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.

Placement, Performance and Complications of the Ash Split Cath™ Hemodialysis Catheter

2002 ◽  
Vol 25 (12) ◽  
pp. 1137-1143 ◽  
Author(s):  
M. Gallieni ◽  
P.A. Conz ◽  
E. Rizzioli ◽  
A. Butti ◽  
D. Brancaccio
Keyword(s):  
Vascular Access ◽  
Good Alternative ◽  
Chronic Hemodialysis ◽  
Dialysis Session ◽  
Dialysis Dose ◽  
Hemodialysis Catheter ◽  
Venous Fistula ◽  
Tunneled Catheter ◽  
Urea Reduction Ratio

A tunneled catheter is the alternative vascular access for those patients in need of hemodialysis who cannot undergo dialysis through an arterio-venous fistula or a vascular graft. This study was undertaken to evaluate the performance of the Ash Split Cath™, a 14 French chronic hemodialysis catheter with D-shaped lumens and a Dacron® cuff. After tunneling through a transcutaneous portion the catheter enters the venous system, where it splits into two separate limbs. Data regarding catheter positioning, function and adequacy of dialysis were collected from two hemodialysis facilities. Twenty-eight Ash-split catheters were placed in 28 patients, with no complications, and immediate technical success was 100%. Patients were followed up for a total of 7,286 catheter days. No catheter-related infections were observed. Only one catheter failed after 15 days, with a primary catheter patency of 96% for the whole study length. Mean blood flow was 303 ± 20 ml/min at 1 week after insertion, 306 ± 17 ml/min at 3 months, 299 ± 44 ml/min at 6 months, and 308 ± 16 ml/min at 12 months. With a mean dialysis session duration of 234 ± 25 minutes, adequate dialysis dose was observed for 96% of catheters, as reflected by a mean urea reduction ratio (URR) of 71%±8 or a mean urea kinetic modeling, or Kt/V, value of 1.51±0.3 during follow up. In conclusion, compared with previous studies we report the best permanent catheter performance, confirming that the Ash-split catheter is a good alternative for vascular access in hemodialysis patients who are not candidates for surgical A-V fistula or graft placement.

scholarly journals Adequacy of Hemodialysis and Its Associated Factors among Patients Undergoing Chronic Hemodialysis in Dar es Salaam, Tanzania

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Samina S. Somji ◽  
Pascal Ruggajo ◽  
Sibtain Moledina
Keyword(s):  
Multivariate Analysis ◽  
Surface Area ◽  
Associated Factors ◽  
Univariate Analysis ◽  
Reduction Rate ◽  
Dar Es Salaam ◽  
Chronic Hemodialysis ◽  
Reduction Ratio ◽  
Hemodialysis Dose ◽  
Urea Reduction Ratio

The worldwide prevalence of maintenance hemodialysis continues to rise. An adequate delivery of hemodialysis dose as measured by Kt/V or urea reduction ratio is a crucial determinant of clinical outcome for chronic hemodialysis patients. The aim of this study was to assess the adequacy of hemodialysis and its associated factors among patients undergoing chronic hemodialysis in Dar es Salaam. This was a cross-sectional study done on patients undergoing chronic hemodialysis in four dialysis centers in Dar es Salaam. Sociodemographic information and treatment characteristics were collected. Urea reduction rate and single-pool Kt/V were calculated to determine the adequacy of hemodialysis. The data were analyzed and any associated factors for inadequate hemodialysis were determined using a chi-square test and a logistic regression analysis. A total of 143 patients participated in the study. Males represented 65.7% of the study population. The mean age (±SD) was 51.7 ± 1.2 years. Only 34.3% (based on urea reduction ratio (URR)) and 40.6% (based on Kt/V) of patients received adequate hemodialysis. The univariate analysis showed that males were more likely to have inadequate dialysis (65.6% versus 48.0%, p=0.048 based on Kt/V). Patients using hemodialyzers with dialyzer surface area less than 1.4 m2 received significantly less hemodialysis dose than those with more than 1.4 m2 (69.0% versus 41.2%, p=0.02, by URR) (62.7% versus 35.3%, p=0.03, by Kt/V criteria). Patients who had hemoglobin <10 g/dl received significantly inadequate hemodialysis dose as compared to patients with hemoglobin ≥10 g/dl by Kt/V criteria (69.8% versus 51.3%, p=0.03). None of the factors acquired significance in the multivariate analysis. The proportion of patients receiving an adequate hemodialysis dose is low (34.3% based on URR and 40.6% based on Kt/V). Male gender, dialyzer surface area of <1.4 m2, and hemoglobin level of <10 g/dl were associated with an inadequate delivered dose of hemodialysis in the univariate analysis but not in the multivariate analysis. This study can increase awareness about the importance of measuring hemodialysis adequacy and giving the correct hemodialysis dose to achieve the intended benefit.

Reading About Persons: The Effects of Conjunctions on the Mental Representation of Person Descriptions

2008 ◽  
Vol 67 (1) ◽  
pp. 5-18 ◽  
Author(s):  
Sabine Krolak-Schwerdt ◽  
Margret Wintermantel ◽  
Nadine Junker ◽  
Julia Kneer
Keyword(s):  
Mental Representation ◽  
The Other ◽  
Person Memory ◽  
Causal Connections ◽  
Single Person ◽  
On Line

Three experiments investigated the processing of person descriptions that consisted of a number of statements about the characteristics of a person. In one condition, each statement referred to a single person attribute and in the other condition, causal and additive conjunctions to verbally link the statements were introduced. Evidence was found that the introduction of verbal links enhanced participants’ memory about the characteristics of the described person. On-line measures of processing showed that the comprehension of person information was strongly facilitated by the introduction of verbal links. Furthermore, the results were due to the introduction of causal connections between person attributes. These findings are discussed in terms of their implications for models of person memory and representation.

English Metre Once More

PMLA ◽  
1948 ◽  
Vol 63 (1) ◽  
pp. 293-326
Author(s):  
Evelyn H. Scholl
Keyword(s):  
The Other ◽  
English School ◽  
English Verse ◽  
On Line ◽  
The Subject

Although hundreds of books and articles have been written on the subject, there is still no agreement upon the question: What is the basis of English metre? There have been three schools of metrics: that of a strict count of syllables; that of accent; and that of equal times. The latest work which I have found to consider a strict count of syllables the sole basis of English metre was published in Heidelberg in 1902. But both of the other schools have their representatives today. It is my purpose to raise the question once more, and to throw light upon it from a hitherto unexplored source of unusual value, The English School of Lutenist Song Writers. I hope to show that the theory of equal times marked by stress best explains the varying phenomena of modern English verse, and especially the inclusion in metrical verse of such extremely irregular poems as “The Listeners” by De la Mare. And I hope also to clarify several metrical terms: the so-called “trochaic substitution” in iambic metre, the “caesura,” and the “run-on line.”

measurements. This paper is confined to the different forms of sampling odourous gases for olfactometric measurements and the problems involved. It refers to existing guidelines for olfactometric measurements in the countries of the EEC, as well. 2. TYPES OF SAMPLING Samples of odourous gas may be collected in unconcentrated or concentrated form. Concentrated sampling is usually neces­ sary when gas chromatography or other chemical analytical meth­ ods are to be used. Unconcentrated sampling is provided if o-dour threshold concentrations are required (2). Depending on the type of olfactometer used dynamic sam­ pling or static sampling are provided. The principle of dynam­ ic sampling is shown in Figure 1. It requires a part-flow of the odourous gas to be continoulsy extracted from the source and subsequently directed to the olfactometer. This sampling method implies that the measurements are carried out close to the source. An advantage of the method is that there is the possibility of controlling a process, directly, and in case of the break-down of the process this can be noticed right away. A disadvantage of the dynamic method is that odour sources that are not readily accessible require a relatively great ef­ fort in order to install the olfactometer and suitable sam­ pling pipes which often should be insulated or heated to avoid adsorption or condensation (3). When static sampling is used a partial stream of the o-dourous air is collected in a sampling vessel. Samples are taken from this vessel or bag to dilute the odourous air for the olfactometer using syringes or on-line tubings. When using this method odour measurement with the panel can be carried out at any arbitrary location, if the vessel is a transport­ able one. An example for static sampling is given in Figure 2. 3. PROBLEMS OF SAMPLING the main problems encountered when sampling odourous air derive from surface effects of the sampling tubes and vessels, namely by - adsorption, - desorption, and - condensation. This depends mainly on the material of the tube, the vessel or the bag (adsorption) or on the nature of the gas, whether it is hot and/or containes a high amount of humidity (condensa­ tion). On the other hand the sample can be altered by trace components bleeding from the material of the walls of the ves­ sel or the tube (desorption). The following factors are to be observed for valid static sampli ng. aTTTToTce of_m£teri aj_ For tWe sampling of odourous gases glas vessels, stain­ less steel tanks (4) and flexible plastic bags (5) were tested. The initial concentrations of the test gases decrease consider­ ably with storage time in glass and steel vessels. In recent years bags made of Polyethylene(6), Teflon (3) and Tedlar (7), (8) were usually used. Figure 3 shows a graph from SCHUETZLE

1986 ◽  
pp. 59-59
Keyword(s):  
Gas Chromatography ◽  
Storage Time ◽  
Dynamic Method ◽  
The Other ◽  
Plastic Bags ◽  
Steel Tanks ◽  
On Line ◽  
Arbitrary Location ◽  
Adsorption Desorption ◽  
Trace Components

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.

scholarly journals Effect Of Surface Area Of Dialyzer Membrane On The Adequacy Of Haemodialysis

2012 ◽  
Vol 7 (2) ◽  
pp. 9-11 ◽  
Author(s):  
NS Chowdhury ◽  
FMM Islam ◽  
F Zafreen ◽  
BA Begum ◽  
N Sultana ◽  
...  
Keyword(s):  
Renal Disease ◽  
Surface Area ◽  
End Stage Renal Disease ◽  
Membrane Surface ◽  
Reduction Ratio ◽  
Urea Clearance ◽  
Membrane Surface Area ◽  
Stage Renal Disease ◽  
End Stage ◽  
Urea Reduction Ratio

Introduction: Patients with end stage renal disease require 12 hours of haemodialysis per week in three equal sessions (4 hours/day for 3 days/week). But the duration and frequency of treatment can be reduced by increasing the surface area of the dialyzer membrane. Methods: In this prospective study 40 patients of end stage renal disease receiving haemodialysis for more than six months were included to observe the effects of increment in the surface area of the dialyzer membrane on the adequacy of haemodialysis. Result: It was observed that 20 patients receiving haemodialysis on a dialyzer with membrane surface area of 1.2 m² did not have satisfactory solute clearance index. Urea reduction ratio was 45.9 ± 3.03 and fractional urea clearance (Kt/V) was 0.76 ± 0.09. On the other hand patients (20 cases) receiving haemodialysis on a dialyzer with membrane surface area of 1.3 m² had a urea reduction ratio 50.76± 5.16 and fractional urea clearance (Kt/V) 0.91 ± 0.16. All the patients of both groups received dialysis for 8 hours/week in two equal sessions (4 hours/day for 2 days/week). Statistically the increment was significant (p<0.001). Conclusion: This study reveals, adequacy of dialysis can be increased by increasing the surface area of the dialyzer membrane. So, considering the poor socioeconomic condition of Bangladesh and patients' convenience, a short duration, low cost dialysis regime can be tried by increasing the surface area of dialyzer membrane. DOI: http://dx.doi.org/10.3329/jafmc.v7i2.10387 JAFMC 2011; 7(2): 9-11

scholarly journals Deferred On-Line Bipartite Matching

10.37236/5756 ◽  
2018 ◽  
Vol 25 (2) ◽  
Author(s):  
Jakub Kozik ◽  
Grzegorz Matecki
Keyword(s):  
Competitive Ratio ◽  
Bipartite Graphs ◽  
Deterministic Algorithm ◽  
The Other ◽  
Bipartite Matching ◽  
Classical Version ◽  
New Model ◽  
On Line

We present a new model for the problem of on-line matching on bipartite graphs. Suppose that one part of a graph is given, but the vertices of the other part are presented in an on-line fashion. In the classical version, each incoming vertex is either irrevocably matched to a vertex from the other part or stays unmatched forever. In our version, an algorithm is allowed to match the new vertex to a group of elements (possibly empty). Later on, the algorithm can decide to remove some vertices from the group and assign them to another (just presented) vertex, with the restriction that each element belongs to at most one group. We present an optimal (deterministic) algorithm for this problem and prove that its competitive ratio equals $1-\pi/\cosh(\frac{\sqrt{3}}{2}\pi)\approx 0.588$.

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