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Tzamaloukas AH, Murata GH, Malhotra D, Piraino B, Rao P, Bernardini J, Oreopoulos DG. Normalization of Clearances in Peritoneal Dialysis Using a Formula for Body Water Derived from an End-Stage Renal Disease Population. Perit Dial Int 2020. [DOI: 10.1177/089686080002000111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective To compare body water (V) estimates from the Chertow formula (VC), which was derived in an end-stage renal disease population, to V estimates from the Watson formulas (VW) in continuous ambulatory peritoneal dialysis (CAPD) patients. To identify CAPD patients in whom VC is preferred to VW for clearance studies. Design Retrospective analysis of clearance studies. Setting Dialysis units of four academic medical centers. Participants 302 subjects on CAPD. Intervention 613 clearance studies by standard methods. Main Outcome Measures Comparisons between VC and VW, and between urea clearance normalized by VC [(Kt/VC)ur] and VW [(Kt/VW)ur]. Results VC exceeded VW by 3.5 ± 1.6 L ( p < 0.001), or 9.6% on average. This degree of overestimation of VW is in the range of body water estimates found in CAPD subjects with severe volume overload (> 5% of body weight) in previous studies. Total (Kt/VW)ur exceeded total (Kt/VC)ur by 8.6%. By linear regression, VC = –0.589 + (1.112 x VW), r = 0.983. VW exceeded VC in only 12 studies. Young age, short height, low body weight, and low prevalence of diabetes characterized the studies with VW > VC. Total (Kt/VW)ur was adequate (≥ 2.0 weekly) in 276 studies. Among these, 74 studies had inadequate total (Kt/VC)ur (< 2.0 weekly). By logistic regression, the predictors of inadequate (Kt/VC)ur, when (Kt/VW)ur was adequate, included the presence of diabetes, great height, and long duration of CAPD. Conclusions VC provides estimates of body water exceeding those provided by VW in a great majority of CAPD patients. Consequently, approximately 25% of the clearance studies that are adequate when VW is used as the normalizing parameter may be inadequate when VC is used. VC may provide a more appropriate estimate of body water than VW in CAPD patients with volume overload.
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Affiliation(s)
- Antonios H. Tzamaloukas
- New Mexico Veterans Affairs Health System and University of New Mexico School of Medicine, Albuquerque, New Mexico
| | - Glen H. Murata
- New Mexico Veterans Affairs Health System and University of New Mexico School of Medicine, Albuquerque, New Mexico
| | | | - Beth Piraino
- Renal/Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - Panduranga Rao
- The Peritoneal Dialysis Program, Division of Nephrology, The Toronto Hospital, Toronto, Ontario, Canada
| | - Judith Bernardini
- Renal/Electrolyte Division, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - Dimitrios G. Oreopoulos
- The Peritoneal Dialysis Program, Division of Nephrology, The Toronto Hospital, Toronto, Ontario, Canada
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Abstract
The ideal normalization parameter for urea and creatinine clearance is not yet known. The best current practices are to normalize urea clearance by anthropometric V, corrected for certain conditions such as edema, and creatinine clearance by BSA. Normalization parameters should be calculated using the actual weight. In addition, the ideal weight also should be used in underweight individuals.
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Affiliation(s)
- Antonios H. Tzamaloukas
- Renal Section Veterans Affairs Medical Center and University of New Mexico School of Medicine Albuquerque, New Mexico, U.S.A
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Tzamaloukas AH, Dombros NV, Murata GH, Nicolopoulou N, Dimitriadis A, Kakavas J, Malhotra SD, Antoniou S, Balaskas EV, Voudiklaris S. Fractional Urea Clearance Estimates Using Two Anthropometric Formulas in Continuous Peritoneal Dialysis: Sex, Height, and Body Composition Differences. Perit Dial Int 2020. [DOI: 10.1177/089686089601600209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objective To compare estimates of urea volume (V) and KT/V obtained by the Watson and Hume anthropometric formulas, and to identify the similarities and differences between these estimates. Design Theoretical analysis applying wide variations in the determinants of anthropometric V (age, height, weight) in hypothetical women and men. Analysis of urea kinetic studies performed in patients on continuous peritoneal dialysis (CPD). Setting Four dialysis units in Albuquerque, two in Athens, and two in Thessaloniki. Participants Three hundred and two CPD patients who had 440 urea kinetic studies. Intervention Standard urea clearance was performed by 24-hour collections of urine and drained dialysate followed by blood sampling. V was estimated by both the Watson and Hume formulas. Main Outcome Measures Estimates of V and KT/V were compared separately in women and men by Student's t-test, linear regression, and limits of agreement (mean difference±2 SD). The agreement of the KT/V estimates was also tested by the kappa ratio using a value of 1.70 weekly as the lowest acceptable KT/V. Results The theoretical analysis indicated important disagreement only in extreme variations from the ordinary in height and, to a lesser extent, weight. Differences due to height variation were pronounced only in hypothetical women. CPD patient findings were as follows: in women, Watson V and weekly KT/V were 30.4±4.4 L and 2.10±0.61, respectively. Corresponding Hume estimates were 30.3±5.4 L and 2.12±0.66, respectively. Corresponding estimates for men were 40.5±5.7 L and 1.92±0.57 (Watson) plus 41.4±5.6 L and 1.88±0.57 (Hume), respectively. By linear regression, KT/VHume = -0.083 + 1.052 (KT/Vw8tson), r = 0.961 (women); and KT/VHume = -0.026 + 0.992 (KT/Vwatson), r = 0.985 (men). Limits of agreement were -1.41 L and 2.10 L for V, and -0.15 and 0.14 weekly for KT/V. In 94.3% of the cases, KT/Vw8tson and KT/VHume agreed (both >1.70 or both <1.70 weekly). Kappa ratio was 0.875 (excellent agreement). The concordant and discordant groups differed in height and degree of obesity, in agreement with the theoretical analysis. Conclusion The Watson and Hume formulas provide similar estimates of V and KT/V in CPD patients. Differences may be noted only if women's height or, to a lesser extent, both sexes’ weight is at a great variance with the ordinary values.
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Affiliation(s)
- Antonios H. Tzamaloukas
- Veterans Affairs Medical Center and University of New Mexico School of Medicine, Athens, Greece
| | | | - Glen H. Murata
- Veterans Affairs Medical Center and University of New Mexico School of Medicine, Athens, Greece
| | | | | | | | - S Deepak Malhotra
- Veterans Affairs Medical Center and University of New Mexico School of Medicine, Athens, Greece
| | | | - Elias V. Balaskas
- Albuquerque, New Mexico, U.S.A.; “AHEPA” University Hospital, Thessaloniki
| | - Sonia Voudiklaris
- Veterans Affairs Medical Center and University of New Mexico School of Medicine, Athens, Greece
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Tzamaloukas AH, Malhotra D, Murata GH. Indicators of Body Size in Peritoneal Dialysis: Their Relation to Urea and Creatinine Clearances. Perit Dial Int 2020. [DOI: 10.1177/089686089801800403] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Antonios H. Tzamaloukas
- Medicine Service Veterans Affairs Medical Center and University of New Mexico School of Medicine Albuquerque, New Mexico, U.S.A
| | - Deepak Malhotra
- Department of Medicine Medical College of Ohio Toledo, Ohio, U.S.A
| | - Glen H. Murata
- Medicine Service Veterans Affairs Medical Center and University of New Mexico School of Medicine Albuquerque, New Mexico, U.S.A
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Konings CJ, Kooman JP, Schonck M, Cox–Reijven PL, Van Kreel B, Gladziwa U, Wirtz J, Gerlag PG, Hoorntje SJ, Wolters J, Heidendal GA, van der Sande FM, Leunissen KM. Assessment of Fluid Status in Peritoneal Dialysis Patients. Perit Dial Int 2020. [DOI: 10.1177/089686080202200607] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Objectives To assess the influence of abnormalities in fluid status and body composition on agreement between multifrequency bioimpedance analysis (MF-BIA), segmental BIA (ΣBIA), the Watson formula, and tracer dilution techniques. Design Cross-sectional. Setting Multicenter. Patients 40 patients (29 males, 11 females) on peritoneal dialysis (PD). Main Outcome Measures Agreement between the various techniques used to assess total body water (TBW) [MF-BIA, deuterium oxide (D2O), and the Watson formula] and extracellular water (ECW) [MF-BIA, bromide dilution (NaBr), and ΣBIA], also in relation to the relative magnitude of the body water compartments [ECW (NaBr):body weight (BW) and TBW (D2O):BW] and body composition (DEXA). Second, the relation between body water compartments with echocardiographic parameters. Results Wide limits of agreement were observed between tracer dilution techniques and MF-BIA [TBW (D2O – MF-BIA) 2.0 ± 3.9 L; ECW (NaBr – MF-BIA) –2.8 ± 3.9 L], which were related to the relative magnitude of the body water compartments: r = 0.70 for ECW and r = 0.40 for TBW. ΣBIA did not improve the agreement [ECW (NaBr – ΣBIA): 3.7 ± 2.9 L]. Also, wide limits of agreement were observed between D2O and the Watson formula (–2.3 ± 3.3 L). The difference between D2O and Watson was related to hydration state and to percentage of fat mass ( r = 0.70 and r = –0.53, p < 0.05). Both ECW and TBW as assessed by BIA and tracer dilution were related to echocardiographic parameters. Conclusion Wide limits of agreement were found between MF-BIA and ΣBIA with dilution methods in PD patients, which were related to hydration state itself. The disagreement between the Watson formula and dilution methods was related to both hydration state and body composition.
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Affiliation(s)
| | | | - Marc Schonck
- University Hospital Maastricht; West Fries Gasthuis Hoorn, Germany
| | | | | | | | - Joris Wirtz
- Sint Laurentius Hospital Roermond University Hospital Maastricht, The Netherlands
| | - Paul G. Gerlag
- Sint Joseph Hospital Veldhoven University Hospital Maastricht, The Netherlands
| | - Steven J. Hoorntje
- Catharina Hospital Eindhoven University Hospital Maastricht, The Netherlands
| | - Johannes Wolters
- Atrium Hospital Heerlen University Hospital Maastricht, The Netherlands
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Coles GA. Have We Underestimated the Importance of Fluid Balance for the Survival of Pd Patients? Perit Dial Int 2020. [DOI: 10.1177/089686089701700403] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Gerald A. Coles
- Institute of Nephrology University of Wales College of Medicine Cardiff, CF2 ISZ, Wales, United Kingdom
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8
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Tzamaloukas AH, Murata GH. Peritoneal Dialysis in Patients with Large Body Size: Can it Deliver Adequate Clearances? Perit Dial Int 2020. [DOI: 10.1177/089686089901900502] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Antonios H. Tzamaloukas
- Sections of Nephrology and General Internal Medicine New Mexico VA Health System and University of New Mexico School of Medicine Albuquerque, New Mexico, U.S.A
| | - Glen H. Murata
- Sections of Nephrology and General Internal Medicine New Mexico VA Health System and University of New Mexico School of Medicine Albuquerque, New Mexico, U.S.A
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Davies SJ, Finkelstein FO. Accuracy of the estimation of V and the implications this has when applying Kt/Vurea for measuring dialysis dose in peritoneal dialysis. Perit Dial Int 2020; 40:261-269. [DOI: 10.1177/0896860819893817] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Background: Current guidelines for the prescription of peritoneal dialysis dose rely on a single cut-off ‘minimal’ value of K t/ V. To apply this in the clinic, this requires an accurate estimation of V, the volume of urea distribution that equates to the total body water (TBW). This analysis sought to determine the accuracy to which V can be estimated. Methods: A literature search was undertaken of studies comparing TBW estimation using two or three of the following methods: isotopic dilution (gold standard), anthropometric equations (e.g. Watson formula) and bioimpedance analysis. Studies of healthy and dialysis populations of all ages were included. Mean differences and 95% limits of agreement (LOA) were extracted and pooled. Results: In 44 studies (31 including dialysis subjects), the between-method population means were typically within 1–1.5 L of each other, although larger bias was seen when applying anthropometric equations to different racial groups. However, the 95% LOA for all comparisons were consistently wide, typically ranging ±12–18% of the TBW. For a typical individual whose TBW is 35 L with a measured K t/ V of 1.7, this translates into a range of K t/ V 1.4–2.05. Conclusions: There are limitations to the accuracy of estimation of V which call into question the validity of applying a single threshold K t/ V value as indicative of adequate dialysis. This should be taken into account in guideline development such that if a target K t/ V was deemed appropriate that this should be expressed as a range; alternatively single targets should be avoided and dialysis dose should be determined according to patient need.
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Affiliation(s)
- Simon J Davies
- Faculty of Medicine and Health Sciences, Keele University, UK
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Sherman RA, Kapoian T. Inherent Errors in the Quantitation of Dialysis Delivery: Implications For CAPD and Daily Hemodialysis. ACTA ACUST UNITED AC 2016; 1:19-22. [DOI: 10.1111/hdi.1997.1.1.19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Medoua GN, Essa'a VJ, Tankou CT, Ndzana ACA, Dimodi HT, Ntsama PM. Validity of anthropometry- and impedance-based equations for the prediction of total body water as measured by deuterium dilution in Cameroonian haemodialysis patients. Clin Nutr ESPEN 2015; 10:e167-e173. [PMID: 28531471 DOI: 10.1016/j.clnesp.2015.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 05/29/2015] [Accepted: 05/29/2015] [Indexed: 01/01/2023]
Abstract
BACKGROUND & AIMS There is no available information on the validity of anthropometry- and impedance-based equations for predicting total body water (TBW) in Cameroonian haemodialysis patients. This study aimed to validate and develop predictive equations of TBW for Cameroonian haemodialysis patients. METHOD TBW in 40 Cameroonian haemodialysis patients (28 men and 12 women) was measured by deuterium dilution and compared with the one predicted by 7 anthropometric and 9 BIA equations. Multiple linear regression analysis was used to develop an equation for predicting TBW as measured by deuterium, from anthropometric parameters. RESULTS Pure errors in predicting TBW showed unacceptable value for all equations tested. In all the cases, unacceptable discrepancies at individual level for clinical purposes were noted. The following equation was developed and showed a better agreement with the deuterium dilution method: TBW = 13.8994 + 0.0017 × Age +0.3190 × Weight +1.8532 × Sex. CONCLUSION Further development and cross-validation of anthropometric and BIA prediction equations specific to African heamodialysis patient are needed. Meanwhile, the equation developed in this study which provided a better agreement with the isotope dilution could be use for Cameroonian haemodialysis patients.
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Affiliation(s)
- Gabriel Nama Medoua
- Centre for Food and Nutrition Research, IMPM, P O Box 6163, Yaoundé, Cameroon.
| | - Véronique J Essa'a
- Centre for Food and Nutrition Research, IMPM, P O Box 6163, Yaoundé, Cameroon
| | - Colman T Tankou
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Cameroon
| | | | - Henriette T Dimodi
- Centre for Food and Nutrition Research, IMPM, P O Box 6163, Yaoundé, Cameroon
| | - Patricia M Ntsama
- Centre for Food and Nutrition Research, IMPM, P O Box 6163, Yaoundé, Cameroon
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Tzamaloukas AH, Raj DSC, Onime A, Servilla KS, Vanderjagt DJ, Murata GH. The prescription of peritoneal dialysis. Semin Dial 2008; 21:250-7. [PMID: 18248525 DOI: 10.1111/j.1525-139x.2007.00412.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In addition to the maintenance of normal extracellular electrolyte composition, the prescription of continuous peritoneal dialysis (CPD) should address four other specific issues: (i) prevention of uremia by achievement of adequate clearance of azotemic substances, (ii) prevention of progressive expansion of the extracellular volume by adequate peritoneal ultrafiltration, (iii) prevention of loss of residual renal function, and (iv) prevention of deterioration of the peritoneal membrane structure and function. Urea clearance, in the form of Kt/V(Urea), is the index of removal of azotemic substances proposed by current guidelines. The target total (renal plus peritoneal) Kt/V(Urea) is >or=1.7 weekly. To provide the desired peritoneal Kt/V(Urea) (K(p)t/V(Urea)), the prescription of peritoneal dialysis must provide a daily drain volume (Dv) defined by the clearance equations as Dv = V x (K(p)t/V(Urea))/(D/P(Urea)), where V is body water obtained from published anthropometric formulas, K(p)t/V(Urea) = (1.7 - renal Kt/V(Urea))/7 and D/P(Urea) is the dialysate-to-plasma urea concentration ratio at the dwell time prescribed. Computer programs obtain the relevant D/P(Urea) values from formal studies of peritoneal transport. In the absence of these studies (for example, at initiation of CPD), D/P(Urea) values can be obtained from published studies with similar dwell times. Body size, indicated by V, is the major determinant of the K(p)t/V(Urea) limit provided by a given CPD schedule. Other obstacles to achievement of adequate urea clearance are created by poor patient compliance, inaccuracies of the anthropometric formulas estimating V, and mechanical complications of CPD that lead to retention of dialysate in the body. The main requirements for the prescription of adequate ultrafiltration are knowledge of the individual peritoneal transport characteristics, monitoring of urinary volume, and restriction of dietary sodium intake. Excessive dietary sodium intake is the major cause of extracellular volume expansion in CPD. Ideally, sodium intake should be kept at the level of total (peritoneal plus renal) sodium removal. Preventing the loss of residual renal function involves avoidance of nephrotoxic influences in the form of medications, radiocontrast agents, urinary obstruction and infection, and possibly other influences, such an elevated calcium-phosphorus product and anemia. Use of the lowest dialysate dextrose concentration that will allow adequate ultrafiltration is currently the most widespread practical measure of prevention of peritoneal membrane deterioration. Formulation of biocompatible dialysate is a major ongoing research effort and may greatly enhance the success of CPD in the future.
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Affiliation(s)
- Antonios H Tzamaloukas
- Renal Section, Department of Medicine, New Mexico VA Health Care System, 1501 San Pedro, SE, Albuquerque, NM 87108, USA.
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Lambie SH, Taal MW, Fluck RJ, McIntyre CW. Online Conductivity Monitoring: Validation and Usefulness in a Clinical Trial of Reduced Dialysate Conductivity. ASAIO J 2005; 51:70-6. [PMID: 15745138 DOI: 10.1097/01.mat.0000150525.96413.aw] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Relatively low dialysate conductivity (Cndi) may improve outcomes by reducing the overall sodium burden in dialysis patients. Excess sodium removal, however, could lead to hemodynamic instability. We performed a randomized controlled trial of reduction of Cndi. For the study, 28 patients were randomized to maintenance of Cndi at 13.6 mS/cm (equivalent to 135 mmol/L of Na+) or serial reduction of Cndi in steps of 0.2 mS/cm, guided by symptoms and blood pressure. Sodium removal estimated from pre- and postplasma concentrations correlated well with removal measured by conductivity monitoring as ionic mass balance (R2 0.66, p < 0.0001). Of the 16 patients randomized to reduction of Cndi, 6 achieved Cndi 13.4 mS/cm, 6 achieved 13.2 mS/cm, and 4 achieved 13.0 mS/cm. No episodes of disequilibrium occurred. Interdialytic weight gain was reduced from 2.34 +/- 0.10 kg to 1.57 +/- 0.11 kg (p < 0.0001). Predialysis systolic blood pressure fell from 144 +/- 3 mm Hg to 137 +/- 4 mm Hg (p < 0.05). The reduction in convective sodium removal was balanced by an increase in diffusive sodium removal (95 +/- 9 mmol cf. 175 +/- 14 mmol, p < 0.0001). Reduction in Cndi monitored by IMB is safe and practical and leads to improved interdialytic weight gains and blood pressure control, while avoiding excessive sodium removal.
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Affiliation(s)
- Stewart H Lambie
- Department of Renal Medicine, Derby City General Hospital, Uttoxeter Road, Derby DE22 3NE
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15
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Piccoli A. Bioelectric impedance vector distribution in peritoneal dialysis patients with different hydration status. Kidney Int 2004; 65:1050-63. [PMID: 14871426 DOI: 10.1111/j.1523-1755.2004.00467.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND In continuous ambulatory peritoneal dialysis (CAPD), total body water (TBW) is estimated by functions of body weight, and by equations of bioelectric impedance analysis (BIA). These procedures may be biased with abnormal tissue hydration. We validated vector BIA (BIVA) patterns of hydration in CAPD patients, based on direct measurements of resistance (R) and reactance (Xc) (RXc graph) without knowledge of the body weight. METHODS Cross-sectional study in 200 adult CAPD patients from two groups: 149 patients (77 males and 72 females) without edema (BMI 24.3 kg/m2), and 51 (29 males and 22 females) with pitting edema (BMI 24.6 kg/m2). Single frequency (50 kHz), whole-body impedance vector was measured with both empty and filled peritoneal cavity. Vector distribution was compared with that from 726 healthy subjects, 1116 hemodialysis patients, and 50 nephrotic patients, all with a same BMI. The performance of BIVA was compared with indications of four anthropometry and four conventional BIA equations for TBW. RESULTS TBW estimates from anthropometry (Watson, Hume and Weyers, Chertow, and Johansson formulas) were misleading, indicating the same hydration in edema. TBW estimates from BIA equations indicated a 10% excess TBW in edema. BIVA were very sensitive to fluid overload, as both R (by 10%) and Xc (by 40%) were reduced in patients with edema (regardless of peritoneal filling). The vector distribution of individual CAPD patients without edema was superposable to that of the healthy, gender-specific, reference population (50%, 75%, and 95% tolerance ellipses, RXc graph) and close to the hemodialysis, presession distribution. Vectors from patients with edema were displaced downward on the RXc graph, out of the 75% ellipse (88% sensitivity and 87% specificity), and close to vectors from nephrotic patients. CONCLUSION CAPD prescription would keep or bring vectors of patients back into the 75% reference ellipse (border for progression from latent to apparent overhydration across the lower pole) regardless of body weight. Whether CAPD patients with vector within the target ellipse have better outcome needs longitudinal evaluation.
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Affiliation(s)
- Antonio Piccoli
- Department of Medical and Surgical Sciences, Nephrology Clinic, University of Padova, Padova, Italy.
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Tzamaloukas AH, Murata GH, Vanderjagt DJ, Glew RH. Estimates of body water, fat-free mass, and body fat in patients on peritoneal dialysis by anthropometric formulas. Kidney Int 2003; 63:1605-17. [PMID: 12675836 DOI: 10.1046/j.1523-1755.2003.00900.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Anthropometric formulas that are used to estimate body water in peritoneal dialysis patients can also be used to estimate fat-free mass and body fat. Evaluation of body composition by the anthropometric formulas rests on two assumptions: (1) fat contains no water, and (2) the water content of the fat-free mass is constant (72%). METHODS We compared estimates of body water, fat-free mass, and body fat by anthropometric formulas to estimates employing dilution of tracer substances to measure body water and standard methods to analyze body composition in studies performed on peritoneal dialysis patients. We also analyzed the potential errors of the estimates of body composition by the formulas. RESULTS Estimates of the average body composition provided by the anthropometric formulas agreed with estimates provided by the standard methods. However, these formulas have the potential of introducing large errors when estimating body composition in individuals differing from the average subject, either because the anthropometric formulas do not account for major determinants of body composition, such as physical exercise, nutrition, and catabolic illness, or because these formulas systematically overestimate body water in subjects who are obese or experiencing volume excess. CONCLUSION Anthropometric formulas currently in existence can provide only approximations of body composition and may be the sources of large errors in evaluating body composition in peritoneal dialysis patients. The potential errors include estimates of body water. These errors may alter the interpretation of urea kinetic studies in certain categories of peritoneal dialysis patients (e.g., obese subjects).
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Affiliation(s)
- Antonios H Tzamaloukas
- Medicine Service, New Mexico Veterans Affairs Health Care System and University of New Mexico School of Medicine, Albuquerque, New Mexico 87108, USA.
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Castillo AA, Lew SQ, Smith AM, Whyte RL, Bosch JP. Discrepancies between adequacy goals in peritoneal dialysis: role of gender. Am J Kidney Dis 2002; 40:1301-5. [PMID: 12460051 DOI: 10.1053/ajkd.2002.36907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND The National Kidney Foundation-Dialysis Outcome Quality Initiative (NKF-DOQI) recommends a weekly creatinine clearance (CrCl) of 60 L/wk/1.73 m2 or greater and a Kt/V of 2.0 or greater as peritoneal dialysis (PD) adequacy standards. It has been described that approximately one quarter of patients may have discrepancies between these goals. The purpose of this study is to identify associated factors in patients reaching both criteria, none, or only weekly Kt/V, where K is clearance, t is time, and V is volume. METHODS We studied 64 patients and their adequacy results in a cross-sectional analysis. Patients were divided in three groups. Group 1 reached both weekly Kt/V and CrCl criteria. Group 2 did not reach either criteria. Group 3 reached only the weekly Kt/V criterion. A new weekly Kt/V also was calculated, assigning to all patients a male V. One patient who met only the CrCl criterion was excluded. RESULTS Groups 2 and 3 had significantly less residual renal function (RRF) than group 1 (residual CrCl, 5.50 and 1.33 versus 37.3 L/wk/1.73 m2, respectively; P < 0.001). Other differences, such as age, weight, peritoneal membrane transport, nutritional parameters, or number of patients with diabetes, were not significantly different. Group 3 made up 19% of patients and was predominantly females. Conversely, group 2 was predominantly males. Using a male V, we obtained a weekly Kt/V below the NKF-DOQI recommendations for group 3 (1.9 versus 2.2; P < 0.05). CONCLUSION Conservation of RRF was the main factor in reaching both PD adequacy criteria. Discrepancies were frequent, accounting for 19% of our population. Female gender explained why patients reached weekly Kt/V only. This difference disappeared when we calculated Kt/V using a male V.
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Affiliation(s)
- Alvaro A Castillo
- Department of Medicine, Division of Renal Diseases and Hypertension, The George Washington University Medical Center, Washington, DC 20037, USA
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Shibagaki Y, Faber MD, Divine G, Shetty A. Feasibility of adequate solute clearance in obese patients on peritoneal dialysis: a cross-sectional study. Am J Kidney Dis 2002; 40:1295-300. [PMID: 12460050 DOI: 10.1053/ajkd.2002.36904] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND It is widely assumed that obese patients are poorly suited for peritoneal dialysis (PD). Mathematical models predicting weight limits to achieve adequate solute clearance in anuric patients on continuous ambulatory PD therapy do not apply to the majority of obese patients on PD therapy. METHODS To define the extent to which obesity or large body size interferes with successful PD, the feasibility of achieving adequate solute clearance, defined by the Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines, was studied. We reviewed prospectively recorded data for 25 obese patients (body mass index > or = 29) from a group of 58 prevalent PD patients treated in an inner-city ambulatory dialysis center. Adequacy of solute clearances was assessed by comparing weekly Kt/V and weekly creatinine clearance (WCC) with those recommended by the K/DOQI. Adequacy also was examined separately for large patients, defined as those with total-body water (TBW) by the Watson and Watson equation of 48 L or greater. Similar analyses were performed separately for 10 anuric obese patients. RESULTS Eighty four percent and 88% of the 25 obese patients achieved K/DOQI targets for weekly Kt/V and WCC, respectively. Among the 10 anuric obese patients, 90% and 70% achieved these targets. Only 60% of those with TBW of 48 L or greater met the Kt/V target. CONCLUSION PD remains a viable option for obese patients with end-stage renal disease. It is possible for the majority of obese patients on PD therapy to achieve solute clearances recommended by the K/DOQI.
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Affiliation(s)
- Yugo Shibagaki
- Division of Nephrology and Department of Biostatistics and Research Epidemiology, Henry Ford Hospital, Detroit, MI, USA
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Wang AYM, Sea MMM, Ip R, Law MC, Chow KM, Lui SF, Li PKT, Woo J. Independent effects of residual renal function and dialysis adequacy on dietary micronutrient intakes in patients receiving continuous ambulatory peritoneal dialysis. Am J Clin Nutr 2002; 76:569-76. [PMID: 12198001 DOI: 10.1093/ajcn/76.3.569] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Dialysis patients are at risk of vitamin and mineral deficiencies, not only because of losses during chronic hemodialysis or peritoneal dialysis but also because of low intakes. OBJECTIVE The objective was to determine the importance of urea clearance (calculated as K(t)/V) and residual renal function (RRF) in predicting micronutrient intakes in a large cohort of patients receiving continuous ambulatory peritoneal dialysis (CAPD). DESIGN We conducted a survey of dietary intakes in 242 CAPD patients and divided them into 3 groups according to their weekly urea clearance and RRF: WD group (n = 84), a urea clearance >/= 1.7 and a glomerular filtration rate (GFR) >/= 1 mL x min(-1) x 1.73 m(-2); DD group (n = 71), a urea clearance >/= 1.7 and a GFR < 1 mL x min(-1) x 1.73 m(-2); and ID group (n = 87), a urea clearance < 1.7. RESULTS Most of the patients had intakes of water-soluble vitamins and minerals that were lower than the recommended dietary allowance; most intakes were significantly higher in the WD group than in the DD and ID groups, except those of niacin and calcium. After age, sex, body weight, and the presence of diabetes were controlled for, total weekly urea clearance and the GFR (but not peritoneal dialysis urea clearance) were significantly associated with intakes of vitamins A and C, the B vitamins, and minerals (calcium, phosphate, iron, and zinc). Low intakes of vitamins and minerals with low RRF and urea clearance were the result of reduced overall food intakes, except for thiamine, vitamin B-6, and folic acid, which were deficient in the diet. CONCLUSIONS Supplementation with most water-soluble vitamins and minerals, including iron and zinc, should be considered in CAPD patients, especially those with low RRF and low urea clearance. The optimal dose needs to be determined.
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Affiliation(s)
- Angela Yee-Moon Wang
- Department of Medicine & Therapeutics, Center for Nutritional Studies, Prince of Wales Hospital, Chinese University of Hong Kong.
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Johansson AC, Samuelsson O, Attman PO, Bosaeus I, Haraldsson B. Limitations in anthropometric calculations of total body water in patients on peritoneal dialysis. J Am Soc Nephrol 2001; 12:568-573. [PMID: 11181805 DOI: 10.1681/asn.v123568] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Having an accurate estimation of total body water (TBW) is essential for the evaluation of dialysis efficacy in peritoneal dialysis (PD) patients. In this study, TBW volumes were measured by tritium dilution (TBW(THO)) in 165 PD patients and compared with TBW calculations according to the Watson formulas. An alternative anthropometric formula based on the present PD population was also developed and validated in an independent sample of 29 PD patients. Furthermore, the relation between TBW(THO) and body surface area (BSA) according to the formula of Gehan was analyzed. Body composition was assessed by a four-compartment model, based on measurements of TBW(THO) and total body potassium. Mean values of TBW by the Watson formulas were almost identical to TBW(THO), and the correlation coefficient for the relationship of calculated to measured volumes was 0.89 (P = 0.001). However, both anthropometric formulas-the Watson formulas as well as the new, alternative one-overestimated TBW in obese patients and vice versa in lean patients. Similarly, TBW was underestimated in patients who were overhydrated. The correlation coefficient between TBW(THO) and BSA was 0.708 for males and 0.797 for females (P = 0.0001 for both). In obese patients, the relationship was even closer (r = 0.924 and 0.911, respectively). In conclusion, anthropometric formulas to calculate TBW showed a considerable intraindividual variability compared with measured values. This was related to body composition features, such as degree of obesity and hydration. In contrast, BSA correlated closely to TBW in obese individuals. TBW as estimated by anthropometric formulas must be analyzed with caution, especially in the very obese or very lean patient.
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Affiliation(s)
| | - Ola Samuelsson
- Department of Nephrology, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Per Ola Attman
- Department of Nephrology, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Ingvar Bosaeus
- Department of Clinical Nutrition, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Börje Haraldsson
- Department of Physiology, Sahlgrenska University Hospital, Göteborg, Sweden
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22
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Oe B, de Fijter CW, Geers TB, Vos PF, Donker AJ, de Vries PM. Diameter of inferior caval vein and impedance analysis for assessment of hydration status in peritoneal dialysis. Artif Organs 2000; 24:575-7. [PMID: 10916069 DOI: 10.1046/j.1525-1594.2000.06502.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In 19 stable peritoneal dialysis (PD) patients, hydration status was evaluated by measurement of vena cava diameter (VCD) and bioelectrical impedance analysis (BIA) variables: intracellular water (ICW), extracellular water (ECW), and total body water (TBW). We investigated whether BIA can replace VCD. VCD did not correlate with TBW but correlated moderately with ECW/TBW (r = 0.42; 0.025 < p < 0.05) and ICW/ECW (r = -0.47; p < 0.025). Patients with underhydration (n = 4; VCD <8 mm/m2) revealed limits for BIA variables as ICW/ECW (>1.50) and ECW/TBW (<0.40). The same held true for overhydration (n = 5; VCD >11.5 mm/m2): ICW/ECW (<1.50) and ECW/TBW (>0.40). Although the positive predictive value of ICW/ECW and ECW/TBW for both under- and overhydration was only 50% and 54%, respectively, there were no false negative values. Although BIA cannot replace VCD in PD patients, the reverse holds true as well. Combining BIA and VCD may lead to a better estimation of hydration status because both techniques provide complementary information.
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Affiliation(s)
- B Oe
- Cardiovascular Research School ICaR-VU, Department of Internal Medicine, Academic Hospital Vrije Universiteit, Amsterdam, The Netherlands
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Cooper BA, Aslani A, Ryan M, Zhu FY, Ibels LS, Allen BJ, Pollock CA. Comparing different methods of assessing body composition in end-stage renal failure. Kidney Int 2000; 58:408-16. [PMID: 10886589 DOI: 10.1046/j.1523-1755.2000.00180.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Accurate measurement of nutritional status in patients with end-stage renal disease is important because of its clear association with prognosis. Total body water (TBW) has additionally been recently recognized as an independent prognostic value because of its relationship with hypertension and cardiac morbidity. The current study was designed to assess the utility of surrogate markers of nutritional state and TBW in patients with end-stage renal disease. METHODS Fifty-four patients with renal disease were studied. TBW obtained using the deuterium dilution technique was compared with estimates derived from anthropometric measures of TBW, including 58% body weight, Watson equations, and bioelectrical impedance analysis (BIA). Anthropometrically derived fat-free mass (FFM) was compared with BIA-derived estimates. Total body nitrogen (TBN) measurements were correlated with TBW estimates and BIA-derived resistance. RESULTS TBW was significantly underestimated by the Watson equation (mean difference, -1.751 L, P = 0.01) and the 58% body weight approximation significantly overestimated it (mean difference, 1.792 L, P = 0.04). The Kushner BIA estimation of TBW did not significantly differ from that of the gold standard determined from D2O dilution (mean difference, -1.221 L, P = 0.12) and was also the method that showed the best agreement with the D2O estimate. However, the limits of agreement were large. Accurate prediction equations for FFM (FFM = -21.768 + 0.001 x ht2 + 6630.669 x 1/R + 0.312 x wt, R2 = 0.95) and TBN (TBN = -668.324 - 3.963 x age + 10.133 x wt + 0. 045 x ht2 + 32141.457 x 1/R, R2 = 0.91) were derived from BIA obtained resistance. CONCLUSIONS The estimation of TBW varies significantly depending on the method of calculation. BIA is the most accurate surrogate marker for the measurement of both TBW and other parameters of body composition.
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Affiliation(s)
- B A Cooper
- Department of Renal Medicine, Royal North Shore Hospital, University of Sydney, New South Wales, Australia
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25
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Rao M, Sharma M, Juneja R, Jacob S, Jacob CK. Calculated nitrogen balance in hemodialysis patients: influence of protein intake. Kidney Int 2000; 58:336-45. [PMID: 10886580 DOI: 10.1046/j.1523-1755.2000.00171.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Optimal nutrient intake is important in the maintenance of a positive nitrogen balance in hemodialysis (HD) patients. The objectives of this study were (1) to assess the influence of two levels of protein intakes on nitrogen balance in stable adult HD patients, and (2) to identify a minimum level of protein intake that would result in a negative nitrogen balance, so that preliminary recommendations may be made in Indian patients on maintenance HD (MHD). METHODS Stable, adult, nondiabetic MHD patients were recruited after informed consent into a cross over trial with a high-protein (HP) diet [1.2 g/kg ideal body weight (IBW)/day), followed by a low-protein (LP) diet (0.6 g/kg IBW/day] after appropriate periods of equilibration; for both diets, 50% of protein was of high biological value, and calorie intake was 35 kCal/kg IBW/day. Duplicate meals and residues were weighed, homogenized, and stored at -20 degrees C for analysis of dietary N by the Kjeldahl method, used to check the consistency of the N content of the diet supplied. Pre- and post- (30-minute equilibrated) blood urea samples were drawn, and details of weights and other HD parameters were recorded. Interdialytic urine collections for urea were obtained. N input came from dietary protein calculated as 16% of the weight of biological protein; N output was calculated using blood-side urea measurements and urinary urea excretion and was the sum of urea N (UN) and nonurea N (NUN) losses (assumed to be equal to 0.031 g N/kg/day). RESULTS Fifteen patients were recruited. Twelve patients completed both limbs of the study. The mean age was 30.3 +/- 12.7 years. The body mass index was 18.9 +/- 2.4. Serum albumin was 3.8 +/- 0.35 g/dL, and Kt/V (equilibrated) was 1.17 +/- 0.3 g/dL. Protein consumed was 1.06 +/- 0.18 g/kg IBW/day in the HP limb versus 0.61 +/- 0.1 g/kg IBW/day in the LP limb (P = 0.000). Energy intake was 33 +/- 6.5 vs. 32.8 +/- 6. 7 kCal/kg IBW/day, respectively (P = 0.8). The normalized protein N appearance (nPNA) was 0.88 +/- 0.2 g/kg/day in the HP limb versus 0. 78 +/- 0.2 g/kg/day in the LP limb (P = 0.02). Dietary N was 73.5 +/- 15.3 g in the HP week and 42.5 +/- 7.5 g in the LP week (P = 0. 000). The difference between this and the sum of (UN + NUN) losses over the week was 29 +/- 13.2 g versus 1.2 +/- 8.1 g, respectively (P = 0.001), showing a strong, uniformly positive nitrogen balance with HP diet and neutral to negative nitrogen balance with LP diet. The ratio of dietary protein intake (DPI) to nPNA was significantly lower (anabolic) in the HP limb (0.7 +/- 0.2 vs. 1.12 +/- 0.3, P = 0. 000). On a scatter plot of nPNA to DPI, a catabolic relationship was demonstrated below a DPI of 0.75 g/kg/day (95% CI, 0.65 to 0.85 g/kg/day). CONCLUSION A DPI of approximately 1.1 g/kg/day produces a positive nitrogen balance and 0.6 g/kg/day a neutral to negative nitrogen balance, demonstrating protein anabolism as a function of protein intake. It is suggested that a protein intake of 0.85 g/kg/day should be considered unsafe. These conclusions apply in stable nondiabetic adult HD patients in the setting of adequate dialysis and adequate calorie intake.
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Affiliation(s)
- M Rao
- Department of Nephrology, Christian Medical College and Hospital, Vellore, India.
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26
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Assessing Adequacy of Peritoneal Dialysis. Int J Artif Organs 1999. [DOI: 10.1177/039139889902200702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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27
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Jager KJ, Merkus MP, Dekker FW, Boeschoten EW, Tijssen JG, Stevens P, Bos WJ, Krediet RT. Mortality and technique failure in patients starting chronic peritoneal dialysis: results of The Netherlands Cooperative Study on the Adequacy of Dialysis. NECOSAD Study Group. Kidney Int 1999; 55:1476-85. [PMID: 10201013 DOI: 10.1046/j.1523-1755.1999.00353.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Recent studies have shown an association between small solute clearance and patient survival. Thus far, little attention has been paid to the potential effects of fluid overload. The aim of this study was to determine the relative importance of baseline patient and treatment characteristics to mortality and technique failure in patients starting peritoneal dialysis. METHODS One hundred and eighteen consecutive new patients were included in this prospective multicenter cohort study. Cox proportional hazards regression was used to predict mortality and technique failure. RESULTS There were 33 deaths and 44 technique failures. The two-year patient survival was 77%, and the two-year technique survival was 64%. Age, systolic blood pressure, and the absolute quantity of small solutes removed at baseline were independent predictors of mortality. A one-year increase in age was associated with a relative risk (RR) of death of 1.05 (95% CI, 1.01 to 1.09) and a 10 mm Hg rise in systolic blood pressure, with a RR of 1.42 (95% CI, 1.17 to 1.73). The removal of 1 mmol/week/1.73 m2 of urinary and dialysate creatinine was associated with a RR of death of 0.95 (95% CI, 0.92 to 0.98) and 0.93 (95% CI, 0.89 to 0.98). The removal of urea had a similar association with the RR of death. Predictors for technique failure were urine volume, peritoneal ultrafiltration, and systolic blood pressure. CONCLUSIONS Dialysate solute removal was an independent predictor of mortality. The association between systolic blood pressure and mortality shows that the maintenance of fluid balance and the removal of small solutes deserve equal attention.
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Affiliation(s)
- K J Jager
- Department of Nephrology, Academic Medical Center, University of Amsterdam, The Netherlands.
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Xiong DW, Borovnicar DJ, Stroud DB, Wahlqvist ML, Strauss BJ. Determination of total body water by IVNAA and 40K counting in young normal and growth hormone deficient adults. Appl Radiat Isot 1998; 49:671-2. [PMID: 9569575 DOI: 10.1016/s0969-8043(97)00229-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- D W Xiong
- Body Composition Laboratory, Monash Medical Centre & Monash University Department of Medicine, Clayton, Victoria, Australia
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Leypoldt JK, Cheung AK. Evaluating volume status in hemodialysis patients. ADVANCES IN RENAL REPLACEMENT THERAPY 1998; 5:64-74. [PMID: 9477217 DOI: 10.1016/s1073-4449(98)70016-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Accurate determination of the volume and distribution of body fluids in end stage renal disease patients will permit improved assessment of dry weight and strategies for optimal fluid removal. Certain biochemical markers and anatomical measures have been proposed as markers of dry weight, but these markers primarily reflect the volume of the intravascular compartment and may not reflect total body volume status. Noninvasive determination of total body water and extracellular fluid volumes using bioimpedance analyses has also been proposed for assessment of dry weight, but such determinations do not yet have sufficient accuracy for routine use. Several devices have been recently developed for continuously monitoring changes in blood volume on-line during routine hemodialysis. Such blood volume monitors cannot be used to determine dry weight directly; however, continuous monitoring of blood volume can be used to detect fluid overload because intradialytic changes in blood volume are small in hemodialysis patients who are overhydrated. Furthermore, continuous monitoring of blood volume can be used to predict symptoms resulting from intradialytic hypovolemia. The combined use of blood volume monitoring and time-dependent ultrafiltration and dialysate sodium profiles will be used increasingly in the future to assist in the prevention of hypotension and symptoms that result from intradialytic hypovolemia, especially when automated systems for controlling intradialytic blood volume are individualized and shown to be safe and effective.
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Affiliation(s)
- J K Leypoldt
- Veterans Affairs Medical Center; and Department of Internal Medicine, University of Utah, Salt Lake City 84112, USA
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Davies S, Spanel P, Smith D. Quantitative analysis of ammonia on the breath of patients in end-stage renal failure. Kidney Int 1997; 52:223-8. [PMID: 9211367 DOI: 10.1038/ki.1997.324] [Citation(s) in RCA: 179] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- S Davies
- Department of Renal Medicine, North Staffordshire Hospitals, Stoke-on-Trent, United Kingdom
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Coomer RW, Schulman G, Breyer JA, Shyr Y. Ambulatory blood pressure monitoring in dialysis patients and estimation of mean interdialytic blood pressure. Am J Kidney Dis 1997; 29:678-84. [PMID: 9159300 DOI: 10.1016/s0272-6386(97)90119-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To define blood pressure (BP) patterns and control in dialysis patients, 48-hour ambulatory BP monitoring was performed in 36 hemodialysis and 18 peritoneal dialysis patients. Monitoring began during a dialysis session for hemodialysis patients. Data revealed significantly lower diastolic BP (DBP) and lower diastolic load (percentage of diastolic values > 90 mm Hg) in hemodialysis patients compared with peritoneal dialysis patients (80.6 mm Hg v 88.8 mm Hg, respectively, [P < 0.03] and 26% v 45%, respectively [P < 0.03]) for the 48-hour period. When the 2 days were analyzed separately, the difference in diastolic pressures and loads was significant only for the first (dialysis) day. Similarly, trends toward lower systolic BP (SBP) and systolic load in hemodialysis patients existed throughout monitoring and were greater in magnitude during the first day. BP data were fit to a random-coefficient growth curve model to detect periodicity. This sensitive model did not detect diurnal variation of BP in either group. The incidence of hypotension did not differ between the two groups (2.0% v 1.0% of total observations, hemodialysis v peritoneal dialysis). In the hemodialysis group, the proportion of hypotensive observations was significantly greater during the 4 hours postdialysis compared with other periods (5.6% v 1.6%; P < 0.02), a finding that likely reflects the practice of holding antihypertensives until after hemodialysis. However, patient diaries did not reflect hypotensive symptoms during this time. In the hemodialysis group, mean BP and predialysis BP did not correlate with interdialytic sodium load or weight gain. Predialysis and postdialysis BP (recorded by dialysis nurses) correlated significantly with mean BP. Predialysis SBP overestimated mean SBP by an average of 10 mm Hg, while postdialysis SBP underestimated mean SBP by an average of 7 mm Hg. To create formulas to estimate mean SBP and DBP in hemodialysis patients, multiple linear regression was used to model these variables against age, sex, race, and average prehemodialysis/posthemodialysis BP. The model achieved a high degree of fit (r2 = 0.72 for SBP; r2 = 0.65 for DBP), demonstrating that prehemodialysis and posthemodialysis BP can be used to predict mean BP in hemodialysis patients. In summary, our data show the absence of a diurnal variation of BP in dialysis patients and lower BP in hemodialysis patients compared with peritoneal dialysis patients. Among hemodialysis patients, more hypotension occurred after dialysis compared with other periods, and predialysis and postdialysis BP can be used to model mean BP levels.
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Affiliation(s)
- R W Coomer
- Division of Nephrology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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CHURCHILL DAVIDN. An evidence based medicine approach to determining the adequacy of peritoneal dialysis. Nephrology (Carlton) 1996. [DOI: 10.1111/j.1440-1797.1996.tb00162.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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KERR PG, XIONG DW, HOWARD J, McGEE O, STRAUSS BJG, ATKINS RC. Evaluation of an in-line dialysate urea monitor including assessment of 'V'. Nephrology (Carlton) 1996. [DOI: 10.1111/j.1440-1797.1996.tb00087.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Affiliation(s)
- P G Blake
- Optimal Dialysis Research Unit, Division of Nephrology, Victoria Hospital, London, Ontario, Canada
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