Effect of Low-Sodium versus Conventional Sodium Dialysate on Left Ventricular Mass in Home and Self-Care Satellite Facility Hemodialysis Patients: A Randomized Clinical Trial.

BACKGROUND: Fluid overload in patients undergoing hemodialysis contributes to cardiovascular morbidity and mortality. There is a global trend to lower dialysate sodium with the goal of reducing fluid overload. METHODS: To investigate whether lower dialysate sodium during hemodialysis reduces left ventricular mass, we conducted a randomized trial in which patients received either low-sodium dialysate (135 mM) or conventional dialysate (140 mM) for 12 months. We included participants who were aged >18 years old, had a predialysis serum sodium ≥135 mM, and were receiving hemodialysis at home or a self-care satellite facility. Exclusion criteria included hemodialysis frequency >3.5 times per week and use of sodium profiling or hemodiafiltration. The main outcome was left ventricular mass index by cardiac magnetic resonance imaging. RESULTS: The 99 participants had a median age of 51 years old; 67 were men, 31 had diabetes mellitus, and 59 had left ventricular hypertrophy. Over 12 months of follow-up, relative to control, a dialysate sodium concentration of 135 mmol/L did not change the left ventricular mass index, despite significant reductions at 6 and 12 months in interdialytic weight gain, in extracellular fluid volume, and in plasma B-type natriuretic peptide concentration (ratio of intervention to control). The intervention increased intradialytic hypotension (odds ratio [OR], 7.5; 95% confidence interval [95% CI], 1.1 to 49.8 at 6 months and OR, 3.6; 95% CI, 0.5 to 28.8 at 12 months). Five participants in the intervention arm could not complete the trial because of hypotension. We found no effect on health-related quality of life measures, perceived thirst or xerostomia, or dietary sodium intake. CONCLUSIONS: Dialysate sodium of 135 mmol/L did not reduce left ventricular mass relative to control, despite improving fluid status. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: The Australian New Zealand Clinical Trials Registry, ACTRN12611000975998.

Dialysate Sodium: Rationale for Evolution over Time.

Oligo-anuric individuals receiving hemodialysis (HD) are dependent on the dialysis machine to regulate sodium and water balance. Interest in adjusting the dialysate sodium concentration to promote tolerance of the HD procedure dates back to the early years of dialysis therapy. Evolution of dialysis equipment technologies and clinical characteristics of the dialysis population have prompted clinicians to increase the dialysate sodium concentration over time. Higher dialysate sodium concentrations generally promote hemodynamic stabilization and reduce intradialytic symptoms but often do so at the expense of stimulating thirst and promoting volume expansion. The opposite may be true for lower dialysate sodium concentrations. Observational data suggest that the association between dialysate sodium and outcomes may differ by serum sodium levels, supporting the trend toward individualization of the dialysate sodium prescription. However, lack of randomized controlled clinical trial data, along with operational safety concerns related to individualized dialysate sodium prescriptions, have prevented expert consensus regarding the optimal approach to the dialysate sodium prescription.

Is Hemodialysis Patient Survival Dependent upon Small Solute Clearance (Kt/V)?: If So How Can Kt/V be Adjusted to Prevent Under Dialysis in Vulnerable Groups?

Small solute clearance achieved during a single hemodialysis session has been traditionally evaluated by urea clearance, normalized for total body water (Kt/Vurea) for more than 30 years. By consensus, the target sessional KtVurea for thrice weekly treatments has been increased from 0.9 to 1.2 over the years. Although this is supported by observational studies, there is a fundamental lack of prospective studies to support this threshold target. In clinical practice achieving sessional Kt/Vurea targets are most closely followed in the US. Yet there appears to be a paradox in that by following Kt/Vurea targets in the US hemodialysis patient survival is better for men and the obese, the opposite of what is seen in the general population. Delivery of a lower dose of hemodialysis to women and smaller men can be explained by underestimation of total body water. The advent of bioimpedance techniques which can measure both body water and body composition will potentially allow a rescaling and re-evaluation of the importance of small solute clearances (Kt/Vurea) in the hemodialysis patient population.

Phosphate Binders and Targets Over Decades: Do We have it Right Now?

In advanced renal disease, the kidney is unable to maintain phosphate balance due to decreased urinary excretion as well as the imbalance of the bone metabolic axis. It is well established that hyperphosphatemia is associated with increased cardiovascular events and mortality in patients with chronic kidney disease (CKD). However, there are no randomized controlled trials that demonstrate a clear benefit on hard outcomes in lowering serum phosphate levels to recommended targets in the CKD or dialysis population. In addition, while calcium-based phosphate binders have traditionally been the standard of care in the treatment of hyperphosphatemia, data regarding the increased risk of vascular mineralization continues to emerge. Clinicians continue to search for new phosphate-lowering therapies as well as investigate novel nutritional perspectives. The Kidney Disease: Improving Global Outcomes is currently revising the guidelines on phosphate goals in CKD. This review will outline the history of phosphate targets and phosphate binders, and explore innovative phosphate-lowering therapies. Based on current data, clinicians moving forward should continue to treat end-stage renal disease patients with hyperphosphatemia based on individual risk factors for vascular mineralization.

Dialysate Composition for Hemodialysis: Changes and Changing Risk.

Dialysate composition is a critical aspect of the hemodialysis prescription. Despite this, trial data are almost entirely lacking to help guide the optimal dialysate composition. Often, the concentrations of key components are chosen intuitively, and dialysate composition may be determined by default based on dialysate manufacturer specifications or hemodialysis facility practices. In this review, we examine the current epidemiological evidence guiding selection of dialysate bicarbonate, calcium, magnesium, and potassium, and identify unresolved issues for which pragmatic clinical trials are needed.

Electrolytes-Enriched Hemodiafiltration Solutions for Continuous Renal Replacement Therapy in Acute Kidney Injury: A Crossover Study.

AIMS: To evaluate the capability of an electrolytes-enriched solution to prevent metabolic disorders during continuous veno-venous hemodiafiltration (CVVHDF). METHODS: Serum biochemistry and clinical tolerance were compared during CVVHDF treatments with an electrolyte-enriched (Phoxilium) or standard solutions in 10 acute renal failure patients. RESULTS: As compared to standard fluids, serum potassium and phosphate levels were maintained in the normal range with Phoxilium without any supplementation but total serum calcium levels were significantly lower. Bicarbonatemia was slightly higher (24-26 vs. 21.5-24.5 mmol/l, p < 0.05) with conventional solutions and was associated with a significant increased level of pH (>7.44). Despite the absence of glucose in the Phoxilium solution, blood glucose levels and glucose supplementation were similar between treatments. Clinical tolerance and efficiency of CVVHDF sessions were comparable. CONCLUSION: Phoxilium effectively prevented hypophosphatemia and hypokalemia during CVVHDF. It was, however, associated with a slight metabolic acidosis and hypocalcemia compared with conventional solutions.

Falsely Elevated Glucose Concentrations in Peritoneal Dialysis Patients Using Icodextrin.

BACKGROUND: Peritoneal dialysis (PD) is used as an alternative to hemodialysis in end-stage renal disease (ESRD). Icodextrin has been used as a hyperosmotic agent in PD. The aim of the study was to assess two different point-of-care testing (POCT) glucose strips, affected and not affected by icodextrin, with serum glucose concentrations of the patients using and not using icodextrin. METHODS: Fifty-two chronic ambulatory peritoneal dialysis (CAPD) patients using icodextrin (Extraneal®) and 20 CAPD patients using another hyperosmotic fluid (Dianeal®) were included in the study. Duplicate capillary and serum glucose concentrations were measured with two different POCT glucose strips and central laboratory hexokinase method. Assay principles of glucose strips were based on glucose dehydrogenase-pyrroloquinoline quinone (GDH-PQQ) and a mutant variant of GDH (Mut Q-GDH). The results of both strips were compared with those of hexokinase method. RESULTS: Regression equations between POCT and hexokinase methods in icodextrin group were y = 2.55x + 1.12 mmol/l and y = 1.057x + 0.16 mmol/l for the GDH-PQQ and Mut Q-GDH methods, respectively. The mean difference between the results of hexokinase and those of GDH-PQQ and Mut Q-GDH in icodextrin group was 3.41 ± 1.56 and 0.72 ± 0.64 mmol/l, respectively. However, the mean differences were found much lower in the control group; 0.64 mmol/l for GDH-PQQ and 0.52 mmol/l for Mut Q-GDH. CONCLUSION: Compared to GDH-PQQ, glucose strips of Mut Q-GDH correlated better with hexokinase method in PD patients using icodextrin.

Buffer-dependent regulation of aquaporin-1 expression and function in human peritoneal mesothelial cells.

BACKGROUND: Biocompatible peritoneal dialysis fluids (PDF) are buffered with lactate and/or bicarbonate. We hypothesized that the reduced toxicity of the biocompatible solutions might unmask specific effects of the buffer type on mesothelial cell functions. METHODS: Human peritoneal mesothelial cells (HPMC) were incubated with bicarbonate (B-)PDF or lactate-buffered (L-)PDF followed by messenger RNA (mRNA) and protein analysis. Gene silencing was achieved using small interfering RNA (siRNA), functional studies using Transwell culture systems, and monolayer wound-healing assays. RESULTS: Incubation with B-PDF increased HPMC migration in the Transwell and monolayer wound-healing assay to 245 ± 99 and 137 ± 11% compared with L-PDF. Gene silencing showed this effect to be entirely dependent on the expression of aquaporin-1 (AQP-1) and independent of AQP-3. Exposure of HPMC to B-PDF increased AQP-1 mRNA and protein abundance to 209 ± 80 and 197 ± 60% of medium control; the effect was pH dependent. L-PDF reduced AQP-1 mRNA. Addition of bicarbonate to L-PDF increased AQP-1 abundance by threefold; mRNA half-life remained unchanged. Immunocytochemistry confirmed opposite changes of AQP-1 cell-membrane abundance with B-PDF and L-PDF. CONCLUSIONS: Peritoneal mesothelial AQP-1 abundance and migration capacity is regulated by pH and buffer agents used in PD solutions. In vivo studies are required to delineate the impact with respect to long-term peritoneal membrane integrity and function.

The effect of bicarbonate peritoneal dialysis solutions on cardiac structural and functional alterations.

BACKGROUND: The systemic effects of absorbed glucose degradation products (GDPs) contained within the conventional peritoneal dialysis solutions (cPDS) are largely unknown, while they appear to affect also cardiovascular function. The aim of the present study was to evaluate if the new bicarbonate-based less bioincompatible new peritoneal dialysis solutions ameliorate cardiac structural and functional status as well as the peritoneal net ultrafiltration (UF) and residual renal function. Patients and methods. This is a single centre, prospective cohort study of 12 stable continues ambulatory peritoneal dialysis patients (four women, eight men) mean aged 71.3 ± of 6.01 years and mean peritoneal dialysis (PD) duration 31.9 ± 21.33 months, treated with the usual cPDS (Medital Bieffe®, with increased GDPs, low pH and lactate as a buffer system). The patients changed for a 6-month period to the newer biocompatible PD solutions (BicaVera, Fresenius® low GDPs, normal pH, bicarbonate as a buffer) and at the end of this time, they returned to their previous schema of conventional solutions, for another 6 months. During the study period, the left ventricle ejection fraction (EF), left ventricle end systolic and diastolic diameter (LVESD, LVEDD), left ventricle mass index (LVMI), glyoxal serum and peritoneal concentrations, net UF and 24 h urine volume were repeatedly estimated: at the beginning of the study (T0), after 6 months with the biocompatible solutions (T6) and at the end of study (T12), after the 6-month period using again the cPDS. The UF volume and glyoxal concentrations were estimated at end of a 4 h dwell of an exchange with a PD solution of 2.27 % glucose. RESULTS: There was a statistically significant difference between the mean levels of EF, LVESD, LVEDD, LVMI, UF and glyoxal serum and peritoneal concentrations at the beginning (T0) and in the middle of the study (T6) (for serum glyoxal P = 0.005, for peritoneal glyoxal P = 0.0004, for EF P = 0.0004, for LVESD P = 0.023, for LVEDD P = 0.002, for LVMI P = 0.0005 and for UF P = 0.005) as well as between the mean values in the middle (T6) and at the end of the evaluation period (T12) (for serum glyoxal P = 0.043, for peritoneal glyoxal P = 0.006, for EF P = 0.00009, for LVESD P = 0.012, for LVEDD P = 0.00014, for LVMI P = 0.00013 and for UF P = 0.048). On the other hand, no statistically significant difference was revealed between the T0 and T12 mean values of glyoxal (serum and peritoneal), EF, LVESD, LVEDD, LVMI and UF. During the study period, there was no statistically significant difference in daily urine volume and glomerular filtration rate. CONCLUSIONS: The use of bicarbonate-based PDS induced a statistically significant improvement of left ventricle structure (LVESD, LVEDD and LVMI) and functional (EF) indicators. These beneficial effects on left ventricle in combination with the improvement of net UF may designate a protective role of the newer bicarbonate peritoneal solutions on cardiovascular function morbidity and mortality risk of PD patients.

Evaluation of three different methods to prevent dialyzer clotting without causing systemic anticoagulation effect.

Thrombogenicity is one of the most important biocompatibility markers of artificial material. Anticoagulation is commonly used to reduce thrombogenicity of the extracorporeal circuit (ECC) during intermittent hemodialysis (IHD). In some situations, systemic anticoagulants are contraindicated. The aim of our study was to compare thrombogenicity parameters during IHD with three different methods without a systemic anticoagulation effect. In a prospective, randomized, and crossover study, we examined 10 stable patients during IHD with (i) regular saline flushes of ECC; (ii) regional citrate anticoagulation (RCA); and (iii) AN69 ST membrane after ECC priming according to the manufacturer's recommendations. Before IHD and after 10, 60, 120, and 240 min, we measured the platelet count and the plasma concentrations of platelet factor 4 (PF4) and thrombin/antithrombin complexes (TAT). All 10 procedures with RCA were successfully completed after 4 h, whereas 6/10 procedures with saline flushes and 5/10 procedures with AN69 ST were finished prematurely because of clotting (P < 0.05). The TAT production was significantly increased during saline flushes and AN69 ST compared with RCA (P < 0.05). Platelet activation demonstrated by rising PF4 was present during all three methods. Markers of coagulation cascade activation were progressively increasing during IHD with RCA, saline flushes, and AN69 ST. The activation was significantly lower during RCA, and according to thrombogenicity, RCA is the most effective among compared anticoagulation methods.

Effects of different levels of endotoxin contamination on inflammatory cytokine production by peripheral blood mononuclear cells after high-flux hemodialysis.

BACKGROUND: In Thailand, dialysate endotoxin contamination levels vary from less than 0.001 to 2.0 EU/ml. This difference has prompted an investigation on the production of proinflammatory cytokines and counter-inflammatory mediators of peripheral blood mononuclear cells (PBMCs) after high-flux dialysis. METHODS: Patients from four hemodialysis (HD) centers who met the inclusion/exclusion criteria were enrolled into the study. PBMCs were isolated by Ficoll density gradient centrifugation and cultured. Supernatants were tested for interleukin 6 (IL-6), IL-1ß and IL-1 receptor antagonist (IL-1Ra) concentration by ELISA. RESULTS: HD centers 1, 2, 3 and 4 had mean dialysate endotoxin contamination levels of 0.001, 0.026, 0.558 and 1.960 EU/ml, respectively. HD center 4 had the highest levels of IL-6 (1,052.3 ± 240.7 pg/10(6) PBMCs), IL-1ß (1,297.1 ± 334.6 pg/10(6) PBMCs) and IL-1Ra (2,713.4 ± 1,255.3 pg/10(6) PBMCs). There were no significant differences in cytokine production between HD centers 1 and 2. CONCLUSION: Our study showed that ultrapure dialysate can minimize the risk of stimulating inflammatory cells. Ultrapure dialysate may prevent or delay endotoxin exposure-related complications.

Haemodynamic consequences of changing potassium concentrations in haemodialysis fluids.

BACKGROUND: A rapid decrease of serum potassium concentrations during haemodialysis produces a significant increase in blood pressure parameters at the end of the session, even if effects on intra-dialysis pressure are not seen. Paradoxically, in animal models potassium is a vasodilator and decreases myocardial contractility. The purpose of this trial is to study the precise haemodynamic consequences induced by acute changes in potassium concentration during haemodialysis. METHODS: In 24 patients, 288 dialysis sessions, using a randomised single blind crossover design, we compared six dialysate sequences with different potassium profiles. The dialysis sessions were divided into 3 tertiles, casually modulating potassium concentration in the dialysate between the value normally used K and the two cut-off points K+1 and K-1 mmol/l. Haemodynamics were evaluated in a non-invasive manner using a finger beat-to-beat monitor. RESULTS: Comparing K-1 and K+1, differences were found within the tertiles regarding systolic (+5.3, +6.6, +2.3 mmHg, p < 0.05, < 0.05, ns) and mean blood pressure (+4.3, +6.4, -0.5 mmHg, p < 0.01, < 0.01, ns), as well as peripheral resistance (+212, +253, -4 dyne.sec.cm-5, p < 0.05, < 0.05, ns). The stroke volume showed a non-statistically-significant inverse trend (-3.1, -5.2, -0.2 ml). 18 hypotension episodes were recorded during the course of the study. 72% with K-1, 11% with K and 17% with K+1 (p < 0.01 for comparison K-1 vs. K and K-1 vs. K+1). CONCLUSIONS: A rapid decrease in the concentration of serum potassium during the initial stage of the dialysis-obtained by reducing the concentration of potassium in the dialysate-translated into a decrease of systolic and mean blood pressure mediated by a decrease in peripheral resistance. The risk of intra-dialysis hypotension inversely correlates to the potassium concentration in the dialysate. TRIAL REGISTRATION NUMBER: NCT01224314.

Risk factors for developing encapsulating peritoneal sclerosis in the icodextrin era of peritoneal dialysis prescription.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is an uncommon but potentially devastating complication of peritoneal dialysis. We have observed an increased incidence in our centre over the last few years. METHODS AND PATIENTS: To look at potential risk factors for developing EPS, we reviewed 39 cases diagnosed between 2000 and 2009 and compared these with a control group of 71 patients who had been treated by peritoneal dialysis for a minimum of 4 years. Both groups extensively used icodextrin, >80% of patients. RESULTS: Both groups had been treated by peritoneal dialysis for a similar time: EPS median 54 months (46-87.5), compared to controls 70 (54-79.5). However, more of the EPS group were treated with peritoneal cyclers (75% vs 46%, X(2) = 6.86, P = 0.009) and prescribed more peritoneal dialysate 14.2 l/day +/- 0.7 vs 10.8 +/- 0.5, P < 0.0001. Although both groups were fast transporters, those with EPS had higher D/P creatinine ratios on peritoneal equilibration testing, 0.84 +/- 0.1 vs 0.77 +/- 0.1, P < 0.05, and lower peritoneal test ultrafiltration volumes, 193 +/- 26 ml vs 283 +/- 21 ml, P < 0.05. Discussion. The patients in the EPS group were faster transporters, with lower peritoneal equilibration and 24-h ultrafiltration volumes, and were exposed to greater volumes of peritoneal dialysates compared to peritoneal dialysis vintage controls.

Effects of icodextrin peritoneal dialysis solution on the peritoneal membrane in the STZ-induced diabetic rat model with partial nephrectomy.

BACKGROUND: Application of icodextrin-based peritoneal dialysis fluid (PDF) provides a potential benefit in patients with diabetes and end-stage renal failure treated with continuous ambulatory peritoneal dialysis (CAPD) because of better ultrafiltration capacity and avoidance of direct glucose exposure. We examined the effect of glucose and icodextrin-based PDF on histological alterations of peritoneal membranes. METHODS: Thirty-two male Wistar rats were divided into four groups: control Wistar rats with non-treated (n = 8), streptozotocin (STZ)-induced diabetic rats with 5/6 kidney ablation (n = 8), STZ-induced diabetic rats with 5/6 kidney ablation injected with a standard lactate-buffered 4.25% glucose-based PDF (Dianeal; n = 8) and STZ-induced diabetic rats with 5/6 kidney ablation injected with 7.5% icodextrin-based PDF (Extraneal; n = 8). Intraperitoneal injection was performed once daily with an instillation volume of 20 ml per injection during 8 weeks. RESULTS: Chronic high-glucose-based PDF exposure resulted in increased vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) expression, accumulation of advanced glycation end-products (AGEs), and up-regulation of the receptor for AGE (RAGE), which were ameliorated in the icodextrin-based PDF group. The peritoneal damages, such as neoangiogenesis and submesothelial fibrosis, were significantly reduced in icodextrin-based PDF compared to high-glucose-based PDF. CONCLUSIONS: Long-term in vivo exposure to high glucose-based PDF promotes the fibrosing process of peritoneal membranes. Icodextrin-based PDF may be helpful in slowing the PDF-induced deterioration of peritoneal function and prolonging the use of peritoneal dialysis in patients with diabetes.

Attenuated cardiac function degradation in ex vivo pig hearts.

Isolated hearts offer the opportunity to evaluate heart function, treatments, and diagnostic tools without in vivo factor interference. However, the early loss of cardiac function and edema occur over time and do limit the duration of the experiment. This research focuses on delaying these limitations using optimal blood control. This study examines whether blood conditioning by means of the combination of blood predilution and hemodialysis can significantly reduce cardiac function degradation. Slaughterhouse porcine hearts were revived in the PhysioHeart™ platform to restore physiological cardiac performance. Twelve hearts were divided into a control group and a dialysis group; in the latter group, hemodialysis was attached to the blood reservoir. Cardiac hemodynamics and blood parameters were recorded and evaluated. Blood conditioning significantly reduced the loss of cardiac pump function (control group vs dialysis group, -14.9 ± 6.3%/h vs -9.7 ± 2.7%/h) and loss of cardiac output (control group vs dialysis group, -11.8 ± 3.4%/h vs -5.9 ± 2.0%/h). Hemodialysis resulted in physiological and stable blood parameters, whereas in the control group ions reached pathological values, while interstitial edema still occurred. The combination of blood predilution and hemodialysis significantly attenuated ex vivo cardiac function degradation and delayed the loss of cardiac hemodynamics. We hypothesized that besides electrolyte and metabolic control, the hemodialysis-accompanied increase in hematocrit resulted in improved oxygen transport. This could have temporarily compensated the deleterious effect of an increased oxygen-diffusion distance due to edema in the dialysis group and resulted in less progression of cell decay. Clinically validated measures delaying edema might improve the effectiveness of the PhysioHeart™ platform.

Biological effects of electrolyzed water in hemodialysis.

BACKGROUND/AIMS: The application of electrolyzed water (EW) at the cathode side to manufacture reverse osmosis (RO) water and hemodialysis (HD) solution can actually lead to less oxidative capacity in chemical terms. The present study examined the biological actions of this water on human polymorphonuclear leukocytes (PMNs), and the clinical feasibility of applying this technology to HD treatment. METHODS: RO water using EW (e-RO) exhibited less chemiluminescence in luminol-hydrogen peroxide and higher dissolved hydrogen levels (-99.0 ppb) compared with control RO water. The effects of e-RO on PMN viability were tested. HD using e-RO was performed for 12 consecutive sessions in 8 patients for the feasibility test. RESULTS: Basal cellular viability and function to generate superoxide radicals of PMNs were better preserved by e-RO application. In the clinical trial, reductions of blood pressure were noted, but no adverse events were observed. There were no changes in the blood dialysis parameters, although methylguanidine levels were significantly decreased at the end of study. CONCLUSION: The present study demonstrated the capacity of e-RO to preserve the viability of PMNs, and the clinical feasibility of applying this water for HD treatment. The clinical application of this technology may improve the bio-compatibility of HD treatment.

Citrate- vs. acetate-based dialysate in bicarbonate haemodialysis: consequences on haemodynamics, coagulation, acid-base status, and electrolytes.

BACKGROUND: A concentrate for bicarbonate haemodialysis acidified with citrate instead of acetate has been marketed in recent years. The small amount of citrate used (one-fifth of the concentration adopted in regional anticoagulation) protects against intradialyser clotting while minimally affecting the calcium concentration. The aim of this study was to compare the impact of citrate- and acetate-based dialysates on systemic haemodynamics, coagulation, acid-base status, calcium balance and dialysis efficiency. METHODS: In 25 patients who underwent a total of 375 dialysis sessions, an acetate dialysate (A) was compared with a citrate dialysate with (C+) or without (C) calcium supplementation (0.25 mmol/L) in a randomised single-blind cross-over study. Systemic haemodynamics were evaluated using pulse-wave analysis. Coagulation, acid-base status, calcium balance and dialysis efficiency were assessed using standard biochemical markers. RESULTS: Patients receiving the citrate dialysate had significantly lower systolic blood pressure (BP) (-4.3 mmHg, p < 0.01) and peripheral resistances (PR) (-51 dyne.sec.cm-5, p < 0.001) while stroke volume was not increased. In hypertensive patients there was a substantial reduction in BP (-7.8 mmHg, p < 0.01). With the C+ dialysate the BP gap was less pronounced but the reduction in PR was even greater (-226 dyne.sec.cm-5, p < 0.001). Analyses of the fluctuations in PR and of subjective tolerance suggested improved haemodynamic stability with the citrate dialysate. Furthermore, an increase in pre-dialysis bicarbonate and a decrease in pre-dialysis BUN, post-dialysis phosphate and ionised calcium were noted. Systemic coagulation activation was not influenced by citrate. CONCLUSION: The positive impact on dialysis efficiency, acid-base status and haemodynamics, as well as the subjective tolerance, together indicate that citrate dialysate can significantly contribute to improving haemodialysis in selected patients.

The mesothelium under the siege of dialysis solutions: old glucose, new glucose, and glucose-free osmotic agents.

Use of one bag of glucose peritoneal dialysis fluid (PDF) results in the development of a dose-related senescent mesothelial cell phenotype not linked to acidic pH or the presence of lactate buffer. This complication derives mostly from oxidative stress induced both by glucose itself and by glucose degradation products (GDPs). New glucose formulations are offered in dual- or three-chambered bags, keeping the glucose at a low pH. The result is a reduced presence but not complete elimination of GDPs. These formulations have the potential to slow injury to the peritoneal membrane. Icodextrin and amino-acid PDFs, used for one exchange daily, have advantages and drawbacks alike. Icodextrin offers excellent ultrafiltration, but on the other hand, mesothelial cells incubated with this osmotic agent show reduced viability and proliferation and DNA damage. These unwanted effects appear to result from a substantial degree of oxidative stress. An amino-acid-based PDF offers a positive nutritional effect; however its ultrafiltration capability is not higher than an equimolar 1.5% glucose solution. Amino-acid solution appears to be more biocompatible than glucose-based fluid. So far glucose PDF offered in a single-compartment bag is not a biocompatible solution for long-term peritoneal dialysis. Icodextrin does not appear to be more biocompatible than glucose. Amino-acid-based solution is less harmful to the mesothelium, but its usefulness is still limited.

Influence of the ionic dialysance monitor on Kt measurement in hemodialysis.

BACKGROUND: Ionic dialysance can provide accurate monitoring of dialysis dose during each hemodialysis session. Increasingly, hemodialysis machines incorporate devices that measure ionic dialysance, allowing the dialysis dose to be determined noninvasively in real time and in each session. Because Kt product was proposed as a measure of hemodialysis dose to avoid the reverse J-shaped curve between urea reduction ratio or Kt/V and mortality, we investigated whether ionic dialysance values and Kt measurements are affected by different ionic dialysance monitors (Diascan and online clearance monitoring [OCM]) and dialysis machines. STUDY DESIGN: Four-period crossover. SETTING & PARTICIPANTS: 31 adult long-term hemodialysis patients using 2 different ionic dialysance monitors in 4 dialysis machines: Diascan in Hospal Integra and Gambro AK-200 machines and OCM in Fresenius 4008S and 5008 machines. PREDICTORS: Ionic dialysance monitor and machine used in 4 hemodialysis sessions for each participant. OUTCOMES: Kt and Kt/V measured by using ionic dialysance and serum urea nitrogen. RESULTS: Mean values for initial and final ionic dialysance were similar for Integra and AK-200 machines, both measured by using Diascan, and for the 4008S and 5008 machines, both measured by using OCM; however, OCM values tended to be greater in the 4008S and 5008 machines. Kt measured in the 4008S and 5008 machines was greater (59.6 +/- 12 and 58.6 +/- 11 L, respectively) than with the Integra and AK-200 machines (53.4 +/- 11 and 53.8 +/- 11 L). Mean urea reduction ratio and Kt/V were 78.0% +/- 8% and 1.89 +/- 0.43 for Diascan monitors and 79.6% +/- 8% and 1.99 +/- 0.44 for OCM monitors, respectively (P < 0.01). Differences between monitors in Kt determination were caused in part by a real difference in dialysis effectiveness (6%) and in part by an intermethod difference (4%). Kt adjusted by Kt/V differences was recalculated, and because of good correlation between Diascan and OCM, we were able to apply a formula (Kt(OCM) = 1.08 Kt(Diascan) - 2; r =0.95) that allowed both Kt quantification methods to be compared. LIMITATIONS: Nonblinded nonrandomized small sample. CONCLUSIONS: Kt is a valid method for judging dialysis dose in real time by using ionic dialysance measurements. Adjustments to correct intermethod differences may be necessary to ensure generalizability among ionic dialysance monitors.

The influence of low dialysate sodium and glucose concentration on volume distributions in body compartments after haemodialysis: a bioimpedance analysis study.

BACKGROUND: Despite the developments in haemodialysis, there are still some difficulties in maintaining the haemodynamic stability. Bioimpedance analysis (BIA) has been proposed for the estimation of dry weight in haemodialysis patients. We aimed to investigate the effects of dialysate sodium and glucose contents on volume distribution in body compartments after haemodialysis by using BIA, a sensitive and reliable method. METHODS: Seventeen chronic haemodialysis patients [11 males, 6 females, mean age: 36.9 (18-64) years] were included in the study. Patients were evaluated in three periods. The patients (period 1-P1) underwent haemodialysis with dialysate of 200 mg/dL glucose and 140 mmol/dL sodium for 4.5 h in the middle session of the first week. At the beginning and the end of the session, haematocrit, vital parameters (blood pressure, pulse), ultrafiltrated volume, plasma osmolarity and plasma renin activity were recorded. Also multi-frequency bioelectric impedance analyses (Bodystat Quadscan 4000) were applied to all patients at 5, 50, 100 and 200 kHz, including the impedance index (Z200/Z5). In the second midweek session the same procedure was repeated with same glucose concentration and 135 mmol/dL sodium including dialysate (period 2-P2), and in the third week, it was performed with a dialysate that included 140 mmol/dL sodium and no glucose (period 3-P3). RESULTS: The change of the ratio of the intracellular volume to total body weight (ICV/TBW) at the beginning and the end of the session was same in all periods. However, there were significant differences in the change (after/before session) ratio for the extracellular volume/total body weight (ECV/TBW) in P2 compared to other periods (P values for P1-P2: <0.001 and P2-P3: 0.007). Likewise, the same was observed in the changes of impedance (P values for P1-P2: 0.08, P1-P3: 0.44 and P2-P3: 0.063). There was a significant increase of hypotensive events in P2 against the other periods (P = 0.001). CONCLUSION: Decreasing dialysate sodium concentration results in important haemodynamic changes but the lack of glucose in dialysate does not result in any changes in haemodynamic and inflammatory parameters. The changes in bioimpedance parameters are parallel to haemodynamic changes in the haemodialysis patients.