  
I. Fridolin
Keyword(s):  
Nutrition Assessment ◽  
Dialysis Dose ◽  
Dialysis Adequacy ◽  
On Line

Model-Based Dialysis Adequacy Prediction by Continuous Dialysate Urea Monitoring

1998 ◽  
Vol 21 (9) ◽  
pp. 526-534 ◽  
Author(s):  
L. Chiari ◽  
A. Cappello ◽  
R. Tartarini ◽  
F. Paolini ◽  
P. Calzavara
Keyword(s):  
Time Course ◽  
Continuous Measurement ◽  
Urea Concentration ◽  
Accurate Estimation ◽  
Dialysis Adequacy ◽  
Variable Volume ◽  
Predictive Skill ◽  
Urea Kinetics ◽  
On Line ◽  
Post Filter

A modeling approach for on-line estimation of urea kinetics from continuous measurement of urea concentration in the effluent dialysate stream (DUN) is presented. On-line identification of urea kinetics response parameters is used to predict and update dialysis adequacy during the treatment. Dialysis adequacy can be quantified in several ways, but its strict dependence on final urea concentration is a major fact. For this reason, a good predictive skill on the time course of DUN may enable better performances in the control of dialysis outcome by treatment parameters adjustment. A post-filter enzymatic sensor performs continuous measurement of DUN on patients undergoing standard haemodialysis. To get an early prediction of the end dialysis urea level, the solution of a variable volume double-pool (VVDP) model is used, whose parameters are identified at each time on the basis of the past DUN history. Unlike the variable volume single-pool (VVSP) model, this enables a prompt and accurate estimation of the final DUN. In fact, after 75 min the estimates always differ by less than 10% from the values measured by the sensor at the end of the treatment. Moreover, values predicted by the model in the last hour always lie within 1% of measured final values. Realtime knowledge of an analytic expression for whole DUN time course also enables the accurate prediction of total removed urea, with no need of cumbersome dialysate collection techniques.

scholarly journals Combining Diffusion, Convection and Absorption: A Pilot Study of Polymethylmethacrylate versus Polysulfone Membranes in the Removal of P-Cresyl Sulfate by Postdilution On-Line Hemodiafiltration

2021 ◽  
Vol 1 (2) ◽  
pp. 121-134
Author(s):  
Pablo Molina ◽  
Julio Peiró ◽  
María A. Martínez-Gómez ◽  
Belén Vizcaíno ◽  
Cristina Esteller ◽  
...  
Keyword(s):  
Adsorptive Capacity ◽  
Dialysis Session ◽  
High Flux ◽  
Dialysis Dose ◽  
Polysulfone Membrane ◽  
Β2 Microglobulin ◽  
Urea Kinetics ◽  
On Line ◽  
Diffusion Convection ◽  
Polysulfone Membranes

Dialytic clearance of p-cresyl sulfate (pCS) and other protein-bound toxins is limited by diffusive and convective therapies, and only a few studies have examined how to improve their removal by adsorptive membranes. This study tested the hypothesis that high-flux polymethylmethacrylate (PMMA) dialysis membranes with adsorptive capacity increase pCS removal compared to polysulfone membranes, in a postdilution on-line hemodiafiltration (OL-HDF) session. Thirty-five stable hemodialysis patients randomly completed a single study of 4 h OL-HDF with PMMA (BG2.1U, Toray®, Tokyo, Japan) and polysulfone (TS2.1, Toray®) membranes. The primary endpoint was serum pCS reduction ratios (RRs) obtained with each dialyzer. Secondary outcomes included RRs of other solutes such as β2-microglobulin, the convective volume obtained after each dialysis session, and the dialysis dose estimated by ionic dialysance (Kt) and urea kinetics (Kt/V). The RRs for pCS were higher with the PMMA membrane than those obtained with polysulfone membrane (88.9% vs. 58.9%; p < 0.001), whereas the β2-microglobulin RRs (67.5% vs. 81.0%; p < 0.001), Kt (60.2 ± 8.7 vs. 65.5 ± 9.4 L; p = 0.01), Kt/V (1.9 ± 0.4 vs. 2.0 ± 0.5; p = 0.03), and the convection volume (18.8 ± 2.8 vs. 30.3 ± 7.8 L/session; p < 0.001) were significantly higher with polysulfone membrane. In conclusion, pCS removal by OL-HDF was superior with high-flux PMMA membranes, appearing to be a good dialysis strategy for improving dialytic clearance of pCS, enabling an acceptable clearance of β2-microglobulin and small solutes.

On-Line Urea Monitoring: A Further Step towards Adequate Dialysis Prescription and Delivery

1995 ◽  
Vol 18 (9) ◽  
pp. 534-543 ◽  
Author(s):  
C. Ronco ◽  
A. Brendolan ◽  
C. Crepaldi ◽  
P. Frisone ◽  
F. Ghiotto ◽  
...  
Keyword(s):  
Nitrogen Concentration ◽  
High Rate ◽  
Dialysis Session ◽  
New Device ◽  
Baxter Healthcare ◽  
Direct Measurements ◽  
Blood Drawing ◽  
Urea Kinetics ◽  
On Line ◽  
Spent Dialysate

The Aim Of This Study Is To Present A Clinical Experience Carried Out With A New Device Designed To Measure On-Line Urea Nitrogen Concentration In The Effluent Dialysate. The Biostat 1000® Urea Monitor (Baxter Healthcare, Dirfield, Iii, Usa) Was Utilized In The Present Study. The Monitor Is Based On The Principle That Multiple Urea Measurements In The Dialysate Effluent From The Dialyzer, Permit To Built A Double Exponential Regression Leading To The Urea Kinetic Parameters Of The Dialysis Session. Data Obtained With The Urea Monitor Were, In The Present Study, Compared With Those Obtained By Direct Measurements Carried Out In Blood And Dialysate And By The Collection Of The Whole Amount Of Spent Dialysate. The Monitor Provided An Accurate Value Of Predialysis Bun Without Any Blood Drawing. Urea Kinetics Were Established From Multiple Dialysate Measurements And No Blood Drawing Was Necessary. The Double Pool Kinetics Were Taken Into Account And Kt/V, Pcr And Sri° Obtained Were Comparable To Those Obtained From Direct Measurement. Since A Projected Value Of Kt/V Can Be Obtained, The Monitor Could Represent A Potential Source Of Information To Detect Possible Filter And Machine Dysfunction, As Well As High Rate Of Recirculation.

scholarly journals Hemodialysis (HD) dose and ultrafiltration rate are associated with survival in pediatric and adolescent patients on chronic HD—a large observational study with follow-up to young adult age

2021 ◽  
Author(s):  
Verena Gotta ◽  
Olivera Marsenic ◽  
Andrew Atkinson ◽  
Marc Pfister
Keyword(s):  
Rank Test ◽  
Primary Analysis ◽  
Ultrafiltration Rate ◽  
Dialysis Dose ◽  
Dialysis Adequacy ◽  
Weibull Regression ◽  
Adult Age ◽  
Kaplan Meier ◽  
Continuous Scale ◽  
Weibull Regression Model

Abstract Background Hemodialysis (HD) dose targets and ultrafiltration rate (UFR) limits for pediatric patients on chronic HD are not known and are derived from adults (spKt/V>1.4 and <13 ml/kg/h). We aimed to characterize how delivered HD dose and UFR are associated with survival in a large cohort of patients who started HD in childhood. Methods Retrospective analysis on a cohort of patients <30 years, on chronic HD since childhood (<19 years), having received thrice-weekly HD 2004–2016 in outpatient DaVita centers. Outcome: Survival while remaining on HD. Predictors: (I) primary analysis: mean delivered dialysis dose stratified as spKt/V ≤1.4/1.4–1.6/>1.6 (Kaplan–Meier analysis), (II) secondary analyses: UFR and alternative dialysis adequacy measures [eKt/V, body-surface normalized Kt/BSA] on continuous scale (Weibull regression model). Results A total of 1780 patients were included (age at the start of HD: 0–12y: n=321, >12–18y: n=1459; median spKt/V=1.55, eKt/V=1.31, Kt/BSA=31.2 L/m2, UFR=10.6 mL/kg/h). (I) spKt/V<1.4 was associated with lower survival compared to spKt/V>1.4–1.6 (P<0.001, log-rank test), and spKt/V>1.6 (P<0.001), with 10-year survival of 69.3% (59.4–80.9%) versus 83.0% (76.8–89.8%) and 84.0% (79.6–88.5%), respectively. (II) Kt/BSA was a better predictor of survival than spKt/V or eKt/V. UFR was additionally associated with survival (P<0.001), with increased mortality <10/>18 mL/kg/h. Associations did not alter significantly following adjustment for demographic characteristics (age, etiology of kidney disease, and ethnicity). Conclusions Our results suggest usefulness of targeting Kt/BSA>30 L/m2 for best long-term outcomes, corresponding to spKt/V>1.4 (>12 years) and >1.6 (<12 years). In contrast to adults, higher UFR of 10–18 ml/kg/h was not associated with greater mortality in this population.

Automated method to determine pharmaceutical compounds in wastewater using on-line solid-phase extraction coupled to LC-MS/MS

2021 ◽  
Author(s):  
César Augusto Marasco Júnior ◽  
Bianca Ferreira da Silva ◽  
Rafaela Silva Lamarca ◽  
Paulo Clairmont Feitosa de Lima Gomes
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Pharmaceutical Compounds ◽  
Phase Extraction ◽  
Automated Method ◽  
On Line

scholarly journals Determination of the delivered hemodialysis dose using standard methods and on-line clearance monitoring

2006 ◽  
Vol 63 (8) ◽  
pp. 743-747 ◽  
Author(s):  
Vlastimir Vlatkovic ◽  
Biljana Stojimirovic
Keyword(s):  
Cumulative Effect ◽  
Chronic Hemodialysis ◽  
Reduction Ratio ◽  
The Other ◽  
Treatment Quality ◽  
Monitoring Methods ◽  
Dialysis Dose ◽  
Co Morbidity ◽  
On Line ◽  
Urea Reduction Ratio

Background/aim: Delivered dialysis dose has a cumulative effect and significant influence upon the adequacy of dialysis, quality of life and development of co-morbidity at patients on dialysis. Thus, a great attention is given to the optimization of dialysis treatment. On-line Clearance Monitoring (OCM) allows a precise and continuous measurement of the delivered dialysis dose. Kt/V index (K = dialyzer clearance of urea; t = dialysis time; V = patient's total body water), measured in real time is used as a unit for expressing the dialysis dose. The aim of this research was to perform a comparative assessment of the delivered dialysis dose by the application of the standard measurement methods and a module for continuous clearance monitoring. Methods. The study encompassed 105 patients who had been on the chronic hemodialysis program for more than three months, three times a week. By random choice, one treatment per each controlled patient was taken. All the treatments understood bicarbonate dialysis. The delivered dialysis dose was determined by the calculation of mathematical models: Urea Reduction Ratio (URR) singlepool index Kt/V (spKt/V) and by the application of OCM. Results. Urea Reduction Ratio was the most sensitive parameter for the assessment and, at the same time, it was in the strongest correlation with the other two, spKt/V indexes and OCM. The values pointed out an adequate dialysis dose. The URR values were significantly higher in women than in men, p < 0.05. The other applied model for the delivered dialysis dose measurement was Kt/V index. The obtained values showed that the dialysis dose was adequate, and that, according to this parameter, the women had significantly better dialysis, then the men p < 0.05. According to the OCM, the average value was slightly lower than the adequate one. The women had a satisfactory dialysis according to this index as well, while the delivered dialysis dose was insufficient in men. The difference between the women and the men was significant. Conclusion. The application of OCM has shown that it is the most rigorous parameter for the assessment of adequacy and that its regular use would contribute to increasing of the delivered dialysis dose and improvement of the treatment quality.

scholarly journals Multiresolution analysis of vibration signals acquired from locomotive Diesel engine for classification of engine states basing on signal statistical parameters

2017 ◽  
Vol 168 (1) ◽  
pp. 68-72
Author(s):  
Piotr BOGUŚ ◽  
Mateusz CIESZYŃSKI ◽  
Jerzy MERKISZ
Keyword(s):  
Diesel Engine ◽  
Complex Analysis ◽  
Statistical Parameters ◽  
Vibration Signals ◽  
Time Frequency ◽  
Significant Difference ◽  
Before And After ◽  
On Line ◽  
Locomotive Diesel

The paper presents a method of classification of locomotive Diesel engine states basing on vibration signals taken from an engine body and using chosen statistical parameters calculated for the original signal and it wavelet multiresolution components. The researches presented in the paper concern estimation of an engine states before and after a general repair. The target application of the presented researches is an on-line diagnostic system which can complement standard OBD systems. To this purpose the applied methods should not base on complex analysis of some spectral, time-frequency or scalogram plots but rather on choosing single diagnostic parameters which are suitable for the fast on-line diagnostic. The results have showed the significant difference in distinguishing of engine work before and after a general repair using some chosen statistical parameters applied to vibration signals.

scholarly journals Estimating the quality of life of hemodialysis patients and adequate clearance

2016 ◽  
Vol 2 (4) ◽  
pp. 291
Author(s):  
Evangelia Prevyzi ◽  
Georgios Argyriou ◽  
Thomai Kollia ◽  
Athanasia Nestor ◽  
Anastasia Kotanidou ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Volume Of Distribution ◽  
Hemodialysis Patients ◽  
Statistical Criterion ◽  
Test Results ◽  
Greek Language ◽  
Dialysis Adequacy ◽  
Significant Difference ◽  
Social Adaptability

Introduction: Dialysis affects the quality of life of hemodialysis patients due on idrasis in physical activities, psychological factors, and social adaptability.  Predominant indicator for assessing the adequacy of dialysis, considered the Kt / V (clearance time/volume of distribution). According to international guidelines, the price which shows adequate dialysis is > 1.2. Aim: The aim of the present study was the association of quality of life of hemodialysis patients with adequate dialysis. Material and Methods: To evaluate the quality of life of hemodialysis patients used the questionnaire KDQOL-SF weighted in the Greek language and the Greek egkyropoiimeno population. Excluded from the study patients with a speaking disability, those who were comatose, aliens, and those undergoing dialysis 3 hours/ 2 times / week. For data processing, used the statistical package SPSS ver.17. Results: Based on the statistical analysis t-test results showed respect to the route of vascular access that patients with graft (31,6%)   had a higher clearance rate adequacy, as well as patients undergoing hemodialysis with high permeability (high-flux) filters (35,8%) and those undergoing dialysis with hemodiafiltration (35,8%).According to the statistical criterion pearson's r and multivariate analysis of linear regression, statistically significant difference was only between Kt / V and forefinger encouraging staff and p = 0,032 and p = 0,015 respectively.Conclusions: The conclusions drawn from this study showed that there was no correlation between quality of life and dialysis adequacy, but only with the index of encouraging staff.

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