Importance Of Residual Renal Function Research Articles

The Importance of Residual Renal Function in Peritoneal Dialysis

The Importance of Residual Renal Function in Peritoneal Dialysis

Measuring residual renal function in dialysis patients: can we dispense with 24-hour urine collections?

Residual renal function is associated with improved survival and quality of life for dialysis patients. Whereas residual renal function is monitored in peritoneal dialysis patients, many hemodialysis centers simply concentrate on achieving dialyzer urea clearance targets. Accurately quantifying residual renal function from urine collections is arduous. Thus, there is a clinical need to develop alternative methods of assessing residual renal function based on serum testing, especially for patients receiving less than thrice weekly dialysis.

Incremental haemodialysis.

Thrice-weekly haemodialysis schedules have become the standard default haemodialysis prescription worldwide. Whereas the measurement of residual renal function is accepted practice for peritoneal dialysis patients and the importance of residual renal function in determining technique success is well established, few centres routinely assess residual renal function in haemodialysis patients. Although intradialytic hypotension and episodes of acute kidney injury may predispose to an earlier loss of residual renal function, a significant proportion of haemodialysis patients maintain some residual function long after dialysis initiation. As such, an incremental approach to the initiation of dialysis with careful monitoring of residual renal function may potentially provide some haemodialysis patients with an improved quality of life and greater preservation of residual renal function whilst fewer dialysis sessions may reduce health care costs. Prospective trials are required to determine the optimum approach to the initiation of haemodialysis for the oliguric patient. Once residual renal function has been lost, then dialysis prescriptions should be re-examined to consider the use of longer or more frequent treatment sessions and switching from low-flux to high-flux dialysis or haemodiafiltration to offset retention of middle sized molecules and protein-bound azotaemic solutes.

Response to Body Mass Index-Mortality Paradox in Hemodialysis: Can It Be Explained by Blood Pressure?

Ferreira-Filho et al1 correctly point out the importance of residual renal function in maintaining volume homeostasis and predicting morbid and mortal outcomes among patients with end-stage renal disease. Although we did not report residual renal function, the vintage stratified by body mass index categories …

Emerging Importance of Residual Renal Function in End‐Stage Renal Failure

Residual renal function (RRF) is well recognized as an important marker of outcomes in peritoneal dialysis (PD), and contributes vitally to solute clearance. Recently, its importance in hemodialysis (HD) has emerged with evidence that it is strongly associated with improved outcomes. The presence of RRF is associated with improved nutrition, reduced erythropoetin requirements, better potassium clearance, and improved quality of life. Retrospective and observational evidence is now available, which suggests that the presence of RRF is independently associated with survival and that this benefit goes beyond what is expected simply from augmentation of small solute clearance. Preservation of RRF is now considered by many to be an important aspect of dialysis strategy. Evidence in favor of one modality over another for preservation of RRF is conflicting, as are the potential benefits of biocompatible fluids in PD. In HD, the evidence in favor of biocompatible membranes is stronger. Emerging evidence is broadly in favor of angiotensin converting enzyme inhibitors for preservation of RRF. Diuretics appear to have a neutral effect. The complexities and practical difficulties in measurement of RRF have resulted in this important parameter being largely ignored in HD. Novel markers of renal function may provide alternative, simple methods of estimating RRF, which may remove the need for urine collections and simplify its measurement.

Residual renal function improves outcome in incremental haemodialysis despite reduced dialysis dose

The importance of residual renal function is well recognized in peritoneal dialysis but its role in haemodialysis (HD) has received much less attention. We studied 650 incident patients in our incremental high-flux HD programme over a 15-year period. Target total Kt/V urea (dialysis plus residual renal) was 1.2 per session and monitored monthly. Renal urea clearance (KRU) was estimated 1-3 monthly. KRU declined during the first 5 years of HD from 3.1 +/- 1.9 at 3 months to 0.9 +/- 1.2 ml/min/1.73 m(2) at 5 years. The percentage of patients with KRU >or= 1 ml/min at these time points was 85% and 31%, respectively. Patients with KRU >or= 1 ml/min had a significantly lower mean creatinine (all time points), ultrafiltration requirement (all time points) and serum potassium (6, 12, 36 and 48 months). Nutritional parameters were also significantly better in respect to nPCR and serum albumin (6, 12, 24 and 36 months). Patients with KRU >or= 1 ml/min had significantly lower erythropoietin requirements and erythropoietin resistance indices (12, 24, 36 and 48 months). Mortality was significantly lower in patients with a KRU >or= 1 at 6, 12 and 24 months after HD initiation, this benefit being maintained after correcting for albumin, age, comorbidities, HDF use and renal diagnosis. Our unique finding was that these benefits occurred despite those with KRU >or= 1 ml/min having a significantly lower dialysis Kt/V at all time points. The associations demonstrated suggest that residual renal function contributes significantly to outcome in HD patients and that efforts to preserve it are warranted. Comparative outcome studies should be controlled for residual renal function.

Relative Importance of Residual Renal Function and Convection in Determining Beta-2-Microglobulin Levels in High-Flux Haemodialysis and On-Line Haemodiafiltration

Convective blood purification improves beta(2)-microglobulin (beta(2)M) removal and may delay the onset of dialysis-related amyloidosis. We assessed the differential effects of high-flux haemodialysis (HD) and on-line haemodiafiltration (HDF) on plasma beta(2)M levels, given the enhanced convective capability of HDF.We measured pre-dialysis beta(2)M levels in 297 patients in a programme employing both high-flux HD and HDF, then analysed the relationship of beta(2)M to modality and other variables.Independent determinants of plasma beta(2)M levels were residual renal function, age, HD vintage, and C-reactive protein load, but not the patient's predominant modality (high-flux HD or HDF). Patients with KRU levels <0.5 ml/min had significantly higher beta(2)M levels than patients with KRU between 0.5 and 1 ml/min.Residual renal function is of overriding importance as a determinant of beta(2)M levels in HD patients and may supersede enhanced convective clearance by HDF. Beneficial effects extend to very low levels of residual renal function.

The “Heart” of Peritoneal Dialysis

Cardiovascular disease accounts for more than half of all deaths in end-stage renal disease patients receiving chronic peritoneal dialysis (PD) treatment. The recent demonstration of the important association between residual renal clearance (but not PD clearance) and overall and cardiovascular survival in chronic PD patients has led us to further explore the mechanisms that can potentially explain the close link between residual renal function and cardiovascular disease in this population. This John Maher Award Lecture provides a review of my own work and that of other groups that provides support for the importance of residual renal function not only in providing small-solute clearance but also in maintaining the cardiovascular health, nutrition status, and wellbeing of PD patients. Data are provided to demonstrate why preservation of residual renal function may be the key to improving survival and cardiovascular outcomes in PD patients.

The importance of residual renal function for patients on dialysis

It is the goal of every practitioner involved in the care of dialysis patients to maximize survival and quality of life. The last two decades have seen a plethora of investigations that have sought to determine how this goal can be achieved. The bulk of the studies have, unfortunately, concentrated on small solute clearance and outcome (measured principally as mortality). The HEMO [1] and ADEMEX [2] studies suggested that this is not a fruitful avenue of investigation. However, the residual kidney function in patients on dialysis, particularly in those on peritoneal dialysis (PD), has proven to be a consistent and powerful predictor of mortality. We will review the evidence supporting the importance of residual renal function (RRF) on outcome, propose some explanations as to why this relationship exists, and suggest ways to prolong the renal function in dialysis patients.

The relative importance of residual renal function compared with peritoneal clearance for patient survival and quality of life: an analysis of the netherlands cooperative study on the adequacy of dialysis (Necosad)-2

Background:The guidelines from the US National Kidney Foundation Dialysis Outcomes Quality Initiative on peritoneal dialysis (PD) assume equivalence between the peritoneal and the renal solute clearance. The authors examined in a prospective cohort study of incident dialysis patients the relative contribution of residual renal function and peritoneal clearance to patient survival and quality of life (QoL). Methods:The authors analyzed the longitudinal data on residual renal function, clearance by dialysis, and QoL of those patients who were treated with PD 3 months after the start of dialysis and participated in a prospective multicenter study in the Netherlands (n = 413). Results:The mean age was 52 years, the mean residual glomerular filtration rate (rGFR) at 3 months was 4.1 mL/min/1.73 m2 (SD: 2.7), and the mean peritoneal creatinine clearance (pCrCl) at 3 months was 4.1 mL/min/1.73 m2 (SD: 1.1). The 2-year survival was 84%. For each mL/min/1.73 m2 increase in rGFR, a 12% reduction in mortality rate was found (relative risk of death [RR] = 0.88, P = 0.039). In contrast, no significant effect of pCrCl on patient survival was established (RR = 0.91, P = 0.47). The differential impact of rGFR and pCrCl was confirmed in an analysis on combined patient and technique survival and in an analysis on a number of generic and disease-specific dimensions of QoL. Conclusion:The beneficial effect of renal clearance and the absence of an effect of peritoneal clearance in the range of values common in current practice on patient outcome indicate that the 2 components of total solute clearance should not be regarded as equivalent. Higher peritoneal clearance targets do not necessarily improve patient outcome.

Importance of Residual Renal Function in Continuous Ambulatory Peritoneal Dialysis: Its Influence on Different Parameters of Renal Replacement Treatment

Objective: To study the influence of residual renal function (RRF) on different parameters of the renal substitutive treatment offered by peritoneal dialysis. Methods: We analyzed the impact of RRF on dialysis dose, nutrition parameters, anemia and phosphocalcic metabolism in 37 patients with end-stage renal disease (ESRD) treated by continuous ambulatory peritoneal dialysis (CAPD). Analytical controls were done every 6 months after an initial assessment at the end of the first month of treatment. Multiple lineal regression models were used as the statistical method to analyze the influence of RRF on different theoretically dependent factors. RRF was calculated as a mean of creatinine and urea clearances. Three observations per patient were used: one at the end of the first month of treatment; a final one at the end of follow-up (mean time 24.2 ± 11.4 months), and at a mean time between them (13.4 ± 6.7 months), with a final number of 111 observations. Results: Dialysis dose: RRF was the most important factor in terms of creatinine clearance (r² = 0.94; β = 0.999), KT/V (r² = 0.68; β = 0.819) and β₂-microglobulin levels (r² = 0.46; β = –0.489). Nutrition parameters: RRF was a determinant factor for normalized protein catabolic rate (r² = 0.53; β = 0.471), percent lean body mass (r² = 0.45; β = 0.446) and albumin levels (r² = 0.25; β = 0.229). Anemia: RRF was the most important factor when studying hemoglobin levels (r² = 0.28; β = 0.407). Phosphocalcic metabolism: Between the analyzed factors, RRF was the only one which reached significance on serum phosphate levels (r² = 0.19; β = –0.594). RRF did not show any relationship with either calcium or PTH levels. Conclusions: Independent of other factors, RRF in CAPD is positively and directly related to dialysis dose, β₂-microglobulin levels, nutrition parameters (albumin, normalized protein catabolic rate and percent lean body mass, hemoglobin and serum phosphate levels.

Importance of Residual Renal Function in End‐Stage Renal Disease

Importance of Residual Renal Function in End‐Stage Renal Disease

Adequacy of dialysis.

Adequacy of dialysis, both hemodialysis and peritoneal dialysis, has been the subject of a number of meetings and papers in the past. Nevertheless, it still remains defined only in general terms. Calculations of clearance of patients on intermittent peritoneal dialysis have shown the importance of residual renal function in patients with peritoneal dialysis.

TREATMENT WITH THE ARTIFICIAL KIDNEY (DIALYSIS)

For patients with chronic renal disease, haemodialysis can provide reasonable rehabilitation and, in most cases, a life expectancy in excess of 10 years. However, dialysis is unable to provide for any loss of the kidneys' endocrine or metabolic activities and the kidneys' excretory capacity is only replaced suboptimally. Recent well controlled studies on the frequency, time and techniques of dialysis, instigated mostly as a consequence of recent hypotheses, such as the "middle molecule" theory and consideration of the potential importance of residual renal function, have resulted in a complete reassessment of the nature of adequate dialysis. Developments such as sorbent-based dialysis are leading to a wearable dialyser. Theoretical and hardware developments are providing not only more adequate treatment, but improved rehabilitation for those patients on chronic dialysis therapy.