Urea kinetics and other dialysis indices in children undergoing ambulatory peritoneal dialysis

2000 ◽  
Vol 4 (3) ◽  
pp. 225-230
Author(s):  
K. Iitaka ◽  
S. Moriya ◽  
K. Tomonaga ◽  
H. Koshino ◽  
M. Hojo
Keyword(s):  
Peritoneal Dialysis ◽  
Urea Kinetics

The Rationale and Ultimate Limitations of Urea Kinetic Modelling in the Estimation of Nutritional Status

1996 ◽  
Vol 16 (4) ◽  
pp. 347-351 ◽  
Author(s):  
Joanne M. Bargman
Keyword(s):  
Peritoneal Dialysis ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Kinetic Modelling ◽  
Nutritional Indices ◽  
Helpful Tool ◽  
Urea Kinetics ◽  
False Sense ◽  
Difficult Issue ◽  
Urea Kinetic Modelling

Objective This paper reviews protein flux and amino acid metabolism and the potential inaccuracies inherent in using urea kinetics as an estimate of these processes, particularly in the patient undergoing peritoneal dialysis. The problems of extrapolating these estimates back to the whole patient are examined, addressing assumptions about neutral nitrogen balance, and the difficult issue of normalizing urea-derived indices to body size. Conclusions Urea kinetics can be a helpful tool for assessing nutritional indices, but there are many caveats and many pitfalls that must be kept in mind to avoid being lulled into a false sense of confidence by the comfort of numbers.

Calculating Standard Kt/V during Hemodialysis Based on Urea Mass Removed

2018 ◽  
Vol 47 (1-3) ◽  
pp. 62-68
Author(s):  
John K. Leypoldt ◽  
Edward F. Vonesh
Keyword(s):  
Peritoneal Dialysis ◽  
Theoretical Consideration ◽  
Compartment Model ◽  
Distribution Volume ◽  
Theoretical Understanding ◽  
Novel Approach ◽  
Urea Kinetics ◽  
Predicted Values ◽  
Urea Distribution Volume ◽  
Urea Reduction Ratio

Background/Aims: We derived a novel equation for calculating weekly urea standard Kt/V (stdKt/V) during hemodialysis (HD) based on urea mass removed, comparable to the approach during peritoneal dialysis. Methods: Theoretical consideration of urea mass balance during HD led to the following equation for stdKt/V, namely, stdKt/V = N × (URR + UFV/V), where N is the number of treatments per week, URR is urea reduction ratio per treatment, UFV is ultrafiltration volume per treatment, and V is postdialysis urea distribution volume. URR required corrections for postdialysis rebound and intradialytic urea generation. We compared the accuracy of this approach with previous equations for stdKt/V by numerical simulations using a 2-compartment model of urea kinetics for thrice-weekly and more frequent HD prescriptions. Results: The proposed equation based on urea mass removed predicted values of stdKt/V that are equivalent to those calculated by previous equations for stdKt/V. Conclusion: This work provides a novel approach for calculating stdKt/V during HD and strengthens the theoretical understanding of stdKt/V.

Urea Kinetics and Clinical Features of Long Term Continuous Ambulatory Peritoneal Dialysis Patients

1993 ◽  
Vol 13 (2_suppl) ◽  
pp. 180-182 ◽  
Author(s):  
Kazuo Kumano ◽  
Yutaka Takagi ◽  
Shinji Yokota ◽  
Satoru Shimura ◽  
Tadasu Sakai
Keyword(s):  
Peritoneal Dialysis ◽  
Serum Albumin ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Clinical Assessment ◽  
Biochemical Parameters ◽  
Clinical Symptoms ◽  
Close Correlation ◽  
Albumin Concentration ◽  
Assessment Scores ◽  
Urea Kinetics

The purpose of this study was to assess urea kinetic modeling (UKM) as a marker for adequate dialysis in continuous ambulatory peritoneal dialysis (CAPD) patients. UKM was conducted on 19 anuric patients on CAPD for more than 2 years. Serum β2-microglobulin (β2M) was also measured as a marker of large molecular weight substances. Patient clinical conditions were evaluated by the doctors and patients as well. The patients were thus asked to complete a questionnaire on uremic symptoms an d daily activities. A comparison was made in urea kinetics and biochemical parameters based on clinical assessment scores. Patient and doctor scores showed a close correlation (r=0.69) and were correlated to days of hospitalization. The peritonitis rate was significantly higher in the “not doing well” group. No correlation could be found between indexes of UKM or β2M plasma level and clinical assessment scores. A signlficant correlation was noted between serum albumin concentration and doctor scores (r=0.52). It was thus concluded that UKM was not a good indicator of the adequacy of dialysis for CAPD, but serum albumin was. However, clinical symptoms and signs are more important than biochemical parameters for assessing adequacy.

scholarly journals Clinical outcome of continuous ambulatory peritoneal dialysis predicted by urea and creatinine kinetics.

1992 ◽  
Vol 2 (9) ◽  
pp. 1430-1435
Author(s):  
J C Brandes ◽  
W F Piering ◽  
J A Beres ◽  
S S Blumenthal ◽  
C Fritsche
Keyword(s):  
Peritoneal Dialysis ◽  
Clinical Outcome ◽  
Creatinine Clearance ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Treatment Time ◽  
Residual Renal Function ◽  
Cross Sectional ◽  
Group I ◽  
Urea Kinetics ◽  
Creatinine Kinetics

The effectiveness of urea kinetics (Kt/V, where K is urea clearance, t is treatment time, and V is the volume of distribution for urea) to assess the adequacy of continuous ambulatory peritoneal dialysis (CAPD) and clinical outcome has not been established prospectively, and cross-sectional clinical studies have been inconclusive. A minimum weekly creatinine clearance of 40 to 50 L is recommended, but the adequacy of this dose is unproven. We introduced a simpler approach to creatinine kinetics in the form of an efficacy number (EN) calculated from data obtained in a standardized 4-h dwell exchange. To determine the most effective model for predicting CAPD adequacy, residual renal function, weekly Kt/V urea, weekly creatinine clearance standardized to body surface area, and EN (liters per gram of creatinine per day) were measured in 18 stable CAPD patients followed prospectively for at least 12 months. Patients were divided into three groups, good (G), intermediate (I), and poor (P), on the basis of uremic symptoms, mortality, hospital days, biochemical indices, and the need for transfer to hemodialysis. When comparing groups G (N = 6) and P (N = 8), weekly Kt/V were 2.3 +/- 0.2 versus 1.5 +/- 0.1 (P less than 0.005), weekly creatinine clearances were 71.5 +/- 8.6 versus 35.1 +/- 1.3 L (P less than 0.001), and EN were 7.4 +/- 0.8 versus 3.6 +/- 0.2 L/g of creatinine/day (P less than 0.005). Creatinine kinetics (weekly clearance and EN) but not urea kinetics could differentiate group I (N = 4) from groups G or P. Both urea and creatinine kinetics predict clinical outcome in CAPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Is Total Creatinine Clearance a Good Predictor of Clinical Outcomes in Continuous Ambulatory Peritoneal Dialysis?

1992 ◽  
Vol 12 (4) ◽  
pp. 353-358 ◽  
Author(s):  
Peter G. Blake ◽  
Elias v. Balaskas ◽  
Sharron Izatt ◽  
Dimitrios G. Oreopoulos
Keyword(s):  
Peritoneal Dialysis ◽  
Creatinine Clearance ◽  
Clinical Outcomes ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Well Being ◽  
Serum Levels ◽  
Residual Renal Function ◽  
Creatinine Concentration ◽  
Urea Kinetics ◽  
One Year

The measurement of the adequacy of dialysis in continuous ambulatory peritoneal dialysis (CAPD) is controversial. The use of weekly total creatinine clearance (TCC) has been recommended, but not validated. We analyzed data from our recent urea kinetics in a CAPD study to investigate TCC and its relationship to patient outcomes. TCC was measured over 24 hours by adding residual renal and peritoneal creatinine clearance, correcting for 1.73 m2 surface area and converting to a weekly value. Seventy-six patients had 218 measurements, on starting CAPD and then at 6–month intervals, with mean follow-up of 20 months (range 1–57 months). The mean TCC was 73.62±32.11 L/week. Due mainly to the loss of residual renal function, the TCC decreased with time (r=-0.40, p<0.0001), from 88.65 L/week initially to 66.11 at one year, 59.84 at two years, and 50.47 at three years. Dialysate-to-plasma creatinine concentration ratios (DIP Cr) increased with time (r=0.28, p<0.0001) from 0.62 initially to 0.66 at one year and 0.73 at two years. The TCC correlated significantly with serum levels of creatinine (r=-0.46, p<0.0001), urea (r=-0.21, p<0.001), potassium (r=-0.14, p<0.05), phosphate (r=-0.25, p<0.001), and hemoglobin (r=0.16, p<0.01), but not with serum albumin or with clinical outcomes including technique failure, hospital days, transfusions, peritonitis rate, nerve conduction velocity, or subjective indices of well-being, except for a weak correlation with the fatigue index (r=0.19, p<0.05). However, of 13 deaths 6 occurred in patients with TCC under 48 L/week (p<0.05). There is little evidence of a proportionality relationship between TCC and clinical outcomes in CAPD, but a TCC of 48 L/week may usefully define a lower limit below which excess mortality occurs.

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