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Kidney International Sep 2016Long-term peritoneal dialysis causes morphologic and functional changes in the peritoneal membrane. Although mesothelial-mesenchymal transition of peritoneal mesothelial... (Review)
Review
Long-term peritoneal dialysis causes morphologic and functional changes in the peritoneal membrane. Although mesothelial-mesenchymal transition of peritoneal mesothelial cells is a key process leading to peritoneal fibrosis, and bioincompatible peritoneal dialysis solutions (glucose, glucose degradation products, and advanced glycation end products or a combination) are responsible for altering mesothelial cell function and proliferation, mechanisms underlying these processes remain largely unclear. Peritoneal fibrosis has 2 cooperative parts, the fibrosis process itself and the inflammation. The link between these 2 processes is frequently bidirectional, with each one inducing the other. This review outlines our current understanding about the definition and pathophysiology of peritoneal fibrosis, recent studies on key fibrogenic molecular machinery in peritoneal fibrosis, such as the role of transforming growth factor-β/Smads, transforming growth factor-β β/Smad independent pathways, and noncoding RNAs. The diagnosis of peritoneal fibrosis, including effluent biomarkers and the histopathology of a peritoneal biopsy, which is the gold standard for demonstrating peritoneal fibrosis, is introduced in detail. Several interventions for peritoneal fibrosis based on biomarkers, cytology, histology, functional studies, and antagonists are presented in this review. Recent experimental trials in animal models, including pharmacology and gene therapy, which could offer novel insights into the treatment of peritoneal fibrosis in the near future, are also discussed in depth.
Topics: Animals; Biomarkers; Biopsy; Dialysis Solutions; Disease Models, Animal; Epithelial Cells; Glucose; Glycation End Products, Advanced; Humans; Inflammation; Peritoneal Dialysis; Peritoneal Fibrosis; Peritoneum; RNA, Long Noncoding; RNA, Small Untranslated; Signal Transduction; Smad Proteins; Transforming Growth Factor beta
PubMed: 27282936
DOI: 10.1016/j.kint.2016.03.040 -
Blood Purification 2015Hemodiafiltration (HDF) seems to represent the gold standard in the field of replacement of renal function by dialysis. High convective fluxes have been correlated with... (Review)
Review
Hemodiafiltration (HDF) seems to represent the gold standard in the field of replacement of renal function by dialysis. High convective fluxes have been correlated with better clinical outcomes. Sometimes, however, there are technical barriers to the achievement of high blood flows adequate to perform effective convective therapies. In spite of optimized procedures, the progressive increase in transmembrane pressure (TMP), the blood viscosity due to hemoconcentration and blood path resistance sometimes becomes inevitable. We propose two possible solutions that can be operated automatically via specific software in the dialysis machine: predilution on demand and backflush on demand. Predilution on demand consists in an automatic feedback of the machine, diverting part of the filtered dialysate into a predilution mode with an infusion of 200 ml in 30 s while the ultrafiltration pump stops. This produces a sudden hemodilution with a return of the parameters to acceptable values. The performance of the filter improves, and the pressure alterations are mitigated. Backflush on demand consists in an automatic feedback of the machine triggered by the TMP control, producing a positive pressure in the dialysate compartment due to a stop of filtration and rapid infusion of at least 100 ml of ultrapure dialysate into the hollow fiber. This not only produces a significant hemodilution, but also backflushes the membrane pores detaching protein layers and improving membrane permeability. These are two examples of how technology will permit to overcome technical barriers to a widespread diffusion of HDF and adequate convective dose delivery.
Topics: Dialysis Solutions; Diffusion; Hemodiafiltration; Humans; Kidney Failure, Chronic; Pressure; Rheology; Software; Vascular Resistance
PubMed: 26344507
DOI: 10.1159/000437403 -
American Journal of Physiology. Heart... Apr 2022
Topics: Bicarbonates; Dialysis Solutions
PubMed: 35324335
DOI: 10.1152/ajpheart.00057.2022 -
Nephrology, Dialysis, Transplantation :... Oct 2018Recent advances in chemical composition and new production techniques resulted in improved biocompatibility and permeability of dialysis membranes. Among these, the... (Review)
Review
Recent advances in chemical composition and new production techniques resulted in improved biocompatibility and permeability of dialysis membranes. Among these, the creation of a new class of membranes called medium cut-off (MCO) represents an important step towards improvement of clinical outcomes. Such membranes have been developed to improve the clearance of medium to high molecular weight (MW) solutes (i.e. uraemic toxins in the range of 5-50 kDa). MCO membranes have peculiar retention onset and cut-off characteristics. Due to a modified sieving profile, MCO membranes have also been described as high-retention onset. The significant internal filtration achieved in MCO haemodialysers provides a remarkable convective clearance of medium to high MW solutes. The marginal loss of albumin observed in MCO membranes compared with high cut-off membranes is considered acceptable, if not beneficial, producing a certain clearance of protein-bound solutes. The application of MCO membranes in a classic dialysis modality characterizes a new technique called expanded haemodialysis. This therapy does not need specific software or dedicated hardware, making its application possible in every setting where the quality of dialysis fluid meets current standards.
Topics: Dialysis Solutions; Hemodiafiltration; Humans; Membranes, Artificial; Molecular Weight; Renal Dialysis
PubMed: 30281134
DOI: 10.1093/ndt/gfy202 -
Scientific Reports Jul 2023Biocompatibility and the ability to mediate the appropriate flux of ions, urea, and uremic toxins between blood and dialysate components are key parameters for membranes...
Biocompatibility and the ability to mediate the appropriate flux of ions, urea, and uremic toxins between blood and dialysate components are key parameters for membranes used in dialysis. Oxone-mediated TEMPO-oxidized cellulose nanomaterials have been demonstrated to be excellent additives in the production and tunability of ultrafiltration and dialysis membranes. In the present study, nanocellulose ionic liquid membranes (NC-ILMs) were tested in vitro and ex vivo. An increase in flux of up to two orders of magnitude was observed with increased rejection (about 99.6%) of key proteins compared to that of polysulfone (PSf) and other commercial membranes. NC-ILMs have a sharper molecular weight cut-off than other phase inversion polymeric membranes, allowing for high throughput of urea and a uremic toxin surrogate and limited passage of proteins in dialysis applications. Superior anti-fouling properties were also observed for the NC-ILMs, including a > 5-h operation time with no systemic anticoagulation in blood samples. Finally, NC-ILMs were found to be biocompatible in rat ultrafiltration and dialysis experiments, indicating their potential clinical utility in dialysis and other blood filtration applications. These superior properties may allow for a new class of membranes for use in a wide variety of industrial applications, including the treatment of patients suffering from renal disease.
Topics: Rats; Animals; Renal Dialysis; Ultrafiltration; Toxins, Biological; Dialysis Solutions; Proteins; Membranes, Artificial; Urea
PubMed: 37474512
DOI: 10.1038/s41598-023-37765-y -
Seminars in Dialysis May 2018Hypophosphatemia is a common and potentially serious complication occurring during continuous renal replacement therapy (CRRT). Phosphate supplementation is required in... (Review)
Review
Hypophosphatemia is a common and potentially serious complication occurring during continuous renal replacement therapy (CRRT). Phosphate supplementation is required in the vast majority of patients undergoing CRRT, particularly beyond the first 48 hours. Supplementation can be provided either as a standalone oral or parenteral treatment or as an additive to CRRT solutions. Each approach has advantages and disadvantages, and clinicians must weigh the individual factors most relevant in their practice setting. Currently there are no consensus protocols for phosphate replacement in CRRT, and many centers replete phosphate in response to hypophosphatemia as opposed to pre-emptively. Repletion protocols have also been challenged in recent years by shortages in injectable phosphate solutions. More recently a commercially available phosphate-containing CRRT solution was approved in the United States, but there has been limited clinical experience with this product. In this review, we present recommendations for phosphate repletion in CRRT to prevent hypophosphatemia, and describe our experience using phosphate-containing CRRT solutions.
Topics: Aged; Dialysis Solutions; Female; Humans; Hypophosphatemia; Infusions, Intravenous; Kidney Failure, Chronic; Male; Middle Aged; Phosphates; Prognosis; Renal Replacement Therapy; Risk Assessment; Treatment Outcome
PubMed: 29405468
DOI: 10.1111/sdi.12677 -
Clinical Journal of the American... Feb 2019Approximately 7%-10% of patients with ESKD worldwide undergo peritoneal dialysis (PD) as kidney replacement therapy. The continuous nature of this dialytic modality and... (Review)
Review
Approximately 7%-10% of patients with ESKD worldwide undergo peritoneal dialysis (PD) as kidney replacement therapy. The continuous nature of this dialytic modality and the absence of acute shifts in pressure and volume parameters is an important differentiation between PD and in-center hemodialysis. However, the burden of hypertension and prognostic association of BP with mortality follow comparable patterns in both modalities. Although management of hypertension uses similar therapeutic principles, long-term preservation of residual diuresis and longevity of peritoneal membrane function require particular attention in the prescription of the appropriate dialysis regimen among those on PD. Dietary sodium restriction, appropriate use of icodextrin, and limited exposure of peritoneal membrane to bioincompatible solutions, as well as adaptation of the PD regimen to the peritoneal transport characteristics, are first-line therapeutic strategies to achieve adequate volume control with a potential long-term benefit on technique survival. Antihypertensive drug therapy is a second-line therapeutic approach, used when BP remains unresponsive to the above volume management strategies. In this article, we review the available evidence on epidemiology, diagnosis, and treatment of hypertension among patients on PD and discuss similarities and differences between PD and in-center hemodialysis. We conclude with a call for randomized trials aiming to elucidate several areas of uncertainty in management of hypertension in the PD population.
Topics: Angiotensin-Converting Enzyme Inhibitors; Blood Pressure; Body Water; Dialysis Solutions; Diet, Sodium-Restricted; Diuretics; Humans; Hypertension; Icodextrin; Kidney Failure, Chronic; Mortality; Peritoneal Dialysis, Continuous Ambulatory; Prevalence; Renal Dialysis
PubMed: 30341090
DOI: 10.2215/CJN.07480618 -
Nephrology, Dialysis, Transplantation :... Oct 2018Expanded haemodialysis (HDx) has emerged as a promising solution to improve haemodialysis effectiveness. A medium cut-off membrane allows the removal of a wider range of... (Review)
Review
Expanded haemodialysis (HDx) has emerged as a promising solution to improve haemodialysis effectiveness. A medium cut-off membrane allows the removal of a wider range of uraemic toxins. However, little is known about the potential interesting applications of HDx therapy. Feedback from the first routine use of HDx therapy under real-life conditions in European facilities was excellent for priming and rinse back. There was no adverse event after 5191 HDx treatments. Patients suffering from itching, restless legs syndrome, persistent asthenia or malnourishment could benefit from HDx therapy. Moreover, we discuss here the promising applications in which HDx could be valuable (myeloma, rhabdomyolysis or cardiovascular diseases). This enthusiastic message is mitigated by reminding why and how prudence should be taken in the design of future HDx studies.
Topics: Dialysis Solutions; Hemodiafiltration; Humans; Membranes, Artificial; Molecular Weight; Multiple Myeloma; Renal Dialysis; Restless Legs Syndrome; Rhabdomyolysis
PubMed: 30281127
DOI: 10.1093/ndt/gfy203 -
Blood Purification 2015Standard low-flux haemodialysis (HD) is not very efficacious, and patient morbidity and mortality rates are still very high. According to the initial study design, the... (Review)
Review
BACKGROUND
Standard low-flux haemodialysis (HD) is not very efficacious, and patient morbidity and mortality rates are still very high. According to the initial study design, the MPO study reported that high-flux HD (hf-HD) showed a significant 37% relative risk reduction of mortality in patients with serum albumin ≤4 g/dl; online haemodiafiltration (HDF) is considered the most efficient technique of using high-flux membranes, as clearances of small solutes, like urea, are higher than in haemofiltration and clearances of middle solutes, like β2-microglobulin, are higher than in hf-HD.
SUMMARY
Three randomized trials have recently been published analysing the effect of online HDF on mortality. Two trials were unable to demonstrate a positive effect of HDF on survival, while 1 showed a significantly better survival in patients randomized to HDF in comparison to those randomized to hf-HD. It is intriguing that post hoc analyses of these 3 studies showed that the patients randomized to online HDF who received the highest convection volumes had a lower risk of mortality and cardiovascular events than those randomized to HD. Four very recently published meta-analyses have shown inconsistent results concerning the effect of convective treatments in improving patient general and cardiovascular survival, while they have consistently shown a significant reduction of the intradialytic symptomatic hypotension in patients treated with convective techniques in comparison with those treated with prevalent diffusive ones. Key Messages: The results of the randomized trials on the effect of HDF in improving patient survival are inconclusive. Moreover, trials specifically designed for testing the effect of increased convection of online HDF on patient survival and morbidity in comparison to patients treated with hf-HD are still awaited.
Topics: Aged; Blood Flow Velocity; Dialysis Solutions; Female; Hemodiafiltration; Humans; Kidney Failure, Chronic; Male; Membranes, Artificial; Randomized Controlled Trials as Topic; Rheology; Risk Factors; Survival Analysis; Urea; beta 2-Microglobulin
PubMed: 26344510
DOI: 10.1159/000437410 -
Kidney360 May 2022
Topics: Dialysis Solutions; Icodextrin; Peritoneal Dialysis
PubMed: 36128486
DOI: 10.34067/KID.0001902022