Effect of ramipril vs amlodipine on renal outcomes in hypertensive nephrosclerosis: a randomized controlled trial.

CONTEXT: Incidence of end-stage renal disease due to hypertension has increased in recent decades, but the optimal strategy for treatment of hypertension to prevent renal failure is unknown, especially among African Americans. OBJECTIVE: To compare the effects of an angiotensin-converting enzyme (ACE) inhibitor (ramipril), a dihydropyridine calcium channel blocker (amlodipine), and a beta-blocker (metoprolol) on hypertensive renal disease progression. DESIGN, SETTING, AND PARTICIPANTS: Interim analysis of a randomized, double-blind, 3 x 2 factorial trial conducted in 1094 African Americans aged 18 to 70 years with hypertensive renal disease (glomerular filtration rate [GFR] of 20-65 mL/min per 1.73 m(2)) enrolled between February 1995 and September 1998. This report compares the ramipril and amlodipine groups following discontinuation of the amlodipine intervention in September 2000. INTERVENTIONS: Participants were randomly assigned to receive amlodipine, 5 to 10 mg/d (n = 217), ramipril, 2.5 to 10 mg/d (n = 436), or metoprolol, 50 to 200 mg/d (n = 441), with other agents added to achieve 1 of 2 blood pressure goals. MAIN OUTCOME MEASURES: The primary outcome measure was the rate of change in GFR; the main secondary outcome was a composite index of the clinical end points of reduction in GFR of more than 50% or 25 mL/min per 1.73 m(2), end-stage renal disease, or death. RESULTS: Among participants with a urinary protein to creatinine ratio of >0.22 (corresponding approximately to proteinuria of more than 300 mg/d), the ramipril group had a 36% (2.02 [SE, 0.74] mL/min per 1.73 m(2)/y) slower mean decline in GFR over 3 years (P =.006) and a 48% reduced risk of the clinical end points vs the amlodipine group (95% confidence interval [CI], 20%-66%). In the entire cohort, there was no significant difference in mean GFR decline from baseline to 3 years between treatment groups (P =.38). However, compared with the amlodipine group, after adjustment for baseline covariates the ramipril group had a 38% reduced risk of clinical end points (95% CI, 13%-56%), a 36% slower mean decline in GFR after 3 months (P =.002), and less proteinuria (P<.001). CONCLUSION: Ramipril, compared with amlodipine, retards renal disease progression in patients with hypertensive renal disease and proteinuria and may offer benefit to patients without proteinuria.

Vancomycin-resistant enterococci among chronic hemodialysis patients: a prospective study of acquisition.

To determine the prevalence and rate of acquisition of vancomycin-resistant enterococci (VRE) among patients undergoing chronic (i.e., long-term) hemodialysis who were admitted to a tertiary care center, serial rectal cultures for VRE were performed at hospital admission and every 5 days until hospital discharge. A total of 7 (6%) of the 119 patients were colonized with VRE at admission. Six (19%) of the 32 patients who remained in the hospital > or =4 days acquired VRE. A nonambulatory status was significantly associated with colonization at admission (OR, 9.7; 95% CI, 1.8-53; P=.01), and vancomycin exposure was significantly associated with VRE acquisition (relative risk, 1.8; 95% CI, 1.1-2.9; P=.02). All patients acquired VRE from epidemiologically linked dialysis patients colonized with similar VRE genotypes. Hospital acquisition of VRE contributes substantially to the increasing prevalence of VRE in the chronic hemodialysis patient population.

Indications for vancomycin in dialysis patients.

Resistance to vancomycin has emerged among Staphylococcus aureus, coagulase-negative staphylococci (CNS), and enterococci, and this emergence has particular prevalence in dialysis units. It has therefore become imperative that physicians use vancomycin judiciously. General recommendations regarding the appropriate use of vancomycin have been developed. Although in theory implementation of these guidelines should not be difficult, the medical community may be unable or unwilling to make the necessary adjustments in practice. The onslaught of cost constraints and bureaucratic encumbrance has occurred simultaneously with the increase in vancomycin resistance among pathogens commonly isolated among the dialysis population. When a patient responds to empiric antibiotic therapy and susceptibility data indicate that an antibiotic other than vancomycin would be appropriate, the clinician far too often does not make the change to this alternative. Previously there was no biological imperative to change the antibiotic. That complacency has infected an entire generation of physicians, and especially nephrologists. Furthermore, there is an active movement against change, driven by concerns such as malpractice accusations and frank errors in the interpretation of medical facts.

Design and statistical issues of the hemodialysis (HEMO) study.

The Hemodialysis Study is a multicenter clinical trial of hemodialysis prescriptions for patients with end stage renal disease. Participants from over 65 dialysis facilities associated with 15 clinical centers in the United States are randomized in a 2 x 2 factorial design to dialysis prescriptions targeted to a standard dose or a high dose, and to either low or high flux membranes. The primary outcome variable is mortality; major secondary outcomes are defined based on hospitalizations due to cardiovascular or infectious complications, and on the decline of serum albumin. The Outcome Committee, consisting of study investigators, uses a blinded review system to classify causes of death and hospitalizations related to the major secondary outcomes. The dialysis dose intervention is directed by the Data Coordinating Center using urea kinetic modeling programs that analyze results from dialysis treatments to monitor adherence to the study targets, adjust suggested dialysis prescriptions, and assist in trouble-shooting problems with the delivery of dialysis. The study design has adequate power to detect reductions in mortality rate equal to 25% of the projected baseline mortality rate for both of the interventions.

Effect of radiographic contrast agents on leukocyte metabolic response.

BACKGROUND: The use of radiographic contrast media in the setting of possible bowel ischemia and potential perforation is known to carry a risk of morbidity and mortality. However, studies of the effect of available contrast media on host immunological defense mechanisms are lacking. We have examined the effect of barium and of two water-soluble contrast agents of differing iodine concentration and osmolality, Conray 30 and Cysto Conray II, on leukocyte phagocytosis. MATERIALS AND METHODS: Blood samples were incubated with the contrast media alone (termed the "resting state"), and in combination with a standard phagocytic challenge (Zymosan polysaccharide extract) and with Staphylococcus epidermidis, Streptococcus faecalis and Escherichia coli, to determine the effect of contrast media upon leukocyte phagocytic response. Incubation with saline was used as control. In the case of barium, the "resting state" and standard challenge experiments were repeated at nine dilutions, ranging from 1:1 to 1:1000. The leukocyte phagocytic response was measured in two ways: CO2 generation (an index of metabolic activity) and chemiluminescence (an index of generation of reactive oxygen species and bacterial killing). RESULTS: Barium, at clinical dilutions, causes a significant increase of baseline "resting state" phagocytic activity, which in turn leads to significant blunting of subsequent response to phagocytic challenge and adversely affects the response to all bacteria tested. There is no baseline activation of leukocytes by the water-soluble media, although there was some inhibition (rather than activation) of leukocyte metabolic activity. The effect of the water-soluble media on bacteria was more complex (although inhibition is minor compared to barium). CONCLUSIONS: Our data demonstrate that barium is a significant activator of phagocytic cells, which results in deactivation of phagocytic response when challenged; these data serve to explain the enhanced adverse effect of barium in cases of fecal peritonitis.

Experimental study of mortality and morbidity of contrast media and standardized fecal dose in the peritoneal cavity.

BACKGROUND: The use of radiographic contrast media in the setting of possible bowel ischemia and potential perforation is known to be associated with increased clinical risk. However, there is a lack of controlled studies using a standard native fecal load to define and compare the intrinsic mortality and morbidity among options of contrast media currently available to the radiologist. We have compared the mortality and gross and histopathologic morbidity of a standard intraperitoneal native fecal dose in the guinea pig, using barium, two iodinated media, saline and air. MATERIALS AND METHODS: The study was performed on adult Hartley guinea pigs. A standard native fecal solution with a colony count of 10(8) aerobes and 2 x 10(7) anaerobes was prepared, and the LD50 of intraperitoneal injection of the solution was determined. The standard solution at the LD50 dose was then used to compare the mortality and morbidity when commercial barium sulfate (18% w/v), Conray 30 (iothalamate meglumine 30%), 1:1 dilution of Conray 30 with sterile water, termed Conray "15" (iothalamate meglumine 15%), saline and air, were added to the intraperitoneal injection of the fecal solution in five groups of 20 animals each. Mortality and acute (96 h) and chronic (30 days) gross and histopathology were assessed and graded according to a standard system and analyzed statistically. RESULTS: Barium was significantly more deleterious than the dilute water-soluble iodinated media, saline and air. Mortality occurred within 24 h in the barium group and within the initial 48 h in all groups as follows: barium 19/20 (95%); Conray 30 16/20 (80%); Conray "15" 7/20 (35%); saline 0; air 0. Acute gross and histopathology showed extensive grade 4 lesions in 19/19 barium animals; less severe lesions were present in a lesser percentage of the animals in the other four groups. Entirely chronic lesions were present only in the single surviving barium animal and were non-significant (< 400 microns) or absent in the other four groups. CONCLUSIONS: In our study, barium incurred the most significant deleterious short and long-term effects in the setting of fecal peritonitis. Dilute water-soluble media offer a much greater margin of safety. Saline under sonographic guidance is less deleterious than any of the positive radiographic contrast media. However, in our study, air was the safest contrast medium in the setting of peritoneal soiling.

Effects of celecoxib and naproxen on renal function in the elderly.

OBJECTIVE: To compare the effects of celecoxib, a cyclooxygenase 2-specific inhibitor, with the nonspecific cyclooxygenase 1 and 2 inhibitor naproxen on renal function in 29 healthy elderly subjects in a single-blind, randomized, crossover study. METHODS: Subjects received either celecoxib, 200 mg twice daily, for 5 days followed by celecoxib, 400 mg twice daily, for the next 5 days, or they received naproxen, 500 mg twice daily, for 10 days. After a 7-day washout, subjects were crossed over to receive the other regimen. RESULTS: After the first dose, the trend was for a greater decrease in glomerular filtration rate with naproxen (-5.31 mL/min per 1.73 m2) compared with celecoxib (-0.86 mL/min per 1.73 m2). The treatment difference became statistically significant on day 6 (-7.53 vs -1.11 mL/min per 1.73 m2 for naproxen and celecoxib, respectively; P=.004). Urinary prostaglandin E2 and 6-keto-prostaglandin F1alpha excretion was significantly reduced from baseline across the treatment interval with both celecoxib and naproxen (P< or =.04). There were no significant differences in prostaglandin excretion between these 2 agents (P> or =.07). Small, transient decreases (P<.05) in urinary sodium excretion were observed after the initiation of both celecoxib and naproxen treatment. Sodium excretion values returned to baseline by the end of the study. CONCLUSIONS: The results indicate that cyclooxygenase 2-specific inhibition in healthy elderly subjects may spare renal hemodynamic function, although the effects on sodium excretion, as well as urinary prostaglandin E2 and 6-keto-prostaglandin F1alpha excretion, appear to be similar to those of nonspecific cyclooxygenase inhibitors such as naproxen.

Relationship between nutritional status and the glomerular filtration rate: results from the MDRD study.

BACKGROUND: The relationship between the protein-energy nutritional status and renal function was assessed in 1785 clinically stable patients with moderate to advanced chronic renal failure who were evaluated during the baseline phase of the Modification of Diet in Renal Disease Study. Their mean +/- SD glomerular filtration rate (GFR) was 39.8 +/- 21.1 mL/min/1.73 m2. METHODS: The GFR was determined by 121I-iothalamate clearance and was correlated with dietary and nutritional parameters estimated from diet records, biochemistry measurements, and anthropometry. RESULTS: The following parameters correlated directly with the GFR in both men and women: dietary protein intake estimated from the urea nitrogen appearance, dietary protein and energy intake estimated from dietary diaries, serum albumin, transferrin, percentage body fat, skinfold thickness, and urine creatinine excretion. Serum total cholesterol, actual and relative body weights, body mass index, and arm muscle area also correlated with the GFR in men. The relationships generally persisted after statistically controlling for reported efforts to restrict diets. Compared with patients with GFR > 37 mL/min/1.73 m2, the means of several nutritional parameters were significantly lower for GFR between 21 and 37 mL/min/1.73 m2, and lower still for GFRs under 21 mL/min/1.73 m2. In multivariable regression analyses, the association of GFR with several of the anthropometric and biochemical nutritional parameters was either attenuated or eliminated completely after controlling for protein and energy intakes, which were themselves strongly associated with many of the nutritional parameters. On the other hand, few patients showed evidence for actual protein-energy malnutrition. CONCLUSIONS: These cross-sectional findings suggest that in patients with chronic renal disease, dietary protein and energy intakes and serum and anthropometric measures of protein-energy nutritional status progressively decline as the GFR decreases. The reduced protein and energy intakes, as GFR falls, may contribute to the decline in many of the nutritional measures.

External beam irradiation as an adjunctive treatment in failing dialysis shunts.

PURPOSE: To evaluate the utility of low-dose irradiation as adjunctive treatment for failing dialysis shunts related to stenoses. MATERIALS AND METHODS: Thirty-one patients with 41 lesions in their dialysis shunts were successfully enrolled for this study. After imaging of the shunt and calculation of venous stenoses, each patient was randomized into one of two segments of the protocol: (i) angioplasty and/or stent placement alone, and (ii) angioplasty and/or stent placement followed by external beam irradiation. All patients with significant venous stenoses (> or =50%) were treated with appropriately sized PTA (percutaneous transluminal angioplasty) and Wallstents. Patients randomized to the external irradiation segment underwent localized irradiation via a Theratron cobalt unit of 7 Gy 0-24 hours and 24-48 hours after intervention. Those patients randomized to the control group received no additional treatment. Clinical follow-up included resumption of successful dialysis with appropriate hemodynamic parameters. Two follow-up shunt images were obtained, follow-up 1 (fu-1) from 90 to 179 days and follow-up 2 (fu-2) from 180 to 365 days. Percentages of significant recurrent stenoses, defined as greater than 50%, were recorded and re-treated as needed. RESULTS: Sixteen of the 31 patients underwent external beam irradiation. There were 21 lesions in the test group that underwent irradiation after intervention, and 20 lesions were treated with intervention alone. There were seven native arteriovenous fistulas and 24 Gore-tex grafts. All stenoses were either venous outflow stenoses (68%) or central stenoses (32%). The authors utilized chi2 analysis to compare restenoses rates between the control and irradiated groups at fu-1 (P<.99) and fu-2 (P<.10). CONCLUSIONS: Although the results show that external beam irradiation has minimal effects on the restenoses of dialysis grafts when used in conjunction with PTA and stent placement, further studies with a larger, more homogenous population are needed to assess the trend of improving patency rates after external beam irradiation.

Vancomycin prescribing practices in hospitalized chronic hemodialysis patients.

To determine the prevalence of and indications for vancomycin administration among hospitalized chronic hemodialysis patients, we performed a 3-month prospective cohort study at a tertiary care center. Modified guidelines for vancomycin use from the Hospital Infections Control Practices Advisory Committee of the Centers for Disease Control and Prevention were used. Vancomycin was administered during 56 of 144 admissions (39%) requiring chronic hemodialysis compared with 336 of 7,212 admissions (5%) not requiring hemodialysis (relative risk, 11; 95% confidence interval, 8 to 15; P < 0.001). Among chronic hemodialysis patients, vancomycin use was judged appropriate for 131 of the 164 vancomycin doses (80%). The most common appropriate indication was empiric therapy in a febrile patient before culture or susceptibility results. Of 32 infections identified in patients who received empiric vancomycin, 15 infections (47%) were caused by beta-lactam-resistant pathogens. Among the 33 doses (20%) judged inappropriate, continued therapy for a presumed infection despite failure to identify a beta-lactam-resistant pathogen was the most common indication. Although vancomycin administration was frequent among hospitalized chronic hemodialysis patients, its use was justified in the majority of cases. Efforts should focus on limiting vancomycin administration for treating infections caused by beta-lactam-sensitive pathogens.

Siblings revisited: old conflicts and new opportunities in later life.

This article discusses and gives clinical examples of crises that occur among and affect adult siblings in later life. They may be related to normative changes or they may be conflicts that have an impact on the well-being of the current family. Both are viewed as unique opportunities for resolution and reconciliation that can lead to a more realistic view of the past, and they may break an unfortunate cycle affecting future generations. Therapists are urged to be aware of and utilize these forces so that healing can take place.

Measurement of the delivery of dialysis in acute renal failure.

BACKGROUND: Recent studies in patients with acute renal failure (ARF) have shown a relationship between the delivered dose of dialysis and patient survival. However, there is currently no consensus on the appropriate method to measure the dose of dialysis in ARF patients. In this study, the dose of dialysis was measured by blood- and dialysate-based kinetic methods in a group of ARF patients who required intermittent hemodialysis. METHODS: Treatments were performed using a Fresenius 2008E volumetric hemodialysis machine with the ability to fractionally collect the spent dialysate. Single-, double-pool, and equilibrated Kt/V were determined from the pre-, immediate post-, and 30-minute post-blood urea nitrogen (BUN) measurements. The solute reduction index was determined from the collected dialysate, as well as the single- and double-pool Kt/V. RESULTS: Forty-six treatments in 28 consecutive patients were analyzed. The mean prescribed Kt/V (1.11 +/- 0.32) was significantly greater than the delivered dose estimated by single-pool (0.96 +/- 0.33), equilibrated (0.84 +/- 0.28), and double-pool (0.84 +/- 0.30) Kt/V (compared with prescribed, each P < 0.001). There was no statistical difference between the equilibrated and double-pool Kt/V (P = NS). The solute removal index, as determined from the dialysate, corresponded to a Kt/V of 0.56 +/- 0.27 and was significantly lower than the single-pool and double-pool Kt/V (each P < 0.001). CONCLUSION: Blood-based kinetics used to estimate the dose of dialysis in ARF patients on intermittent hemodialysis provide internally consistent results. However, when compared with dialysate-side kinetics, blood-based kinetics substantially overestimated the amount of solute (urea) removal.

Change in access blood flow over time predicts vascular access thrombosis.

BACKGROUND: Vascular access thrombosis accounts for at least $1 billion dollars in annual expenses and 25% of hospitalizations for chronic hemodialysis patients. Low vascular access blood flow (less than 800 ml/min) has been shown to modestly increase the relative risk for thrombosis in the subsequent three months. In this study, it is hypothesized that a time-dependent decrease in vascular access blood flow may be more predictive of subsequent thrombosis especially in vascular accesses with flows more than 800 ml/min, since it would indicate the development of a critical outlet stenosis in the graft. METHODS: Ninety-five accesses in 91 CHD patients were prospectively followed over 18 months. Vascular access blood flow was measured every six months by the ultrasound dilution technique. Thrombotic events were recorded during the three study periods. RESULTS: A total of 34 thrombotic events in 95 accesses were documented through the total study duration. Accesses that thrombosed had a 22% decrease in vascular access blood flow during the first observation period and a further 41% decrease during the second observation period as compared to 4% drop and 15% increase during the first and second observation periods, respectively, for accesses that did not thrombose. There was an estimated 13.6-fold (95%, confidence interval 2.68 to 69.16) increase in the relative risk of thrombosis for accesses with more than 35% decrease in vascular access blood flow compared to those accesses with no change in blood flow. There was no statistical difference in the average vascular access blood flow of all patients over the study period. CONCLUSIONS: Accesses that show a large (>15%) decrement in vascular access blood flow are associated with a high risk of thrombosis. Serial measurements of vascular access blood flow predict access thrombosis.

Prescribed versus delivered dialysis in acute renal failure patients.

The current study was designed first to determine separately the prescribed and delivered dose of dialysis and, second, to determine what factors lead to failure to deliver the prescribed dose of dialysis in patients with acute renal failure (ARF). Forty patients, who collectively underwent 136 dialysis treatments, were studied prospectively at two institutions. The results showed that almost half the prescriptions (49%) were for a Kt/V less than 1.2 and, more importantly, nearly 70% of the treatments delivered a Kt/V less than 1.2, the minimally acceptable dose defined in the Dialysis Outcomes Quality Initiative (DOQI) guidelines for chronic hemodialysis (CHD) patients. Patient predialysis weight was the most important variable associated with a low prescribed and delivered dose of dialysis, as well as lack of delivery of the prescribed dose of dialysis. From the statistical model, it is estimated that for every 10-kg increase in predialysis weight, the chance of prescribing or delivering a Kt/V less than 1.2 increased 4.6- and 1.95-fold, respectively. The lower than prescribed blood flow achieved by the temporary catheters and patients not receiving anticoagulation were variables also associated with not receiving the prescribed Kt/V. It is concluded that patients with ARF are prescribed and receive a dose of dialysis that would be considered inadequate for CHD patients. Until the association between dose of dialysis and outcome is better defined, it would be prudent that both the dialysis prescription and the delivery of dialysis to patients with ARF should be performed with the same care and goals as that currently received by patients with end-stage renal disease (ESRD).

Cardiac troponin-I accurately predicts myocardial injury in renal failure.

BACKGROUND: Non-specific elevations of creatine kinase isoenzymes (CK-MB) and cardiac troponin-T may be seen in renal failure, confusing the diagnosis of myocardial infarction. Cardiac troponin-I (cTn-I) has been shown to be specific for myocardial damage in several disease states, but has not been prospectively evaluated in the setting of renal failure. METHODS: This prospective case series evaluated 56 patients with acute or chronic renal failure or end-stage renal disease to assess the sensitivity and specificity of cTn-I for detecting myocardial injury in this patient population. During a 6-month period, patients admitted with suspected myocardial injury by history, physical examination, and electrocardiography were evaluated. Cardiac troponin-I (cTn-I) measurements were assessed between 8 and 48 h after admission. Appropriate medical care and further cardiac testing (echocardiography, stress testing, or arteriography) was performed at the discretion of the primary physician. RESULTS: Myocardial injury was diagnosed in 18/56 (32%) patients by positive cTn-I levels, while only 7/56 (13%) patients had evidence of myocardial damage by CK-MB. Twenty-one of 56 (38%) patients had indeterminate CK-MB levels and 53% of these patients demonstrated myocardial ischaemia on follow-up testing. Sixteen patients had negative cardiac studies; all of these patients had negative cTn-I levels, while seven of these 16 (44%) patients had indeterminate CK-MB measurements. All of the patients with positive cTn-I levels had positive cardiac studies. Positive troponin levels were associated with increased in-hospital mortality. Sensitivity and specificity for CK-MB were 44 and 56% respectively, and 94 and 100% for cTn-I. CONCLUSION: These data support the use of cTn-I for diagnosing myocardial injury in patients with renal failure. Elevated cTn-I levels are associated with increased short-term mortality in renal failure patients. The accuracy of cTn-I could potentially limit unnecessary cardiac testing in renal failure patients, while the enhanced sensitivity contributes to risk stratification and aids in diagnosing true myocardial injury in this population susceptible to non-specific elevations in other muscle enzymes.

Comparison of methods to predict equilibrated Kt/V in the HEMO Pilot Study.

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. Four techniques of approximating eKt/V that eliminated the requirement for the 30-minute postdialysis sample were also evaluated. The first adjusted the single compartment Kt/V using a linear equation with slope based on the relative rate of solute removal (K/V) to predict eKt/V (rate method). The second and third techniques used equations or mathematical curve fitting algorithms to fit data that included one or more samples drawn during dialysis (intradialysis methods). The fourth technique (dialysate-side) predicted eKt/V from an analysis of the time-dependent profile of dialysate urea nitrogen concentrations (BioStat method; Baxter Healthcare, Inc., Round Lake, IL, USA). The Pilot Study demonstrated the feasibility of conventional and high dose targets of about 1.0 and 1.4 for eKt/V. Based on the blood side standard method, the mean +/- SD eKt/V for patients randomized to these targets was 1.14 +/- 0.11 and 1.52 +/- 0.15 (N = 19 and 16 patients, respectively). Single-pool Kt/Vs were about 0.2 Kt/V units higher. Results were similar when eKt/V was based on dialysate side measurements: 1.10 +/- 0.11 and 1.50 +/- 0.11. The approximations of eKt/V by the three blood side methods that eliminated the delayed 30-minute post-dialysis sample correlated well with eKt/V from the standard blood side method: r = 0.78 and 0.76 for the single-sample (Smye) and multiple-sample intradialysis methods (N = 295 and 229 sessions, respectively) and 0.85 for the rate method (N = 295). The median absolute difference between eKt/V computed using the standard blood side method and eKt/V from the four other methods ranged from 0.064 to 0.097, with the smallest difference (and hence best accuracy) for the rate method. The results suggest that, in a dialysis patient population selected for ability to achieve an equilibrated Kt/V of about 1.45 in less than a 4.5 hour period, use of the pre and postdialysis samples and a kinetically derived rate equation gives reasonably good prediction of equilibrated Kt/V. Addition of one or more intradialytic samples does not appear to increase accuracy of predicting the equilibrated Kt/V in the majority of patients. A method based on dialysate urea analysis and curve-fitting yields results for equilibrated Kt/V that are similar to those obtained using exclusively blood-based techniques of kinetic modeling.