Safety and Feasibility of Regional Citrate Anticoagulation for Continuous Renal Replacement Therapy With Calcium-Containing Solutions: A Randomized Controlled Trial

BACKGROUND

Calcium-free (Ca-free) solutions are theoretically the most ideal for regional citrate anticoagulation (RCA) in continuous renal replacement therapy (CRRT). However, the majority of medical centers in China had to make a compromise of using commercially available calcium-containing (Ca-containing) solutions instead of Ca-free ones due to their scarcity. This study was designed to probe into the potential of Ca-containing solution as a secure and efficient substitution for Ca-free solutions.

METHODS

In this prospective, randomized single-center trial, 99 patients scheduled for CRRT were randomly assigned in a 1:1:1 ratio to one of three treatment groups: continuous veno-venous hemodialysis Ca-free dialysate (CVVHD Ca-free) group, continuous veno-venous hemodiafiltration calcium-free dialysate (CVVHDF Ca-free) group, and continuous veno-venous hemodiafiltration Ca-containing dialysate (CVVHDF Ca-containing) group at cardiac intensive care unit (CICU). The primary endpoint was the incidence of metabolic complications. The secondary endpoints included premature termination of treatment, thrombus of filter, and bubble trap after the process.

RESULTS

The incidence of citrate accumulation (18.2% vs. 12.1% vs. 21.2%) and metabolic alkalosis (12.1% vs. 0% vs. 9.1%) did not significantly differ among three groups (p > 0.05 for both). The incidence of premature termination was comparable among the groups (18.2% vs. 9.1% vs. 9.1%, p = 0.582). The thrombus level of the filter and bubble trap was similar in the three groups (p > 0.05 for all).

CONCLUSIONS

In RCA-CRRT for CICU population, RCA-CVVHDF with Ca-containing solutions and traditional RCA with Ca-free solutions had a comparable safety and feasibility.

TRIAL REGISTRATION

ChiCTR2100048238 in the Chinese Clinical Trial Registry.

Adsorption and Clearance of the Novel Fluorescent Tracer Agent MB-102 During Continuous Renal Replacement Therapy: In Vitro Results

MB-102 is a novel fluorescent tracer agent that is exclusively removed from the body by glomerular filtration. This agent can be detected transdermally to provide a real-time measurement of glomerular filtration rate at the point-of-care and is currently in clinical studies for such. MB-102 clearance during continuous renal replacement therapy (CRRT) is unknown. Its plasma protein binding (~0%), molecular weight (~372 Da) and volume of distribution (15-20 L) suggest that it may be removed by renal replacement therapies. To determine the disposition of MB-102 during CRRT, an in vitro study assessing the transmembrane clearance (CL TM ) and adsorptive clearance of MB-102 was conducted. A validated in vitro bovine blood continuous hemofiltration (HF) and continuous hemodialysis (HD) models were performed using two types of hemodiafilters to evaluate CL TM of MB-102. For HF, three different ultrafiltration rates were evaluated. For HD, four different dialysate flow rates were evaluated. Urea was used as a control. No MB-102 adsorption to the CRRT apparatus or either of hemodiafilters was observed. MB-102 is readily removed by HF and HD. Dialysate and ultrafiltrate flow rates directly influence MB-102 CLTM. Hence MB-102 CLTM should be measurable for critically ill patients receiving CRRT.

Prevalence and determinants of low plasma zinc levels in adult peritoneal dialysis patients

OBJECTIVE

Zinc is an essential trace element, being a cofactor for almost 300 enzymes. As zinc is widely available in the diet, the European Best Practice Guidelines do not recommend routine supplementation in dialysis patients. However, some medicines prescribed to dialysis patients may potentially reduce absorption, and there may be increased losses with dialysis. As older and co-morbid patients are now treated by peritoneal dialysis (PD) we wished to determine the prevalence of patients with low plasma zinc levels.

DESIGN AND METHODS

We prospectively measured plasma zinc in 550 PD patients attending for their first peritoneal membrane assessment using atomic absorption spectroscopy. Body composition was determined by bioimpedance.

RESULTS

Plasma zinc was measured in 550 patients, mean age 58.7 years, 60.6% male, mean value 10.8 ± 2.2 umol/L, with 66.5% having low zinc levels (<11.5 umol/L). Normal plasma zinc was associated with haemoglobin (odds ratio (OR) 1.41 (95% confidence limits (95%CL) 1.22-1.63), serum albumin (OR 1.04 (95%CL 1.002-1.087), higher glucose dialysates L/day (OR 1.06 (1.001-1.129), and negatively with 24-hour urinary protein losses (OR 0.786 (95%CL 0.673-0.918) and age (OR 0.985 (95%CL 0.972-1.0). There was no association with dialysis adequacy, original renal disease or dietary protein estimation. Prescription of phosphate binders had no effect on zinc levels (10.7 ± 2.2 vs 10.8 ± 2.3 umol/L).

CONCLUSIONS

Most PD patients had low plasma zinc levels, associated with older age, probably reflecting reduced intake, urinary protein losses, and lower albumin and haemoglobin most likely linked to greater co-morbidity, low grade inflammation and volume expansion requiring higher glucose dialysates.

Ferric pyrophosphate citrate for parenteral administration of maintenance iron: structure, mechanism of action, clinical efficacy and safety

Anemia is a common complication in patients with hemodialysis-dependent chronic kidney disease (HDD-CKD). Anemia is principally the result of erythropoietin deficiency, inflammation, and iron deficiency. High molecular weight iron oxide nanoparticles (IONP) are routinely administered intravenously to replace iron losses and, although effective, there are lingering concerns about possible safety issues. Ferric pyrophosphate citrate (FPC, Triferic, Triferic AVNU [Triferic and Triferic AVNU are the proprietary name for ferric pyrophosphate citrate. Triferic and Triferic AVNU are registered trademarks of Rockwell medical Inc.]) is a complex iron salt that donates iron directly to plasma transferrin. FPC is devoid of any carbohydrate moiety and is administered via the dialysate or intravenously during each hemodialysis session to replace iron and maintain hemoglobin. Controlled clinical trials of up to 48 weeks in duration have demonstrated the efficacy of regular administration of dialysate FPC for maintaining hemoglobin levels and iron balance in HDD-CKD patients. Clinical data also suggest that dialysate FPC may reduce the dose requirements for and use of erythropoiesis-stimulating agents and IONPs in HDD-CKD patients. Safety data from clinical studies and post-marketing surveillance show that FPC is well tolerated and not associated with an increased risk of infection, inflammation, iron overload, or serious hypersensitivity reactions. FPC represents an effective and well-tolerated choice for iron replacement and maintenance of hemoglobin in the long-term management of HDD-CKD patients.

The impact of amino acid dialysate on anthropometric measures in adult patients on peritoneal dialysis: A systematic review and meta-analysis

BACKGROUND

Glucose-containing dialysate underpins peritoneal dialysis (PD) therapy. However, its use is associated with amino acid loss in the dialysis effluent, a risk factor for protein-energy wasting (PEW) in PD patients. Amino acid-based dialysis solutions (AAD) may ameliorate this loss. However, the evidence of clinical benefit in preventing PEW is unclear. The aim of this review was to assess the effect of AAD versus standard dialysis solutions (STD) on anthropometric measures and serum albumin.

METHODS

Studies up until 30 September 2020 were identified from databases including MEDLINE and Embase, using a prespecified protocol (PROSPERO - CRD42020209581). Studies evaluating adults on PD were included. Data pertaining to muscle mass (primary outcome), other anthropometric measures and serum albumin were extracted. A meta-analysis of the eligible studies was conducted.

RESULTS

A total of 6945 abstracts were reviewed, from which 14 studies (9 randomised and 5 non-randomised) were included. There was no significant difference in any of the anthropometric measures, between AAD and STD during follow-up. Serum albumin at 6 months was statistically lower with AAD compared to STD [mean difference = -0.89 (95%CI -1.77 to -0.01, p = 0.046)]. The quality of evidence was graded low for each outcome.

CONCLUSIONS

AAD may not alter anthropometric measures when compared to STD. The impact on serum albumin is uncertain, with an estimated difference that is unlikely to be of clinical value. These findings should be cautiously interpreted due to low quality of the evidence. Robust studies are needed to address the limitations in evidence.

Removal of Protein-Bound Uremic Toxins Using Binding Competitors in Hemodialysis: A Narrative Review

Removal of protein-bound uremic toxins (PBUTs) during conventional dialysis is insufficient. PBUTs are associated with comorbidities and mortality in dialysis patients. Albumin is the primary carrier for PBUTs and only a small free fraction of PBUTs are dialyzable. In the past, we proposed a novel method where a binding competitor is infused upstream of a dialyzer into an extracorporeal circuit. The competitor competes with PBUTs for their binding sites on albumin and increases the free PBUT fraction. Essentially, binding competitor-augmented hemodialysis is a reactive membrane separation technique and is a paradigm shift from conventional dialysis therapies. The proposed method has been tested in silico, ex vivo, and in vivo, and has proven to be very effective in all scenarios. In an ex vivo study and a proof-of-concept clinical study with 18 patients, ibuprofen was used as a binding competitor; however, chronic ibuprofen infusion may affect residual kidney function. Binding competition with free fatty acids significantly improved PBUT removal in pre-clinical rat models. Based on in silico analysis, tryptophan can also be used as a binding competitor; importantly, fatty acids or tryptophan may have salutary effects in HD patients. More chemoinformatics research, pre-clinical, and clinical studies are required to identify ideal binding competitors before routine clinical use.

Differentiation of Human-Induced Pluripotent Stem Cell-Derived Endocrine Progenitors to Islet-like Cells Using a Dialysis Suspension Culture System

The production of functional islet-like cells from human-induced pluripotent stem cells (hiPSCs) is a promising strategy for the therapeutic use and disease modeling for type 1 diabetes. However, the production cost of islet-like cells is extremely high due to the use of expensive growth factors for differentiation. In a conventional culture method, growth factors and beneficial autocrine factors remaining in the culture medium are removed along with toxic metabolites during the medium change, and it limits the efficient utilization of those factors. In this study, we demonstrated that the dialysis suspension culture system is possible to reduce the usage of growth factors to one-third in the differentiation of hiPSC-derived endocrine progenitor cells to islet-like cells by reducing the medium change frequency with the refinement of the culture medium. Furthermore, the expression levels of hormone-secretion-related genes and the efficiency of differentiation were improved with the dialysis suspension culture system, possibly due to the retaining of autocrine factors. In addition, we confirmed several improvements required for the further study of the dialysis culture system. These findings showed the promising possibility of the dialysis suspension culture system for the low-cost production of islet-like cells.

Novel Use of Premixed Dialysate Bags during Water Supply Interruption in Acute Hospital Setting

Patients on dialysis are exposed to large amounts of water during conventional intermittent hemodialysis; hence, there are strict regulations regarding the quality of water used to prepare dialysate. Occasionally, water systems fail due to natural disasters or structural supply issues, such as water-main breaks or unplanned changes in municipal or facility water quality. It is critical to regularly monitor and immediately recognize such a failure and take steps to avoid exposing the patients to contaminants. In addition to the recognition of the problem, the ability to pivot and continue to provide safe treatment to inpatients who are dependent on dialysis is essential, both from an ultrafiltration and a clearance standpoint. At our hospital, an unforeseen water disruption occurred and we were able to continue to provide KRT with premade, bagged dialysate to mitigate the effect on our patients on dialysis. This is a novel method using available machines and dialysate, which we normally stock for continuous KRT, for short dialysis sessions. The methodology is similar to that which has been widely used for short daily home hemodialysis with low dialysate flow rate. Because this situation occurred in the midst of the SARS-CoV-2 pandemic, we had to be mindful of dialysate volumes and staffing time. Here, we present our investigation into the cause of the water-system failure and how we quickly implemented the alternative dialysis method. Short dialysis with low-flow dialysate will not deliver the same Kt/V per session as standard dialysis; however, this method was successfully implemented and tailored with adjustments for patients requiring higher clearance for specific indications, such as severe hyperkalemia.

A Novel Formulation of Glucose-Sparing Peritoneal Dialysis Solutions with l-Carnitine Improves Biocompatibility on Human Mesothelial Cells

The main reason why peritoneal dialysis (PD) still has limited use in the management of patients with end-stage renal disease (ESRD) lies in the fact that the currently used glucose-based PD solutions are not completely biocompatible and determine, over time, the degeneration of the peritoneal membrane (PM) and consequent loss of ultrafiltration (UF). Here we evaluated the biocompatibility of a novel formulation of dialytic solutions, in which a substantial amount of glucose is replaced by two osmometabolic agents, xylitol and l-carnitine. The effect of this novel formulation on cell viability, the integrity of the mesothelial barrier and secretion of pro-inflammatory cytokines was evaluated on human mesothelial cells grown on cell culture inserts and exposed to the PD solution only at the apical side, mimicking the condition of a PD dwell. The results were compared to those obtained after exposure to a panel of dialytic solutions commonly used in clinical practice. We report here compelling evidence that this novel formulation shows better performance in terms of higher cell viability, better preservation of the integrity of the mesothelial layer and reduced release of pro-inflammatory cytokines. This new formulation could represent a step forward towards obtaining PD solutions with high biocompatibility.

Adsorption of Uremic Toxins Using Ti3C2Tx MXene for Dialysate Regeneration

The COVID-19 pandemic has become a major worldwide crisis. Although respiratory symptoms are a key feature of the disease, many people who are hospitalized with COVID-19 also suffer acute kidney injury, a condition that exacerbates patient mortality and may have to be treated through renal replacement therapy. Much of the focus on hospital capacity during the pandemic has centered on the availability of ventilators. However, supplies for dialysis treatment, including dialysate, have also run dangerously low in hospitals at the epicenter of the pandemic. Therefore, there is an urgent need to develop materials that can efficiently and rapidly regenerate dialysate, removing toxins and restoring electrolyte concentrations so that this vital resource remains readily available. In this work, Ti3C2Tx, a two-dimensional transition-metal carbide (MXene) that is known to efficiently adsorb urea, was used to remove creatinine and uric acid from an aqueous solution and dialysate, with a maximum adsorption capacity of 45.7 and 17.0 mg/g, respectively. We systematically analyzed and modeled the adsorption kinetics, isotherms, and thermodynamics, thus determining the rate-limiting step and adsorption mechanism. A fixed-bed column loaded with Ti3C2Tx was designed to further evaluate the adsorption performance under continuous fluid-flow conditions, mirroring conditions of continuous renal replacement therapy modalities. The maximum capacity and 50% breakthrough volume were calculated to further approach the practical application of Ti3C2Tx for removal of uremic toxins. Our findings suggest that Ti3C2Tx has the potential to be used as an efficient sorbent for the regeneration of dialysate, allowing for accelerated dialysate regeneration by removing filtered toxins and leading to more portable dialysis devices.

Unfavorable Effects of Peritoneal Dialysis Solutions on the Peritoneal Membrane: The Role of Oxidative Stress

One of the main limitations to successful long-term use of peritoneal dialysis (PD) as a renal replacement therapy is the harmful effects of PD solutions to the structure and function of the peritoneal membrane (PM). In PD, the PM serves as a semipermeable membrane that, due to exposure to PD solutions, undergoes structural alterations, including peritoneal fibrosis, vasculopathy, and neoangiogenesis. In recent decades, oxidative stress (OS) has emerged as a novel risk factor for mortality and cardiovascular disease in PD patients. Moreover, it has become evident that OS plays a pivotal role in the pathogenesis and development of the chronic, progressive injury of the PM. In this review, we aimed to present several aspects of OS in PD patients, including the pathophysiologic effects on the PM, clinical implications, and possible therapeutic antioxidant strategies that might protect the integrity of PM during PD therapy.

[Management of hemodialysis patient subject to medical-nuclear investigation]

In recent years imaging techniques that use radionuclides have become more and more clinically relevant as they can provide functional information for specific anatomical districts. This has also involved nephrology, where radionuclides are used to study patients with different degrees of renal function failure up to terminal uremia. Although chronic kidney disease, and dialysis in particular, may affect the distribution and the elimination of radiopharmaceuticals, to date there are no consistent data on the risks associated with their use in this clinical context. In addition to the lack of data on the safety of radio-exposure in dialysis patients, there is also a shortage of information concerning the risk for healthcare staff involved in conducting the dialysis sessions performed after a nuclear test. This study, performed on 29 uremic patients who underwent hemodialysis immediately after a scintigraphic examination, assessed the extent of radio-contamination of the staff and of hemodialysis devices such as monitor, kits and dialysate. The data collected has been used to quantify the radiological risk in dialysis after the exposure to the most common radionuclides.

Enhancement of solute clearance using pulsatile push-pull dialysate flow for the Quanta SC+: A novel clinic-to-home haemodialysis system

BACKGROUND AND OBJECTIVE

The SC+ haemodialysis system developed by Quanta Dialysis Technologies is a small, easy-to-use dialysis system designed to improve patient access to self-care and home haemodialysis. A prototype variant of the standard SC+ device with a modified fluidic management system generating a pulsatile push-pull dialysate flow through the dialyser during use has been developed for evaluation. It was hypothesized that, as a consequence of the pulsatile push-pull flow through the dialyser, the boundary layers at the membrane surface would be disrupted, thereby enhancing solute transport across the membrane, modifying protein fouling and maintaining the surface area available for mass and fluid transport throughout the whole treatment, leading to solute transport (clearance) enhancement compared to normal haemodialysis (HD) operation.

METHODS

The pumping action of the SC+ system was modified by altering the sequence and timings of the valves and pumps associated with the flow balancing chambers that push and pull dialysis fluid to and from the dialyser. Using this unique prototype device, solute clearance performance was assessed across a range of molecular weights in two related series of laboratory bench studies. The first measured dialysis fluid moving across the dialyser membrane using ultrasonic flowmeters to establish the validity of the approach; solute clearance was subsequently measured using fluorescently tagged dextran molecules as surrogates for uraemic toxins. The second study used human blood doped with uraemic toxins collected from the spent dialysate of dialysis patients to quantify solute transport. In both, the performance of the SC+ prototype was assessed alongside reference devices operating in HD and pre-dilution haemodiafiltration (HDF) modes.

RESULTS

Initial testing with fluorescein-tagged dextran molecules (0.3 kDa, 4 kDa, 10 kDa and 20 kDa) established the validity of the experimental pulsatile push-pull operation in the SC+ system to enhance clearance and demonstrated a 10 to 15% improvement above the current HD mode used in clinic today. The magnitude of the observed enhancement compared favourably with that achieved using pre-dilution HDF with a substitution fluid flow rate of 60 mL/min (equivalent to a substitution volume of 14.4 L in a 4-hour session) with the same dialyser and marker molecules. Additional testing using human blood indicated a comparable performance to pre-dilution HDF; however, in contrast with HDF, which demonstrated a gradual decrease in solute removal, the clearance values using the pulsatile push-pull method on the SC+ system were maintained over the entire duration of treatment. Overall albumin losses were not different.

CONCLUSIONS

Results obtained using an experimental pulsatile push-pull dialysis flow configuration with an aqueous blood analogue and human blood ex vivo demonstrate an enhancement of solute transport across the dialyser membrane. The level of enhancement makes this approach comparable with that achieved using pre-dilution HDF with a substitution fluid flow rate of 60 mL/min (equivalent to a substitution volume of 14.4 L in a 4-hour session). The observed enhancement of solute transport is attributed to the disruption of the boundary layers at the fluid-membrane interface which, when used with blood, minimizes protein fouling and maintains the surface area.

Glucose Exposure in Peritoneal Dialysis Is a Significant Factor Predicting Peritonitis

INTRODUCTION

Loss of residual renal function (RRF) as well as high peritoneal glucose exposure are associated with increased peritonitis frequency in peritoneal dialysis (PD) patients. Our objective was to investigate the contribution of RRF and peritoneal glucose exposure to peritonitis in PD patients.

METHODS

In this prospective longitudinal cohort study, 105 incident end-stage renal disease patients that started PD between January 2006 and 2015 were studied. Follow-up was 5 years with censoring at death or switch to another treatment modality. Cox regression models were used to calculate the association between glucose exposure, RRF, and peritonitis. Kaplan-Meier analysis was used to examine the difference in occurrence of peritonitis between patients with high and low glucose exposure and between those with and without residual diuresis.

RESULTS

One hundred and five patients were followed for a mean of 23 months. Fifty-one patients developed a peritonitis. Cox regression models at 6 months showed that glucose exposure and not residual diuresis significantly predicted PD peritonitis. Kaplan-Meier analysis after 6 months of follow-up showed that time to first PD peritonitis was significantly longer in the low glucose exposure group. Similarly, patients with RRF had a significantly longer interval to first peritonitis compared to patients without RRF.

CONCLUSION

A higher exposure to glucose rather than loss of RRF is associated with an increased risk of peritonitis. This confirms the detrimental effects of glycemic harm to the peritoneal host defense on invading microorganisms and argues for the use of the lowest PD glucose concentrations possible.

Impact of hemodialysis on the concentrations of sodium and potassium during infusion of sodium thiosulfate using an In Vitro hemodialysis model

INTRODUCTION

The purpose of this study was to evaluate the impact of hemodialysis on the concentrations of sodium and potassium in the blood when a 25 g dose of sodium thiosulfate injection is infused over 60 minutes in combination with hemodialysis.

METHODS

Sodium thiosulfate (25 g) was prepared by diluting 100 mL of 250 mg/mL Sodium Thiosulfate Injection with 800 mL of 5% dextrose. This was added to the circulating blood surrogate solution at a rate of 15 mL/minute using an infusion pump of an in vitro model of dialysis machine. Serial samples were collected before the administration of the sodium thiosulfate solution, after 15 minutes, 30 minutes, and 60 minutes of infusion from pre-and post-dialyzer ports in both the dialysate circuit and the extracorporeal circuit.

FINDINGS

The concentration of sodium thiosulfate in pre-dialyzer and post-dialyzer samples of the circulating blood surrogate solution peaked at 30 minutes and 15 minutes, respectively and then remained relatively unchanged during the remainder of the infusion. Mean sodium concentrations (mEq/L) in the circulating blood surrogate solution collected after exposure to a dialyzer were 103.2 ± 12.2, 114.2 ± 18.8, 117.2 ± 7.5, 93.5 ± 5.9 at 0, 15, 30, and 60 minutes, respectively (p = 0.248). Mean potassium concentrations (mEq/L) in the circulating blood surrogate solution collected after exposure to a dialyzer were 1.4 ± 0.3, 1.6 ± 0.3, 1.5 ± 0.1, 1.2 ± 0.1 at 0, 15, 30, and 60 minutes, respectively (p = 0.365). Sodium and potassium concentrations in dialysate increased marginally after exposure to the dialyzer.

DISCUSSION

Our study demonstrates that neither potassium nor sodium accumulated in circulating blood surrogate solution when a dose of sodium thiosulfate was infused in conjunction with hemodialysis.

Renal Association Clinical Practice Guideline on Haemodialysis

This guideline is written primarily for doctors and nurses working in dialysis units and related areas of medicine in the UK, and is an update of a previous version written in 2009. It aims to provide guidance on how to look after patients and how to run dialysis units, and provides standards which units should in general aim to achieve. We would not advise patients to interpret the guideline as a rulebook, but perhaps to answer the question: "what does good quality haemodialysis look like?"The guideline is split into sections: each begins with a few statements which are graded by strength (1 is a firm recommendation, 2 is more like a sensible suggestion), and the type of research available to back up the statement, ranging from A (good quality trials so we are pretty sure this is right) to D (more like the opinion of experts than known for sure). After the statements there is a short summary explaining why we think this, often including a discussion of some of the most helpful research. There is then a list of the most important medical articles so that you can read further if you want to - most of this is freely available online, at least in summary form.A few notes on the individual sections: 1. This section is about how much dialysis a patient should have. The effectiveness of dialysis varies between patients because of differences in body size and age etc., so different people need different amounts, and this section gives guidance on what defines "enough" dialysis and how to make sure each person is getting that. Quite a bit of this section is very technical, for example, the term "eKt/V" is often used: this is a calculation based on blood tests before and after dialysis, which measures the effectiveness of a single dialysis session in a particular patient. 2. This section deals with "non-standard" dialysis, which basically means anything other than 3 times per week. For example, a few people need 4 or more sessions per week to keep healthy, and some people are fine with only 2 sessions per week - this is usually people who are older, or those who have only just started dialysis. Special considerations for children and pregnant patients are also covered here. 3. This section deals with membranes (the type of "filter" used in the dialysis machine) and "HDF" (haemodiafiltration) which is a more complex kind of dialysis which some doctors think is better. Studies are still being done, but at the moment we think it's as good as but not better than regular dialysis. 4. This section deals with fluid removal during dialysis sessions: how to remove enough fluid without causing cramps and low blood pressure. Amongst other recommendations we advise close collaboration with patients over this. 5. This section deals with dialysate, which is the fluid used to "pull" toxins out of the blood (it is sometimes called the "bath"). The level of things like potassium in the dialysate is important, otherwise too much or too little may be removed. There is a section on dialysate buffer (bicarbonate) and also a section on phosphate, which occasionally needs to be added into the dialysate. 6. This section is about anticoagulation (blood thinning) which is needed to stop the circuit from clotting, but sometimes causes side effects. 7. This section is about certain safety aspects of dialysis, not seeking to replace well-established local protocols, but focussing on just a few where we thought some national-level guidance would be useful. 8. This section draws together a few aspects of dialysis which don't easily fit elsewhere, and which impact on how dialysis feels to patients, rather than the medical outcome, though of course these are linked. This is where home haemodialysis and exercise are covered. There is an appendix at the end which covers a few aspects in more detail, especially the mathematical ideas. Several aspects of dialysis are not included in this guideline since they are covered elsewhere, often because they are aspects which affect non-dialysis patients too. This includes: anaemia, calcium and bone health, high blood pressure, nutrition, infection control, vascular access, transplant planning, and when dialysis should be started.

Continuous ambulatory peritoneal dialysis (CAPD) in children: a successful case for a bright future in a developing country

The authors report the first case of successful peritoneal dialysis (PD) in a developing country performed about a 13-year-old adolescent followed-up for stage V chronic kidney disease (CKD) with anuria. After 3 months of hemodialysis, the parents opted for continuous ambulatory peritoneal dialysis (CAPD) as they wished to return home located 121km from Dakar. After PD catheter insertion, the plan proposed to the patient consisted 3-4 hours stasis of isotonic dialysate during the day and a night stasis of 8 hours of icodextrin for an injection volume of 1L per session. The patient and his mother were trained and assessed on the PD technique. After dialysis adequacy was tested while hospitalised, they were able to return home and continued the sessions following the same plan prescribed and while keeping in touch, by telephone, with the medical team. The technique assessment at the day hospital every 2 weeks revealed dialysis adequacy and satisfactory tolerance of PD at home after 04 months of observation. It was the first case of successful CAPD in the pediatrics unit in this context. Scaling this technique is a challenge for the pediatric nephrologist in developing countries like Senegal.

Neutral pH and low-glucose degradation product dialysis fluids induce major early alterations of the peritoneal membrane in children on peritoneal dialysis

The effect of peritoneal dialysates with low-glucose degradation products on peritoneal membrane morphology is largely unknown, with functional relevancy predominantly derived from experimental studies. To investigate this, we performed automated quantitative histomorphometry and molecular analyses on 256 standardized peritoneal and 172 omental specimens from 56 children with normal renal function, 90 children with end-stage kidney disease at time of catheter insertion, and 82 children undergoing peritoneal dialysis using dialysates with low-glucose degradation products. Follow-up biopsies were obtained from 24 children after a median peritoneal dialysis of 13 months. Prior to dialysis, mild parietal peritoneal inflammation, epithelial-mesenchymal transition and vasculopathy were present. After up to six and 12 months of peritoneal dialysis, blood microvessel density was 110 and 93% higher, endothelial surface area per peritoneal volume 137 and 95% greater, and submesothelial thickness 23 and 58% greater, respectively. Subsequent peritoneal changes were less pronounced. Mesothelial cell coverage was lower and vasculopathy advanced, whereas lymphatic vessel density was unchanged. Morphological changes were accompanied by early fibroblast activation, leukocyte and macrophage infiltration, diffuse podoplanin presence, epithelial mesenchymal transdifferentiation, and by increased proangiogenic and profibrotic cytokine abundance. These transformative changes were confirmed by intraindividual comparisons. Peritoneal microvascular density correlated with peritoneal small-molecular transport function by uni- and multivariate analysis. Thus, in children on peritoneal dialysis neutral pH dialysates containing low-glucose degradation products induce early peritoneal inflammation, fibroblast activation, epithelial-mesenchymal transition and marked angiogenesis, which determines the PD membrane transport function.

Assessment and Management of Hypertension among Patients on Peritoneal Dialysis

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.

Low dialysate sodium levels for chronic haemodialysis

BACKGROUND

Cardiovascular (CV) disease is the leading cause of death in dialysis patients, and strongly associated with fluid overload and hypertension. It is plausible that low dialysate [Na+] may decrease total body sodium content, thereby reducing fluid overload and hypertension, and ultimately reducing CV morbidity and mortality.

OBJECTIVES

This review evaluated harms and benefits of using a low (< 138 mM) dialysate [Na+] for maintenance haemodialysis (HD) patients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 7 August 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs), both parallel and cross-over, of low (< 138 mM) versus neutral (138 to 140 mM) or high (> 140 mM) dialysate [Na+] for maintenance HD patients were included.

DATA COLLECTION AND ANALYSIS

Two investigators independently screened studies for inclusion and extracted data. Statistical analyses were performed using random effects models, and results expressed as risk ratios (RR) for dichotomous outcomes, and mean differences (MD) or standardised MD (SMD) for continuous outcomes, with 95% confidence intervals (CI). Confidence in the evidence was assessed using GRADE.

MAIN RESULTS

We included 12 studies randomising 310 patients, with data available for 266 patients after dropout. All but one study evaluated a fixed concentration of low dialysate [Na+], and one profiled dialysate [Na+]. Three studies were parallel group, and the remaining nine cross-over. Of the latter, only two used a washout between intervention and control periods. Most studies were short-term with a median (interquartile range) follow-up of 3 (3, 8.5) weeks. Two were of a single HD session, and two of a single week's HD. Half of the studies were conducted prior to 2000, and five reported use of obsolete HD practices. Risks of bias in the included studies were often high or unclear, lowering confidence in the results.Compared to neutral or high dialysate [Na+], low dialysate [Na+] had the following effects on "efficacy" endpoints: reduced interdialytic weight gain (10 studies: MD -0.35 kg, 95% CI -0.18 to -0.51; high certainty evidence); probably reduced predialysis mean arterial blood pressure (BP) (4 studies: MD -3.58 mmHg, 95% CI -5.46 to -1.69; moderate certainty evidence); probably reduced postdialysis mean arterial BP (MAP) (4 studies: MD -3.26 mmHg, 95% CI -1.70 to -4.82; moderate certainty evidence); probably reduced predialysis serum [Na+] (7 studies: MD -1.69 mM, 95% CI -2.36 to -1.02; moderate certainty evidence); may have reduced antihypertensive medication (2 studies: SMD -0.67 SD, 95% CI -1.07 to -0.28; low certainty evidence). Compared to neutral or high dialysate [Na+], low dialysate [Na+] had the following effects on "safety" endpoints: probably increased intradialytic hypotension events (9 studies: RR 1.56, 95% 1.17 to 2.07; moderate certainty evidence); probably increased intradialytic cramps (6 studies: RR 1.77, 95% 1.15 to 2.73; moderate certainty evidence).Compared to neutral or high dialysate [Na+], low dialysate [Na+] may make little or no difference to: intradialytic BP (2 studies: MD for systolic BP -3.99 mmHg, 95% CI -17.96 to 9.99; diastolic BP 1.33 mmHg, 95% CI -6.29 to 8.95; low certainty evidence); interdialytic BP (2 studies:, MD for systolic BP 0.17 mmHg, 95% CI -5.42 to 5.08; diastolic BP -2.00 mmHg, 95% CI -4.84 to 0.84; low certainty evidence); dietary salt intake (2 studies: MD -0.21g/d, 95% CI -0.48 to 0.06; low certainty evidence).Due to very low quality of evidence, it is uncertain whether low dialysate [Na+] changed extracellular fluid status, venous tone, arterial vascular resistance, left ventricular mass or volumes, thirst or fatigue. Studies did not examine cardiovascular or all-cause mortality, cardiovascular events, or hospitalisation.

AUTHORS' CONCLUSIONS

It is likely that low dialysate [Na+] reduces intradialytic weight gain and BP, which are effects directionally associated with improved outcomes. However, the intervention probably also increases intradialytic hypotension and reduces serum [Na+], effects that are associated with increased mortality risk. The effect of the intervention on overall patient health and well-being is unknown. Further evidence is needed in the form of longer-term studies in contemporary settings, evaluating end-organ effects in small-scale mechanistic studies using optimal methods, and clinical outcomes in large-scale multicentre RCTs.

Ultrapure Filter does not Confer Short-Term Benefits over Two Reverse Osmosis Systems in Chronic Hemodialysis Patients

BACKGROUND

Dialysate purity contributes to the inflammatory response that afflicts hemodialysis patients.

OBJECTIVES

To compare the clinical and laboratory effects of using ultrapure water produced by a water treatment system including two reverse osmosis (RO) units in series, with a system that also includes an ultrapure filter (UPF).

METHODS

We performed a retrospective study in 193 hemodialysis patients during two periods: period A (no UPF, 6 months) and period B (same patients, with addition of UPF, 18 months), and a historical cohort of patients treated in the same dialysis unit 2 years earlier, which served as a control group.

RESULTS

Mean C-reactive protein, serum albumin and systolic blood pressure worsened in period B compared to period A and in the controls.

CONCLUSIONS

A double RO system to produce ultrapure water is not inferior to the use of ultrapure filters.

Model of fluid and solute shifts during hemodialysis with active transport of sodium and potassium

Background

Mathematical models are useful tools to predict fluid shifts between body compartments in patients undergoing hemodialysis (HD). The ability of a model to accurately describe the transport of water between cells and interstitium (J_v,ISIC), and the consequent changes in intracellular volume (ICV), is important for a complete assessment of fluid distribution and plasma refilling. In this study, we propose a model describing transport of fluid in the three main body compartments (intracellular, interstitial and vascular), complemented by transport mechanisms for proteins and small solutes.

Methods

The model was applied to data from 23 patients who underwent standard HD. The substances described in the baseline model were: water, proteins, Na, K, and urea. Small solutes were described with two-compartment kinetics between intracellular and extracellular compartments. Solute transport across the cell membrane took place via passive diffusion and, for Na and K, through the ATPase pump, characterized by the maximum transport rate, Jp_MAX. From the data we estimated Jp_MAX and two other parameters linked to transcapillary transport of fluid and protein: the capillary filtration coefficient Lp and its large pores fraction α_LP. In an Expanded model one more generic solute was included to evaluate the impact of the number of substances appearing in the equation describing J_v,ISIC.

Results

In the baseline model, median values (interquartile range) of estimated parameters were: Lp: 11.63 (7.9, 14.2) mL/min/mmHg, α_LP: 0.056 (0.050, 0.058), and Jp_MAX: 5.52 (3.75, 7.54) mmol/min. These values were significantly different from those obtained by the Expanded model: Lp: 8.14 (6.29, 10.01) mL/min/mmHg, α_LP: 0.046 (0.038, 0.052), and Jp_MAX: 16.7 (11.9, 25.2) mmol/min. The relative RMSE (root mean squared error)averaged between all simulated quantities compared to data was 3.9 (3.1, 5.6) %.

Conclusions

The model was able to accurately reproduce most of the changes observed in HD by tuning only three parameters. While the drop in ICV was overestimated by the model, the difference between simulations and data was less than the measurement error. The biggest change in the estimated parameters in the Expanded model was a marked increase of Jp_MAX indicating that this parameter is highly sensitive to the number of species modeled, and that the value of Jp_MAX should be interpreted only in relation to this factor.

Mammalian Target of Rapamycin Complex 1 Activation Disrupts the Low-Density Lipoprotein Receptor Pathway: A Novel Mechanism for Extracellular Matrix Accumulation in Human Peritoneal Mesothelial Cells

Peritoneal fibrosis (PF) is characterized by progressive extracellular matrix (ECM) accumulation. Increasing evidence has suggested that ECM synthesis was increased in human peritoneal mesothelial cells (HPMCs) under high-glucose conditions, but the effects of high-glucose peritoneal dialysis solution (PDS) on ECM synthesis have not been fully elucidated. The aim of this study was to explore the potential mechanisms of high-glucose PDS-induced production of ECM in HPMCs. HPMCs were stimulated by high-glucose PDS. The activity of mammalian target of rapamycin complex 1 (mTORC1) was inhibited by rapamycin or regulatory-associated protein of mTOR (raptor) siRNA. Morphological changes in the cells were observed under an inverted microscope. Oil red O, filipin staining and high-performance liquid chromatography were used to examine lipid accumulation. The expression of low-density lipoprotein receptor (LDLr) regulation, the mTORC1 pathway and ECM-associated markers were assessed by real-time polymerase chain reaction and western blot analysis. The results showed that after treatment with PDS, HPMCs showed notable elongation consistent with the morphology of myofibroblasts, and the expression of ECM proteins such as α-smooth muscle actin, fibroblast specific protein-1 and collagen I was increased. In addition, there was a parallel increase in the ECM and lipid accumulation. Moreover, the effect of intracellular lipid deposition was closely correlated with the dysregulation of LDLr, which was mediated through the upregulation of LDLr, sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP), and SREBP-2 and through the enhanced coexpression of the SCAP with the Golgin. Further analysis showed that PDS enhanced the protein phosphorylation of mTOR, eukaryotic initiation factor 4E-binding protein 1, and p70 S6 kinase. Interestingly, blocking mTORC1 activity reversed the dysregulation of LDLr, even in the presence of PDS. These effects were also accompanied by a decrease in the expression of ECM components. Our findings demonstrated that increased mTORC1 activity exacerbated ECM formation in HPMCs by disrupting LDLr regulation, which contributed to lipid disorder-mediated PF.

Quality of water used in Palestinian hemodialysis centers

OBJECTIVES

Worldwide, hemodialysis (HD) patients are increasing every year, including Palestine. Dialysis fluid contamination due to the use of unpurified water is a common problem worldwide. Chemical and microbiological contaminants in the dialysis fluid could cross the dialyzer membrane and cause harm to dialysis patients. The objectives of this study were to evaluate the water quality used in centers in the West Bank, Palestine. The outcomes of this study will reflect the water purification system situation and come up with valuable recommendations to health decision makers.

STUDY DESIGN

This is a laboratory-based study that covered all dialysis centers in the West Bank, Palestine.

METHODS

Water samples were collected from all dialysis centers, and the samples were tested chemically and microbiologically according to the standard international and pharmacopeial methods.

RESULTS

The results showed that the water quality in most dialysis centers did not comply with the minimum requirements of HD water. Microbiological contamination was detected in 12.5% of the dialysis centers. The test for chloride failed in 87% of the dialysis centers. Moreover, tests for conductivity, total organic carbon (TOC), and lead were not within the allowed limits in all the dialysis centers.

CONCLUSIONS

Our study revealed evidence of chemical and bacterial contamination in the dialysis centers in Palestine. The outcomes of this study showed an urgent need for immediate steps to be taken by the concerned authorities to improve the water quality used in Palestinian HD centers.

Biocompatible dialysis fluids for peritoneal dialysis

BACKGROUND

Biocompatible peritoneal dialysis (PD) solutions, including neutral pH, low glucose degradation product (GDP) solutions and icodextrin, have previously been shown to favourably influence some patient-level outcomes, albeit based on generally sub-optimal quality studies. Several additional randomised controlled trials (RCT) evaluating biocompatible solutions in PD patients have been published recently. This is an update of a review first published in 2014.

OBJECTIVES

This review aimed to look at the benefits and harms of biocompatible PD solutions in comparison to standard PD solutions in patients receiving PD.

SEARCH METHODS

The Cochrane Kidney and Transplant Specialised Register was searched up to 12 February 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All RCTs and quasi-RCTs in adults and children comparing the effects of biocompatible PD solutions (neutral pH, lactate-buffered, low GDP; neutral pH, bicarbonate(± lactate)-buffered, low GDP; glucose polymer (icodextrin)) in PD were included. Studies of amino acid-based solutions were excluded.

DATA COLLECTION AND ANALYSIS

Two authors extracted data on study quality and outcomes. Summary effect estimates were obtained using a random-effects model, and results were expressed as risk ratios and 95% confidence intervals (CI) for categorical variables, and mean differences (MD) or standardised mean differences (SMD) and 95% CI for continuous variables.

MAIN RESULTS

This review update included 42 eligible studies (3262 participants), including six new studies (543 participants). Overall, 29 studies (1971 participants) compared neutral pH, low GDP PD solution with conventional PD solution, and 13 studies (1291 participants) compared icodextrin with conventional PD solution. Risk of bias was assessed as high for sequence generation in three studies, allocation concealment in three studies, attrition bias in 21 studies, and selective outcome reporting bias in 16 studies.Neutral pH, low GDP versus conventional glucose PD solutionUse of neutral pH, low GDP PD solutions improved residual renal function (RRF) preservation (15 studies, 835 participants: SMD 0.19, 95% CI 0.05 to 0.33; high certainty evidence). This approximated to a mean difference in glomerular filtration rate of 0.54 mL/min/1.73 m² (95% CI 0.14 to 0.93). Better preservation of RRF was evident at all follow-up durations with progressively greater preservation observed with increasing follow up duration. Neutral pH, low GDP PD solution use also improved residual urine volume preservation (11 studies, 791 participants: MD 114.37 mL/day, 95% CI 47.09 to 181.65; high certainty evidence). In low certainty evidence, neutral pH, low GDP solutions may make little or no difference to 4-hour peritoneal ultrafiltration (9 studies, 414 participants: SMD -0.42, 95% CI -0.74 to -0.10) which approximated to a mean difference in peritoneal ultrafiltration of 69.72 mL (16.60 to 122.00 mL) lower, and may increase dialysate:plasma creatinine ratio (10 studies, 746 participants: MD 0.01, 95% CI 0.00 to 0.03), technique failure or death compared with conventional PD solutions. It is uncertain whether neutral pH, low GDP PD solution use led to any differences in peritonitis occurrence, hospitalisation, adverse events (6 studies, 519 participants) or inflow pain (1 study, 58 participants: RR 0.51, 95% CI 0.24 to 1.08).Glucose polymer (icodextrin) versus conventional glucose PD solutionIn moderate certainty evidence, icodextrin probably reduced episodes of uncontrolled fluid overload (2 studies, 100 participants: RR 0.30, 95% CI 0.15 to 0.59) and augmented peritoneal ultrafiltration (4 studies, 102 participants: MD 448.54 mL/d, 95% CI 289.28 to 607.80) without compromising RRF (4 studies, 114 participants: SMD 0.12, 95% CI -0.26 to 0.49; low certainty evidence) which approximated to a mean creatinine clearance of 0.30 mL/min/1.73m² higher (0.65 lower to 1.23 higher) or urine output (3 studies, 69 participants: MD -88.88 mL/d, 95% CI -356.88 to 179.12; low certainty evidence). It is uncertain whether icodextrin use led to any differences in adverse events (5 studies, 816 participants) technique failure or death.

AUTHORS' CONCLUSIONS

This updated review strengthens evidence that neutral pH, low GDP PD solution improves RRF and urine volume preservation with high certainty. These effects may be related to increased peritoneal solute transport and reduced peritoneal ultrafiltration, although the evidence for these outcomes is of low certainty due to significant heterogeneity and suboptimal methodological quality. Icodextrin prescription increased peritoneal ultrafiltration and mitigated uncontrolled fluid overload with moderate certainty. The effects of either neutral pH, low GDP solution or icodextrin on peritonitis, technique survival and patient survival remain uncertain and require further high quality, adequately powered RCTs.

MXene Sorbents for Removal of Urea from Dialysate: A Step toward the Wearable Artificial Kidney

The wearable artificial kidney can deliver continuous ambulatory dialysis for more than 3 million patients with end-stage renal disease. However, the efficient removal of urea is a key challenge in miniaturizing the device and making it light and small enough for practical use. Here, we show that two-dimensional titanium carbide (MXene) with the composition of Ti₃C₂T _x, where T _x represents surface termination groups such as -OH, -O-, and -F, can adsorb urea, reaching 99% removal efficiency from aqueous solution and 94% from dialysate at the initial urea concentration of 30 mg/dL, with the maximum urea adsorption capacity of 10.4 mg/g at room temperature. When tested at 37 °C, we achieved a 2-fold increase in urea removal efficiency from dialysate, with the maximum urea adsorption capacity of 21.7 mg/g. Ti₃C₂T _x showed good hemocompatibility; it did not induce cell apoptosis or reduce the metabolizing cell fraction, indicating no impact on cell viability at concentrations of up to 200 μg/mL. The biocompatibility of Ti₃C₂T _x and its selectivity for urea adsorption from dialysate open a new opportunity in designing a miniaturized dialysate regeneration system for a wearable artificial kidney.

The Effect of Increasing Dialysate Magnesium on Serum Calcification Propensity in Subjects with End Stage Kidney Disease: A Randomized, Controlled Clinical Trial

BACKGROUND AND OBJECTIVES

Serum calcification propensity is a novel functional test that quantifies the functionality of the humeral system of calcification control. Serum calcification propensity is measured by T50, the time taken to convert from primary to secondary calciprotein particle in the serum. Lower T50 represents higher calcification propensity and is associated with higher risk of cardiovascular events and death in patients with ESKD. Increasing magnesium in serum increases T50, but so far, no clinical trials have investigated whether increasing serum magnesium increases serum calcification propensity in subjects with ESKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a single-center, randomized, double-blinded, parallel group, controlled clinical trial, in which we examined the effect of increasing dialysate magnesium from 1.0 to 2.0 mEq/L for 28 days compared with maintaining dialysate magnesium at 1.0 mEq/L on T50 in subjects undergoing hemodialysis for ESKD. The primary end point was the value of T50 at the end of the intervention.

RESULTS

Fifty-nine subjects were enrolled in the trial, and of these, 57 completed the intervention and were analyzed for the primary outcome. In the standard dialysate magnesium group, T50 was 233±81 minutes (mean±SD) at baseline (mean of days -7 and 0) and 229±93 minutes at follow-up (mean of days 21 and 28), whereas in the high dialysate magnesium group, T50 was 247±69 minutes at baseline and 302±66 minutes at follow-up. The difference in T50 between the two groups at follow-up (primary analysis) was 73 minutes (between-group difference; 95% confidence interval, 30 to 116; P<0.001), and the between-group difference in serum magnesium was 0.88 mg/dl (95% confidence interval, 0.66 to 1.10; P=0.001).

CONCLUSIONS

Increasing dialysate magnesium increases T50 and hence, decreases calcification propensity in subjects undergoing maintenance hemodialysis.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_08_21_CJASNPodcast_18_9_B.mp3.

Eosinophilia in a peritoneal dialysis patient: Answers

Icodextrin is a starch-derived glucose polymer used in peritoneal dialysis dialysate to treat volume overload by increasing ultrafiltration in patients with end-stage renal disease. Reported adverse reactions to icodextrin are mild and rare and mainly consist of skin rash that resolves spontaneously after discontinuation of treatment. We describe a young patient with extreme eosinophilia that appeared with the use of icodextrin, disappeared after its discontinuation, and reappeared after a rechallenge with the drug. The eosinophilia was not associated with peritonitis, was asymptomatic, and fully resolved after discontinuation of the drug. Severe eosinophilia can potentially cause tissue damage in several organs, which would indicate that blood eosinophil count is recommended in routine complete blood counts while icodextrin peritoneal dialysis is being administered.

Changes in Total Protein Concentration Due to Fluid Removal During and Shortly after Hemodialysis

BACKGROUND

Changes in plasma volume during hemodialysis are complex and have been shown to depend on the rate of fluid removal and the degree of fluid overload. We examined changes in total protein concentration during and shortly after a dialysis treatment in archived data from the HEMO study.

METHODS

During follow-up months 4 and 36 of the HEMO study, additional blood samples were obtained during a typical dialysis session at 30 and 60 min after dialysis. In 315 studies from 282 patients where complete data were available, we calculated the concentration change in total protein and compared it to the modeled change in both total body water and extracellular fluid space as derived from 2-pool urea kinetic modeling.

RESULTS

The mean postdialysis modeled urea volume (V) was 31.1 ± 6.18 L. Mean fluid removal was 2.76 ± 1.27 kg, over a session length of 207 ± 28 min. The ratio of predialysis V to postdialysis V averaged 1.090 ± 0.040. The mean TP ratios (post/pre) at 0, 30, and 60 min postdialysis averaged 1.121 ± 0.070 (SD), 1.091 ± 0.090, and 1.091 ± 0.086. The dialysate to serum sodium gradient, studied in a different group of treatments where this information was available, had no impact on these findings, nor did the length of the interdialytic interval.

CONCLUSIONS

On average, after equilibration, the change in plasma volume due to fluid removal is similar to the modeled change in total body water (urea space), irrespective of dialysate to serum sodium gradient. This supports previous observations that during dialysis with ultrafiltration, plasma volume contracts to a lesser degree than the interstitial volume and that some fluid may be removed from spaces other than the extracellular fluid.

Translational Research of Peritoneal Dialysis Solution with Dissolved Molecular Hydrogen

BACKGROUND

Improved biocompatibility of peritoneal dialysis solution (PDS) is crucial for peritoneal membrane preservation, thereby ensuring long-term peritoneal dialysis (PD) and preventing encapsulating peritoneal sclerosis. We previously reported the protective effect of molecular hydrogen (H2) on mesothelial cells from PDS in nonuremic rats.

SUMMARY

In the present study, we examined the effect of H2-containing PDS (commercially available neutral pH type) regarding the protection of peritoneal tissue in experimental chronic kidney disease rats. Furthermore, we conducted a 2-week clinical trial in which H2-containing PDS was used in place of standard PDS and its feasibility was examined. In the experimental study, test solutions were injected through the subcutaneous port into the abdomen for 3 weeks. Histological study revealed a significant increase in the number of mesothelial cells and a significant decrease in peritoneal thickness in the H2-PD group as compared to the control and PD groups. Also, results of immunostaining analysis revealed increased vimentin and apoptotic cells in the membrane of the PD group, indicating that H2 may play a role in ameliorating PDS-induced peritoneal injury and preserving peritoneal integrity. In the clinical trial with 6 prevalent PD patients, all subjects completed the study with no adverse effects. Moreover, there were substantial changes in surrogate markers, such as increased CA125 and mesothelin, in the effluent in selected cases, suggesting enhanced mesothelial regeneration by H2. Key Message: H2-enriched PDS is a candidate novel PDS with improved biocompatibility. Further, our results support the significance of H2-PD clinical trials in the future.

The effect of peritoneal dialysis with alkaline dialysate in peritonitis carcinomatosis: an experimental study in mice

OBJECTIVE

The aim of this study was to neutralize acidic pH using an alkaline dialysate for continuous ambulatory peritoneal dialysis (CAPD) in mice with peritoneal carcinomatosis (PC) and to investigate the change of the pH level in the acidic fluid along with its effects on liver oxidative stress, liver and kidney histopathology and the lifespan of the body.

MATERIALS AND METHODS

A total of 38 mice were randomly divided into 4 groups.PC development was inhibited by intraperitoneal injection of Ehrlich tumor cells in all mice in each group.

RESULTS

In the group-1 receiving CAPD, the pH levels of acidic liquid were higher; and the levels of liver TBARS were lower with higher reduced glutathione levels. Histopathological damage in group-1 was less than in group-2. In Group 3 receiving CAPD, the average lifespan extended by 10.4%. The average lifespan extended by 26.1%.

CONCLUSION

This study indicated that applying CAPD with alkaline dialysate in PC contributed to the neutralization of acidosis of the intraperitoneal acid structure;had favorable effects on oxidative stress markers in liver tissue; prevented histopathological injury in liver and kidney tissues, and extended the life span of the body in mice. As this is a simple, inexpensive, and easily available method, larger studies are warranted to evaluate its effects.

Dialysate Potassium and Mortality in a Prospective Hemodialysis Cohort

BACKGROUND

Studies examining the association of dialysate potassium concentration and mortality in hemodialysis patients show conflicting findings. We hypothesized that low dialysate potassium concentrations are associated with higher mortality, particularly in patients with high pre-dialysis serum potassium concentrations.

METHODS

We evaluated 624 hemodialysis patients from the prospective Malnutrition, Diet, and Racial Disparities in Kidney Disease study recruited from 16 outpatient dialysis facilities over 2011-2015 who underwent protocolized collection of dialysis treatment characteristics every 6 months. We examined the association of dialysate potassium concentration, categorized as 1, 2, and 3 mEq/L, with all-cause mortality risk in the -overall cohort, and stratified by pre-dialysis serum potassium (< 5 vs. ≥5 mEq/L) using case-mix adjusted Cox models.

RESULTS

In baseline analyses, dialysate potassium concentrations of 1 mEq/L were associated with higher mortality, whereas concentrations of 3 mEq/L were associated with similar mortality in the overall cohort (reference: 2 mEq/L): adjusted hazard ratios (aHRs; 95% CI) 1.70 (1.01-2.88) and 0.95 (0.64-1.39), respectively. In analyses stratified by serum potassium, baseline dialysate potassium concentrations of 1 mEq/L were associated with higher mortality in patients with serum potassium ≥5 mEq/L but not in those with serum potassium < 5 mEq/L: aHRs (95% CI) 2.87 (1.51-5.46) and 0.74 (0.27-2.07), respectively (p interaction = 0.04). These findings were robust with incremental adjustment for serum potassium, potassium-binding resins, and potassium-modifying medications.

CONCLUSION

Low (1 mEq/L) dialysate potassium -concentrations were associated with higher mortality, particularly in hemodialysis patients with high pre-dialysis serum potassium. Further studies are needed to identify therapeutic strategies that mitigate inter-dialytic serum potassium accumulation and subsequent high dialysate serum potassium gradients in this population.

[Update 2017 of the KDIGO guidelines on Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). What are the real changes?]

Guidelines for the assessment, diagnosis and therapy of the alterations that characterize the CKD-MBD are an important support in the clinical practice of the nephrologist. Compared to the KDIGO guidelines published in 2009, the 2017 update made changes on some topics on which there was previously no strong evidence both in terms of diagnosis and therapy. The recommendations include the diagnosis of bone anomalies in CKD-MBD and the treatment of mineral metabolism abnormalities with particular regard to hyperphosphataemia, calcium levels, secondary hyperparathyroidism and anti-resorptive therapies. The Italian Study Group on Mineral Metabolism, in reviewing the 2017 recommendations, aimed to assess the weight of the evidence that led to this update. In fact, on some topics there has not been a substantial difference on the degree of evidence compared to the previous guidelines. The Italian Study Group emphasizes the points that may still reserve critical issues, including interpretation, and invites an evaluation that is articulated and personalized for each patient.

β-Blocker Dialyzability in Maintenance Hemodialysis Patients: A Randomized Clinical Trial

BACKGROUND AND OBJECTIVES

There is a paucity of data available to describe drug dialyzability. Of the available information, most was obtained before implementation of modern hemodialysis membranes. Our study characterized dialyzability of the most commonly prescribed β-blockers in patients undergoing high-flux hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients on hemodialysis (n=8) were recruited to an open label, pharmacokinetic, four-way crossover trial. Single doses of atenolol, metoprolol, bisoprolol, and carvedilol were administered on separate days in random order to each patient. Plasma and dialysate drug concentrations were measured, and dialyzability was determined by the recovery clearance and arterial venous difference methods.

RESULTS

Using the recovery clearance method, the dialytic clearance values for atenolol, metoprolol, bisoprolol, and carvedilol were 72, 87, 44, and 0.2 ml/min, respectively (P<0.001). Applying the arterial venous difference method, the dialytic clearance values of atenolol, metoprolol, bisoprolol, and carvedilol were 167, 114, 96, and 24 ml/min, respectively (P<0.001).

CONCLUSIONS

Atenolol and metoprolol are extensively cleared by hemodialysis compared with the negligible dialytic clearance of carvedilol. Contrary to estimates of dialyzability on the basis of previous literature, our data indicate that bisoprolol is also dialyzable. This finding highlights the importance of conducting dialyzability studies to definitively characterize drug dialytic clearance.

Associations between dialysate sodium concentration and plasma sodium concentration of dogs receiving intermittent hemodialysis treatments

OBJECTIVE To compare dialysate sodium concentration and patient plasma sodium concentration of dogs during intermittent hemodialysis treatments. SAMPLE 211 intermittent hemodialysis treatments performed on 40 client-owned dogs for the management of dialysis-dependent uremia. PROCEDURES Medical records were reviewed to determine the plasma sodium concentration of each dog before and after routine hemodialysis treatments. Associations between detected changes in plasma sodium concentration and dialysate sodium concentration were evaluated by use of Spearman rank correlations and linear regression analysis. RESULTS Significant linear correlations were found between the dialysate sodium concentration and patient sodium concentration. The starting dialysate-to-patient sodium gradient was associated with the strongest correlation to the change in patient sodium concentration at the end of the dialysis session. Modest correlations existed between the dialysate sodium concentration and postdialysis patient sodium concentration as well as between the predialysis dialysate-to-patient sodium gradient and postdialysis dialysate-to-patient sodium gradient. CONCLUSIONS AND CLINICAL RELEVANCE The dialysate sodium concentration was correlated with the patient sodium concentration in dogs, and the dialysate-to-patient sodium gradient could be used to further refine this association to predict the postdialysis patient sodium concentration and potentially manage dysnatremia during hemodialysis. Prospective studies should be performed to determine how these associations can be used to correct aberrations as well as to avoid unwanted alterations in patient sodium concentrations.

Influence of different peritoneal dialysis fluids on the in vitro activity of fosfomycin against Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa

Peritonitis is still the main infectious complication among patients on peritoneal dialysis. For treatment of peritoneal dialysis-related peritonitis, the intraperitoneal administration of antibiotics admixed to peritoneal dialysis fluids (PDFs) should be preferred. However, the influence of diverse PDFs on the activity of frequently used antibiotics has been investigated insufficiently. Thus, the present study set out to investigate the in vitro activity of fosfomycin against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Staphylococcus aureus in commercially available PDFs. Time-kill curves in four different PDFs (Dianeal®, Extraneal®, Nutrineal®, and Physioneal®) were performed over 24 h with two different concentrations of fosfomycin (150 and 400 mg/L) and without antibiotics as control. Cation-adjusted Mueller Hinton broth (CA-MHB) was used as a comparator solution. In blank PDFs, bacterial growth of each organism evaluated was reduced when compared to CA-MHB. For S. aureus in blank Physioneal®, a reduction under the limit of detection was observed within 24 h. The activity of fosfomycin was reduced in all PDFs when compared to CA-MHB except for P. aeruginosa in Nutrineal® where the activity of fosfomycin was increased when investigated at 400 mg/L. Against E.coli, bactericidal activity was demonstrated in Extraneal®, Nutrineal®, and Physioneal®. Fosfomycin resistance (MIC > 1024 mg/L) was observed for P. aeruginosa in CA-MHB at both concentrations and in Nutrineal® at 150 mg/L. Fosfomycin is active in PDFs particularly against the frequently isolated enterobacterium E. coli. The choice of the respective PDF considerably influences the microbiological outcome in vitro. Further studies are warranted to investigate the clinical relevance of these findings.

Weekly Standard Kt/Vurea and Clinical Outcomes in Home and In-Center Hemodialysis

BACKGROUND AND OBJECTIVES

Patients undergoing hemodialysis with a frequency other than thrice weekly are not included in current clinical performance metrics for dialysis adequacy. The weekly standard Kt/Vurea incorporates treatment frequency, but there are limited data on its association with clinical outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used multivariable regression to examine the association of dialysis standard Kt/Vurea with BP and metabolic control (serum potassium, calcium, bicarbonate, and phosphorus) in patients incidental to dialysis treated with home (n=2373) or in-center hemodialysis (n=109,273). We further used Cox survival models to examine the association of dialysis standard Kt/Vurea with mortality, hospitalization, and among patients on home hemodialysis, transfer to in-center hemodialysis.

RESULTS

After adjustment for potential confounders, patients with dialysis standard Kt/Vurea <2.1 had higher BPs compared with patients with standard Kt/Vurea 2.1 to <2.3 (3.4 mm Hg higher [P<0.001] for home hemodialysis and 0.9 mm Hg higher [P<0.001] for in-center hemodialysis). There were no clinically meaningful associations between dialysis standard Kt/Vurea and markers of metabolic control, irrespective of dialysis modality. There was no association between dialysis standard Kt/Vurea and risk for mortality, hospitalization, or transfer to in-center hemodialysis among patients undergoing home hemodialysis. Among patients on in-center hemodialysis, dialysis standard Kt/Vurea <2.1 was associated with higher risk (adjusted hazard ratio, 1.11; 95% confidence interval, 1.07 to 1.14) and standard Kt/Vurea ≥2.3 was associated with lower risk (adjusted hazard ratio, 0.97; 95% confidence interval, 0.94 to 0.99) for death compared with standard Kt/Vurea 2.1 to <2.3. Additional analyses limited to patients with available data on residual kidney function showed similar relationships of dialysis and total (dialysis plus kidney) standard Kt/Vurea with outcomes.

CONCLUSIONS

Current targets for standard Kt/Vurea have limited utility in identifying individuals at increased risk for adverse clinical outcomes for those undergoing home hemodialysis but may enhance risk stratification for in-center hemodialysis.

Comparison of Kinetic Characteristics of Amino Acid-Based and Dipeptide-Based Peritoneal Dialysis Solutions

A mixture of dipeptides (DP) has been proposed as alternatives (to glucose and amino acids, (AA)) osmotic agent in peritoneal dialysis (PD) solutions. DP based solutions may have metabolic and nutritional advantages compared to AA based solutions, as some sources of AA (such as tyrosine) are poorly soluble in water. In a previous study, we compared the kinetic characteristics of DP and AA based solutions; however, the amount of AA differed substantially. The aim of the present study was to compare solutions with almost equal amounts of AA.

Methods

The following solutions were used: (1) amino acid (AA) solution containing leucine, valine, lysine, isoleucine, threonine, phenylalanine and histidine (tyrosine was omitted because of its poor solubility), (2) dipeptide (DP) solution containing leucyl-valine, lysyl-isoleucine, threonyl-phenylalanine and histidyl-tyrosine. Sixteen Sprague-Dawley rats were divided in two groups and were subjected to intraperitoneal injection of either 25 mL of AA (n=8) or DP solution. Dialysate and blood samples were taken frequently postinfusion for measurement of AA and DP concentrations as well as AA from DP.

Results

Kinetic models were developed for estimation of diffusive mass transport coefficient between peritoneal cavity and blood (KBD), DP hydrolysis rate coefficient (KH) and AA clearance in the body (KC). Calculations showed that KH is about ten times lower than KBD. Thus, hydrolysis rate in peritoneal cavity is much lower than the diffusive transport rate of DP. KBD for AA appeared to be similar to KBD for dipeptides. KC was much higher than KBD for AA. This finding explains the rapid clearance of amino acids from blood. Nevertheless, the AA-based solution resulted in much higher peak concentrations of AA in blood after 120 min of the dwell than AA concentrations achieved following the use of the DP-based solution.

Conclusions

Peritoneal transport characteristics of AA and DP were similar; however their kinetics in blood differs substantially. The DP solution resulted in a less pronounced increase in AA concentrations in blood, suggesting that DP solution could provide AA in a more physiological way.

Theoretical Morphological Approach to Simple Peritoneal Sclerosis

The term peritoneal sclerosis can be applied to a vast range of peritoneal alterations. At one end of the range we have the slight peritoneal sclerosis constantly associated with peritoneal dialysis, which may be defined as simple sclerosis. Its clinical impact is slight.

The role of glucose in determining peritoneal sclerosis is supported by morphological studies and therefore backed by much biochemical and immunological data.

New Generation Ceramic Membranes have the Potential of Removing Endotoxins from Dialysis Water and Dialysate

Poor water properties, use of concentrated bicarbonate, and biofilm growth in pipes and storage tanks often cause dialysis water and dialysate contamination with bacteria and endotoxins. High-flux dialysis with bicarbonate may favor endotoxin transfer from the dialysate into the blood exposing patients to serious short - and long-term side effects. Ultrafiltration across hydrophobic synthetic membranes effectively removes endotoxins from dialysis water by combined filtration and adsorption. However, repeated sterilization worsens the membrane separation properties, and limits their use. Ceramic membranes are generally more resistant to harsh operating conditions than polymeric membranes, and may represent an alternative for endotoxin removal. Previously, we proved that the ceramic membranes commercially available at that time were not retentive enough to ensure production of endotoxin-free dialysis water.

In this paper, we investigated the endotoxin removal capacity of new generation commercial ceramic membranes with nominal molecular weight cut-off down to 1,000. In dead-end filtration, all investigated membranes produced water meeting, the European standards, or close to, when challenged with low endotoxin concentrations, but only one membrane type succeeded at high endotoxin concentrations. In cross-flow filtration, none produced water meeting the European standard. Moreover, sterilization and rinsing procedures altered the separation properties of two out of three membrane types.

[Effect of high glucose-based peritoneal dialysis fluids on NLRP3-IL-1β in human peritoneal mesothelial cells]

OBJECTIVE

To explore the effect of high glucose-based peritoneal dialysis fluids on NLRP3-IL-1β in human peritoneal mesothelial cells.

METHODS

HMrSV5 cells (SV40 immortalized human peritoneal mesothelial cell line) were grown in type I collagen-coated dishes in DMEM/F12 containing 10% fetal calf serum (FCS). All experiments on HMrSV5 cells were performed between passages 5 and 10. The cells were divided into 7 groups: control, 1.5% dextrose, 2.5% dextrose, 4.25% dextrose, rotenone, thenoyltrifluoroacetone (TTFA), and antimycin A. Immunoblotting was used to evaluate the expression of IL-1β. Small interfering RNA (siRNA) targeting NLRP3 was used to downregulate the expression of NLRP3 and Western blot was used to evaluate the expression of IL-1β in human peritoneal mesothelial cells exposed to 4.25% dextrose. In the meanwhile, resveratrol (RSV) was used to induce autophagy, 3-methyladenine (3-MA) and siRNA against Beclin 1 or ATG5 were used to block auto-phagy, flow cytometric was used to analyze the respiring (mitotracker deep red), total (mitotracker green) and reactive oxygen species (ROS)-generating mitochondria (mitoSOX); Western blot was used to evaluate the expression of IL-1β.

RESULTS

The IL-1β relative expressions were 0, 0.175±0.082, 0.418±0.163, 2.357±0.288, 2.642±0.358, 3.271±0.462, and 0.123±0.091, indicating that the cells exposed to high glucose-based peritoneal dialysis fluids and cells treated with mitochondria respiratory chain key enzyme complex I, and complex III inhibitors increased the IL-1β expression. And we found that NLRP3 knock-down significantly blocked the upregulation of IL-1β. In addition, the fluorescence intensity of total mitochondria and ROS-generating mitochondria in the following groups: control, negative control, RSV, 3-MA, ATG5 siRNA, Beclin1 siRNA were 1.76±0.42, 1.83±0.55, 1.85±0.62, 7.36±0.92, 5.35±0.77, 5.06±0.62 and 821.68±95.12, 868.15±102.82, 723.39±92.56, 1 660.08±113.65, 1 433.01±107.24, 1 562.36±112.88 respectively. The increased concentrations of mitochondrial ROS and IL-1β upregulation were confirmed in the inhibition but not the induction of auto-phagy. We also found that downregulation of ATG5 and Beclin1 sensitized cells for the release of IL-1β induced by MSU (monosodium urate) or nigericin which was the NLRP3 inflammasome activator. RSV treatment attentuated this effect.

CONCLUSION

Long-term application of high glucose-based peritoneal dialysis fluids can trigger the consistent activation of NLRP3-IL-1β in peritoneal mesothelial cells. Timely initiation of autophagy may block the NLRP3-IL-1β activation and provide a basis for the further development of a potential therapeutic strategy for delay of chronic inflammation and peritoneal fibrosis associated with peritoneal dialysis.

Stability of Vancomycin in Icodextrin Peritoneal Dialysis Solution

Background:

Icodextrin is a glucose polymer used as an alternative osmotic agent in peritoneal dialysis (PD) solutions. There are few data regarding the long-term stability of vancomycin in icodextrin PD solution.

Objective:

To determine the chemical stability of vancomycin in icodextrin PD solution in polyvinyl chloride containers over a 7 day period at 4, 24, and 37 °C.

Methods:

Study samples were prepared by adding 2000 mg vancomycin HCl to commercially available 2.0 L bags of icodextrin 7.5% PD solution. Nine bags were prepared and stored in the following conditions: 3 under refrigeration (5 °C), 3 at room temperature (24 °C), and 3 at body temperature (37 °C). Samples were withdrawn from each bag immediately after preparation and at predetermined intervals over the subsequent 7 days. Solutions were visually inspected for precipitation, cloudiness, or discoloration at each sampling interval. Total concentration of vancomycin in dialysate fluid was determined by high performance liquid chromatography.

Results:

Under refrigeration, a mean ± SD of 99.7% ± 0.5% of the initial vancomycin concentration remained at 168 hours (7 days). At room temperature, 97.5% ± 3.4% remained at 168 hours. At body temperature, 94.3% ± 3.9% remained at 24 hours. Stability was not assessed beyond these time points.

Conclusions:

Premixed vancomycin-icodextrin PD solutions, whether stored refrigerated or at room temperature, were found to be stable for up to 7 days. However, we recommend that these solutions be kept refrigerated whenever possible. Solutions stored at body temperature were stable for up to 24 hours, permitting the practice of prewarming solutions prior to administration.

Comparison of two different modes of molecular adsorbent recycling systems for liver dialysis

BACKGROUND

In children acute liver failure is a rare but life-threatening condition from which two-thirds do not recover with supportive therapy. Treatment is limited by the availability of liver transplants. Molecular adsorbent recirculating system (MARS) dialysis is a bridge to transplantation that enhances the chances of survival during the waiting period for a transplant, although it cannot improve survival. Open albumin dialysis (OPAL) is a new mode of albumin dialysis developed to further improve dialysis efficiency.

CASE DIAGNOSIS/TREATMENT

We report a paediatric case of acute-on-chronic liver failure and compare the two modes of albumin dialysis, namely, the MARS and OPAL, used to treat this patient's cholestatic pruritus. Removal of total and direct bilirubin, ammonia and bile acids were measured by serial blood tests. There was an increased removal of bile acids with the OPAL mode, whereas the removal of total and direct bilirubin and ammonia was similar in both modes. The patient reported better improvement in pruritus following OPAL compared to dialysis with the MARS.

CONCLUSION

OPAL may offer a better solution than the MARS in the treatment of refractory pruritus in liver failure.

Pharmacokinetics and Pharmacodynamics of Extended Infusion Versus Short Infusion Piperacillin-Tazobactam in Critically Ill Patients Undergoing CRRT

BACKGROUND AND OBJECTIVES

Infection is the most common cause of death in severe AKI, but many patients receiving continuous RRT do not reach target antibiotic concentrations in plasma. Extended infusion of β-lactams is associated with improved target attainment in critically ill patients; thus, we hypothesized that extended infusion piperacillin-tazobactam would improve piperacillin target attainment compared with short infusion in patients receiving continuous RRT.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted an institutional review board-approved observational cohort study of piperacillin-tazobactam pharmacokinetics and pharmacodynamics in critically ill patients receiving continuous venovenous hemodialysis and hemodiafiltration at three tertiary care hospitals between 2007 and 2015. Antibiotic concentrations in blood and/or dialysate samples were measured by liquid chromatography, and one- and two-compartment pharmacokinetic models were fitted to the data using nonlinear mixed effects regression. Target attainment for piperacillin was defined as achieving four times the minimum inhibitory concentration of 16 μg/ml for >50% of the dosing cycle. The probabilities of target attainment for a range of doses, frequencies, and infusion durations were estimated using a Monte Carlo simulation method. Target attainment was also examined as a function of patient weight and continuous RRT effluent rate.

RESULTS

Sixty-eight participants had data for analysis. Regardless of infusion duration, 6 g/d piperacillin was associated with ≤45% target attainment, whereas 12 g/d was associated with ≥95% target attainment. For 8 and 9 g/d, target attainment ranged between 68% and 85%. The probability of target attainment was lower at higher effluent rates and patient weights. For all doses, frequencies, patient weights, and continuous RRT effluent rates, extended infusion was associated with higher probability of target attainment compared with short infusion.

CONCLUSIONS

Extended infusions of piperacillin-tazobactam are associated with greater probability of target attainment in patients receiving continuous RRT.

Optical Estimation of Beta 2 Microglobulin during Hemodiafiltration – Does It Work?

BACKGROUND

Currently, urea reduction seems to be the most widely used dialysis dose parameter. The aim of this study was to investigate the possibility to monitor beta 2-microglobulin (β2-M) elimination by utilizing the ultraviolet (UV) absorbance of spent dialysate.

METHODS

Blood and spent dialysate were collected during two week's sessions in 8 patients, one week in hemodialysis (HD) and one in hemodiafiltration (HDF). Correlation analysis between UV-wavelengths and concentrations of solutes in spent dialysate was performed. The reduction ratio (RR) of concentrations in blood, dialysate and UV-absorbance were compared.

RESULTS

Differences between HD and HDF were discovered in wavelength correlation maxima for the solutes. Relative error in RR (%) was larger (p < 0.05) for β2-M than for the other solutes. The most reasonable explanation is that β2-M does not absorb UV-radiation; instead, the absorbance of surrogate substances is measured.

CONCLUSION

A high correlation between UV-absorbance and β2-M can be achieved for HDF but not for HD. Still, UV-absorbance could perhaps be used in solely HDF mode for estimation of β2-M removal.

The Effects of High Level Magnesium Dialysis/Substitution Fluid on Magnesium Homeostasis under Regional Citrate Anticoagulation in Critically Ill

BACKGROUND

The requirements for magnesium (Mg) supplementation increase under regional citrate anticoagulation (RCA) because citrate acts by chelation of bivalent cations within the blood circuit. The level of magnesium in commercially available fluids for continuous renal replacement therapy (CRRT) may not be sufficient to prevent hypomagnesemia.

METHODS

Patients (n = 45) on CRRT (2,000 ml/h, blood flow (Qb) 100 ml/min) with RCA modality (4% trisodium citrate) using calcium free fluid with 0.75 mmol/l of Mg with additional magnesium substitution were observed after switch to the calcium-free fluid with magnesium concentration of 1.50 mmol/l (n = 42) and no extra magnesium replenishment. All patients had renal indications for CRRT, were treated with the same devices, filters and the same postfilter ionized calcium endpoint (<0.4 mmol/l) of prefilter citrate dosage. Under the high level Mg fluid the Qb, dosages of citrate and CRRT were consequently escalated in 9h steps to test various settings.

RESULTS

Median balance of Mg was -0.91 (-1.18 to -0.53) mmol/h with Mg 0.75 mmol/l and 0.2 (0.06-0.35) mmol/h when fluid with Mg 1.50 mmol/l was used. It was close to zero (0.02 (-0.12-0.18) mmol/h) with higher blood flow and dosage of citrate, increased again to 0.15 (-0.11-0.25) mmol/h with 3,000 ml/h of high magnesium containing fluid (p<0.001). The arterial levels of Mg were mildly increased after the change for high level magnesium containing fluid (p<0.01).

CONCLUSIONS

Compared to ordinary dialysis fluid the mildly hypermagnesemic fluid provided even balances and adequate levels within ordinary configurations of CRRT with RCA and without a need for extra magnesium replenishment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01361581.

[High glucose dialysate enhances peritoneal fibrosis through upregulating glucose transporters GLUT1 and SGLT1]

Objective: To investigate the role of glucose transporter 1 (GLUT1) and sodium-glucose cotransporter 1 (SGLT1) in high glucose dialysate-induced peritoneal fibrosis. Methods: Thirty six male SD rats were randomly divided into 6 groups (6 in each):normal control group, sham operation group, peritoneal dialysis group (PD group), PD+phloretin group (PD+T group), PD+phlorizin group (PD+Z group), PD+phloretin+phlorizin group (PD+T+Z group). Rat model of uraemia was established using 5/6 nephrotomy, and 2.5% dextrose peritoneal dialysis solution was used in peritoneal dialysis. Peritoneal equilibration test was performed 24 h after dialysis to evaluate transport function of peritoneum in rats; HE staining was used to observe the morphology of peritoneal tissue; and immunohistochemistry was used to detect the expression of GLUT1, SGLT1, TGF-β1 and connective tissue growth factor (CTGF) in peritoneum. Human peritoneal microvascular endothelial cells (HPECs) were divided into 5 groups:normal control group, peritoneal dialysis group (PD group), PD+phloretin group (PD+T group), PD+phlorezin group (PD+Z group), and PD+phloretin+phlorezin group (PD+T+Z group). Real time PCR and Western blotting were used to detect mRNA and protein expressions of GLUT1, SGLT1, TGF-β1, CTGF in peritoneal membrane and HPECs. Results:In vivo, compared with sham operation group, rats in PD group had thickened peritoneum, higher ultrafiltration volume, and the mRNA and protein expressions of GLUT1, SGLT1, CTGF, TGF-β1 were significantly increased (all P<0.05); compared with PD group, thickened peritoneum was attenuated, and the mRNA and protein expressions of GLUT1, SGLT1, CTGF, TGF-β1 were significantly decreased in PD+T, PD+Z and PD+T+Z groups (all P<0.05). Pearson's correlation analysis showed that the expressions of GLUT1, SGLT1 in peritoneum were positively correlated with the expressions of TGF-β1 and CTGF (all P<0.05). In vitro, the mRNA and protein expressions of GLUT1, SGLT1, TGF-β1, CTGF were significantly increased in HPECs of peritoneal dialysis group (all P<0.05), and those in PD+T, PD+Z, and PD+T+Z groups were decreased (all P<0.05). Pearson's correlation analysis showed that the expressions of GLUT1, SGLT1 in HPECs were positively correlated with the expressions of TGF-β1 and CTGF (all P<0.05). Conclusion: High glucose peritoneal dialysis fluid may promote peritoneal fibrosis by upregulating the expressions of GLUT1 and SGLT1.