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Comparison of the Watson formula and bioimpedance spectroscopy for measuring body volume and calculating kt/V in patients with peritoneal dialysis. Ren Fail 2024; 46:2313360. [PMID: 38345032 PMCID: PMC10863529 DOI: 10.1080/0886022x.2024.2313360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 01/28/2024] [Indexed: 02/15/2024] Open
Abstract
CONCLUSION There were significant differences between Vwat and Vbis and between Kt/Vwat and Kt/Vbis. Kt/Vwat may underestimate small-solute dialysis adequacy in most cases. Kt/Vbis instead of Kt/Vwat could be accounted for in creating individualized dialysis prescriptions if the patient has no obvious clinical symptoms.
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Effects of Kt/ Vurea on outcomes according to age in patients on maintenance hemodialysis. Clin Kidney J 2024; 17:sfae116. [PMID: 38766271 PMCID: PMC11099659 DOI: 10.1093/ckj/sfae116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Indexed: 05/22/2024] Open
Abstract
Background The guidelines recommended target and minimum single-pool Kt/Vurea are 1.4 and 1.2, respectively, in hemodialysis patients. However, the optimal hemodialysis dose remains controversial. We investigated the effects of Kt/Vurea on patient outcomes according to age, with a focus on older patients. Methods This study used the hemodialysis quality assessment program and claims datasets. Patients were divided into four subgroups according to age (<65, 65-74, 75-84, and ≥85 years). Each group was divided into three subgroups according to Kt/Vurea : reference (ref) (1.2 ≤ Kt/Vurea ≤ 1.4), low (< 1.2), and high (> 1.4). Results The low, ref, and high Kt/Vurea groups included 1668, 8156, and 16 546 (< 65 years); 474, 3058, and 7646 (65-74 years); 225, 1362, and 4194 (75-84 years); and 14, 126, and 455 (≥85 years) patients, respectively. The low Kt/Vurea group had higher mortality rates than the ref Kt/Vurea group irrespective of age [adjusted hazard ratio (aHR), 95% confidence interval (CI): 1.23, 1.11-1.36; 1.14, 1.00-1.30; 1.28, 1.09-1.52; and 2.10, 1.16-3.98, in patients aged <65, 65-74, 75-84, and ≥85 years, respectively]. The high Kt/Vurea group had lower mortality rates than the ref Kt/Vurea group in patients aged <65 and 65-74 years (aHR, 95% Cl: 0.87, 0.82-0.92 and 0.93, 0.87-0.99 in patients aged <65 and 65-74 years, respectively). Conclusions These results support the current recommendations of a minimum Kt/Vurea of 1.2 even in patients age ≥85 years. In young patients, Kt/Vurea above the recommended threshold can be beneficial for survival.
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Validation of formulas calculating normalized protein catabolic rate in patients undergoing home hemodialysis. J Nephrol 2023; 36:1965-1974. [PMID: 37341963 DOI: 10.1007/s40620-023-01674-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 05/05/2023] [Indexed: 06/22/2023]
Abstract
Depner and Daugirdas developed a simplified formula to estimate the normalized protein catabolic rate in patients on twice- or thrice-weekly hemodialysis (JASN, 1996). The aim of our work was to establish formulas in more frequent schedules and validate them in home-based hemodialysis patients. We realized that the structure of Depner and Daugirdas' normalized protein catabolic rate formulas has a general meaning and can be expressed as PCRn = C0/[a + b*(Kt/V) + c/(Kt/V)] + d, where C0 is pre-dialysis blood urea nitrogen, Kt/V is dialysis dose, a, b, c, d are the specific coefficients for each combination of home-based hemodialysis schedules and the day of blood sampling. The same applies to the formula that adjusts C0 (C'0) for residual kidney clearance of blood water urea (Kru) and urea distribution volume (V): C'0 = C0*[1 + (a1 + b1/(Kt/V))*Kru/V]. On this basis, we computed the six coefficients (a, b, c, d, a1, b1) for each of the 50 possible combinations and simulated a total of 24,000 weekly dialysis cycles using the Daugirdas Solute Solver software recommended by the KDOQI 2015 guidelines. From the associated statistical analyses we obtained 50 sets of coefficient values, which were validated comparing the paired normalized protein catabolic rate values (i.e., those estimated with our formulas with those modeled with Solute Solver) in 210 datasets of 27 patients on home-based hemodialysis. The mean values ± SD were 1.06 ± 0.262 and 1.07 ± 0.283 g/kg/day, respectively, with a mean difference of 0.004 ± 0.034 g/kg/day (p = 0.11). The paired values were highly correlated (R2 = 0.99). In conclusion, even if the coefficient values were validated in a relatively small sample of patients, they allow an accurate estimation of normalized protein catabolic rate in home-based hemodialysis patients.
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Kt/V or Bicarbonate: What Is More Important for Growth in Pediatric Peritoneal Dialysis Patients? Blood Purif 2023; 51 Suppl 1:61-67. [PMID: 37231795 DOI: 10.1159/000530268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 03/17/2023] [Indexed: 05/27/2023]
Abstract
INTRODUCTION Growth retardation is a common problem in pediatric patients with chronic kidney disease. It is unknown if the growth of children on peritoneal dialysis (PD) can be augmented by more dialysis. METHODS We studied the effect of various peritoneal adequacy parameters on delta height standard deviation scores (SDSs) and growth velocity z-scores in 53 children (27 males) on PD, who underwent 2 longitudinal adequacy tests at 9-month intervals. None of the patients were on growth hormone. Intraperitoneal pressure and standard KDOQI guidelines were compared to the outcome measures delta height SDS and height velocity z-scores, using univariate and multivariate tests. RESULTS At the time of the second PD adequacy test, their mean age was 9.2 ± 5.3 years; mean fill volume was 961 ± 254 mL/m2; and median total infused dialysate volume was 5.26 L/m2/day (range 2.03-15.32 L). The median total weekly Kt/V was 3.79 (range 0.9-9.5), and the median total creatinine clearance was 56.6 (range 7.6-133.48) L/week, higher than previous pediatric studies. The delta height SDS was a median of -0.12 (range -2 to +3.95)/year. The mean height velocity z-score was -1.6 ± 4.0. The only relationships discovered were between the delta height SDS and age, bicarbonate, and intraperitoneal pressure, but not for Kt/V or creatinine clearance. CONCLUSION Our findings highlight the importance of normalization of bicarbonate concentrations to improve height z-score.
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Reassessing the utility of access recirculation and Kt/V for the prediction of arteriovenous fistula failure using online clearance monitoring: the SHUNT STUDY. J Nephrol 2023; 36:677-686. [PMID: 36445562 DOI: 10.1007/s40620-022-01525-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 11/06/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND The arteriovenous fistula (AVF) is prone to thrombosis which can be avoided by use of monitoring and surveillance programmes. Although surveillance imaging techniques have been shown to be more sensitive and specific than clinical monitoring during dialysis, monitoring may have significant advantages in terms of cost and time saving. In this study we evaluate the yield of two monitoring techniques [blood temperature monitoring (BTM) access recirculation (AR) and Kt/V via online-clearance-monitoring (OCM)]. METHODS In this single-centre prospective observational study, 101 patients were followed-up for one year. The primary outcome measure was a composite of AVF failure. OCM-Kt/V and BTM-AR were recorded at every dialysis session. RESULTS Of all baseline characteristics only a prior history of percutaneous transluminal angioplasty (PTA) to the AVF conferred a significant change in AVF survival (failure events/100 pt years with prior PTA vs. without = 64.0 vs. 17.3, log-rank p = 0.0014; unadjusted hazard ratio (HR) 3.74 (95% CI 1.56-8.94) p = 0.003). Participants with baseline AR < 10% vs. > 15% had poorer AVF survival (p = 0.0002) and HR for baseline AR 10-15% group vs. AR > 15% group = 4.5 (95% CI 1.55-13.05). There was no combination of change in (Δ) AR, ΔKt/V or its presence over any number of dialysis sessions that provided an acceptable combination of sensitivity and specificity or discrimination for AVF failure. CONCLUSIONS BTM-AR and OCM-Kt/V are specific but insufficiently sensitive tools for the prediction of AVF failure. BTM-AR and OCM-Kt/V use at every dialysis session appears to add little to the traditional, infrequent use of these evaluations.
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Peritoneal Dialysis Adequacy: Too Much of a Good Thing? KIDNEY360 2022; 3:1777-1779. [PMID: 36514734 PMCID: PMC9717664 DOI: 10.34067/kid.0000922022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 08/08/2022] [Indexed: 05/23/2023]
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Kt/V reach rate is associated with clinical outcome in incident peritoneal dialysis patients. Ren Fail 2022; 44:482-489. [PMID: 35285393 PMCID: PMC8928818 DOI: 10.1080/0886022x.2022.2048854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background The urea clearance index (Kt/V) is an important index for predicting the clinical outcome of peritoneal dialysis (PD) patients, but it changes with time depending on the clinical condition. This study aimed to investigate the association between the Kt/V reach rate (defined as the percentage of Kt/V measurements that reached ≥ 1.70) and clinical outcome in incident PD patients. Methods In this retrospective cohort study, 210 patients were enrolled from the First Affiliated Hospital of Zhengzhou University from 1 January 2013 to 31 October 2019. The target Kt/V reach rate in the first year was applied as the predictor variable. Kaplan-Meier survival curves were drawn to evaluate differences in prognosis. The association between Kt/V reach rate and the composite clinical outcome (death or transfer to hemodialysis) was tested by Cox regression analysis. Results The dialysis adequacy group (Kt/V reach rate 3/3 times) and the dialysis intermittent adequacy group (1/3 or 2/3 times) had significantly better clinical outcomes than the dialysis inadequacy group (0/3 times). There was no difference in clinical outcome between the lower-rate group (reach rate 1/3 times) and the higher-rate group (2/3 times). Compared with the dialysis inadequacy group, the dialysis intermittent adequacy group and dialysis adequacy group had significantly lower risks of the composite outcome (HR 0.487, 95% CI 0.244–0.971, p = 0.041; HR 0.150, 95% CI 0.043–0.520, p = 0.003) in the fully adjusted analysis. Conclusion Higher Kt/V reach rates are associated with a better prognosis in incident PD patients.
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Changes in practice patterns in Japan from before to after JSDT 2013 guidelines on hemodialysis prescriptions: results from the JDOPPS. BMC Nephrol 2021; 22:339. [PMID: 34649519 PMCID: PMC8518149 DOI: 10.1186/s12882-021-02543-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/27/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Japanese Society for Dialysis Therapy (JSDT) published in 2013 inaugural hemodialysis (HD) guidelines. Specific targets include 1.4 for single-pool Kt/V (spKt/V) with a minimum dose of 1.2, minimum dialysis session length of 4 hours, minimum blood flow rate (BFR) of 200 mL/min, fluid removal rate no more than 15 mL/kg/hr, and hemodiafiltration (HDF) therapy for certain identified symptoms. We evaluated the effect of these guidelines on actual practice in the years spanning 2005 - 2018. METHODS Analyses were carried out to describe trends in the above HD prescription practices from December 2005 to April 2013 (before guideline publication) to August 2018 based on prevalent patient cross-sections from approximately 60 randomly selected HD facilities participating in the Japan Dialysis Outcomes and Practice Patterns Study. RESULTS From April 2006 to August 2017 continual rises occurred in mean spKt/V (from 1.35 to 1.49), and percent of patients having spKt/V>1.2 (71% to 85%). Mean BFR increased with time from 198.3 mL/min (April 2006) to 218.4 mL/min (August 2017) , along with percent of patients with BFR >200 ml/min (65% to 85%). HDF use increased slightly from 6% (April 2006 and August 2009) to 8% by April 2013, but increased greatly thereafter to 23% by August 2017. In contrast, mean HD treatment time showed little change from 2006-2017, whereas mean UFR declined from 11.3 in 2006 to 8.4 mL/Kg/hour in 2017. CONCLUSIONS From 2006 - 2018 Japanese HD patients experienced marked improvement in reaching the spKt/V target specified by the 2013 JSDT guidelines. This may have been due to moderate increase in mean BFR even though mean HD session length did not change much. In addition, HDF use increased dramatically in this time period. Other HD delivery changes during this time, such as increased use of super high flux dialyzers, also merit study. While we cannot definitively conclude a causal relationship between the publication of the guidelines and the subsequent practice changes in Japan, those changes moved practice closer to the recommendations of the guidelines.
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Toward an individualized determination of dialysis adequacy: a narrative review with special emphasis on incremental hemodialysis. Expert Rev Mol Diagn 2021; 21:1119-1137. [PMID: 34595991 DOI: 10.1080/14737159.2021.1987216] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
INTRODUCTION The search for the 'perfect' renal replacement therapy has been paralleled by the search for the perfect biomarkers for assessing dialysis adequacy. Three main families of markers have been assessed: small molecules (prototype: urea); middle molecules (prototype β2-microglobulin); comprehensive and nutritional markers (prototype of the simplified assessment, albumin levels; composite indexes as malnutrition-inflammation score). After an era of standardization of dialysis treatment, personalized dialysis schedules are increasingly proposed, challenging the dogma of thrice-weekly hemodialysis. AREAS COVERED In this review, we describe the advantages and limitations of the approaches mentioned above, focusing on the open questions regarding personalized schedules and incremental hemodialysis. EXPERT OPINION In the era of personalized dialysis, the assessment of dialysis adequacy should be likewise personalized, due to the limits of 'one size fits all' approaches. We have tried to summarize some of the relevant issues regarding the determination of dialysis adequacy, attempting to adapt them to an elderly, highly comorbidity population, which would probably benefit from tailor-made dialysis prescriptions. While no single biomarker allows precisely tailoring the dialysis dose, we suggest using a combination of clinical and biological markers to prescribe dialysis according to comorbidity, life expectancy, residual kidney function, and small and medium-size molecule depuration.
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What Total Body Water Measurement Should Be Used for Prescribing the Dialysis Dose in Low-Flow Home Daily Dialysis? Blood Purif 2021; 51:540-547. [PMID: 34404044 DOI: 10.1159/000517815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/13/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION In low-flow home daily dialysis (HDD), the dialysis dose is evaluated from the total body water (TBW). TBW can be estimated by anthropometric methods or bioimpedance spectroscopy. METHODS A multicentric cross-sectional study of patients in HDD for >3 months was conducted to assess the correlation and the difference between the anthropometric estimate of TBW (Watson-TBW) and the bioimpedance estimate (BIS-TBW) and to analyse the impact on the dialysate volume prescribed. RESULTS Forty patients from 10 centres were included. The median BIS-TBW and Watson-TBW were 35.1 (29.1-41.4 L) and 36.9 (32-42.4 L), respectively. The 2 methods had a good correlation (r = 0.87, p < 0.05). However, Bland-Altman analysis showed an overestimation of TBW with Watson's formula, with a bias of 2.77 L. For 4, 5, or 6 sessions per week, the use of Watson-TBW increases the dialysate prescription per week by 100 L, 45 L, or 10 L, respectively, over our entire cohort. There is no increase in the volume of dialysate prescribed with the 7 sessions per week schedule. CONCLUSION BIS-TBW and Watson-TBW estimation have a good correlation; however, Watson's equation overestimates TBW. This overestimation is negligible for a prescription frequency of >5 sessions per week.
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Assessment of peritoneal thickness using CT in relation to dialysis adequacy in peritoneal dialysis patients. Ther Apher Dial 2021; 25:954-961. [PMID: 34370378 DOI: 10.1111/1744-9987.13719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/27/2021] [Accepted: 08/06/2021] [Indexed: 11/27/2022]
Abstract
Studies assessing peritoneal thickness by CT in peritoneal dialysis (PD) patients are lacking. In this study, we aimed to investigate the association between peritoneal thickness as measured by CT and dialysis adequacy with peritoneal membrane characteristics in PD patients. Ninety-four PD patients were enrolled. Peritoneal thickness was measured by CT. Patients with and without a decrease in Kt/V of at least 0.3 over time were classified as Group 1 and Group 2, respectively. An increase of 0.1 unit of dialysate/plasma (D/P) creatinine over time were considered significant. The relationship between peritoneal membrane thickness, change in Kt/V, and peritoneal membrane characteristics were investigated. There were 31 (33.0%) patients in Group 1. The duration of PD (86.0 ± 64.1 vs. 59.6 ± 45.2 months, p: 0.023), peritoneal thickness (1.02 ± 0.37 vs. 0.87 ± 0.21 mm, p: 0.015), peritoneal calcification (7 [22.6%] vs. 3 [4.8%] patients, p: 0.013], increased D/P creatinine ratio (14 [45.2%] vs. 14 [22.2%] patients, p: 0.031) and CRP (13.9 ± 11.2 vs. 7.1 ± 4.8 mg/L, p: 0.045) were significantly higher in Group 1, whereas albumin (3.6 ± 0.5 vs. 3.8 ± 0.6 g/dL, p: 0.047) and parathyroid hormone (355.2 ± 260.2 vs. 532.1 ± 332.9 ng/L, p: 0.015) levels were significantly lower. Peritoneal thickness was significantly correlated with duration of PD (r: 0.775, p < 0.001) and CRP (r: 0.282, p: 0.006). Regression analysis showed that peritoneal thickness (Exp (B) [95% CI]: 0.029 [0.003-0.253], p: 0.001) was independent predictor of decreased Kt/V in PD patients. In conclusion, prolonged PD duration and increased peritoneal thickness are associated with a decrease in Kt/V over time. CT may be an alternative and noninvasive method instead of peritoneal biopsy for determining the structural changes of the peritoneal membrane .
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Hemodialysis (HD) dose and ultrafiltration rate are associated with survival in pediatric and adolescent patients on chronic HD-a large observational study with follow-up to young adult age. Pediatr Nephrol 2021; 36:2421-2432. [PMID: 33651178 PMCID: PMC8260402 DOI: 10.1007/s00467-021-04972-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/19/2021] [Accepted: 01/27/2021] [Indexed: 12/19/2022]
Abstract
BACKGROUND Hemodialysis (HD) dose targets and ultrafiltration rate (UFR) limits for pediatric patients on chronic HD are not known and are derived from adults (spKt/V>1.4 and <13 ml/kg/h). We aimed to characterize how delivered HD dose and UFR are associated with survival in a large cohort of patients who started HD in childhood. METHODS Retrospective analysis on a cohort of patients <30 years, on chronic HD since childhood (<19 years), having received thrice-weekly HD 2004-2016 in outpatient DaVita centers. OUTCOME Survival while remaining on HD. PREDICTORS (I) primary analysis: mean delivered dialysis dose stratified as spKt/V ≤1.4/1.4-1.6/>1.6 (Kaplan-Meier analysis), (II) secondary analyses: UFR and alternative dialysis adequacy measures [eKt/V, body-surface normalized Kt/BSA] on continuous scale (Weibull regression model). RESULTS A total of 1780 patients were included (age at the start of HD: 0-12y: n=321, >12-18y: n=1459; median spKt/V=1.55, eKt/V=1.31, Kt/BSA=31.2 L/m2, UFR=10.6 mL/kg/h). (I) spKt/V<1.4 was associated with lower survival compared to spKt/V>1.4-1.6 (P<0.001, log-rank test), and spKt/V>1.6 (P<0.001), with 10-year survival of 69.3% (59.4-80.9%) versus 83.0% (76.8-89.8%) and 84.0% (79.6-88.5%), respectively. (II) Kt/BSA was a better predictor of survival than spKt/V or eKt/V. UFR was additionally associated with survival (P<0.001), with increased mortality <10/>18 mL/kg/h. Associations did not alter significantly following adjustment for demographic characteristics (age, etiology of kidney disease, and ethnicity). CONCLUSIONS Our results suggest usefulness of targeting Kt/BSA>30 L/m2 for best long-term outcomes, corresponding to spKt/V>1.4 (>12 years) and >1.6 (<12 years). In contrast to adults, higher UFR of 10-18 ml/kg/h was not associated with greater mortality in this population.
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Routine assessment of kidney urea clearance, dialysis dose and protein catabolic rate in the once-weekly haemodialysis regimen. J Nephrol 2021; 34:2009-2015. [PMID: 33891294 DOI: 10.1007/s40620-021-01033-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/16/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND The dialysis dose (Kt/V) and normalized protein catabolic rate (PCRn) are the most useful indices derived from the urea kinetic model (UKM) in haemodialysis (HD) patients. The kidney urea clearance (Kru) is another important UKM parameter which plays a key role in the prescription of incremental HD. Ideally, the three kinetic parameters should be assessed using the complex software Solute Solver based on the double pool UKM. In the clinical setting, however, the three indices are estimated with simplified formulae. The recently introduced software SPEEDY assembles the aforementioned equations in a plain spreadsheet, to produce quite accurate results of Kru, Kt/V and PCRn. Unfortunately, specific equations to compute Kt/V and PCRn for patients on a once-weekly HD regimen (1HD/wk) were not available at the time SPEEDY was built-up. We devised a new version of SPEEDY (SPEEDY-1) and an even simpler variant (SPEEDY-1S), using two recently published equations for the 1HD/wk schedule . Moreover, we also added a published equation to estimate the equivalent renal clearance (EKR) normalized to urea distribution volume (V) of 35 L (EKR35) from Kru and Kt/V . Aim of the present study was to compare the results obtained using the new methods (SPEEDY-1 and SPEEDY-1S) with those provided by the reference method Solute Solver. SUBJECTS AND METHODS One hundred historical patients being treated with the once-weekly HD regimen were enrolled. A total of 500 HD sessions associated to the availability of monthly UKM studies were analysed in order to obtain Kru, single pool Kt/V (spKt/V), equilibrated Kt/V (eKt/V), V, PCRn and EKR35 values by using Solute Solver, SPEEDY-1 and SPEEDY-1S. RESULTS When comparing the paired values of the above UKM parameters, as computed by SPEEDY-1 and Solute Solver, respectively, all differences but one were statistically significant at the one-sample t-test; however, the agreement limits at Bland-Altman analysis showed that all differences were negligible. When comparing the paired values of the above UKM parameters, as computed by SPEEDY-1S and Solute Solver, respectively, all differences were statistically significant; however, the agreement limits showed that the differences were negligible as far as Kru, spKt/V and eKt/V are concerned, though much larger regarding V, PCRn and EKR35. CONCLUSIONS We implemented SPEEDY with a new version specific for the once-weekly HD regimen, SPEEDY-1. It provides accurate results and is presently the best alternative to Solute Solver. Using SPEEDY-1S led to a larger difference in PCRn and EKR35, which could be acceptable for clinical practice if SPEEDY-1 is not available.
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Kt/V: achievement, predictors and relationship to mortality in hemodialysis patients in the Gulf Cooperation Council countries: results from DOPPS (2012-18). Clin Kidney J 2021; 14:820-830. [PMID: 33777365 PMCID: PMC7986324 DOI: 10.1093/ckj/sfz195] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 12/16/2019] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Dialysis adequacy, as measured by single pool Kt/V, is an important parameter for assessing hemodialysis (HD) patients' health. Guidelines have recommended Kt/V of 1.2 as the minimum dose for thrice-weekly HD. We describe Kt/V achievement, its predictors and its relationship with mortality in the Gulf Cooperation Council (GCC) (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates). METHODS We analyzed data (2012-18) from the prospective cohort Dialysis Outcomes and Practice Patterns Study for 1544 GCC patients ≥18 years old and on dialysis >180 days. RESULTS Thirty-four percent of GCC HD patients had low Kt/V (<1.2) versus 5%-17% in Canada, Europe, Japan and the USA. Across the GCC countries, low Kt/V prevalence ranged from 10% to 54%. In multivariable logistic regression, low Kt/V was more common (P < 0.05) with larger body weight and height, being male, shorter treatment time (TT), lower blood flow rate (BFR), greater comorbidity burden and using HD versus hemodiafiltration. In adjusted Cox models, low Kt/V was strongly related to higher mortality in women [hazard ratio (HR) = 1.91, 95% confidence interval (CI) 1.09-3.34] but not in men (HR = 1.16, 95% CI 0.70-1.92). Low BFR (<350 mL/min) and TT (<4 h) were common; 41% of low Kt/V cases were attributable to low BFR or TT (52% for women and 36% for men). CONCLUSION Relatively large proportions of GCC HD patients have low Kt/V. Increasing BFR to ≥350 mL/min and TT to ≥4 h thrice weekly will reduce low Kt/V prevalence and may improve survival in GCC HD patients-particularly among women.
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The Nitty-Gritties of Kt/Vurea Calculations in Hemodialysis and Peritoneal Dialysis. Indian J Nephrol 2021; 31:97-110. [PMID: 34267430 PMCID: PMC8240937 DOI: 10.4103/ijn.ijn_245_19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 10/02/2019] [Accepted: 12/23/2020] [Indexed: 11/04/2022] Open
Abstract
In advanced Chronic Kidney Disease, patients require renal replacement therapy (dialysis or transplantation) for clearance of toxins, electrolyte and acid-base balance and removal of excess fluid. Dialysis adequacy should be taken into consideration in the adjustment of the dialysis prescription. Kt/Vurea is one method of measuring dialysis adequacy that is commonly used in clinical practice. Different formulae for calculating Kt/V are available. The appropriate Kt/V formula to be used depends on the clinical scenario, as well as parameters such as gender and size of patient, frequency of dialysis, mode of dialysis (ie hemodialysis vs, peritoneal dialysis), inter-dialysis weight gain, clinical symptoms, complications (fluid overload, hyperkalemia, intolerance to dialysis, etc), and residual kidney function. Nutrition parameters including serum protein and albumin levels, vitamin B12 and β2-microglobulin levels should be factored into the assessment of dialysis adequacy. In this review, we have described how Kt/Vurea is calculated in hemodialysis and peritoneal dialysis with examples. We reviewed the available literature by searching for papers related to calculating Kt/Vurea, single pool Kt/V, double pool Kt/V, weekly Kt/V, standard Kt/V, surface area normalized Kt/V, and various equations commonly practiced in clinical practice. We found several original articles, some review articles along with detailed information from manufacturers of different dialyzers published on their websites or as package inserts. Understanding the different equations available for calculating Kt/Vurea and the application of these results in the clinical setting is important for refining patient care and for designing clinical studies.
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Routine online assessment of dialysis dose: Ionic dialysance or UV-absorbance monitoring? Semin Dial 2021; 34:116-122. [PMID: 33529406 DOI: 10.1111/sdi.12949] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/01/2020] [Accepted: 12/17/2020] [Indexed: 11/29/2022]
Abstract
For three-weekly hemodialysis, a single-pool Kt/V target of at least 1.4 together with a minimal dialysis dose Kt at 45 L for men and 40 L for women per each session is currently recommended. Fully automatic online calculation of Kt and Kt/V from conductivity or UV-absorbance measurements in the dialysate is standardly implemented on some hemodialysis monitors and makes it possible to estimate the dialysis dose without the need for blood or dialysate samples. Monitoring the UV-absorbance of the spent dialysate is the most direct method for estimating Kt/V as it does not require an estimate of V. Calculation of ionic dialysance from conductivity measurements is the most direct method for estimating Kt and BSA-scaled dialysis dose. Both ionic dialysance monitoring and UV-absorbance monitoring may help detect a change in urea clearance occurring during the session, but this change must be interpreted differently depending on the monitoring being considered. An abrupt decrease in urea clearance results in a decrease in ionic dialysance but, paradoxically, a sudden increase in estimated urea clearance provided by dialysate UV-absorbance monitoring. Healthcare teams who monitor both ionic dialysance and UV-absorbance in their hemodialysis units must be clearly informed of this difficulty.
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Improving the "second generation Daugirdas equation" to estimate Kt/V on the once-weekly haemodialysis schedule. J Nephrol 2021; 34:907-912. [PMID: 33515379 DOI: 10.1007/s40620-020-00936-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/28/2020] [Indexed: 11/25/2022]
Abstract
INTRODUCTION The haemodialysis (HD) dose, as expressed by Kt/V urea, is currently routinely estimated with the second generation Daugirdas (D2) equation (Daugirdas in J Am Soc Nephrol 4:1205-1213, 1993). This equation, initially devised for a thrice-weekly schedule, was modified to be used for all dialysis schedules (Daugirdas et al. in Nephrol Dial Transplant 28:2156-2160, 2013), by adopting a variable factor that adjusts for the urea generation (GFAC) over the preceding inter-dialysis interval (PIDI, days). This factor was set at 0.008 for the mid-week session of the standard thrice-weekly HD schedule. In theory, by setting PIDI = 7, one could get GFAC = 0.0025, to be used in patients on the once-weekly (1HD/wk) schedule, but actually this has never been tested. Moreover, GFAC was derived not taking into account the residual kidney urea clearance (Kru). Aim of the present study was to provide a specific value of GFAC for patients on a once-weekly hemodialysis schedule. SUBJECTS AND METHODS The equation to predict GFAC (GFAC-1) in the 1HD/wk schedule was established in a group of 80 historical Italian patients (group 1) and validated in a group of 100 historical Spanish patients (group 2), by comparing the Kt/V computed using GFAC-1 (Kt/VGFAC-1) with the reference Kt/V (Kt/VSS) values, as computed with the web-based Solute-Solver software (SS) (Daugirdas et al. in Am J Kidney Dis 54:798-809, 2009). Three more sets of Kt/V (Kt/V0.008, Kt/V0.0025 and Kt/V0.0035) values were computed using the GFAC of the original D2 equation (0.008), the GFAC predicted by PIDI/7 (0.0025) and the mean observed GFAC-1 (0.0035), respectively. They were compared with the reference Kt/VSS values. RESULTS The predicting equation obtained from group 1 was: GFAC-1 = 0.0022 + 0.0105 × Kru/V (R2 = 0.93). Mean Kt/VSS in the group 2 was 1.54 ± 0.29 SD (N = 500 HD sessions). The mean percent differences for Kt/V0.008, Kt/V0.0025, Kt/VGFAC-1, and Kt/V0.0035 were 5.1 ± 1.0%, - 1.4 ± 0.7%, 0.0 ± 0.3%, - 0.3 ± 0.7%, respectively. No statistically significant difference was found between Kt/V values, except for Kt/V0.008. CONCLUSION A linear relationship was found between GFAC and Kru/V in patients on the 1HD/wk schedule. Such a relationship is able to improve the "second generation Daugirdas equation" for an accurate estimate of the single pool Kt/V in this setting. However, a simple replacement in the D2 equation of 0.008 with the mean observed GFAC (0.0035) could suffice in the clinical practice.
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Influential factors on dose by ionic dialysance in daily practice in chronic hemodialysis. Nephrol Ther 2021; 17:101-107. [PMID: 33461895 DOI: 10.1016/j.nephro.2020.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 11/03/2020] [Accepted: 11/03/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND The determination of Kt/V by ionic dialysance is a technique that has extended its use in hemodialysis clinics. The clinical guidelines have reflected the need to validate this method as a determinant of the dose of dialysis. OBJECTIVES Determine in daily practice, the influence of hemodialysis characteristics and medication on Kt/V results by ionic dialysance (Kt/V OCM) and compare them with Kt/V measures by serum urea (Kt/V Daugirdas). DESIGN Cross-sectional and observational study. PARTICIPANTS 127 patients on chronic hemodialysis. MEASUREMENTS Descriptive variables, study variables (Kt/VOCM, Kt/VDaugidas), and the variables that modified the effect (patient temperature, serum sodium, vascular access, recirculation, blood flow, hemodialysis technique, dialyzer, acid concentrate, conductivity, dialyzate flow). RESULTS The mean of Kt/V Daugirdas was 1.84 and the Kt/VOCM mean 1.65; Pearson's was CC r=0.54; P<0.001 and Lin CCC=0.48. In the linear regression, the variables related to hemodialysis technique showed no statistical association with the measurement obtained by Kt/VOCM. Monosodium phosphate and 20% sodium chloride dispensing were associated with a higher Kt/VOCM. CONCLUSIONS The different technical aspects noted during HD sessions do not influence Kt/V OCM outcomes. Kt/V determined by ionic dialysance isn't similar to that determined by serum urea. When assessing dialysis doses measured by dialysance, consider that it is not the same as determined with serum urea, but it provides an approximation to estimate dialysis doses in real time. It is necessary to consider if drugs or supplements have been administered that can modify it when interpreting the results.
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Blood temperature monitoring-guided vascular access intervention improved dialysis adequacy. J Vasc Access 2020; 22:515-520. [PMID: 33021432 DOI: 10.1177/1129729820949030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES The aim of this study was to investigate whether blood temperature monitoring-guided vascular access intervention could improve dialysis adequacy. METHODS We retrospectively evaluated all patients who received outpatient-based prevalent hemodialysis patients (n = 84) in our artificial kidney room between January 2019 and October 2019. Through blood temperature monitoring, access blood flow was calculated every month and Kt/V was calculated every 3 months. The reference point was set at the time of vascular intervention in the patients (n = 27) who underwent intervention or at the middle of the study period in patients (n = 57) who did not undergo intervention. The mean blood temperature monitoring-estimated access flow and Kt/V before and after the reference point were calculated and compared. RESULTS Among 84 patients, 30 (35.7%) showed access flow rates of <500 mL/min, calculated by blood temperature monitoring during the study period. Twenty-seven patients (32.1%) underwent vascular intervention, of whom 24 (28.6%) showed access flow rates of <500 mL/min, 2 (2.4%) showed weak bruit or thrill incapable of needling, and 1 (1.2%) presented acute occlusion. Six patients (7.1%) whose access flow rates were <500 mL/min refused to undergo intervention. All angiographies in the patients whose access flow rates were <500 mL/min who underwent intervention showed a significant stenosis. The mean change in blood temperature monitoring-estimated access flow and Kt/V before and after vascular intervention was 483.3 ± 490.6 and 0.19 ± 0.21, respectively, which showed significant differences (all p < 0.05). A weak positive correlation between the mean change in blood temperature monitoring-estimated access flow and Kt/V was shown in all study patients by Pearson's correlation analysis (r = 0.234, p = 0.033). CONCLUSION Access flow estimation by blood temperature monitoring might identify candidates who require vascular intervention. Blood temperature monitoring-guided vascular intervention significantly improved access flow and dialysis adequacy.
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Online hemodiafilteration use in children: a single center experience with a twist. BMC Nephrol 2020; 21:306. [PMID: 32723294 PMCID: PMC7388526 DOI: 10.1186/s12882-020-01957-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/15/2020] [Indexed: 11/10/2022] Open
Abstract
Background Haemodiafilteration (HDF) is a promising new modality of renal replacement therapy (RRT). It is an improvement in the quality of hemodialysis (HD) and thus in the quality of patients’lives. The main obstacle to using HDF is the cost, especially in developing countries. The purpose of this study was to evaluate the benefits of incorporating HDF with different regimens in the treatment of children with end stage renal disease (ESRD). Methods Thirty-four children with ESRD on regular HD in Pediatric Dialysis Unit, Children’s Hospital, Ain Shams University were followed up in 2 phases: initial phase (all patients: HD thrice weekly for 3 months) and second phase, patients were randomized into 2 groups, HDF group and HD group, the former was subdivided into once and twice weekly HDF subgroups. Evaluation using history, clinical and laboratory parameters at 0, 3, 9 and 18 months was carried out. Results On short term, we found that the HDF group was significantly superior to HD group regarding all clinical and laboratory parameters. Also, twice HDF subgroup was significantly superior to once HDF subgroup. This was confirmed on long term follow up, but the once HDF proved comparable to twice subgroup. Conclusions Incorporating online hemodiafilteration (OL-HDF) in the RRT of children was beneficial in most of the clinical and laboratory parameters measured. It’s not all or non; OL-HDF, even once a week, can improve outcomes of HD without significantly affecting the cost.
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Routine Kt/V and Normalized Protein Nitrogen Appearance Rate Determined From Conductivity Access Clearance With Infrequent Postdialysis Serum Urea Nitrogen Measurements. Am J Kidney Dis 2020; 76:22-31. [PMID: 32220509 DOI: 10.1053/j.ajkd.2019.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 12/23/2019] [Indexed: 11/11/2022]
Abstract
RATIONALE & OBJECTIVES Conventional monitoring of hemodialysis dose is implemented using urea kinetic modeling based on single-pool Kt/V, which requires both pre- and postdialysis serum urea nitrogen (SUN) measurements. We compared this conventional approach to one in which Kt/V is calculated using conductivity clearance, thereby reducing the need for regular postdialysis SUN measurements. STUDY DESIGN Comparative study of 2 diagnostic tests. SETTING & PARTICIPANTS Prevalent patients receiving maintenance hemodialysis for at least 2 years for whom both urea reduction ratio (URR) and average conductivity clearance (Kecn) were measured. TESTS COMPARED During the initial 8 months (baseline interval), average Kecn and URR were used to calculate a median patient-specific, modeled, calibration solute distribution volume (Vcal). During months 9 to 16 (period 1) and 17 to 24 (period 2), Kt/V was conventionally computed using URR and also by a new method using Vcal and Kecn without postdialysis SUN values. We examined the percentage error between these 2 methods of calculating Kt/V. OUTCOMES Concordance between the 2 methods of calculating Kt/V. RESULTS Among 1,093 patients, mean individual-level median single-pool Kt/V values derived using the conventional method during the baseline interval, period 1, and period 2 were 1.62±0.24 (SD), 1.66±0.24, and 1.67±0.24, respectively. During periods 1 and 2, patient-level median Kt/V values derived using Kecn were 1.64±0.24 and 1.65±0.24, respectively. Percent differences between patient-level median values of Kt/V (conductivity minus conventional URR methods) were-0.63%±7.7% and-0.75%±8.4% for periods 1 and 2. Normalized protein nitrogen appearance were comparable between the 2 methods. LIMITATIONS Data were collected over 2 years. Study was limited to in-center hemodialysis patients dialyzed 3 times per week. Dialysis session length was not adjusted for treatment interruptions. CONCLUSIONS A new method of calculating Kt/V based on Kecn that requires fewer postdialysis SUN measurements provided diagnostic data comparable to those from conventional use of URR and has the potential to avoid errors related to postdialysis blood sampling and measurement.
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Intradialytic Nutrition and Hemodialysis Prescriptions: A Personalized Stepwise Approach. Nutrients 2020; 12:nu12030785. [PMID: 32188148 PMCID: PMC7146606 DOI: 10.3390/nu12030785] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/11/2020] [Accepted: 03/13/2020] [Indexed: 12/11/2022] Open
Abstract
Dialysis and nutrition are two sides of the same coin—dialysis depurates metabolic waste that is typically produced by food intake. Hence, dietetic restrictions are commonly imposed in order to limit potassium and phosphate and avoid fluid overload. Conversely, malnutrition is a major challenge and, albeit to differing degrees, all nutritional markers are associated with survival. Dialysis-related malnutrition has a multifactorial origin related to uremic syndrome and comorbidities but also to dialysis treatment. Both an insufficient dialysis dose and excessive removal are contributing factors. It is thus not surprising that dialysis alone, without proper nutritional management, often fails to be effective in combatting malnutrition. While composite indexes can be used to identify patients with poor prognosis, none is fully satisfactory, and the definitions of malnutrition and protein energy wasting are still controversial. Furthermore, most nutritional markers and interventions were assessed in hemodialysis patients, while hemodiafiltration and peritoneal dialysis have been less extensively studied. The significant loss of albumin in these two dialysis modalities makes it extremely difficult to interpret common markers and scores. Despite these problems, hemodialysis sessions represent a valuable opportunity to monitor nutritional status and prescribe nutritional interventions, and several approaches have been tried. In this concept paper, we review the current evidence on intradialytic nutrition and propose an algorithm for adapting nutritional interventions to individual patients.
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High dose haemodialysis and haemodiafiltration parameters and the relationship with advanced vascular calcification. BMC Nephrol 2020; 21:86. [PMID: 32143589 PMCID: PMC7060583 DOI: 10.1186/s12882-020-01738-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 02/24/2020] [Indexed: 12/02/2022] Open
Abstract
Background Vascular calcification (VC) is a risk factor for cardiovascular disease in end-stage renal disease (ESRD) patients undergoing maintenance haemodialysis (MHD). However, evidence is still insufficient about the association between dialysis parameters and VC. Thus, this study was to evaluate association of dialysis parameters with VC. Methods We enrolled 297 ESRD patients undergoing MHD at six distinct centers in Korea. Study participants were categorized into 3 groups by the scoring system of abdominal aortic calcification based on lateral lumbar radiography (no VC group: 0, mild VC group: 1–7 and advanced VC group: 8–24). We compared the features of dialysis parameters according to the severity of VC. Multivariate logistic regression analysis was used to calculate adjusted odd ratios (ORs) and 95% confidence interval (CI) for mild and advanced VC in each haemodialysis parameter (adjusted OR [95% CI]). Results Pooled Kt/V (spKt/V), equilibrated Kt/V (eKt/V), standard Kt/V (stdKt/V) and the proportion of haemodiafiltration were increased along with the severity of VC. Multivariate regression analysis indicated that advanced VC was positively associated with spKt/V (5.27 [1.51–18.41]), eKt/V (6.16 [1.45–26.10]), stdKt/V (10.67 [1.74–65.52]) and haemodiafiltration (3.27 [1.74 to 6.16]). Conclusion High dose dialysis and haemodiafiltration were significantly associated with advanced VC.
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2005 Guidelines on targets for solute and fluid removal in adults being treated with chronic peritoneal dialysis: 2019 Update of the literature and revision of recommendations. Perit Dial Int 2020; 40:254-260. [PMID: 32048566 DOI: 10.1177/0896860819898307] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The International Society for Peritoneal Dialysis guidelines for small solute clearance and fluid removal in peritoneal dialysis (PD) were published in 2005. The aim of this article is to update those guidelines by reviewing the literature that supported those guidelines and examining publications since then. METHODS An extensive search of publications was performed through electronic databases and a hand search through reference lists from the existing guideline and selected articles. RESULTS There have been no prospective intervention trials to inform the area of small solute clearance in PD since the publication of the original guideline in 2005. The trials to date are largely limited to a few prospective cohort studies and retrospective studies. These have, however, consistently demonstrated that residual renal function (RRF) is more often associated with patient outcome than peritoneal clearance. One of the few randomised controlled trials performed in this area does suggest that a weekly Kt/V of 2.27 ± 0.02 provides no statistically significant survival advantage over a weekly Kt/V of 1.80 ± 0.02. The lower limit of Kt/V is unknown but there is weak evidence to suggest that anuric people doing PD should have a weekly Kt/V of at least 1.7. CONCLUSIONS There continues to be very poor evidence in the area of small solute clearance and fluid removal in PD. The evidence that exists suggests that RRF is more important than peritoneal clearance and that there appears to be no survival advantage in aiming for a weekly Kt/V >1.70.
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What volume to choose to assess online Kt/V? J Nephrol 2019; 33:137-146. [PMID: 31392658 DOI: 10.1007/s40620-019-00636-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 07/31/2019] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Urea distribution volume (V) can be assessed in different ways, among them the anthropometric Watson Volume (VW). However, many studies have shown that VW does not coincide with V and that the latter can be more accurately estimated with other methods. The present multicentre study was designed to answer the question: what V to choose to assess online Kt/V? MATERIALS AND METHODS Pre- and postdialysis blood urea nitrogen concentrations and the usual input data set for urea kinetic modelling were obtained for a single dialysis session in 201 Caucasian patients treated in 9 Italian dialysis units. Only dialysis machines measuring ionic dialysance (ID) were utilized. ID reflects very accurately the mean effective dialyser urea clearance (Kd). Six different V values were obtained: the first one was VW; the second one was computed from the equation established by the HEMO Study to predict the single pool-adjusted modelled V from VW (VH) (Daugirdas JT et al. KI 64: 1108, 2003); the others were estimated kinetically as: 1. V_ID, in which ID is direct input in the in the double pool variable volume (dpVV) calculation by means of the Solute-solver software; 2. V_Kd, in which the estimated Kd is direct input in the dpVV calculation by means of the Solute-solver software; 3. V_KTV, in which V is calculated by means of the second generation Daugirdas equation; 4. V_SPEEDY, in which ID is direct input in the dpVV calculation by means of the SPEEDY software able to provide results quite similar to those provided by Solute-solver. RESULTS Mean± SD of the main data are reported: measured ID was 190.6 ± 29.6 mL/min, estimated Kd was 211.6 ± 29.0 mL/min. The relationship between paired data was poor (R2 = 0.34) and their difference at the Bland-Altman plot was large (21 ± 27 mL/min). VW was 35.3 ± 6.3 L, VH 29.5 ± 5.5, V_ID 28.99 ± 7.6 L, V_SPEEDY 29.4 ± 7.6 L, V_KTV 29.7 ± 7.0 L. The mean ratio VW/V_ID was 1.22, (i.e. VW overestimated V_ID by about 22%). The mean ratio VH/V_ID was 1.02 (i.e. VH overestimated V_ID by only 2%). The relationship between paired data of V_ID and VW was poor (R2 = 0.48) and their mean difference at the Bland-Altman plot was very large (- 6.39 ± 5.59 L). The relationship between paired data of V_ID and VH was poor (R2 = 47) and their mean difference was small but with a large SD (- 0.59 ± 5.53 L). The relationship between paired data of V_ID and V_SPEEDY was excellent (R2 = 0.993) and their mean difference at the Bland-Altman plot was very small (- 0.54 ± 0.64 L). The relationship between paired data of V_ID and V_KTV was excellent (R2 = 0.985) and their mean difference at the Bland-Altman plot was small (- 0.85 ± 1.06 L). CONCLUSIONS V_ID can be considered the reference method to estimate the modelled V and then the first choice to assess Kt/V. V_SPEEDY is a valuable alternative to V_ID. V_KTV can be utilized in the daily practice, taking also into account its simple way of calculation. VW is not advisable because it leads to underestimation of Kt/V by about 20%.
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Static pressures, intra-access blood flow and dynamic Kt/V profiles in the prediction of dialysis access function. World J Nephrol 2019; 8:59-66. [PMID: 31363462 PMCID: PMC6656661 DOI: 10.5527/wjn.v8.i3.59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/26/2019] [Accepted: 03/27/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Hemodialysis machine-generated circuit pressures and clearance profiles are potential predictors of quality assurances. In our practice, we previously we observed that elevated static access pressures were associated with abnormal Kt/V values, high access recirculation and deviation of the Kt/V profile (Abnormal Kt/V profile) from normally expected values (Normal Kt/V profile).
AIM To hypothesize that static or derived access pressures would correlate with direct intra-access blood flow rates and that clearance (Kt/V) profiles would correlate with measured Kt/V values.
METHODS Static access pressures, real-time adequacy of dialysis and intra-access blood flow were investigated in end stage renal disease patients undergoing hemodialysis. Wilcoxon-Mann-Whitney test, chi-square test or Fisher’s exact test was used to investigate differences between the groups; Spearman’s rank correlation test to investigate relationships between static pressures, direct intra-access pressures and Kt/V profiles; and multinomial logistic regression models to identify the independent effect of selected variables on Kt/V profiles. Odds ratio were calculated to measure the association between the variables and Kt/V profiles.
RESULTS One hundred and seven patients were included for analysis. There were no significant differences between genders, and types of vascular access between the normal vs. abnormal clearance (Kt/V) profile groups. No significant correlation could be demonstrated between static access pressures and Kt/V profiles, static access pressures and intra-access blood flow, intra-access blood flow and Kt/V profiles, measured Kt/V and Kt/V profiles or recirculation and Kt/V profiles.
CONCLUSION In this study utilizing measured versus estimated data, we could not validate that dialysis machine generated elevated static pressures predict intra-access blood flow disturbances or that abnormal Kt/V profiles predict access recirculation or inadequate dialysis. These parameters, though useful estimates, cannot be accepted as quality assurance for dialysis adequacy or access function without further evidences.
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Does the Blood Pump Flow Rate have an Impact on the Dialysis Dose During Low Dialysate Flow Rate Hemodialysis? Blood Purif 2019; 46:279-285. [PMID: 30048973 DOI: 10.1159/000486843] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 01/14/2018] [Indexed: 11/19/2022]
Abstract
We conducted a prospective study to assess the impact of the blood pump flow rate (BFR) on the dialysis dose with a low dialysate flow rate. Seventeen patients were observed for 3 short hemodialysis sessions in which only the BFR was altered (300,350 and 450 mL/min). Kt/V urea increased from 0.54 ± 0.10 to 0.58 ± 0.08 and 0.61 ± 0.09 for BFR of 300, 400 and 450 mL/min. For the same BFR variations, the reduction ratio (RR) of β2microglobulin increased from 0.40 ± 0.07 to 0.45 ± 0.06 and 0.48 ± 0.06 and the RR phosphorus increased from 0.46 ± 0.1 to 0.48 ± 0.08 and 0.49 ± 0.07. In bivariate analysis accounting for repeated observations, an increasing BFR resulted in an increase in spKt/V (0.048 per 100 mL/min increment in BPR [p < 0.05, 95% CI (0.03-0.06)]) and an increase in the RR β2m (5% per 100 mL/min increment in BPR [p < 0.05, 95% CI (0.03-0.07)]). An increasing BFR with low dialysate improves the removal of urea and β2m but with a potentially limited clinical impact.
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Urea reduction ratio may be a simpler approach for measurement of adequacy of intermittent hemodialysis in acute kidney injury. BMC Nephrol 2019; 20:82. [PMID: 30841863 PMCID: PMC6404330 DOI: 10.1186/s12882-019-1272-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 02/27/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Assessment of adequacy of intermittent hemodialysis (IHD) is conventionally based upon urea kinetic models for calculation of single pool Kt/Vurea (Kt/V), with 1.2 accepted as minimum adequate clearance for thrice weekly IHD. In the Acute Renal Failure Trial Network (ATN) Study, adequacy of IHD in patients with acute kidney injury (AKI) was assessed using Kt/V. However, equations for Kt/V require volume of distribution of urea, which is highly variable in AKI. Therefore, simpler methods are needed to assess adequacy of IHD in AKI. We assessed correlation of urea reduction ratio (URR) with Kt/V and determined URR thresholds corresponding to Kt/V values to determine if URR could be a simpler means to assess the delivered dose of IHD. METHODS Using patients who received IHD for 2.5-6 h and with pre-dialysis BUN ≥20 mg/dL, we plotted URR against Kt/V. We determined URR thresholds (0.60 to 0.75) corresponding to Kt/V ≥ 1.2, 1.3, and 1.4. We generated receiver operating characteristic (ROC) curves for increasing URR values for each level of Kt/V to identify the corresponding thresholds of URR. RESULTS There was strong correlation between URR and Kt/V. ROC curves comparing URR with Kt/V ≥ 1.2, 1.3, and 1.4 had area under the curves (AUC) of 0.99. Sensitivity and specificity of URR ≥0.67 for corresponding values of Kt/V ≥ 1.2 were 0.769 (95% CI: 0.745 to 0.793) and 0.999 (95% CI: 0.997 to 1.000), respectively and the sensitivity and specificity of URR ≥0.67 for corresponding values of Kt/V ≥ 1.4 were 0.998 (95% CI: 0.995 to 1.000) and 0.791 (95% CI: 0.771 to 0.811), respectively. CONCLUSIONS Targeting a URR ≥0.67 provides a simplified means of assessing adequacy of IHD in patients with AKI. Use of URR will enhance ability to assess delivery of small solute clearance and improve adherence with clinical practice guidelines in AKI.
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The Effect of Mechanically-Generated Vibrations on the Efficacy of Hemodialysis; Assessment of Patients' Safety: Preliminary Reports. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16040594. [PMID: 30781708 PMCID: PMC6406417 DOI: 10.3390/ijerph16040594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/12/2019] [Accepted: 02/14/2019] [Indexed: 11/24/2022]
Abstract
Muscle activity during a hemodialysis procedure improves its efficacy. We have formulated a hypothesis that vibrations generated by a specially-designed dialysis chair can, the same as physical exercise, affect the filtering of various fluids between fluid spaces during the hemodialysis procedure. This prospective and interventional study included 21 dialyzed patients. During a single dialysis session, each patient used a prototype device with the working name “vibrating chair”. The chair’s drive used a low-power cage induction motor, which, along with the worm gear motor, was a part of the low-frequency (3.14 Hz) vibration-generating assembly with an amplitude of 4 mm. Tests and measurements were performed before and after the vibration dialysis. After a single hemodialysis session including five 3-min cycles of vibrations, an increase in Kt/V in relation to non-vibration Kt/V (1.53±0.26 vs. 1.62±0.23) was seen. Urea reduction ratio increased significantly (0.73±0.03 vs. 0.75±0.03). A significant increase in systolic blood pressure was observed between the first and the third measurement (146±18 vs. 156±24). The use of a chair generating low-frequency vibrations increased dialysis adequacy; furthermore, it seems an acceptable and safe alternative to intradialytic exercise.
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Correlation between Dt/V derived from ionic dialysance and blood-driven Kt/V of urea in African-American hemodialysis patients, based on body weight and ultrafiltration volume. Clin Kidney J 2018; 11:734-741. [PMID: 30288271 PMCID: PMC6165765 DOI: 10.1093/ckj/sfx155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 12/04/2017] [Indexed: 11/14/2022] Open
Abstract
Background The Dt/V obtained by using ionic dialysance (D) as a surrogate for urea clearance (K) is a well-validated adjunct measure of hemodialysis adequacy, with a variable level of correlation with urea-based Kt/V. However, this correlation has not been examined based on patients’ body size and ultrafiltration (UF) volume during the dialysis session. Methods Simultaneous evaluations of online Dt/V and single-pool variable-volume urea Kt/V were made. Patients were categorized into three subgroups based on their weight (<60, 60–80 and ≥80 kg), body mass index (<25, 25–30 and >30 kg/m2) and UF volume (<1.5, 1.5–3 and >3 L). The correlation between Dt/V and Kt/V was evaluated for the entire cohort per dialysis session in each subgroup. Results Mean Kt/V was greater than the mean Dt/V (1.72 versus 1.50, P < 0.001), with an overall correlation r value of 0.602. This correlation was stronger in the medium weight group versus lower and higher weights. The correlation between Dt/V and Kt/V was inversely related to the UF volume (r = 0.698, 0.621 and 0.558 for those with UF volume of <1.5, 1.5–3.0 and >3 L, respectively). A total of 99.3% of patients with Dt/V of >1.2 also had Kt/V >1.2 and 9.5% of those with Dt/V <1.2 had their Kt/V <1.2. Conclusions There is a moderate degree of correlation between Dt/V and Kt/V in African-American hemodialysis patients, which is impacted by body size and UF volume. A Dt/V of >1.2 strongly predicts adequate dialysis as defined by Kt/V of >1.2.
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Unlike Kt, high Kt/V is associated with greater mortality: The importance of low V. Nefrologia 2018; 39:58-66. [PMID: 30075965 DOI: 10.1016/j.nefro.2018.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 02/26/2018] [Accepted: 04/03/2018] [Indexed: 10/28/2022] Open
Abstract
INTRODUCTION Kt/V has been used as a synonym for haemodialysis dose. Patient survival improved with a Kt/V>1; this target was subsequently increased to 1.2 and 1.3. The HEMO study revealed no significant relationship between Kt/V and mortality. The relationship between Kt/V and mortality often shows a J-shaped curve. Is V the confounding factor in this relationship? The objective of this study is to determine the relationship between mortality and Kt/V, Kt and body water content (V) and lean mass (bioimpedance). METHODS We studied a cohort of 127 prevalent haemodialysis patients, who we followed-up for an average of 36 months. Kt was determined by ionic dialysance, and V and nutrition parameters by bioimpedance. Kt/V, Kt corrected for body surface area (Kt/BSA) and target Kt/BSA were calculated. The mean data from 18,998 sessions were used as haemodialysis parameters, with a mean of 155 sessions per patient. RESULTS Mean age was 70.4±15.3 years and 61% were male; 76 were dialysed via an arteriovenous fistula and 65 were on online haemodiafiltration. Weight was 70.6 (16.8)kg; BSA 1.8 (0.25) m2; total body water (V) 32.2 (7.41) l and lean mass index (LMI) 11.1 (2.7)kg/m2. Mean Kt/V was 1.84 (0.44); Kt 56.1 (7)l and Kt/BSA 52.8 (10.4)l. The mean target Kt/BSA was 49.7 (4.5)l. Mean Kt/BSA-target Kt/BSA +6.4 (7.0)l. Patients with a higher Kt/V had worse survival rates than others; with Kt this is not the case. Higher Kt/V values are due to a lower V, with poorer nutrition parameters. LMI and serum albumin were the parameters that best independently predicted the risk of death and are lower in patients with a higher Kt/V and lower V. CONCLUSION Kt/V is not useful for determining dialysis doses in patients with low or reduced body water. Kt or the Kt/BSA are proposed as an alternative.
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Efficiency and nutritional parameters in an elderly high risk population on hemodialysis and hemodiafiltration in Italy and France: different treatments with similar names? BMC Nephrol 2018; 19:171. [PMID: 29986663 PMCID: PMC6038182 DOI: 10.1186/s12882-018-0948-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/14/2018] [Indexed: 12/29/2022] Open
Abstract
Background Choice of dialysis is context sensitive, explored for PD and extracorporeal dialysis, but less studied for haemodialysis (HD) and hemodiafiltration (HDF), both widely employed in Italy and France; reasons of choice and differences in prescriptions may impact on dialysis-related variables, particularly relevant in elderly, high-comorbidity patients. Methods The study involved two high-comorbidity in-hospital cohorts, treated in Centers with similar characteristics, in Italy (Cagliari) and France (Le Mans). All patients (204) agreed to participate. Stable cases on thrice-weekly dialysis, with at least 2 months follow-up were selected (180 patients, Males 59.4%, median age 71 years, vintage 4.3 years, Charlson index 9). Univariate and multivariate correlations between baseline data, HD-HDF, dialysis efficiency and nutritional markers were assessed. Results In Le Mans HDF was mainly chosen to increase efficiency (large surface dialysers, high convective volume; 76.3% of the patients), in Cagliari to improve tolerance (smaller surfaces, lower convective volume; 59% of patients). Kt/V was similar in HD and HDF, and in both settings(median Kt/V Daugirdas 2: 1.6); in the setting of high efficiency no correlation was found between Kt/V, BMI, urea, creatinine, n-PCR and phosphate. The relationship between Kt/V and albumin was divergent: a weak consensual increase was present in Cagliari, a decrease in Le Mans, suggesting a role of albumin losses with high convective volumes. In the multivariate analysis, after adjustment for other covariates (including comorbidity and type of treatment) low albumin level < 3.5 g/dl was highly correlated with setting of study: Le Mans (OR: 7.155 (2.955–17.324)). The multivariate analysis confirmed a role of type of treatment, with higher risk of low albumin levels in HDF (OR: 3.592 (1.466–8.801)), and of comorbidity (Charlson index> = 7 (OR: 3.153 (1.311–7.582)), MIS index> = 7 (OR: 5.916 (2.457–14.241)). Conclusions The different prescriptions of HD and HDF may have similar effects on dialysis efficiency, but diverging effects on crucial nutritional markers, such as albumin levels, probably more evident in high-comorbidity populations.
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Principles of Renal Function Measurement (Limitations of Gotch's Kt/V). Can J Kidney Health Dis 2018; 5:2054358118776020. [PMID: 29899999 PMCID: PMC5985543 DOI: 10.1177/2054358118776020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 02/24/2018] [Indexed: 11/16/2022] Open
Abstract
Kt/V is a nondimensional number and a scaling parameter that has, with arbitrary definitions, been recast as a measure of dialysis by Gotch and Lysaght. This editorial discusses the concept of nondimensional numbers within the context of dialysis measurement, modeling, and medical evidence. It concludes that Gotch's Kt/V, Lysaght's Kt/V, and standardized Kt/V are not well suited to measure dialysis. An ideal dialysis measure would be proportional to toxins cleared by the kidney, portable with regard to dialysis modality, practical (largely devoid of calculations) and reflective of the pathology/physiology.
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Measuring residual renal function for hemodialysis adequacy: Is there an easier option? Hemodial Int 2018; 21 Suppl 2:S41-S46. [PMID: 29064172 DOI: 10.1111/hdi.12592] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 08/01/2017] [Indexed: 02/04/2023]
Abstract
Most patients starting hemodialysis (HD) have residual renal function. As such, there has been increased interest in starting patients with less frequent and shorter dialysis session times. However, for this incremental approach to be successful, patients require regular monitoring of residual renal function, so that as residual renal function declines, the amount of HD is appropriately increased. Currently most dialysis centers rely on interdialytic urine collections. However, many patients find these inconvenient and there may be marked intrapatient variability due to compliance issues. Thus, alternative markers of residual renal function are required for routine clinical practice. Currently three middle sized molecules; cystatin C, β2 microglobulin, and βtrace protein have been investigated as potential endogenous markers of glomerular filtration. Although none is ideal, combinations of these markers have been proposed to provide a more accurate estimation of glomerular clearance, and in particular cut offs for minimal residual renal function. However, in patients with low levels of residual renal function it remains unclear as to whether the benefits of residual renal function equally apply to glomerular filtration or tubular function.
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Relationship between plasma levels of homocysteine and the related B vitamins in patients with hemodialysis adequacy or inadequacy. Nutrition 2018; 53:103-108. [PMID: 29674265 DOI: 10.1016/j.nut.2018.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/28/2018] [Accepted: 02/01/2018] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Hemodialysis (HD) with dialysis adequacy could increase the excretion of B vitamins (folate, vitamin B6, and B12) and raise the plasma level of homocysteine. Here we determined the associations of plasma homocysteine with B vitamins in patients with HD adequacy or inadequacy. METHODS We recruited 68 patients who had received HD treatments (three times a week, 4 h each). Based on the individual's hemogram and quarterly urea reduction rate (Kt/V), patients were pooled into one of the following two groups: the first group with dialysis adequacy (Kt/V > 1.2, n = 48) and the second with dialysis inadequacy (Kt/V ≤ 1.2, n = 20). We also recorded the anthropometric date of each patient and their biochemical data and dietary intakes. Plasma levels of homocysteine, cysteine, folate, pyridoxal 5'-phosphate (PLP), and vitamin B12 were measured twice, once before and once after HD. RESULTS The plasma levels of homocysteine, cysteine, folate, PLP, and vitamin B12 dropped significantly at the end of HD. The plasma levels of vitamin B12 were negatively correlated with the plasma levels of homocysteine, both pre- and post-HD, and in both groups regardless of dialysis adequacy or inadequacy. In contrast, plasma levels of folate and PLP were not correlated with homocysteine at both pre- or post-HD in both groups. CONCLUSIONS The plasma level of vitamin B12, but not folate or vitamin B6, was negatively correlated with that of homocysteine both before and after HD treatment, and regardless of dialysis adequacy or inadequacy.
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Volume Estimates in Chronic Hemodialysis Patients by the Watson Equation and Bioimpedance Spectroscopy and the Impact on the Kt/Vurea calculation. Can J Kidney Health Dis 2018; 5:2054358117750156. [PMID: 29348925 PMCID: PMC5768265 DOI: 10.1177/2054358117750156] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/03/2017] [Indexed: 11/15/2022] Open
Abstract
Background Accurate assessment of total body water (TBW) is essential for the evaluation of dialysis adequacy (Kt/Vurea). The Watson formula, which is recommended for the calculation of TBW, was derived in healthy volunteers thereby leading to potentially inaccurate TBW estimates in maintenance hemodialysis recipients. Bioimpedance spectroscopy (BIS) may be a robust alternative for the measurement of TBW in hemodialysis recipients. Objectives The primary objective of this study was to evaluate the accuracy of Watson formula-derived TBW estimates as compared with TBW measured with BIS. Second, we aimed to identify the anthropometric characteristics that are most likely to generate inaccuracy when using the Watson formula to calculate TBW. Finally, we derived novel anthropometric equations for the more accurate estimation of TBW. Design and Setting This was a cross-sectional study of prevalent in-center HD patients at St Michael's Hospital. Patients One hundred eighty-four hemodialysis patients (109 men and 75 women) were evaluated in this study. Measurements Anthropometric measurements including weight, height, waist circumference, midarm circumference, and 4-site skinfold (biceps, triceps, subscapular, and suprailiac) thickness were measured; fat mass was measured using the formula by Durnin and Womersley. We measured TBW by BIS using the Body Composition Monitor (Fresenius Medical Care, Bad Homburg, Germany). Methods We used the Bland-Altman method to calculate the difference between the TBW derived from the Watson method and the BIS. To derive new equations for TBW estimation, Pearson's correlation coefficients between BIS-TBW (the reference test) and other variables were examined. We used the least squares regression analysis to develop parsimonious equations to predict TBW. Results TBW values based on the Watson method had a high correlation with BIS-TBW (correlation coefficients = 0.87 and P < .001). Despite the high correlation, the Watson formula overestimated TBW by 5.1 (4.5-5.8) liters and 3.8 (3.0-4.5) liters, in men and women, respectively. Higher fat mass and waist circumference (general and abdominal obesity) were correlated with the greater TBW overestimation by the Watson formula. We created separate equations for men and women based on weight and waist circumference. Limitations The main limitation of our study was the lack of an external validation for our novel estimating equation. Furthermore, though BIS has been validated against traditional reference standards, our assumption that it represents the "gold standard" for body compartment assessment may be flawed. Conclusions The Watson formula generally overestimates TBW in chronic dialysis recipients, particularly in patients with the highest waist circumference. Widespread reliance on the Watson formula for derivation of TBW may lead to the underestimation of Kt/Vurea..
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Interventions to improve hemodialysis adequacy: protocols based on real-time monitoring of dialysate solute clearance. Clin Kidney J 2017; 11:394-399. [PMID: 29942505 PMCID: PMC6007261 DOI: 10.1093/ckj/sfx110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 08/28/2017] [Indexed: 11/22/2022] Open
Abstract
Background The monitoring of dialysate ultraviolet (UV) absorbance is a validated technology to measure hemodialysis adequacy and allows for continuous and real-time tracking every session as opposed to the typical once-monthly assessments. Clinical care guidelines are needed to interpret the findings so as to troubleshoot problematic absorbance patterns and intervene during an individual treatment as needed. Methods When paired with highly structured clinical care protocols that allow autonomous nursing actions, this technology has the potential to improve treatment outcomes. These devices measure the UV absorbance of dialysate solutes to calculate and then display the delivered as well as predicted clearance for that session. Various technical factors can affect the course of dialysate absorbance, confound the device’s readout of clearance results and thus lead to challenges for the dialysis unit staff to properly monitor dialysis adequacy. We analyze optimal and problematic patterns to the device’s ‘clearance’ display (e.g. due to thrombosis of hollow fibers, inadequate access blood flow or recirculation) and provide specific interventions to ensure delivery of an adequate dialysis dose. A rigorous algorithm is presented with representative device monitor display profiles from actual hemodialysis sessions. Procedural rationale and interventions are described for each individual scenario. Conclusion Real-time hemodialysate UV absorbance patterns can be used for protocol-based intradialytic interventions to optimize solute clearance.
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Abstract
Background Patients starting dialysis often have substantial residual kidney function. Incremental hemodialysis provides a hemodialysis prescription that supplements patients’ residual kidney function while maintaining total (residual + dialysis) urea clearance (standard Kt/Vurea) targets. We describe our experience with incremental hemodialysis in patients using NxStage System One for home hemodialysis. Case presentation From 2011 to 2015, we initiated 5 incident hemodialysis patients on an incremental home hemodialysis regimen. The biochemical parameters of all patients remained stable on the incremental hemodialysis regimen and they consistently achieved standard Kt/Vurea targets. Of the two patients with follow-up >6 months, residual kidney function was preserved for ≥2 years. Importantly, the patients were able to transition to home hemodialysis without automatically requiring 5 sessions per week at the outset and gradually increased the number of treatments and/or dialysate volume as the residual kidney function declined. Conclusions An incremental home hemodialysis regimen can be safely prescribed and may improve acceptability of home hemodialysis. Reducing hemodialysis frequency by even one treatment per week can reduce the number of fistula or graft cannulations or catheter connections by >100 per year, an important consideration for patient well-being, access longevity, and access-related infections. The incremental hemodialysis approach, supported by national guidelines, can be considered for all home hemodialysis patients with residual kidney function.
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Association of Alternative Approaches to Normalizing Peritoneal Dialysis Clearance with Mortality and Technique Failure: A Retrospective Analysis Using the United States Renal Data System-Dialysis Morbidity and Mortality Study, Wave 2. Perit Dial Int 2017; 37:85-93. [PMID: 27680757 PMCID: PMC5448711 DOI: 10.3747/pdi.2015.00227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 08/03/2016] [Indexed: 11/15/2022] Open
Abstract
♦ BACKGROUND: Total body water (V) is an imprecise metric for normalization of dialytic urea clearance (Kt). This poses a risk of early mortality/technique failure (TF). We examined differences in the distribution of peritoneal Kt/V when V was calculated with actual weight (AW), ideal weight (IW), and adjusted weight (ADW). We also examined the associations of these Kt/V measurements, Kt/body surface area (BSA), and non-normalized Kt with mortality and TF. ♦ METHODS: This is a retrospective cohort study of 534 incident peritoneal dialysis (PD) patients from the Dialysis Morbidity and Mortality Study Wave 2 linked with United States Renal Data System through 2010. Using Cox-proportional hazard models, we examined the relationship of several normalization strategies for peritoneal urea clearance, including Kt/VAW, Kt/VIW, Kt/VADW, Kt/BSA, and non-normalized Kt, with the outcomes of mortality and TF. Harrell's c-statistics were used to assess the relative predictive ability of clearance metrics for mortality and TF. The distributions of Kt/VAW, KT/VIW, and KT/VADW were compared within and between body mass index (BMI) strata. ♦ RESULTS: Median patient age: 59 (54% male; 72% white; 91% continuous ambulatory PD [CAPD]). Median 24-hour urine volume: 700 mL; median estimated glomerular filtration rate (eGFR) at initiation: 7.15 mL/min/1.73 m2. Technique failure and transplant-censored mortality at 5 years: 37%. Death and transplant-censored TF at 5 years: 60%. There were no significant differences in initial eGFR and 24-hour urine volume across BMI strata. There were statistically significant differences in each Kt/V calculation within the underweight, overweight, and obese strata. After adjustment, there were no significant differences in the hazard ratios (HRs) for TF/mortality for each clearance calculation. Harrell's c-statistics for mortality for each clearance calculation were 0.78, and for TF, 0.60 - 0.61. ♦ CONCLUSIONS: Peritoneal urea clearances are sensitive to subtle changes in the estimation of V. However, there were no detectable significant associations of Kt/VAW, Kt/VIW, Kt/VADW, Kt/BSA, or Kt with TF or mortality.
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The Use of Incremental Peritoneal Dialysis in a Large Contemporary Peritoneal Dialysis Program. Can J Kidney Health Dis 2016; 3:2054358116679131. [PMID: 28781885 PMCID: PMC5518964 DOI: 10.1177/2054358116679131] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 09/23/2016] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The use of an incremental peritoneal dialysis (PD) strategy in a large contemporary patient population has not been described. OBJECTIVE We report the use of this strategy in clinical practice, the prescriptions required, and the clearances achieved in a large center which has routinely used this approach for more than 10 years. DESIGN This is a cross-sectional observational study. SETTING A single large Canadian academic center. PATIENTS This study collected data on 124 prevalent PD patients at a single Canadian academic center. METHODS AND MEASUREMENTS The proportion of patients who achieve the clearance target on a low clearance or incremental PD prescription; the actual PD prescriptions and consequent total, peritoneal, and renal urea clearances [Kt/V] achieved; and patient and technique survival and peritonitis rate in comparison with national and international reports. RESULTS Of the 124 prevalent PD patients in this PD unit, 106 (86%) were achieving the Kt/V target, and of these, 54 (44% of all patients) were doing so using incremental PD prescriptions. Fifty of these incremental PD patients were using automated PD (APD) with either no day dwell (68%) or less than 7 days a week treatment (12%) or both (20%). Patient survival in our PD unit was not different from that reported in Canada as a whole. Peritonitis rates were better than internationally recommended standards. LIMITATIONS This is an observational study with no randomized control group. CONCLUSIONS Incremental PD is feasible in a contemporary PD population treated mainly with APD. Almost half of the patients were able to achieve clearance targets while receiving less onerous and less costly low clearance prescriptions. We suggest that incremental PD should be widely used as a cost-effective strategy in PD.
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Low-Sodium Versus Standard-Sodium Peritoneal Dialysis Solution in Hypertensive Patients: A Randomized Controlled Trial. Am J Kidney Dis 2015; 67:753-61. [PMID: 26388284 DOI: 10.1053/j.ajkd.2015.07.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 07/27/2015] [Indexed: 12/30/2022]
Abstract
BACKGROUND Peritoneal dialysis (PD) solutions with reduced sodium content may have advantages for hypertensive patients; however, they have lower osmolarity and solvent drag, so the achieved Kt/Vurea may be lower. Furthermore, the increased transperitoneal membrane sodium gradient can influence sodium balance with consequences for blood pressure (BP) control. STUDY DESIGN Prospective, randomized, double-blind clinical trial to prove the noninferiority of total weekly Kt/Vurea with low-sodium versus standard-sodium PD solution, with the lower confidence limit above the clinically accepted difference of -0.5. SETTING & PARTICIPANTS Hypertensive patients (≥ 1 antihypertensive drug, including diuretics, or office systolic BP ≥ 130 mmHg) on continuous ambulatory PD therapy from 17 sites. INTERVENTION 108 patients were randomly assigned (1:1) to 6-month treatments with either low-sodium (125 mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 338-491 mOsm/L) or standard-sodium (134 mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 356-509 mOsm/L) PD solution. OUTCOMES Primary end point: weekly total Kt/Vurea; secondary outcomes: BP control, safety, and tolerability. MEASUREMENTS Total Kt/Vurea was determined from 24-hour dialysate and urine collection; BP, by office measurement. RESULTS Total Kt/Vurea after 12 weeks was 2.53 ± 0.89 in the low-sodium group (n = 40) and 2.97 ± 1.58 in the control group (n = 42). The noninferiority of total Kt/Vurea could not be confirmed. There was no difference for peritoneal Kt/Vurea (1.70 ± 0.38 with low sodium, 1.77 ± 0.44 with standard sodium), but there was a difference in renal Kt/Vurea (0.83 ± 0.80 with low sodium, 1.20 ± 1.54 with standard sodium). Mean daily sodium removal with dialysate at week 12 was 1.188 g higher in the low-sodium group (P < 0.001). BP changed marginally with standard-sodium solution, but decreased with low-sodium PD solution, resulting in less antihypertensive medication. LIMITATIONS Broader variability of study population than anticipated, particularly regarding residual kidney function. CONCLUSIONS The noninferiority of the low-sodium PD solution for total Kt/Vurea could not be proved; however, it showed beneficial clinical effects on sodium removal and BP.
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The impact of Vascular Access on the Adequacy of Dialysis and the Outcome of the Dialysis Treatment: One Center Experience. Mater Sociomed 2015; 27:114-7. [PMID: 26005389 PMCID: PMC4404955 DOI: 10.5455/msm.2015.27.4-114-117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/03/2015] [Indexed: 11/03/2022] Open
Abstract
INTRODUCTION Chronic kidney disease (CKD) is a gradually reduction in glomerular filtration rate (GFR) caused by destruction of a large number of nephrons. Kidney failure is the final stage of CKD with GFR <15ml/min/1.73m(2) or requiring dialysis. Patients must provide vascular access, which is also the "life line" and "Achilles heel" of hemodialysis treatment. AIM The purpose of this research is to show the demographic structure of the hemodialysis center in Konjic, and also demonstrate the impact of vascular access to the adequacy and the outcome of dialysis treatment. METHODS This cross-sectional study included 36 patients on hemodialysis in Center in Konjic from September 2010 to December 2014. The method of collecting data is performed through medical records and the quality of dialysis is taken to be Kt/V> 1.2. Statistical analysis was performed using SPSS software and Student T-test. RESULTS The mortality of patients treated by dialysis is 37.8%. The ratio of male and female patients is 55.6% vs. 44.5%, with an average age of 52.91±14.36 years and an average duration of hemodialysis of five years. The highest percentage of patients dialyzed through arterio-venous fistula (AVF) on the forearm (72.2%). In that patients the most common complication is thrombosis with 30.5%, which require recanalization in 11% and replacement in 19.5% of patients. Of the other dialysis patients, 16.7% of patients are dialyzed via a temporary and 11.1% via a permanent catheter (the most common complication in that patients is infection in 83.3% cases) in v.subclavia. Although the AVF is more frequently, experience shows frequent implantation of a permanent catheter in elderly patients due to the less quality of their blood vessels. Although the Kt/V by patients who are dialyzed through temporary catheter is less than 1.2 and by the other two access is greater than 1.2, our results confirm that vascular access does not have an influence on quality of dialysis. Average Kt/V shows that the adequate dialysis dose is delivered in this Center, which means that despite the impact of vascular access in HD quality, other factors also can affect on dialysis treatment, which was noticed by patients and staff. CONCLUSION Despite the largest mortality rate in patients with a permanent catheter and least in patients with AVF, the type of vascular access does not affect the outcome of dialysis treatment.
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Predictive value of echocardiography and its relation to Kt/V and anthropometric parameters in hemodialysis patients. Ren Fail 2015; 37:589-96. [PMID: 25656832 DOI: 10.3109/0886022x.2015.1007821] [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] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In order to evaluate the predictive value of echocardiograph parameters for mortality of hemodialysis patients and their relation to Kt/V and anthropometry, a prospective, single center study was analyzed post-hoc. METHODS This analysis encompassed 106 patients on maintenance hemodialysis monitored for 108 months from 1996 to 2004. spKt/V was calculated using the Daugirdas formula. Anthropometric measurements included mid-arm muscle measurements (MAMC) and percentage of body fat (%fat). Echocardiography included the estimations of left ventricular wall thickness, dimensions and volumes (EDV, ESV), systolic LV function (ejection fraction - EFLV, fractional shortening - VCF, stroke volume - SV) and diastolic LV function (E/A, VTI-A wave of transmitral flow velocity), left atrial diameter, as well as assessment of clinical and biochemical parameters. The Cox proportional hazard model was used to estimate predictive values of echocardiograph parameters. RESULTS Kt/V correlated significantly with left ventricular systolic and diastolic volumes and function, septal and posterior wall thickness and left atrium dimension. MAMC and %fat also correlated with many echocardiograph parameters. Multivariate Cox regression selected age [HR 1.07; CI (1.03-1.12); p < 0.01], albumin [HR 0.88; CI (0.79-0.97); p < 0.05] and left atrium dimension - binary [values > 4 cm were marked as "1" and others "0" - HR 3.76; CI (1.56-9.03); p < 0.01] as independent predictors of death. CONCLUSION Left atrium dimension was the most important predictor of mortality among the echocardiograph parameters. Many of these parameters were related to Kt/V and anthropometric measurements and could be the combined consequence of hypervolemia and hypertension.
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Improvements in renal replacement therapy practice patterns in estonia. NEPHRON EXTRA 2014; 4:108-18. [PMID: 25177339 PMCID: PMC4130824 DOI: 10.1159/000363349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Background The clinical performance indicators (CPI) are important tools to assess and improve the quality of renal replacement therapy (RRT). The aim of the current study was to compare the results of a longitudinal set of CPI in RRT patients and to determine the extent to which the guidelines for anaemia, calcium phosphate management and other CPI are met in Estonian renal centres. Methods A long-term retrospective, observational, cross-sectional CPI analysis was undertaken in RRT patients from 2007 to 2011. The following CPI set of well-designed measures based on good evidence was analysed: anaemia management variables, laboratory analyses of mineral metabolism, nutritional status variables and dialysis adequacy variables. Results Relatively small changes in the analysed mean CPI values were noticed during the study period. In the course of the study, we noticed an improvement in anaemia control, but not all centres achieved the standard of >80% of the dialysis patients with a haemoglobin (Hb) level >100 g/l. There was a trend of decreasing Hb concentrations below 125 g/l in both haemodialysis (HD) and peritoneal dialysis (PD) patients. In 2011, hyperphosphataemia was present in 58% of the HD and 47% of the PD patients, whereas centre differences varied between 50 and 60% of both the HD and PD patients. HD adequacy was achieved in 77% of the HD patients. Conclusion An improvement in the data collection was noticed, and the analysis of CPI allows renal centres to assess and compare their practices with others. The collection and evaluation of CPI of RRT patients is an important improvement and significantly increases the awareness of nephrologists.
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A Pilot Study Examining the Effects of Tolvaptan on Residual Renal Function in Peritoneal Dialysis for Diabetics. Perit Dial Int 2014; 35:552-8. [PMID: 25082843 DOI: 10.3747/pdi.2013.00290] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 03/18/2014] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND For patients with end-stage renal disease (ESRD), peritoneal dialysis (PD) serves as a possible renal replacement therapy. However, most PD patients, particularly those with ESRD and diabetes mellitus, reportedly discontinue PD early, resulting in shorter survival periods and poorer prognosis because of overhydration. Recently, the vasopressin-2 receptor antagonist tolvaptan was approved for volume control in patients with heart failure. The present study aimed to identify the effects of tolvaptan in diabetic PD patients. METHODS In this pilot study, the tolvaptan group (n = 12) were treated with 15 mg/day of tolvaptan 2 weeks after PD initiation and were prospectively analyzed for 1 year, and patients in the control group (n = 12) did not receive tolvaptan and were retrospectively analyzed for 1 year. In addition to the biochemical tests, echocardiograms, serum atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels, peritoneal Kt/V, and creatinine clearance (CCr) were examined at baseline and at 6 and 12 months after PD initiation. RESULTS In the control group, the urine volume, renal Kt/V, and renal CCr levels consistently decreased; however, these parameters were stably maintained during the study period in the tolvaptan group. Atrial natriuretic peptide, CRP levels and the left ventricular mass index of the tolvaptan-treated group were significantly lower than those in the control group, whereas total protein and albumin levels were significantly higher at 6 and 12 months in the tolvaptan group. There were no obvious adverse effects. CONCLUSIONS These data suggest that tolvaptan may preserve residual renal function and improve volume control in PD patients with diabetes mellitus.
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A comparison between residual renal function and peritoneal clearance for Na/H2O and urea removal in peritoneal dialysis patients. Ren Fail 2014; 36:1008-12. [PMID: 24896304 DOI: 10.3109/0886022x.2014.917763] [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] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND To compare the Na/H2O and urea removal between residual renal function (RRF) and peritoneal clearance (PC) in peritoneal dialysis patients. Try to explore the difference between RRF and PC in prognosis of chronic kidney disease patients who need peritoneal dialysis (PD) treatment. METHODS Weekly Na/H2O and urea removal by PC and RRF were investigated individually. Independent samples t-test was carried out to compare the efficiency of removal between RRF and PC treatment. Pearson correlated analysis was applied to reveal the relationship between Na/H2O and urea removal and Kt/V. RESULTS Although a higher Na/H2O removal rate by RRF was showed in this investigation, the difference was not statistical significant compared to the one by PC. On the other hand, urea removal by RRF was obviously higher than PC. For every 0.1 Kt/V, Na/H2O removal by RRF was distinctly higher than PD. The Na and H2O removal of RRF were 147.88 ± 83.72 mmol and 46.54 ± 39.11 mmol, respectively; and the ones of PD were 11.40 ± 6.08 mmol and 4.47 ± 4.79 mmol. By using statistical assay, the correlations relevance between Na/H2O removal and Kt/V in RRF were showed stronger than in PC. However, the total removal of Na/H2O showed a poor correlation with Kt/V in both RRF and PC. CONCLUSIONS The removal efficiency of RRF is much higher than PC. This study suggests that it is important to adjust dialysis program when RRF gets declined. Also the correlation between Na/H2O removal rate and Kt/V is an important monitoring factor for the patients who are receiving peritoneal dialysis.
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Abstract
The availability of hemodialysis machines equipped with online clearance monitoring (OCM) allows frequent assessment of dialysis efficiency and adequacy without the need for blood samples. Accurate estimation of the urea distribution volume (V) is required for Kt/V calculated from OCM to be consistent with conventional blood sample-based methods. A total of 35 patients were studied. Ionic dialysance was measured by conductivity monitoring. The second-generation Daugirdas formula was used to calculate the Kt/V single-pool (Kt/VD). Values of V to allow comparison between OCM and blood-based Kt/V were determined using Watson formula (VWa), bioimpedance spectroscopy (Vimp), and blood-based kinetic data (Vukm). Comparison of Kt/Vw ocm calculated by the ionic dialysance and Vw (Kt/Vw ocm) with Kt/VD shows that using VW leads to significant systematic underestimation of dialysis dose by 24%. Better agreement between Kt/V ocm and Kt/VD was observed when using Vimp and Vukm. Bio-impedancemetry and the indirect method using the second-generation Daugirdas equation are two methods of clinical interest for estimating V to ensure greater agreement between OCM and blood-based Kt/V.
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Evaluation of nutritional parameters of hemodialysis patients. Hippokratia 2012; 16:236-40. [PMID: 23935290 PMCID: PMC3738730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND This study was performed to investigate nutritional parameters of hemodialysis patients by using anthropometric and biochemical measurements. METHODS Data from the last 6 months of 22 adult hemodialysis patients with a mean age of 61 ± 14 years were analyzed retrospectively. Dialysis vintage, normalized protein catabolic rate (nPCR), serum biochemical parameters, mid arm muscle circumference (MAMC) were determined as mean and standard deviation. Correlations between the variables were computed by coefficient p of Pearson. RESULTS We found significant positive correlations: age of patients versus C-reactive protein, MAMC versus LDL-Cholesterol, MAMC versus body mass index, albumin versus hemoglobin. There were also significant negative correlations: age versus serum creatinine, age versus albumin, age versus intact parathyroid hormone (iPTH), dialysis vintage versus MAMC. CONCLUSION In conclusion, age seem to be negatively associated with iPTH and albumin. As dialysis vintage increases, muscle mass seems to decrease.
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Online conductivity monitoring of dialysis adequacy versus Kt/V derived from urea reduction ratio: A prospective study from a Saudi center. Int J Nephrol Renovasc Dis 2009; 2:27-31. [PMID: 21694918 PMCID: PMC3108763 DOI: 10.2147/ijnrd.s7316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Ad equate delivered dose of solute removal (as assessed by urea reduction and calculation of Kt/V) is an important determinant of clinical outcome in chronic hemodialysis (HD) patients. This requires both prescription of an adequate dose of HD and regular assessment that the delivered treatments are also adequate. Online conductivity monitoring using sodium flux as a surrogate for urea allows the repeated noninvasive measurement of Kt/V on each HD treatment. METHODS We prospectively studied 17 (9 males, 8 females) established chronic HD patients over an eight-week period (408 treatments). A pre- and post-dialyzer measurement of the conductivity is performed by two mutually independent temperature-compensated conductivity cells equipped with Fresenius 4008 S(®) dialysis machines. Urea reduction was measured (once a week) by a single pool calculation using immediate post-treatment sampling. No changes were made to any of the dialysis prescriptions over the study period. Values of calculated Kt/V and simultaneously obtained online Kt/V were compared. RESULTS There was a statistically significant difference between calculated Kt/V and online Kt/V over the study period. The mean calculated Kt/V was 1.37 ± 0.09, and mean online Kt/V 1.02 ± 0.15 (P = 0.000), calculated Kt/V ≥ 1.2 was achieved in all our patients while online Kt/V ≥ 1.2 was achieved in only 17.64 %. Yet there was moderate correlation between calculated Kt/V and online Kt/V (r(2) = 0.48). CONCLUSIONS Online conductivity monitoring results underestimates dialysis efficiency compared to calculated Kt/V readings. This difference has to be considered when applying Kt/V to clinical practice.
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Use of Systemic Blood Urea Nitrogen Levels Obtained 30 Minutes before the End of Hemodialysis to Portray Equilibrated, Postdialysis Blood Urea Nitrogen Values. Hemodial Int 2000; 4:15-17. [PMID: 28455913 DOI: 10.1111/hdi.2000.4.1.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Blood urea nitrogen (BUN) levels obtained at 30 minutes before the end of dialysis were found to be closely similar to equilibrated, postdialysis BUN values obtained 30 minutes after the end of dialysis. Because of this similarity, the former BUN values can be used to derive equilibrated urea reduction ratio, or equilibrated Kt/V instead.
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