Estimating Urea Clearance in Patients on Continuous Ambulatory Peritoneal Dialysis: A Multivariate Analysis

1998 ◽  
Vol 21 (9) ◽  
pp. 515-520 ◽  
Author(s):  
G.H. Murata ◽  
A.H. Tzamaloukas ◽  
S. Voudiklari ◽  
A. Dimitriadis ◽  
E. V. Balaskas ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Linear Models ◽  
Urine Volume ◽  
Residual Renal Function ◽  
Urea Clearance ◽  
Clearance Studies ◽  
Multivariate Linear Models

The purpose of this study was to determine if Kt/V urea in continuous ambulatory peritoneal dialysis (CAPD) could be estimated by a multivariate model based upon simple clinical observations. The study included 439 clearance studies in 301 CAPD patients followed in 8 dialysis centers. Weekly urea clearance, 24 h urine volume and 24 h drain volume were normalized to body water by the formulae of Watson (Kt/V, UV/V, and DV/V respectively). Adequate dialysis was defined as Kt/V ≥2.0 weekly. Subjects at 2 units were used to derive the models, while others were used for model validation. Stepwise multiple linear regression was performed on the derivation set (DS) to identify the clinical variables that correlated with Kt/V. The model was then used to estimate Kt/V for the validation set (VS). In the DS, 110 clearance studies were performed in subjects with residual renal function. Multiple linear regression showed that weekly Kt/V was defined by the expression: Kt/V = 1.48 + 24.1 (UV/V) + 2.92(DV/V) - 0.049 (serum creatinine) (r=0.750, p<0.001). In 204 VS studies, the correlation between estimated and measured Kt/V was 0.633. There were marked differences in the proportion of adequately dialyzed patients when Kt/V estimated from the formula shown was <2.0, between 2.0 and 2.3, and >2.3 weekly (7.9%, 54.7% and 79.7%, respectively; p<0.001). In the 33 studies done in DS anuric patients, regression analysis showed the following: Kt/V = 0.46 + 2.59 (DV/V) + 0.009(age) (r=0.562; p = 0.003). In 92 VS studies in anuric subjects, there was strong correlation between estimated and measured Kt/V (r=0.740). Again, there were marked differences in the frequency of adequate dialysis in anuric patients with estimated Kt/V <2.0, between 2.0 and 2.3, and >2.3 weekly (8.1%, 68.8%, and 100%, respectively; p<0.001). The risk of low Kt/V can be estimated by multivariate linear models requiring only simple clinical measurements.

Renal Clearances in Continuous Ambulatory Peritoneal Dialysis: Differences between Diabetic and Non-Diabetic Subjects

2001 ◽  
Vol 24 (4) ◽  
pp. 203-207 ◽  
Author(s):  
A.H. Tzamaloukas ◽  
G.H. Murata ◽  
D. Malhotra
Keyword(s):  
Renal Function ◽  
Creatinine Clearance ◽  
Urine Volume ◽  
Residual Renal Function ◽  
Cross Sectional Study ◽  
Diabetic Group ◽  
Urea Clearance ◽  
Cross Sectional ◽  
Clearance Studies ◽  
Renal Clearances

We analyzed the effect of diabetes on the decline of residual renal function during the course of CAPD in a cross-sectional study including 105 diabetic subjects (41 women) who had 207 clearance studies and 125 non-diabetic subjects (50 women, 265 clearance studies). CAPD duration was 11.5±10.5 months in the diabetic group (DG) and 16.8±18.6 months in the non-diabetic group (NDG, P < 0.001). The DG had lower urine volume than the NDG (0.52±0.46 vs 0.61±0.50 L/24-h, P < 0.05), while urine-to-plasma concentration ratio was higher in the DG for creatinine (13.5±9.4 vs 11.5±11.0, P <0.05) and did not differ for urea. Weekly renal Kt/V urea (DG 0.51±0.57, NDG 0.53±0.49) and Ccr (DG 31.0±28.7 NDG 29.3±26.5 L/1.73 m2) did not differ. The slopes of the regressions of CAPD duration on renal clearances did not differ. These regressions allowed estimates of the time, from the onset of CAPD, at which renal clearances become negligible. These estimates differed for both urea clearance (DG 35.3, NDG 50.5 months) and creatinine clearance (DG 43.2, NDG 57.6 months). The slope of the regression of renal urea clearance on renal creatinine clearance was steeper in the DG, suggesting a higher renal creatinine clearance in the DG than in the NDG when renal urea clearance is the same in the two groups. Subtle differences in the rate of decline of renal function can be detected between diabetic and non-diabetic subjects on CAPD by detailed statistical analysis. These findings are supportive of the studies which have identified diabetes mellitus as a predictor of loss of residual renal function during the course of CAPD. In addition, the relationship between the renal urea and creatinine clearances differs between diabetic and non-diabetic subjects on CAPD. Therefore, the dose of CAPD required for adequate total clearances may differ between diabetic and non-diabetic subjects.

scholarly journals Measurement of residual renal function in patients treated with continuous ambulatory peritoneal dialysis.

1996 ◽  
Vol 7 (5) ◽  
pp. 745-750 ◽  
Author(s):  
R W van Olden ◽  
R T Krediet ◽  
D G Struijk ◽  
L Arisz
Keyword(s):  
Renal Function ◽  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Clearance Rate ◽  
Residual Renal Function ◽  
Tubular Secretion ◽  
Urea Clearance ◽  
Cimetidine Treatment ◽  
Collection Period ◽  
The Difference

Renal function contributes markedly to the adequacy of continuous ambulatory peritoneal dialysis (CAPD). The best way to measure it in clinical practice has not been established. Ten stable CAPD patients with residual renal function were investigated to compare the GFR measured as inulin clearance (Cli) with the creatinine clearance (Clc), the urea clearance (Clu), and with 0.5(Clc + Clu). Thereafter, an analysis of whether the administration of cimetidine could improve the accuracy of these clearances was performed. Two clearance periods (CP) of 24 h were investigated. During CP-2, patients received 400 mg cimetidine twice daily, for a total dose of 1200 mg. Two h before the urine and dialysate collection period, inulin was administered iv. Calculations were done for each CP for Cli, Clc, Clu, Clc-Cli, the Clc/Cli ratio, and the tubular secretion of creatinine (TSc). No differences between CP-1 and CP-2 were present for urinary excretion of volume and solutes, and clearance rates of inulin and urea. The median TSc decreased from 0.71 mumol/min (range, -0.24 to 5.90) in CP-1 to 0.30 mumol/min (range, -0.18 to 0.64) in CP-2 (P < 0.05). Therefore, the median ratio of Clc/Cli decreased from 1.23 (range, 0.87 to 2.20) in CP-1 to 1.11 (range, 0.95 to 1.51) in CP-2 (P < 0.05). The median overestimation of the Cli in CP-1 by the Clc was 0.90 mL/min (range, -0.28 to 3.80) and by the 0.5(Clc + Clu) was 0.30 (range, -0.67 to 1.52). The median overestimation of Cli during cimetidine treatment in CP-2 was 0.43 mL/min (range, -0.21 to 1.20). The range, in differences between Cli and Clc, in CP-2 was smaller than that between Cli and 0.5(Clc + Clu) in CP-1. The difference between the clearance rate of inulin and creatinine or the combined clearance rate of urea and creatinine was not influenced by the magnitude of the average GFR. It can be concluded that the administration of cimetidine improved the accuracy of measuring the GFR with the Clc in CAPD patients.

scholarly journals Residual renal function and blood count in patients on continuous ambulatory peritoneal dialysis

2006 ◽  
Vol 134 (11-12) ◽  
pp. 503-508
Author(s):  
Natasa Jovanovic ◽  
Mirjana Lausevic ◽  
Biljana Stojimirovic
Keyword(s):  
Renal Failure ◽  
Renal Function ◽  
Peritoneal Dialysis ◽  
Chronic Renal Failure ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Blood Count ◽  
Residual Renal Function ◽  
Co Morbidity ◽  
Positive Correlations

Introduction:Most of patients with chronic renal failure are affected by normochromic, normocytic anemia caused by different etiological factors. Anemia causes a series of symptoms in chronic renal failure, which can hardly be recognized from the uremic signs. Anemia adds to morbidity and mortality rates in patients affected by advanced chronic renal failure. Blood count partially improves during the first months after starting the chronic renal replacement therapy, in correlation with the quality of depuration program, with extension of erythrocyte lifetime and with hemoconcentration due to reduction of plasma volume. Recent trials found that higher residual renal function (RRF) significantly reduced co-morbidity, the rate and duration of hospitalization and risk of treatment failure. Objective: The aim of the study was to follow blood count parameters in 32 patients on chronic continuous ambulatory peritoneal dialysis (CAPD) during the first six months of treatment, to evaluate the influence of demographic and clinical factors on blood count and RRF, and to examine the correlation between RRF and blood count parameters. Method: A total of 32 patients affected by end-stage renal disease of different major cause during the first six months of CADP treatment were studied. RRF and blood count were evaluated as well as their relationship during the follow-up. Results: Blood count significantly improved in our patients during the first six months of CAPD treatment even if Hb and HTC failed to reach normal values. Iron serum level slightly decreased because of more abundant erythropoiesis and iron utilization during the first six months of treatment. RRF slightly decreased. After six months of CAPD treatment, the patients with higher RRF had significantly higher Hb, HTC and erythrocyte number and a lot of positive correlations between RRF and anemia markers were observed. Conclusion: After 6-month follow-up period, the patients with higher RRF had significantly higher blood count parameters, and several positive correlations between RRF and blood count markers were confirmed.

scholarly journals Chemometric approach in the development of the colorimetric method for the estimation of food colorants in meat products

2014 ◽  
Vol 68 (6) ◽  
pp. 781-791 ◽  
Author(s):  
Radivoj Petronijevic ◽  
Vesna Matekalo-Sverak ◽  
Aurelija Spiric ◽  
Ilija Vukovic ◽  
Jelena Babic ◽  
...  
Keyword(s):  
Linear Regression ◽  
Mathematical Models ◽  
Multiple Linear Regression ◽  
Linear Models ◽  
Colorimetric Method ◽  
Meat Products ◽  
Food Colorants ◽  
Food Colorant ◽  
Control Batch

The aim of this research was to develop a novel colorimetric method based on mathematical models, by multiple linear regression (MLR), from the CIE L*a*b* measurements and data of the HPLC determination of food colorants. Calibration set of 10 production batches of finely grinded cooked sausage with food colorants added was manufactured in industrial conditions as follows: one control batch and 9 products with various quantities of added food colorants: E120 (3.4, 7.5 and 12.5 mg/kg), E 124 (5.0, 15.0, 25.0 mg/kg) and E 129 (5.0, 15.0, 25.0 mg/kg). The estimation of the added food colorants was assessed by measuring L*, a*, b* parameters of cross-section. The quantification of food colorants was achieved by HPLC-PDA. Food colorants were extracted from meat products using Accelerated Solvent Extraction (ASE). Quantification of food colorants was achieved in the range from 1 to 100 mg / kg, and recovery values were from 76.15% to 107.04%, for E 120, from 97.61% to 101.03%, for E 124 and from 99.91% to 101.67%, for E 129. Correlation of the results obtained using HPLC and colorimetric measuring data was assessed by Multiple Linear Regression (MLR). The results from colorimetric and chromatographic determinations in four experimental batches (three batches with different quantities of food colorants and one control batch) were used for calibration. Coefficients of determination (R2) for linear models in experimental batches were 0.954, for E 124, 0.987, for E 120 and 0.993, for E 129. Correlation functions of food colorant quantities and corresponding L*a*b* values were established. The obtained mathematical models were tested for the estimation of the content of dyes in 21 samples of finely grinded cooked sausages purchased in retail stores. Food colorants were confirmed in 20 samples (95.24 %), and one sample (4.76 %) did not contain any of these compounds. Out of the positive samples, sixteen samples (80.00 %) contained E 120, while four samples (20.00 %) contained E 129. Food colorant E124 was not established in any of the analyzed samples. Colorimetric CIE L*a*b* method might be used during sensory evaluation of meat products for the assessment of the added food colorants.

scholarly journals Decreased renal function increases the nighttime urine volume rate by carryover of salt excretion to the nighttime

2021 ◽  
Author(s):  
Kentaro Takezawa ◽  
Sohei Kuribayashi ◽  
Koichi Okada ◽  
Yosuke Sekii ◽  
Yusuke Inagaki ◽  
...  
Keyword(s):  
Renal Function ◽  
Regression Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Excretion Rate ◽  
Linear Regression Analysis ◽  
Urine Volume ◽  
Multiple Linear Regression Analysis ◽  
Volume Rate ◽  
Salt Excretion

Abstract Purpose: To determine the pathophysiology of nocturnal polyuria associated with renal dysfunction.Methods: Patients who underwent laparoscopic nephrectomy were studied prospectively. The diurnal variation in urine volume, osmolality, and salt excretion were measured on preoperative day two and postoperative day seven. The factors associated with an increase in the nighttime urine volume rate with decreased renal function were evaluated by multiple linear regression analysis.Results: Forty-nine patients were included. The eGFR decreased from 73.3 ± 2.0 to 47.2 ± 1.6 mL/min/1.73 m2 (P < 0.01) and the nighttime urine volume rate increased from 40.6% ± 2.0% to 45.3% ± 1.5% (P = 0.04) with nephrectomy. The nighttime urine osmolality decreased from 273 ± 15 to 212 ± 10 mOsm/kg (P < 0.01) and the nighttime salt excretion rate increased from 38.7% ± 2.1% to 48.8% ± 1.7% (P < 0.01) with nephrectomy. Multiple linear regression analysis revealed that the increase in the nighttime urine volume rate was strongly affected by the increase in the nighttime salt excretion rate.Conclusion: A decrease in renal function causes an increase in the nighttime urine volume rate, mainly due to an increase in nighttime salt excretion.Trial registration number: UMIN000036760 (University Hospital Medical Information Network Clinical Trials Registry)Date of registration: From June 1st, 2019 to October 31th 2020

Gender, degree of obesity, and discrepancy between urea and creatinine clearance in peritoneal dialysis.

1998 ◽  
Vol 9 (3) ◽  
pp. 497-499
Author(s):  
A H Tzamaloukas ◽  
D Malhotra ◽  
G H Murata
Keyword(s):  
Peritoneal Dialysis ◽  
Creatinine Clearance ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Ideal Weight ◽  
Clearance Studies ◽  
Obese Subjects ◽  
The Difference ◽  
The Relationship ◽  
Linear Manner ◽  
One Way Anova

The effect of gender and degree of obesity on the size indicators V, used to normalize urea clearance (Kt/Vur), and body surface area (BSA), used to normalize creatinine clearance (Ccr), in peritoneal dialysis was studied by: (1) mathematical comparison of the formulae used to estimate V (Watson and Hume) with the Dubois formula used to estimate BSA in peritoneal dialysis; and (2) comparison of percent deviation of BSA (delta BSA%) and V (delta V%) from ideal weight estimates in 933 clearance studies performed in actual patients (555 in men and 378 in women on continuous ambulatory peritoneal dialysis). V was estimated by the Watson formulae and BSA by the Dubois formula in these studies. delta BSA% and delta V% were stratified in 10% increments in deviation of body weight from ideal (delta W%) in these studies. Mathematically, the relationship between V and BSA is not linear. In the same subject, as obesity develops (delta W% increases) and BSA increases in a linear manner, V increases exponentially. In addition, there are substantial differences in the relationship between V and BSA caused by gender. For the same height and BSA, men have a larger V than women. In the clearance studies performed in actual continuous ambulatory peritoneal dialysis patients, the difference between delta V% and delta BSA% increased significantly (P < 0.0001) from the wasted to the obese subjects by one-way ANOVA in both men and women. Normalization of urea and creatinine clearances by different size indicators creates two types of mathematical distortion in the relationship between the two clearances. One distortion is caused by the degree of obesity. The second distortion is caused by gender. Use of the same size indicator to normalize both urea and creatinine clearances would eliminate these distortions.

Continuous Ambulatory Peritoneal Dialysis is Better than Automated Peritoneal Dialysis as First-Line Treatment in Renal Replacement Therapy

2007 ◽  
Vol 27 (2_suppl) ◽  
pp. 153-157
Author(s):  
Philip Kam-Tao Li ◽  
Kwok Yi Chung ◽  
Kai Ming Chow
Keyword(s):  
Peritoneal Dialysis ◽  
Renal Replacement Therapy ◽  
Replacement Therapy ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Large Scale ◽  
Residual Renal Function ◽  
Health Care Economics ◽  
Automated Peritoneal Dialysis ◽  
First Line ◽  
Randomized Controlled Studies

This article examines the roles of continuous ambulatory peritoneal dialysis (CAPD) versus automated peritoneal dialysis (APD) as first-line renal replacement therapy. To date, no high-quality large-scale randomized controlled studies have compared CAPD with APD as first-line therapy. However, a discussion on this issue is important so that nephrologists can decide and patients can have a choice of modality on which to start dialysis, especially in the context of health care economics. We review the literature and present Hong Kong as the model of a “CAPD first” policy, an appealing, cost-effective approach for any country. An ideal renal replacement therapy should provide optimal survival, lowest possible risk for comorbidity, highest level of quality of life, and equally important, acceptable cost to society. When we consider this subject in the context that all patients should be started on one first-line modality, the data suggest that a “CAPD first” policy has all these advantages, with APD probably having the edge only with regard to patient preference. The present review highlights preservation of residual renal function, removal and balancing of sodium, incidence of peritonitis, peritoneal membrane transport status, patient rehabilitation, and financial issues in demonstrating that a “CAPD first” policy is the model that should be adopted.

Predictors of Residual Renal Function Decline in Peritoneal Dialysis Patients: ThebalANZ Trial

2017 ◽  
Vol 37 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Htay Htay ◽  
Yeoungjee Cho ◽  
Elaine M. Pascoe ◽  
Darsy Darssan ◽  
Carmel Hawley ◽  
...  
Keyword(s):  
Renal Function ◽  
Peritoneal Dialysis ◽  
Demographic Data ◽  
Urine Volume ◽  
Renin Angiotensin System ◽  
Residual Renal Function ◽  
Angiotensin System ◽  
Low Glucose ◽  
Glucose Exposure

ObjectivePreservation of residual renal function (RRF) is associated with improved survival. The aim of the present study was to identify independent predictors of RRF and urine volume (UV) in incident peritoneal dialysis (PD) patients.MethodsThe study included incident PD patients who were balANZ trial participants. The primary and secondary outcomes were RRF and UV, respectively. Both outcomes were analyzed using mixed effects linear regression with demographic data in the first model and PD-related parameters included in a second model.ResultsThe study included 161 patients (mean age 57.9 ± 14.1 years, 44% female, 33% diabetic, mean follow-up 19.5 ± 6.6 months). Residual renal function declined from 7.5 ± 2.9 mL/min/1.73 m2at baseline to 3.3 ± 2.8 mL/min/1.73 m2at 24 months. Better preservation of RRF was independently predicted by male gender, higher baseline RRF, higher time-varying systolic blood pressure (SBP), biocompatible (neutral pH, low glucose degradation product) PD solution, lower peritoneal ultrafiltration (UF) and lower dialysate glucose exposure. In particular, biocompatible solution resulted in 27% better RRF preservation. Each 1 L/day increase in UF was associated with 8% worse RRF preservation ( p = 0.007) and each 10 g/day increase in dialysate glucose exposure was associated with 4% worse RRF preservation ( p < 0.001). Residual renal function was not independently predicted by body mass index, diabetes mellitus, renin angiotensin system inhibitors, peritoneal solute transport rate, or PD modality. Similar results were observed for UV.ConclusionsCommon modifiable risk factors which were consistently associated with preserved RRF and residual UV were use of biocompatible PD solutions and achievement of higher SBP, lower peritoneal UF, and lower dialysate glucose exposure over time.

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