Publications by authors named "Keshaviah P"

Several studies have recently confirmed that hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) survival is highly associated with delivered therapy Kt/V(urea). A direct comparison of equivalently dosed CAPD and HD has not previously been performed. A total of 968 incident HD patients at the Regional Kidney Disease Program from 1987 to June 1995 were studied, and these results were compared with those of the Canadian-United States prospective trial (CANUSA) consisting of 680 incident CAPD patients from September 1990 to December 31, 1992, with follow-up through December 31, 1993.

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India has made great strides in health care since gaining independence in 1947. Much still needs to be done. Scarce health care resources are directed at priorities that include infant and maternal mortality, immunizations, malnutrition, communicable disease prevention, and access to protected water and sanitation.

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The traditional approach of initiating dialysis when the patient begins to manifest uremic symptoms may result in the development of significant malnutrition with detrimental effects on subsequent morbidity and mortality. The recently issued Dialysis Outcome Quality Initiative guidelines suggest that dialysis be initiated when the Kt/V from residual renal function decreases to less than 2.0.

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Background: The postdialysis blood urea nitrogen (BUN; Ct) is a pivotal parameter for assessing hemodialysis adequacy by conventional blood-side methods, but Ct is relatively unstable because of hemodialysis-induced disequilibrium. The uncertainty associated with this method is potentially reduced or eliminated by measuring urea removed on the dialysate side, a more direct approach that can determine adequacy from the fraction of urea removed and by substituting an estimate of the equilibrated postdialysis BUN (Ceq) for Ct. For a patient with a known urea volume (V), Ceq, the equilibrated Kt/V (eKt/V), and the solute removal index (SRI) can be calculated from the predialysis BUN (C0), total urea nitrogen removed (A), and V from simple mass balance calculations (dialysate/volume method).

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The objective of this study was to evaluate the association of peritoneal membrane transport with technique and patient survival. In the Canada-USA prospective cohort study of adequacy of continuous ambulatory peritoneal dialysis (CAPD), a peritoneal equilibrium test (PET) was performed approximately 1 mo after initiation of dialysis; patients were defined as high (H), high average (HA), low average (LA), and low (L) transporters. The Cox proportional hazards method evaluated the association of technique and patient survival with independent variables (demographic and clinical variables, nutrition, adequacy, and transport status).

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The ongoing HEMO Study, a National Institutes of Health (NIH) sponsored multicenter trial to test the effects of dialysis dosage and membrane flux on morbidity and mortality, was preceded by a Pilot Study (called the MMHD Pilot Study) designed to test the reliability of methods for quantifying hemodialysis. Dialysis dose was defined by the fractional urea clearance per dialysis determined by the predialysis BUN and the equilibrated postdialysis BUN after urea rebound is completed (eKt/V). In the Pilot Study the blood side standard for eKt/V was calculated from the predialysis, postdialysis, and 30-minute postdialysis BUN.

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In a prospective cohort study of 680 incident continuous peritoneal dialysis (PD) patients in North America, dialysis in the United States compared with Canada was associated with a relative risk (RR) of death of 1.93 (95% confidence interval [CI], 1.14 to 3.

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The dialyzer mass transfer-area coefficient (KoA) for area is an important determinant of urea removal during hemodialysis and is considered to be constant for a given dialyzer. We determined urea clearance for 22 different models of commercial hollow fiber dialyzers (N = approximately 5/model, total N = 107) in vitro at 37 degrees C for three countercurrent blood (Qb) and dialysate (Qd) flow rate combinations. A standard bicarbonate dialysis solution was used in both the blood and dialysate flow pathways, and clearances were calculated from urea concentrations in the input and output flows on both the blood and dialysate sides.

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It has recently been suggested that sonophoresis, or the application of ultrasound (US) in the kilohertz range, could enhance peritoneal mass transport. To examine this hypothesis, six nephrectomized rabbits were exposed to ultrasound while under isoflurane anesthesia. An additional five also had bilateral nephrectomies and were used as a control group.

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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.

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Quantification of the dialysis dose and assessment of nutritional status and response to nutritional therapy have become standard parts of the management of the chronic dialysis patient. Although advances in these areas have led to a more rational basis for therapy, certain misconceptions and points of confusion appear to have occurred. Recognizing the importance of a standard nomenclature to the development of concepts and the communication of research findings, we have attempted to compile a list of terms that are commonly used in the field of dialysis.

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Recent studies suggest that the relationship of the net normalized protein catabolic rate (which is the normalized protein equivalent of nitrogen appearance [nPNA]) to the weekly clearance of urea normalized to total body water (Kt/V urea) in patients on continuous ambulatory peritoneal dialysis (CAPD) is curvilinear, rather than linear, as has been thought. The authors have reexamined the relationship of nPNA to weekly Kt/V urea in a CAPD population by cross-sectional analysis to see if the curvilinear definition of the relationship is as good as or better than the usual linear description. They also examined this relationship in the hemodialysis populations at the Dialysis Clinics Inc.

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Lean body mass (LBM), which is fat free body mass, can be used as an index of nutritional status. We evaluated three techniques for LBM estimation, including dual energy x-ray absorptiometry (DEXA), creatinine kinetics (CrKin), and bioimpedance (BI) in 10 patients on continuous ambulatory peritoneal dialysis (CAPD). Two different formulae were applied for BI LBM estimation, Segal (S) and Deurenberg (D).

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Dialyzer small-molecule clearance measurements are commonly made to help identify the cause of inadequate dialysis prescriptions, to determine the efficacy of reuse procedures, or to choose between different types of dialyzers. Clearance measurements can be blood-side- or dialysate-side-based. While blood-side clearance measurement is the classical technique, it suffers from several serious flaws that decrease its accuracy.

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The removal-based SRI can be applied to the CAPD setting, and this new index of dialysis dose is numerically equal to the KT/V for a continuous therapy like CAPD. This is not true for hemodialysis where the SRI is numerically lower than the KT/V. If therapy prescriptions for CAPD, APD, and HD are all adjusted to provide the same removal at the same predialysis BUN, then the values of SRI will be the same in all three modalities despite differences in the frequency and duration of the therapy modalities.

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The BioStat 1000 is a new device which employs dialysate-based urea kinetics to calculate the dose of dialysis (Kt/V) based on a two-pool model and protein catabolic rate (PCR). Previous methods relying on blood sampling techniques were subject to error and difficult to implement. This paper describes the features of the Biostat and the results of the first clinical validation study with an early prototype.

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A peritoneal dialysate fill volume of 2 L has become the standard of clinical practice, but the relationships between body size, fill volume, and mass transfer area coefficient (KoA) have not been well established. These relationships were studied in 10 stable peritoneal dialysis patients who underwent six peritoneal equilibration studies (2 h each) at fill volumes of 0.5, 1, 1.

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The mortality of dialysis patients in the United States has been a concern since the US Renal Data System 1989 report, which showed a lower survival rate in the United States compared with Europe. The differences were thought to be multifactorial, including case mix, malnutrition, and adequacy of dialysis. We reviewed the Regional Kidney Disease Program's 1976 to 1989 database for the pattern of co-morbidity, dialysis therapy, and low serum albumin in 1,082 nondiabetic and 691 diabetic patients followed to September 15, 1991.

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To evaluate different methods of measuring lean body mass (LBM) in chronic peritoneal dialysis (CPD) patients, we first made comparisons in seven normal subjects. Seven methods (total body potassium [TBK] counting, bioelectrical impedance with calculations according to Segal and Deurenberg, near-infrared interactance with and without exercise level included as a variable, anthropometric measurements, and creatinine kinetics) were compared with the standard method of underwater weighing (UW) for measuring LBM. Significant correlations with LBM measured by UW (r > 0.

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A new technique for estimating lean body mass (LBM) from creatinine kinetics has been developed. It is based on the principle that creatinine production is proportional to LBM and that, in the steady state, creatinine production is equal to the sum of creatinine excretion (urinary and dialytic) and metabolic degradation. This technique was applied to 17 normal subjects, 26 stable, chronic hemodialysis (HD) patients, and 71 stable, chronic peritoneal dialysis (PD) patients.

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