The Effect of Dialysate Temperature on Dialysis Adequacy and Hemodynamic Stability: An Experimental Study with Crossover Design.

Cool dialysate has variable impact on hemodynamic stability and dialysis adequacy. Hemodynamic stability and dialysis adequacy are crucial indicators for better life expectancy and cardiovascular mortality. This research aims to evaluate the impact of cool dialysate temperature (35.5°C) compared to standard dialysate temperature (37°C) on blood pressures, pulse rate, and dialysis adequacy (Urea reduction ratio and online Kt/V) in a cross over design. Material and Methods. Consenting ESRD patients on maintenance haemodialysis (HD) with minimum 3 months dialysis vintage and functioning permanent vascular access are included for the study. Each participant had two sessions of HD at 37°C followed by two sessions at 35.5° C on a Fresenius 4008S HD machine. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and Pulse rate are measured pre-HD, every hourly and post dialysis. Pre-HD Blood urea nitrogen (BUN) and post-HD BUN are measured, and Urea reduction rate was calculated for each HD session. Kt/V was calculated by ionic conductance by HD machine for each session. Results. 25 patients (5 females and 20 males) were enrolled. The mean age was 54 ± 9.58 years. Dialysis vintage was 21.48 ± 6.9 months for study participants 10 patients (40%) were diabetic nephropathy, 9 patients (36%) were presumed chronic glomerulonephritis, 2 patients (8%) were lupus nephritis and 4 patients (16%) were chronic interstitial nephritis. There was statistically no difference between pre-HD BUN (p = 0.330), post-HD BUN (p = 0.776), URR (p = 0.718) and Kt/V (p = 0.534) among the dialysis sessions done at 37°C and 35.5°C. SBP variability in the low temperature (35.5°C) group at 4th hour and post dialysis assumed statistical significance with p = 0.05 and p = 0.025 respectively. DBP variability in the low temperature (35.5°C) group at 3rd hour, 4th hour and post-dialysis demonstrated statistical significance with p = 0.027, p = 0.36 and p = 0.016 respectively. Pulse rate variability was more in the low temperature (35.5°C) group at 3rd hour and 4th hour which showed statistical significance with p = 0.037 and p = 0.05 respectively. Conclusion. Cool dialysate is non inferior to standard dialysate temperature in terms of dialysis adequacy and is associated with less variability in diastolic blood pressure, systolic blood pressure and more pulse rate variability thereby contributing to better hemodynamic stability.

Calcium mass balance in adults during single hemodialysis and hemodiafiltration treatments using lower calcium dialysate concentrations.

BACKGROUND: Debate continues as to the optimum hemodialysis (HD) dialysate calcium concentration. Although current guidelines advocate 1.25-1.5 mmol/L, some investigators have suggested these may cause calcium gains. As such we investigated whether using dialysate calcium of 1.25 mmol/L risked calcium gains, and whether there were differences between hemodiafiltration and high flux HD. METHODS: We continuously collect an aliquot of effluent dialysate during dialysis sessions, and calculated dialysis calcium mass balance by the difference between the amount of calcium delivered as fresh dialysate and that lost in effluent dialysate. RESULTS: We studied 106 stable outpatients, 64% male, mean age 64.4 ± 16.2 years, median dialysis vintage 32 (22-60) months. Most sessions (69%) used a 1.0 mmol/L calcium dialysate, with a median sessional loss of 13.7 (11.5-17.1) mmol, whereas using 1.25 mmol/L the median loss was 7.4 (4.9-10.1) mmol, but with 6.9% had a positive balance (p = 0.031 vs dialysate calcium 1.0 mmol/L). Most patients (85.8%) were treated by hemodiafiltration, but there was no difference in sessional losses (11.7 (8.4-15.8) vs 13.5 (8.1-16.8)) with high flux HD. Dialysis sessional calcium balance was associated with the use of lower dialysate calcium concentration (ß -19.5, 95% confidence limits (95%CL) -27.7 to -11.3, p < 0.001), and sessional duration (ß 0.07 (95% CL) 0.03-012, p = 0.002). CONCLUSION: Ideally, the choice of dialysate calcium should be individualized, but clinicians should be aware, that even when using a dialysate calcium of 1.25 mmol/L, some patients are at risk of a calcium gain during hemodiafiltration and high-flux hemodialysis.

Can regional anticoagulation with calcium-free dialysate be extended to maintenance hemodialysis?

BACKGROUND: Regional anticoagulation in hemodialysis avoids the use of heparin, which is responsible for both hemorrhagic and non-hemorrhagic complications. Typically, blood is decalcified by injecting citrate into the arterial line of the extracorporeal circuit. Calcium-free dialysate improves anticoagulation efficacy but requires injection of a calcium-containing solution into the venous line and strict monitoring of blood calcium levels. Recent improvements have made regional anticoagulation with calcium-free dialysate safer and easier. OBSERVATIONS: (1) Adjusting the calcium injection rate to ionic dialysance avoids the risk of dyscalcemia, thus making unnecessary the monitoring of blood calcium levels. This adjustment could be carried out automatically by the hemodialysis monitor. (2) As calcium-free dialysate reduces the amount of citrate required, this can be supplied by dialysate obtained from currently available concentrates containing citric acid. This avoids the need for citrate injection and the risk of citrate overload. (3) Calcium-free dialysate no longer needs the dialysate acidification required for avoiding calcium carbonate precipitation in bicarbonate-containing dialysate. CONCLUSIONS: Regional anticoagulation with calcium-free dialysate enables an acid- and heparin-free procedure that is more biocompatible and environmentally friendly than conventional bicarbonate hemodialysis. The availability of specific acid-free concentrates and adapted hemodialysis monitors is required to extend this procedure to maintenance hemodialysis.

Interdialytic weight gain and low dialysate sodium concentration in patients on chronic hemodialysis: a systematic review and meta-analysis.

PURPOSE: The present systematic review and meta-analysis aimed at evaluating the effect of low dialysate sodium concentration on interdialytic weight gain (IDWG) in chronic hemodialysis patients. METHODS: Studies were eligible for inclusion if they were English language papers published in a peer-reviewed journal and met the following inclusion criteria: (1) studies in adult patients (over 18 years of age), (2) included patients on chronic hemodialysis since at least 6 months; (3) compared standard (138-140 mmol/l) or high (> 140 mmol/l) dialysate sodium concentration with low (< 138 mmol/l) dialysate sodium concentration; (4) Included one outcome of interest: interdialytic weight gain. Medline, PubMed, Web of Science, and the Cochrane Library were searched for the quality of reporting for each study was performed using the Quality Assessment Tool of Controlled Intervention Studies of the National Institutes of Health. The quality of reporting of each cross-over study was performed using the Revised Cochrane Risk of Bias (RoB) tool for cross-over trials as proposed by Ding et al. RESULTS: Nineteen studies (710 patients) were included in the analysis: 15 were cross-over and 4 parallel randomized controlled studies. In cross-over studies, pooled analysis revealed that dialysate sodium concentration reduced IDWG with a pooled MD of - 0.40 kg (95% CI - 0.50 to - 0.30; p < 0.001). The systematic review of four parallel, randomized, studies revealed that the use of a low dialysate sodium concentration was associated with a significant reduction of the IDWG in two studies, sustained and almost significant (p = 0.05) reduction in one study, and not significant reduction in one study. CONCLUSION: Low dialysate sodium concentration reduces the IDWG in prevalent patients on chronic hemodialysis.

The impact of low and high dialysate calcium concentrations on cardiovascular disease and death in patients undergoing maintenance hemodialysis: a systematic review and meta-analysis.

BACKGROUND: The optimal dialysate calcium (Ca) concentration for patients undergoing hemodialysis remains inconclusive, particularly concerning cardiovascular protection. METHODS: We conducted a systematic review of 19 randomized controlled trials (RCTs) and a meta-analysis of eight RCTs to determine the optimal dialysate Ca concentration for cardiovascular protection. We compared outcomes in patients receiving maintenance hemodialysis treated with either a low-Ca dialysate (LCD) (1.125 or 1.25 mmol/L) or a high-Ca dialysate (HCD) (1.5 or 1.75 mmol/L). The outcomes were coronary artery calcification score (CACS), all-cause and cardiovascular death, cardiovascular function and structure, and serum biochemical parameters. RESULTS: There was no significant difference between LCD and HCD concerning CACS (standardized mean difference [SMD] = -0.16, 95% confidence interval [CI]: [-0.38, 0.07]), the risk of all-cause death, and cardiovascular death in patients treated with chronic maintenance hemodialysis. Conversely, LCD was associated with a significantly lower intima-media thickness (SMD = -0.49, 95% CI [-0.94, -0.05]) and pulse wave velocity than HCD (SMD = -0.86, 95% CI [-1.21, -0.51]). Furthermore, LCD significantly decreased serum Ca levels (mean difference [MD] = 0.52 mg/dL, 95% CI [0.19, 0.85]) and increased serum parathyroid hormone levels (MD = 44.8 pg/mL, 95% CI [16.2, 73.3]) compared with HCD. Notably, most RCTs examined in our analysis did not include patients receiving calcimimetics. CONCLUSIONS: Our meta-analysis showed no significant differences in cardiovascular calcification and death between LCD and HCD and revealed a paucity of RCTs on dialysate Ca concentrations, including those involving patients on calcimimetics, indicating the urgent need for further studies.

Utilidad del sistema de recirculación de adsorbentes moleculares en la falla hepática: "diálisis hepática" / Usefulness of the molecular adsorbent recirculating system in liver failure: "liver dialysis"

INTRODUCCIÓN. La falla hepática ya sea aguda o crónica reagudizada representa un reto para el clínico ya que sus complicaciones conllevan una gran mortalidad, esto se ve aún más complicado ya que las opciones terapéuticas son limitadas, incluso muchas veces no se puede acceder a un programa de trasplante hepático oportuno que mejore la sobrevida de estos pacientes, es así que se ha desarrollado un sistema de "diálisis" hepática conocido como sistema de recirculación de adsorbentes moleculares el cual hace un efecto de detoxificación para eliminar sustancias que generan una noxa en el cuerpo humano. OBJETIVO. Entender la utilidad del sistema recirculante molecular adsorbente en la falla hepática, conocer sus indicaciones y complicaciones. METODOLOGÍA. Se realizó una revisión de la literatura con un enfoque descriptivo, retrospectivo cualitativo no experimental, de documentos que tratan sobre la utilización del sistema MARS para tratar la falla hepática, con evidencia desde el año 2004 hasta el 2021. La revisión bibliográfica se llevó a cabo en bases de datos como Pubmed, Embase, BVS, Google Scholar y Elsevier. RESULTADOS. Se identificaron 30 artículos que cumplieron criterios de inclusión de un grupo original de 343 artículos revisados. Se ha determinado que la evidencia sobre este sistema está compuesta sobre todo por reportes de caso y son pocos los ensayos controlados aleatorizados que empleen su uso, sin embargo, se ha podido determinar que este sistema es un puente al trasplante renal mientras se estabiliza al paciente en la Unidad de Cuidados Intensivos, disminuye los marcadores de falla hepática. CONCLUSIÓN. En Latinoamérica su uso es casi nulo de ahí la necesidad de entender el mecanismo de este novedoso sistema.

INTRODUCTION. Hepatic failure, whether acute or chronic, represents a challenge for the clinician since its complications entail a great mortality, this is even more complicated since the therapeutic options are limited, even many times it is not possible to access a timely liver transplant program to improve the survival of these patients, Thus, a hepatic "dialysis" system known as molecular adsorbent recirculation system has been developed, which has a detoxification effect to eliminate substances that generate a noxa in the human body. OBJECTIVE. To understand the usefulness of the molecular adsorbent recirculating system in liver failure, to know its indications and complications. METHODOLOGY. A literature review was performed with a descriptive, retrospective qualitative non-experimental qualitative approach, of papers dealing with the use of the MARS system to treat liver failure, with evidence from 2004 to 2021. The literature review was conducted in databases such as Pubmed, Embase, BVS, Google Scholar and Elsevier. RESULTS. Thirty articles were identified that met inclusion criteria from an original group of 343 articles reviewed. It has been determined that the evidence on this system is mainly composed of case reports and there are few randomized controlled trials that employ its use, however, it has been determined that this system is a bridge to renal transplantation while the patient is stabilized in the Intensive Care Unit, decreasing the markers of liver failure. CONCLUSIONS. In Latin America its use is almost null, hence the need to understand the mechanism of this novel system.

Antimicrobial activity of hemodialysis catheter lock solutions in relation to other compounds with antiseptic properties.

Proper protection of vascular access after haemodialysis is one of the key measures for the prevention of catheter-related infections. Various substances with bactericidal and anticoagulant properties are used to fill catheters, but due to the unsatisfactory clinical effects and occurrence of adverse reactions, the search for new substances is still ongoing. In the present paper, we compared the in vitro antimicrobial activity of solutions used for tunnelled catheter locking (taurolidine, trisodium citrate) and solutions of substances that could potentially be used for this purpose (sodium bicarbonate, polyhexanide-betaine). The studies have been conducted on bacteria that most commonly cause catheter-related infections. The values of both minimum inhibitory concentration and minimum biofilm eradication concentration of the substances were determined. The ability of the tested substances to eradicate biofilm from the dialysis catheter surface was also evaluated. The results showed that polyhexanide-betaine inhibited the growth of all microbes comparably to taurolidine, even after ≥ 32-fold dilution. The activity of trisodium citrate and sodium bicarbonate was significantly lower. Polyhexanide exhibited the highest activity in the eradication of bacterial biofilm on polystyrene plates. The biofilm formed on a polyurethane dialysis catheter was resistant to complete eradication by the test substances. Polyhexanide-betaine and taurolidine showed the highest activity. Inhibition of bacterial growth regardless of species was observed not only at the highest concentration of these compounds but also after dilution 32-128x (taurolidine) and 32-1024x (polyhexanide-betaine). Therefore, it can be assumed that taurolidine application as a locking solution prevents catheter colonization and systemic infection development. Taurolidine displays high antimicrobial efficacy against Gram-positive cocci as well as Gram-negative bacilli. On the contrary, the lowest antibacterial effect displayed product contained sodium bicarbonate. The inhibitions of bacterial growth were not satisfactory to consider it as a substance for colonization prevention. Polyhexanidine-betaine possessed potent inhibitory and biofilm eradication properties comparing to all tested products. PHMB is applied as a wound irrigation solution worldwide. However, based on our results, we assume that the PHMB is a promising substance for catheter locking solutions thanks to its safety and high antimicrobial properties.

Methods for dose quantification in continuous renal replacement therapy: Toward a more precise approach.

Periodic dose assessment is quintessential for dynamic dose adjustment and quality control of continuous renal replacement therapy (CRRT) in critically ill patients with acute kidney injury (AKI). The flows-based methods to estimate dose are easy and reproducible methods to quantify (estimate) CRRT dose at the bedside. In particular, quantification of effluent flow and, mainly, the current dose (adjusted for dialysate, replacement, blood flows, and net ultrafiltration) is routinely used in clinical practice. Unfortunately, these methods are critically influenced by several external unpredictable factors; the estimated dose often overestimates the real biological delivered dose quantified through the measurement of urea clearance (the current effective delivered dose). Although the current effective delivered dose is undoubtedly more precise than the flows-based dose estimation in quantifying CRRT efficacy, some limitations are reported for the urea-based measurement of dose. This article aims to describe the standard of practice for dose quantification in critically ill patients with AKI undergoing CRRT in the intensive care unit. Pitfalls of current methods will be underlined, along with solutions potentially applicable to obtain more precise results in terms of (a) adequate marker solutes that should be used in accordance with the clinical scenario, (b) correct sampling procedures depending on the chosen indicator of transmembrane removal, (c) formulas for calculations, and (d) quality controls and benchmark indicators.

Euglycemic Ketosis During Continuous Kidney Replacement Therapy With Glucose-Free Solution: A Report of 8 Cases.

In this report, we describe 8 patients with critical illness and diabetes mellitus who developed euglycemic ketosis during continuous kidney replacement therapy (CKRT) with a glucose-free CKRT solution. Two patients had chronic kidney disease stage 5, while the rest had acute kidney injury. The patients had improvement in all metabolic parameters following CKRT commencement, except for a worsening high anion gap metabolic acidosis, in spite of improvement in serum lactate. This led to detection of elevated serum ß-hydroxybutyrate in the setting of normoglycemia. Following diagnosis of ketosis, the patients' caloric intake was increased from a median of 15 (IQR, 10-20) to 25 (IQR, 20-29) kcal/kg/d by adding a dextrose infusion. This allowed for a corresponding increase in the insulin administered, from a median of 0.2 (IQR, 0-0.2) to 3.0 (IQR, 2.3-3.9) U/h. These contributed to a complete resolution of ketosis. This report of 8 cases demonstrates that critically ill patients are at risk of developing euglycemic ketosis during CKRT, which can be mitigated by providing adequate caloric intake and using glucose-containing CKRT solutions with appropriate insulin therapy. We recommend vigilance in evaluating for euglycemic ketosis in patients who have a persistent metabolic acidosis despite improvements in solute control during CKRT.

Intraperitoneal vancomycin treatment of multifocal methicillin-resistant Staphylococcus aureus osteomyelitis in a patient on peritoneal dialysis.

PURPOSE: We report the case of a 2-year-old girl with end-stage renal disease managed by peritoneal dialysis (PD) who developed methicillin-resistant staphylococcal osteomyelitis of the left shoulder and was successfully treated with intraperitoneal (IP) administration of vancomycin for 2 weeks followed by oral clindamycin therapy. SUMMARY: The patient was hospitalized with tactile fever and a 3-day history of worsening fussiness. Radiography of the left shoulder showed findings indicative of osteomyelitis. Vancomycin was administered via central venous line for 3 days, during which time the patient underwent PD 24 hours a day. After magnetic resonance imaging revealed proximal humeral osteomyelitis, septic arthritis of the shoulder joint, and osteomyelitis of the scapula, the patient underwent incision and drainage of the left shoulder joint. Both blood and joint drainage cultures grew methicillin-resistant Staphylococcus aureus that was sensitive to vancomycin. The patient's central venous catheter was removed on hospital day 4; due to difficulties with peripheral i.v. access and a desire to avoid placing a peripherally inserted central venous catheter, vancomycin administration was changed to the IP route, with vancomycin added to the PD fluid. During IP treatment, serum vancomycin levels were maintained at 13.5 to 18.5 mg/L, and the calculated ratio of vancomycin area under the curve to minimum inhibitory concentration was maintained above 400. After completing a 14-day course of IP vancomycin therapy, the patient was switched to oral clindamycin, with subsequent complete resolution of osteomyelitis. CONCLUSION: IP vancomycin was effective for treatment of invasive S. aureus infection in this case. This approach should be considered in patients undergoing PD for whom peripheral i.v. access options are limited and/or not preferred.

Effects of the dialysate calcium concentrations and mineral bone disease treatments on mortality in The French Renal Epidemiology and Information Network (REIN) registry.

BACKGROUND: In patients on hemodialysis (HD), the various chemical elements in the dialysate may influence survival rates. In particular, calcium modifies mineral and bone metabolism and the vascular calcification rate. We studied the influence of the dialysate calcium concentration and the treatments prescribed for mineral bone disease (MBD) on survival. METHODS: All patients in REIN having initiated HD from 2010 to 2013 were classified according to their exposure to the different dialysate calcium concentrations in their dialysis unit. Data on the individual patients' treatments for MBD were extracted from the French national health database. Cox proportional hazard models were used to estimate mortality hazard ratios (HR) associated with time-dependent exposure to dialysate calcium concentrations and MBD therapies, adjusted for comorbidities, laboratory and technical data. RESULTS: Dialysate calcium concentration of 1.5 mmol/L was used by 81% of the dialysis centers in 2010 and in 83% in 2014. Most centers were using several formulas in up to 78% for 3 formulas in 2010 to 86% in 2014. In full adjusted Cox survival analyses, the percentage of calcium >1.5 mmol/L and <1.5 mmol/l by center and the number of formula used per center were not associated with survival. Depending on the daily dose used, the MBD therapies were associated with survival improvement for calcium, native vitamin D, active vitamin D, sevelamer, lanthanum and cinacalcet in the second and third tertiles of dose. CONCLUSION: No influence of the dialysate calcium concentration was evidenced on survival whereas all MBD therapies were associated with a survival improvement depending on the daily dose used.

Ambrisentan use in a HIV-1 infected patient with end-stage renal disease and pulmonary hypertension: minimal removal by hemodialysis - a case report.

BACKGROUND: Ambrisentan is a selective endothelin receptor antagonist used for the treatment of pulmonary arterial hypertension (PAH). Little is known about ambrisentan removal by hemodialysis in patients with end-stage renal disease (ESRD). CASE PRESENTATION: A 53-year-old woman with HIV/hepatitis C virus (HCV) co-infection, PAH and ESRD on regular hemodialyis was admitted in our hospital due to refractory heart failure while on treatment with bosentan (125 mg twice daily) and tadalafil (20 mg once daily) for PAH and antiretroviral treatment (cART) including darunavir/cobicistat (800/150 mg once daily). Excessive exposure to bosentan due to drug interactions between bosentan and darunavir/cobicistat was suspected. Bosentan was replaced by ambrisentan, with progressive improvement in her clinical condition. Pre- and postdialyzer cocentrations of ambrisentan in plasma were determined and hemodialysis extraction ratio for ambrisentan was 2%. CONCLUSIONS: Our results suggest that hemodialysis results in minimal ambrisentan removal, and therefore no specific ambrisentan dosage adjustment seems to be required in ESRD patients undergoing hemodialysis.

Influence of dialysate Ca concentrations on the therapeutic effects of etelcalcetide with concomitant drugs in patients with secondary hyperparathyroidism.

AIM: Secondary hyperparathyroidism (SHPT), a complication of haemodialysis, is commonly treated with calcimimetics. The impact of dialysates containing different calcium (Ca) concentrations on clinical efficacy of calcimimetics are unclear. We examined whether dialysate Ca concentrations influence the efficacy and dosing of etelcalcetide with concomitant drugs. METHODS: We performed post hoc analyses of a 52-week, open-label, multicentre study of etelcalcetide in Japanese SHPT patients to determine whether dialysate Ca influences the therapeutic effects of etelcalcetide with concomitant drugs. We evaluated the differences in serum intact parathyroid hormone (iPTH), corrected Ca (cCa) and phosphate levels among three dialysate Ca concentration groups (2.5, 2.75 or 3.0 mEq/L Ca). Tartrate-resistant acid phosphatase 5b (TRACP-5b) and bone alkaline phosphatase (BAP) levels were also compared. Since the dialysate Ca concentration may influence dose adjustment, we assessed the etelcalcetide and concomitant drug doses. RESULTS: There were no clinically meaningful differences in iPTH, cCa and phosphate levels among the 2.5, 2.75 and 3.0 mEq/L groups (n = 34, 64 and 35, respectively) over 52 weeks. At Week 52, more than 82%, 71% and 67% of patients had iPTH, cCa and phosphate levels within target ranges (60-240 pg/mL, 8.4-10.0 mg/dL and 3.5-6.0 mg/dL, respectively) across the three groups. TRACP-5b and BAP levels decreased by Week 52 regardless of dialysate Ca. Changes in etelcalcetide and concomitant drug doses were generally similar in each group. CONCLUSION: The efficacy and dosing of etelcalcetide with concomitant drugs were essentially unaffected by the dialysate Ca concentration. Patients showed improvements in bone hypermetabolism during treatment.

Effect of hemodialysis on extracellular vesicles and circulating submicron particles.

BACKGROUND: Although hemodialysis is a highly effective treatment for diffusive clearance of low molecular weight uremic toxins, its effect on circulating extracellular vesicles and submicron particles is less clear. The purpose of this study was to examine the impact of hemodialysis on circulating levels of submicron particles. METHODS: Plasma samples from patients were collected immediately before and after the mid-week hemodialysis session. Total submicron particles were assessed by nanoparticle tracking analysis and levels of endothelial (CD144+), platelet (CD41+), leukocyte (CD45+), and total (Annexin V+) membrane microparticles (MPs) were assessed by flow cytometry. RESULTS: Total submicron particle number was significantly lower post-dialysis with reductions in particles < 40 nm, 40-100 nm, and 100-1000 nm in size. Circulating annexin V+ MPs, platelet MPs, leukocyte MPs, and endothelial MPs were all reduced following dialysis. Assessment of protein markers suggested that extracellular vesicles were not present in the dialysate, but rather adsorbed to the dialysis membrane. CONCLUSIONS: In summary, hemodialysis is associated with reductions in circulating submicron particles including membrane MPs. Accordingly, there may be significant interdialytic variation in circulating submicron particles. Investigators interested in measuring extracellular vesicles in patients undergoing hemodialysis should therefore carefully consider the timing of biosampling.

Effect of Dialysate Glucose Concentration on Hepcidin Clearance in Maintenance Hemodialysis Patients.

INTRODUCTION: Hepcidin is a key regulator of iron homeostasis, takes part in pathophysiology of anemia and cardiovascular disease in maintenance hemodialysis (MHD) patients. The aim of this study was to compare the effect of glucose-free and glucose-containing dialysate on the clearance of hepcidin-25 during a hemodialysis (HD) session and discuss its potential mechanism in MHD patients. METHODS: In a longitudinal interventional study of 30 stable MHD patients without diabetes, we measured serum hepcidin-25 and plasma catecholamines (adrenaline, noradrenaline, and dopamine) during HD session using glucose-free dialysate and then switched to 5.55 mmol/L glucose-containing dialysate. One-way analysis of variance (ANOVA) was used to identify the effect of two dialysates on the intra-dialysis changes of hepcidin-25 and catecholamines. Spearman and Pearson correlation coefficients were performed to detect the relationships between hepcidin-25 and catecholamines. RESULTS: Glucose-free dialysate achieved a greater reduction of hepcidin-25 than 5.55 mmol/L glucose-containing dialysate in a single bicarbonate HD session [-8.43 (-15.44 to -1.42) vs. 0.46 (-6.09 to 7.00) %, P < .05]. The intra-dialysis changes of catecholamines showed no significant differences between the two dialysates. The serum hepcidin-25 levels were positively associated with plasma catecholamines levels at pre-, intra- and post-HD (R = 0.22~0.62 with P < .05). CONCLUSIONS: Our findings suggest that glucose-containing dialysate might up-regulate hepcidin-25 synthesis through activation of the sympathetic nervous system or oxidative stress, possibly mediated by increased production of catecholamines. Adequately designed studies are needed to confirm and reveal the mechanisms of dialysate glucose concentration on hepcidin-25 kinetics during HD sessions.

Extended Experience in the Use of Antibiotic Lock for Eradication of Biofilm Bacteria on Tenckhoff Catheter.

Whilst antibiotic lock is effective to eradicate biofilm bacteria on hemodialysis catheters, this adjunctive method has scarcely been tested in peritoneal dialysis (PD) patients. After our previous successful experience of its use to salvage two Tenckhoff catheters, we encountered another patient with problematic biofilm-associated PD peritonitis who strongly refused catheter removal. As a result, antibiotic lock was given once daily, initially, with continuation of the usual PD schedule. However, relapsing peritonitis could not be prevented until we administered antibiotic lock without dialysate in the abdomen, which led to successful eradication of biofilm bacteria. To investigate the significance of having "dry abdomen" during antibiotic lock treatment, we injected an equivalent amount of contrast into the Tenckhoff catheter under fluoroscopy. We observed that the catheter lock solution could be retained over a long period of time only with "dry abdomen," whereas rapid dissipation of the lock solution occurred in the presence of dialysate. We concluded that whilst antibiotic lock in a once-daily regimen can be highly effective against biofilm bacteria on a Tenckhoff catheter, it is essential to withhold PD exchanges during the dwell of antibiotic lock to prevent it from dissolving into the surrounding dialysate.

High Dialysate Calcium Concentration is Associated with Worsening Left Ventricular Function.

Dialysate calcium concentration (d[Ca]) might have a cardiovascular impact in patients on haemodialysis (HD) since a higher d[Ca] determines better hemodynamic tolerability. We have assessed the influence of d[Ca] on global longitudinal strain (GLS) by two-dimensional echocardiography using speckle-tracking imaging before and in the last hour of HD. This is an observational crossover study using d[Ca] 1.75 mmol/L and 1.25 mmol/L. Ultrafiltration was the same between interventions; patients aged 44 ± 13 years (N = 19). The 1.75 mmol/L d[Ca] was associated with lighter drop of blood pressure. Post HD serum total calcium was higher with d[Ca] 1.75 than with 1.25 mmol/L (11.5 ± 0.8 vs. 9.1 ± 0.5 mg/dL, respectively, p < 0.01). In almost all segments strain values were significantly worse in the peak HD with 1.75 mmol/L d[Ca] than with 1.25 mmol/L d[Ca]. GLS decreased from -19.8 ± 3.7% at baseline to -17.3 ± 2.9% and -16.1 ± 2.6% with 1.25 d[Ca] and 1.75 d[Ca] mmol/L, respectively (p < 0.05 for both d[Ca] vs. baseline and 1.25 d[Ca] vs. 1.75 d[Ca] mmol/L). Factors associated with a worse GLS included transferrin, C-reactive protein, weight lost, and post dialysis serum total calcium. We concluded that d[Ca] of 1.75 mmol/L was associated with higher post dialysis serum calcium, which contributed to a worse ventricular performance. Whether this finding would lead to myocardial stunning needs further investigation.