Increasing Dialysis Dose Research Articles

The effect of continuous venovenous hemodiafiltration on amino acid delivery, clearance, and removal in children.

In critically ill children with acute kidney injury (AKI), continuous kidney replacement therapy (CKRT) enables nutrition provision. The magnitude of amino acid loss during continuous venovenous hemodiafiltration (CVVHDF) is unknown and needs accurate quantification. We investigated the mass removal and clearance of amino acids in pediatric CVVHDF. This is a prospective observational cohort study of patients receiving CVVHDF from August 2014 to January 2016 in the pediatric intensive care unit (PICU) of a tertiary children's hospital. Fifteen patients (40% male, median age 2.0 (IQR 0.7, 8.0) years) were enrolled. Median PICU and hospital lengths of stay were 20 (9, 59) and 36 (22, 132) days, respectively. Overall survival to discharge was 66.7%. Median daily protein prescription was 2.00 (1.25, 2.80) g/kg/day. Median daily amino acid mass removal was 299.0 (174.9, 452.0) mg/kg body weight, and median daily amino acid mass clearance was 18.2 (13.5, 27.9) ml/min/m2, resulting in a median 14.6 (8.3, 26.7) % protein loss. The rate of amino acid loss increased with increasing dialysis dose and blood flow rate. CVVHDF prescription and related amino acid loss impact nutrition provision, with 14.6% of the prescribed protein removed. Current recommendations for protein provision for children requiring CVVHDF should be adjusted to compensate for circuit-related loss. A higher resolution version of the Graphical abstract is available as Supplementary information.

Roles of peritoneal clearance and residual kidney removal in control of uric acid in patients on peritoneal dialysis

BackgroundThere have been few systematic studies regarding clearance of uric acid (UA) in patients undergoing peritoneal dialysis (PD). This study investigated peritoneal UA removal and its influencing factors in patients undergoing PD.MethodsThis cross-sectional study enrolled patients who underwent peritoneal equilibration test and assessment of Kt/V from April 1, 2018 to August 31, 2019. Demographic data and clinical and laboratory parameters were collected, including UA levels in dialysate, blood, and urine.ResultsIn total, 180 prevalent patients undergoing PD (52.8% men) were included. Compared with the normal serum UA (SUA) group, the hyperuricemia group showed significantly lower peritoneal UA clearance (39.1 ± 6.2 vs. 42.0 ± 8.0 L/week/1.73m2; P = 0.008). Furthermore, higher transporters (high or high-average) exhibited greater peritoneal UA clearance, compared with lower transporters (low or low-average) (42.0 ± 7.0 vs. 36.4 ± 5.6 L/week/1.73 m2; P < 0.001). Among widely used solute removal indicators, peritoneal creatinine clearance showed the best performance for prediction of higher peritoneal UA clearance in receiver operating characteristic curve analysis [area under curve (AUC) 0.96; 95% confidence interval [CI], 0.93–0.99]. Peritoneal UA clearance was independently associated with continuous SUA [standardized coefficient (β), − 0.32; 95% CI, − 6.42 to − 0.75] and hyperuricemia [odds ratio (OR), 0.86; 95% CI, 0.76–0.98] status, only in patients with lower (≤2.74 mL/min/1.73 m2) measured glomerular filtration rate (mGFR). In those patients with lower mGFR, lower albumin level (β − 0.24; 95%CI − 7.26 to − 0.99), lower body mass index (β − 0.29; 95%CI − 0.98 to − 0.24), higher transporter status (β 0.24; 95%CI 0.72–5.88) and greater dialysis dose (β 0.24; 95%CI 0.26–3.12) were independently associated with continuous peritoneal UA clearance. Furthermore, each 1 kg/m2 decrease in body mass index (OR 0.79; 95% CI 0.63–0.99), each 1 g/dL decrease in albumin level (OR 0.08; 95%CI 0.01–0.47), and each 0.1% increase in average glucose concentration in dialysate (OR 1.56; 95%CI 1.11–2.19) were associated with greater peritoneal UA clearance (> 39.8 L/week/1.73m2).ConclusionsFor patients undergoing PD who exhibited worse residual kidney function, peritoneal clearance dominated in SUA balance. Increasing dialysis dose or average glucose concentration may aid in controlling hyperuricemia in lower transporters.

Incremental Peritoneal Dialysis May be Beneficial for Preserving Residual Renal Function Compared to Full-dose Peritoneal Dialysis

Maintaining residual renal function (RRF) is a crucial issue in peritoneal dialysis (PD). Incremental dialysis is the practice of initiating PD exchanges less than four times a day in consideration of RRF, and increasing dialysis dose in a step-wise manner as the RRF decreases. We aimed to compare the outcomes of incremental PD and full-dose PD in terms of RRF preservation and other outcomes. This was a single-center, observational study. Data were extracted retrospectively from a cohort of incident PD patients over 16 years old who started PD between 2007 and 2015 in the PD Unit of Seoul National University Hospital. We used inverse probability weighting (IPW) adjustment based on propensity scores to balance covariates between the incremental and full-dose PD groups. Multivariate, time-dependent Cox analyses were performed. Among 347 incident PD patients, 176 underwent incremental PD and 171 underwent conventional full-dose PD. After IPW adjustment, the incremental PD group exhibited a lower risk of developing anuria (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.43–0.88). Patient survival, technique survival, and peritonitis-free survival were all similar between these groups (P > 0.05 by log-rank test). Incremental PD was beneficial for preserving RRF and showed similar patient survival when compared to conventional full-dose PD.

The impact of blood flow rate on dialysis dose and phosphate removal in hemodialysis patients.

The inadequacy of dialysis and hyperphosphatemia are both associated with morbidity and mortality in chronic hemodialysis (HD) patients. Blood flow rate (BFR) during HD is one of the important determinants of increasing dialysis dose. The aim of this study was to determine the effect of increasing BFR on dialysis dose and phosphate removal. Forty-four patients were included in a cross-sectional study. Each patient received six consecutive dialysis sessions as follows: three consecutive sessions with a BFR of 250 mL/min, followed by three others with BFR of 350 mL/min without changing the other dialysis parameters. Patients' body weight was recorded, and blood samples (serum urea and phosphate) were collected before and after each dialysis session. For assessing the efficacy of dialysis, urea reduction ratio (URR), Kt/VDiascan (Kt by Diascan and V by Watson), Kt/V Daugirdas (Daugirdas 2nd generation), equilibrated Kt/V, and phosphate reduction rate (PRR) were used. The increase of BFR by 100 mL/min resulted in a significant increase of URR, Kt/V Diascan, Kt/VDaugirdas, equilibrated Kt/V, and PRR: URR; 75.41 ± 5.60; 83.51 ± 6.12; P <0.001), (Kt/VDiascan; 1.28 ± 0.25; 1.55 ± 0.15; P <0.001), (Kt/VDaugirdas; 1.55 ± 0.26; 2.10 ± 0.61; P = 0.001), equilibrated Kt/V; 1.40 ± 0.19; 1.91 ± 0.52; P = 0.001), and (PRR; 50.32 ± 12.22; 63.66 ± 13.10; P = 0.010). Adequate dialysis, defined by single-pool Kt/V ≥1.4, was achieved using two different BFRs: 250 and 350 mL/min, respectively, in 73% and 100% of the cases. Increasing the BFR by 40% is effective in increasing dialysis dose and phosphate reduction rate during high-flux HD. The future prospective studies are needed to evaluate the impact of increasing BFR on phosphate removal using the total amount of phosphate removed, and also evaluate the cardiovascular outcome of phosphate reduction and dialysis improvement.

The impact of blood flow rate during hemodialysis on all-cause mortality.

Background/AimsInadequacy of dialysis is associated with morbidity and mortality in chronic hemodialysis (HD) patients. Blood flow rate (BFR) during HD is one of the important determinants of increasing dialysis dose. However, the optimal BFR is unclear. In this study, we investigated the impact of the BFR on all-cause mortality in chronic HD patients.MethodsPrevalent HD patients were selected from Clinical Research Center registry for end-stage renal disease cohort in Korea. We categorized patients into two groups by BFR < 250 and ≥ 250 mL/min according to the median value of BFR 250 mL/min in this study. The primary outcome was all-cause mortality.ResultsA total of 1,129 prevalent HD patients were included. The number of patients in the BFR < 250 mL/min was 271 (24%) and in the BFR ≥ 250 mL/min was 858 (76%). The median follow-up period was 30 months. Kaplan-Meier analysis showed that the mortality rate was significantly higher in patients with BFR < 250 mL/min than those with BFR ≥ 250 mL/min (p = 0.042, log-rank). In the multivariate Cox regression analyses, patients with BFR < 250 mL/min had higher all-cause mortality than those with BFR ≥ 250 mL/min (hazard ratio, 1.66; 95% confidence interval, 1.00 to 2.73; p = 0.048).ConclusionsOur data showed that BFR < 250 mL/min during HD was associated with higher all-cause mortality in chronic HD patients.

Grossesse en insuffisance rénale terminale : épidémiologie, prise en charge et pronostic

Pregnancy in patients presenting end-stage renal disease is rare and there are currently no recommendations for the management of these patients. In hemodialysis patients, reduced fertility and medical reluctance limit the frequency of pregnancies. Although the prognosis has significantly improved, a significant risk for unfavorable maternal (pre-eclampsia, eclampsia) and fetal (pre-term birth, intrauterine growth restriction, still death) outcome still remains. Increasing dialysis dose with the initiation of daily dialysis sessions, early adaptation of medications to limit teratogenicity and management of chronic kidney disease complications (anemia, hypertension) are required. A tight coordination between nephrologists and obstetricians remains the central pillar of the care. In peritoneal dialysis, pregnancy is also possible with modification of the exchange protocol and reducing volumes.

Twice-Weekly and Incremental Hemodialysis Treatment for Initiation of Kidney Replacement Therapy

Mortality is highest in the first months of maintenance hemodialysis (HD) therapy. In many Western countries, patients who transition to kidney replacement therapy usually begin thrice-weekly HD regardless of their level of residual kidney function (RKF). RKF is a major predictor of survival. RKF may decline more rapidly with thrice-weekly HD treatments, is associated with a reduced need for dialytic solute clearance, and is an important factor in the prescription of peritoneal dialysis. In this article, we review the concept of incremental HD, in which weekly dialysis dose, in particular HD treatment frequency, is based on a variety of clinical factors, such as RKF (including urine output > 0.5 L/d), volume status, cardiovascular symptoms, body size, potassium and phosphorus levels, nutritional status, hemoglobin level, comorbid conditions, hospitalizations, and health-related quality of life. These 10 clinical criteria may identify which patients might benefit from beginning maintenance HD therapy twice weekly. Periodic monitoring of these criteria will determine the timing for increasing dialysis dose and frequency. We recognize that twice-weekly HD represents a major paradigm shift for many clinicians and jurisdictions. Therefore, we propose conducting randomized controlled trials of twice-weekly versus thrice-weekly HD to assess the potential of twice-weekly HD to improve survival and health-related quality of life while simultaneously reducing costs, protecting fragile vascular accesses, and optimizing resource use during the first year of hemodialysis therapy. Such incremental and individualized HD therapy may prove to be the most appropriate approach for transitioning to dialytic therapy.

Conversion from conventional in-centre thrice-weekly haemodialysis to short daily home haemodialysis ameliorates uremia-associated clinical parameters

Under physiological conditions, kidneys work continuously, 168 h/week. In contrast, patients with end-stage renal disease are usually dialysed only 12 h/week. Even if considered adequate by current Kt/V-based dose estimates, this unphysiological dose is associated with an unacceptable annual mortality rate of 10-20%. Increasing dialysis dose might ameliorate this mortality rate. Eleven patients were switched from their conventional haemodialysis (cHD, 3 × 4 h/week) to an intensified short daily home haemodialysis regimen (sdhHD, 6 × 3 h/week) and followed up for 12 months. Different parameters were evaluated before treatment conversion and quarterly during follow-up [i.e. dialysis efficacy, mean arterial pressure (MAP), antihypertensive drug score, haemoglobin, transferrin saturation, ferritin, dose of erythropoiesis-stimulating agents (ESA), iron requirement, parameters of nutrition (body weight, albumin, protein), C-reactive protein, calcium-phosphate product, alkaline phosphatase (AP), intact parathyroid hormone (iPTH) and amount of phosphate-binding pharmacotherapy]. HD efficacy as assessed by cumulative blood volume increased after dialysis intensification (P < 0.01). The pre- and post-dialytic MAP declined during the study period (P < 0.0001), while antihypertensive drugs could be reduced (P = 0.02). Haemoglobin levels improved (P < 0.0001). Additionally, the need for ESAs fell under intensified sdhHD (P = 0.008). Nutritional status improved [albumin, P = 0.03; total serum protein, P = 0.02; 'dry' body weight (BW) and body mass index (BMI) (both P < 0.001)]. The calcium-phosphate product declined (P < 0.01), without changes in the dose of phosphate binders. Conversion from conventional in-centre to short daily home HD leads to an improvement in numerous dialysis-associated metabolic variables and thus represents an attractive treatment modality for selected patients.

The D&amp;T report

The D&amp;T report

Daily nocturnal hemodialysis—a paradigm shift worthy of disrupting current dialysis practice

Various strategies have been considered in attempts to improve the outcomes of dialysis patients. Such strategies include increasing dialysis dose, using alternative depuration methods, changing dialysis schedules and focusing on preventing or treating specific co-morbidities and complications. In this Viewpoint, Andreas Pierratos discusses the first three strategies, and concludes that he believes that a paradigm shift, a disruptive change-in the form of daily home nocturnal hemodialysis-is needed to improve dialysis outcomes.

The Effect of Increasing Dialysis Dose in Overweight Hemodialysis Patients on Quality of Life: A 6-Week Randomized Crossover Trial

Using standard hemodialysis regimens, overweight patients often do not reach Kidney Disease Outcomes Quality Initiatives (KDOQI) Kt/V targets, and this has been associated with lower health-related quality of life (HRQL). Whether increasing dialysis adequacy in large patients not achieving KDOQI targets improves HRQL is unknown. Randomized blinded crossover study. Overweight (>80 kg) underdialyzed patients from 6 dialysis units in 2 Canadian dialysis programs. Six-week treatment periods with a standard dialysis regimen (4 hours 3 times weekly) and 3 augmented regimens: 4.5 hours of hemodialysis, 4 hours of hemodialysis with increased dialysate flow, and 4 hours of hemodialysis with 2 dialyzers in parallel. The End-Stage Renal Disease Symptom domain of the Kidney Disease Quality-of-Life Short-Form questionnaire (primary outcome) and the Health Utilities Index Mark 2 (secondary outcome). We enrolled 18 patients (mean weight, 109.7 +/- 16.2 [SD] kg); 12 completed all 4 regimens. Mean Kt/Vs during the study were 1.27 (95% confidence interval [CI], 1.19 to 1.35), 1.41 (95% CI, 1.32 to 1.50), 1.31 (95% CI, 1.22 to 1.39), and 1.41 (95% CI, 1.33 to 1.49) for patients receiving standard dialysis, 4.5 hours of hemodialysis, hemodialysis with increased dialysate flow, and hemodialysis with 2 dialyzers, respectively. Kidney Disease Quality-of-Life End-Stage Renal Disease Symptom domain and Health Utilities Index Mark 2 scores were 75.9 (95% CI, 70.7 to 81.2) and 0.69 (95% CI, 0.56 to 0.81) for patients receiving standard dialysis, respectively. These did not differ when patients received the 3 augmented dialysis regimens (P = 0.2 and P = 0.5, respectively). Small sample size and inability to fully blind patients to the treatment they were receiving. Improving hemodialysis adequacy for large underdialyzed patients did not lead to improved HRQL. Our findings suggest that augmentation of the dialysis regimen is not required for these patients in the absence of overt uremic symptoms.

Is more frequent hemodialysis beneficial and what is the evidence?

The HEMO study results have shown that increasing dialysis dose in conventional thrice weekly hemodialysis does not improve patient outcomes. Interest has therefore turned to more frequent (daily) hemodialysis treatments. This review covers the rationale for such an approach together with a current review of the published study data. Recent studies have suggested improvements in a number of intermediate patient outcomes such as cardiovascular (blood pressure control, left ventricular hypertrophy), anemia, phosphate control, nutritional status and quality of life. Some of these outcomes are associated with increased survival in the dialysis population. The inference from these studies is that more frequent hemodialysis will indeed reduce mortality and morbidity. To date, however, the studies have all been small and underpowered to detect such primary outcomes. No randomized controlled trials are yet reported. The US National Institutes of Health have sponsored larger scale North American based studies and an International Registry of Daily Dialysis patients has been created to attain further information of the possible benefits of such therapy. In spite of the paucity of hard evidence the studies to date have been enough to convince some jurisdictions to recognize and fund daily hemodialysis treatments.

Nutritional requirements in maintenance hemodialysis

There is a high prevalence of nutritional disorders in maintenance hemodialysis patients. This fact has been recently confirmed because larger routine assesments of MHD patients body composition are now performed. Food records and dietary interviews show spontaneous low intakes of protein and energy in many patients. An increasing dialysis dose above a Kt/V (single pool) of 1.5 may not improve patients nutritional intakes. Inflammation may further impair the balance between protein synthesis and catabolism and cause anorexia. In response to these abnormalities, the management of energy, protein, vitamins, and trace elements intake will be discussed with special emphasis on calcium, phosphorus, enteral support, and parenteral nutrition.

Current Canadian Approaches to Dialysis for Acute Renal Failure in the ICU

Background: Although there is a very high mortality rate (>50%) with acute renal failure (ARF) in the intensive care unit (ICU), there is no general consensus on the best dialysis treatment for this condition. Methods: We surveyed by mail questionnaire, all adult academic and community registered Canadian nephrology centers that offer treatment for ARF. Results: The overall response rate was 59% (53/90). Comparing current dialysis methods with those utilized 5 years ago, the largest increase was in continuous renal replacement therapies (CRRT) (26 vs. 9%). Both intermittent hemodialysis (IHD) and peritoneal dialysis decreased in utilization. The predominant current CRRT methods utilized venovenous access (80%), as compared to 5 years ago when arteriovenous was the most common (52%). Despite data from chronic dialysis (and preliminary data in ARF) suggesting reduced mortality and morbidity with increasing dialysis dose, there was no formal method of dialysis prescription monitoring in over 75% of the centers. Conclusion: Notwithstanding a lack of definitive evidence of superior outcomes with CRRT compared to older methods, the utilization of CRRT is dramatically increasing for the treatment of ARF in Canada. Whether this shift towards CRRT, and whether more attention to dialysis dose in ARF, might be expected to lead to better outcomes, requires further evaluation.

EFFECTS OF HEMODIALYSIS DOSE ON ANEMIA, HYPERTENSION, AND NUTRITION

There is good evidence that by improving dialysis adequacy, morbidity, and mortality of hemodialysis (HD) patients decrease. Dialysis adequacy has also been related to the better control of arterial blood pressure (BP), anemia and improvement of patients' nutritional status. This is a self-control study of 34 HD patients, (23 males, 11 females), aged 52.6 ± 15.5 years, HD duration 55.9 ± 61.2 months, referring to the effect of increasing delivered dialysis dose, over a two-year period, on their clinical and laboratory parameters. Delivered HD dose increased statistically significantly: Urea reduction ratio (URR) increased from 52 ± 8 to 71 ± 7% and Kt/V from 0.93 ± 0.19 to 1.55 ± 0.29 (p<0.001). Hb increased statistically significantly from 10.4 ± 1.7 to 11.0 ± 1.3 g/dL (p<0.05) while no difference has been noticed in weekly EPO dose. Both systolic and diastolic BP decreased statistically significantly (from 147 ± 24 to 133 ± 25 mmHg and from 73 ± 12 to 66 ± 13 mmHg respectively, p = 0.001). Serum albumin increased from 4.3 ± 0.4 to 4.6 ± 0.3 g/dL (p = 0.002) and nPCR from 0.93 ± 0.16 to 1.20 ± 0.17 (p<0.001). We conclude that increasing dialysis dose results in both clinical and laboratory improvement regarding hypertension, nutritional status and control of HD patients' anemia.

Effects of increasing dialysis dose on serum albumin and mortality in hemodialysis patients

Dialysis dose and malnutrition have a great impact on the clinical outcome of chronic hemodialysis patients. The interrelationships between them, however, remain undefined. Thus, we performed a study to determine the effects of increasing the dialysis dose on serum albumin concentrations and mortality in hemodialysis patients. We examined urea kinetic modeling, biochemical nutritional indices, comorbid conditions, patient survival time, and annual mortality rate. Dialysis dose, measured by Kt/V, significantly increased from 1.3 ± 0.3 in 1987 to 1.5 ± 0.4 in 1990 and to 1.7 ± 0.4 in 1993. Serum albumin level also increased, from 3.8 ± 0.4 g/dL in 1987 to 4.0 ±0.4 g/dL in 1990 and to 4.3 ± 0.3 g/dL in 1993. In 1993, 76% of patients had Kt/V ≥1.50 compared with 45% in 1990 and 28% in 1987, whereas 82% of patients had a serum albumin level ≥4.0 g/dL in 1993 compared with 58% in 1990 and 29% in 1987. Protein catabolic rate and hematocrit also increased from 1987 to 1993, but not serum cholesterol or triglyceride. The annual mortality rate decline from 16.1% in 1987 to 13.2% in 1990 and to 8.0% in 1993. The decrease in mortality appeared to be unrelated to differences in patient selection or comorbid conditions. Serum albumin levels, hematocrit, Kt/V, and protein catabolic rate were significantly related to patient survival after age, sex, and diabetic status had been adjusted. Furthermore, there was a positive correlation between Kt/Vs and serum albumin concentrations ( r = 0.216, P <0.001). Thus, it appears that increasing the dose of dialysis improves serum albumin levels and perhaps survival rate in hemodialysis patients as well.