Postdialysis urea rebound: Determinants and influence on dialysis delivery in chronic hemodialysis patients

Leblanc, Martine; Charbonneau, Robert; Lalumière, Gaston; Cartier, P; Déziel, Clement

doi:10.1016/s0272-6386(96)90549-1

Cited by 58 publications

(45 citation statements)

References 12 publications

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“…Figures 2 and 3 show that the difference between spKt/V and dpKt/V tends to be greater as the Kt/V value increases, supporting previously reported data that HD effficiency is the major and most significant determinant of UR in children [21]. Studies in adults performed during short, high-efficiency, and long slow hemodialysis sessions showed overestimation of Kt/V by spUKM in the range from 14 up to 35% [8, 9, 10, 11, 12, 15]. The difference of 0.26 ± 0.18 Kt/V U observed in our study is clinically significant.…”

Section: Discussionsupporting

confidence: 83%

“…Reports in adults showed that using end-dialysis urea (Ct) results in overestimation of actual Kt/V, urea reduction ratio (URR), and nPCR and underestimation of V, with subsequent erroneous evaluation and prescription of HD and diet [8, 9, 10, 11, 12, 13, 14, 15]. While the role of UR in Kt/V estimation has been studied in children previously [5, 16], its effect on URR, urea generation rate (G), nPCR, and V has not been investigated in children yet.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Postdialysis Urea Rebound on the Quantification of Pediatric Hemodialysis

Marsenić

Pavličić

Bigović

et al. 2000

Nephron

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Urea rebound (UR) causes single pool urea kinetic modeling (UKM), which is based on end-dialysis urea instead of its equilibrated value (Ceq), to erroneously quantify hemodialysis (HD) treatment. We estimated the impact of postdialysis UR on the results of formal variable volume single pool (VVSP) UKM [Kt/V, urea distribution volume (V), urea generation rate (G), normalized protein catabolic rate (nPCR), and urea reduction ratio (URR)] in children on chronic HD. Thirty-eight standard pediatric HD sessions in 15 stable patients (9 female, 6 male) aged 14.5 ± (SD) 3.28 years were investigated. The HD sessions lasted 3.75 ± 0.43 h. The single pool urea clearance was 4.84 ± 1.25 ml/min/kg. All HD sessions were evaluated by VVSP and URR (%) with postdialysis urea taken at the end of HD and with Ceq taken 60 min after the end of HD, incorporating double pool effects and representing true double pool values. The anthropometric V was calculated by Cheek and Mellits formulae for children. VVSP significantly overestimated Kt/V by 0.26 ± 0.18 U (1.68 ± 0.36 vs. 1.42 ± 0.30, p < 0.0001), i.e., 19.05 ± 13.07%, G/V (0.20 ± 0.04 vs. 0.18 ± 0.04, p < 0.0001), nPCR (1.26 ± 0.23 vs. 1.18 ± 0.22 g/kg/day, p < 0.0001), and URR (73.92 ± 6.49 vs. 69.22 ± 7.06, p < 0.0001). VVSP significantly underestimated kinetic V in comparison to anthropometric V (18.74 ± 4.04 vs. 20.76 ± 4.43 liters or expressed as V/body weight: 58 ± 8 vs. 65 ± 9%, p < 0.05), while double pool kinetic V was more accurate (21.45 ± 4.34 liters, V/body weight: 64 ± 6%, p > 0.05). We conclude that UR has a significant effect on all results of UKM even after standard pediatric HD, and the degree of this efffect is documented. We suggest an increase of the minimum required prescribed single pool Kt/V in children and reduction of any delivered single pool Kt/V by approxiamtely 0.26 Kt/V U. Overestimation of nPCR by approximately 0.08 g/kg/day and underestimation of V by 8.5% should be kept in mind.

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Section: Discussionsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Effects of Postdialysis Urea Rebound on the Quantification of Pediatric Hemodialysis

Marsenić

Pavličić

Bigović

et al. 2000

Nephron

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“…Some reports using this simplified method have indicated relative good agreement with the original rate equation (23)(24)(25). Our data suggest that the simplified calculation overestimates rebound slightly (probably most of this is due to underestimation of the effect of urea generation, which becomes progressively more important at low postdialysis BUN values), as does the rate equation, possibly explaining the enhanced agreement between the simplified method and the original rate equation in some studies.…”

Section: Discussionsupporting

confidence: 55%

“…The median absolute deviation between the two measures was 0.052. two effects cancel. To allow comparison with such previous studies (23)(24)(25), we used the same simplified calculations with the HEMO data. ⌬Kt/V ϭ spKt/V Ϫ eKt/V was calculated by the simplified method and compared with the results of formal kinetic modeling.…”

Section: Rebound Using Simplified Estimates Of Spkt/v and Ekt/ Vmentioning

confidence: 99%

Factors that Affect Postdialysis Rebound in Serum Urea Concentration, Including the Rate of Dialysis

Daugirdas¹,

Greene²,

Depner³

et al. 2004

Journal of the American Society of Nephrology

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Abstract. Previous studies have suggested that postdialysis urea rebound is related to K/V, the rate of dialysis, but a systematic analysis of factors that affect rebound has not been reported. With the use of 30-min and, in a subset, 60-min postdialysis samples, postdialysis urea rebound was measured to (1) determine how well previously proposed equations based on the rate of dialysis (K/V) predict rebound in a large sample of patients with varying characteristics, (2) determine whether other factors besides K/V affect rebound, and (3) estimate more precise values for coefficients in prediction equations for rebound. Rebound was calculated relative to both immediate and 20-s postdialysis samples to study early components of rebound unrelated to access recirculation. The equilibrated Kt/V (eKt/V) computed by fitting the two-pool variable volume model to the 30-min postdialysis sample agreed well with eKt/V based on the 60-min postdialysis sample. Using the pre-, post-, and 30-min postdialysis samples for 1245 patients with arteriovenous (AV) accesses, the median intercompartmental mass transfer coefficient (Kc) was 797 ml/min for rebound computed relative to the 20-s postdialysis samples and 592 ml/min relative to the immediate postdialysis samples. K/V was the strongest predictor of rebound among 22 factors considered. Other factors associated with greater rebound for 1331 patients using AV accesses or venous catheters included access type, black race, male gender, absence of congestive heart failure, greater age, ultrafiltration rate, and low predialysis or intradialysis systolic BP. Equations of the form eKt/V ϭ single-pool Kt/V Ϫ B ϫ (K/V) were fit to the data. With AV access, the optimum values for the slope term (B) were 0.39 and 0.46 (in h Ϫ1 ) for single-pool Kt/V calculated based on 20-s postdialysis or immediate postdialysis samples, respectively. For patients using venous catheters, the respective values for B were 0.22 and 0.29. Postdialysis urea rebound can be predicted with acceptable accuracy from a postdialysis sample using a zero-intercept, K/V-based rate equation. Several patient or treatment-specific factors predict enhanced or reduced rebound. Rate equation slope coefficients for K/V of 0.39 (AV access) and 0.22 (venous access) are proposed when a 15-to 20-s slow-flow method is used to draw the postdialysis blood. Slightly higher K/V slope coefficients (0.46 and 0.29, respectively) should be used if a shorter (e.g

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“…The presence of inflammation in the dialysis population was defined as serum concentration of CRP ≥10 mg/l. The dialysis dose was expressed as single-pool Kt/V that was calculated using the second-generation Daugirdas formula [16] and as equilibrated Kt/V based on the regional blood flow two-pool model [17,18] at each 2-month interval. Interdialytic weight gain (IDWG) is expressed as the difference between the predialysis weight and the weight at the end of the previous dialysis session, and IDWG % is obtained using the percentage relationship between the average IDWG and the patient’s dry weight.…”

Section: Methodsmentioning

confidence: 99%

Brain Natriuretic Peptide between Traditional and Nontraditional Risk Factors in Hemodialysis Patients: Analysis of Cardiovascular Mortality in a Two-Year Follow-Up

Selim

Stojceva-Taneva²,

Spasovski³

et al. 2011

Nephron Clin Pract

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Background: The ability of brain natriuretic peptide (BNP) together with other traditional and nontraditional risk factors to predict cardiovascular (CV) mortality in hemodialysis (HD) patients has not been well established. The aim of this prospective study was to determine the predictive cutoff values of baseline measurement of BNP along with the known CV disease risk factors to predict all-cause and CV mortality in HD patients. Methods: BNP concentration before HD was measured in 125 prevalent HD patients (age 53.0 ± 13.5 years, HD vintage 75.2 ± 61.0 months). In addition, several traditional CV risk factors (blood pressure, dyslipidemia, diabetes mellitus, body mass index, left ventricular hypertrophy) and uremia/dialysis-related CV risk factors (anemia, calcium and phosphate impairment, malnutrition, inflammation, ultrafiltration, HD duration, Kt/V) were examined. Results: During the 2-year follow-up, we lost 28 out of 125 patients (22.5%), with CV disease (65.7%) being the main cause of mortality. The cutoff point for BNP, as predictor of the clinical outcome, according to the ROC curve was 1,194 pg/ml for CV mortality with sensitivity and specificity of 63 and 65%, respectively (AUC 0.61 and confidence interval (CI) 95% 0.47–0.75). Kaplan-Meier analysis showed that all-cause (log-rank, p = 0.002) and CV mortality (log-rank, p = 0.001) were the cause of a significantly lower survival in patients with a mean BNP >1,200 pg/ml. The univariate Cox regression analysis found the following factors to be predictors of all-cause mortality: hemoglobin (<110 g/l), phosphorus (>1.78 mmol/l), albumin (<40 g/l), C-reactive protein (CRP ≧10 mg/l), BNP (>1,200 pg/ml) and cardiac ejection fraction (≤55%). The multivariate Cox regression analyses demonstrated that only CRP ≧10 mg/l with a hazard ratio (HR) 6.82 (CI 95% 1.86–24.9, p = 0.004) and BNP >1,200 pg/ml with HR 5.79 (CI 95% 1.58–21.3, p = 0.004) were predictors of all-cause mortality. BNP >1,200 pg/ml with HR 13.52 (CI 95% 1.68–108.9, p = 0.014) was found to be an even stronger predictor of CV mortality than CRP ≧10 mg/l with HR 6.53 (CI 95% 1.35–31.6, p = 0.020). Conclusions: Our study pointed out that BNP >1,200 pg/ml as a marker of cardiac dysfunction and CRP ≧10 mg/l as a marker of inflammation identify HD patients at increased risk of CV mortality.

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Postdialysis urea rebound: Determinants and influence on dialysis delivery in chronic hemodialysis patients

Cited by 58 publications

References 12 publications

Effects of Postdialysis Urea Rebound on the Quantification of Pediatric Hemodialysis

Effects of Postdialysis Urea Rebound on the Quantification of Pediatric Hemodialysis

Factors that Affect Postdialysis Rebound in Serum Urea Concentration, Including the Rate of Dialysis

Brain Natriuretic Peptide between Traditional and Nontraditional Risk Factors in Hemodialysis Patients: Analysis of Cardiovascular Mortality in a Two-Year Follow-Up

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