HAEMODIALYSIS TECHNIQUES AND ADEQUACY 1

Nephrology Dialysis Transplantation, May 2014

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HAEMODIALYSIS TECHNIQUES AND ADEQUACY 1

SP410 COMBINING RENAL CELLS AND MICRO- AND NANOTECHNOLOGIES: A NEW ROUTE TO THE DEVELOPMENT OF BIOARTIFICIAL PLATFORMS FOR IN VITRO TESTING DRUG NEPHROTOXICITY Anna Giovanna Sciancalepore Anna Giovanna Sciancalepore 1 Center for Biomolecular Nanotechnologies @unile, Arnesano (LE), Italy Fabio Sallustio Fabio Sallustio 2 University of Bari, Bari, Italy 3 University of Salento, Lecce, Italy 4 Consorzio Carso, Valenzano (Bari), Italy Salvatore Girardo Salvatore Girardo 5 National Nanotechnology Laboratory of Consiglio Nazionale Delle Ricerche, Arnesano (LE), Italy 6 Technische Universität Dresden, Dresden, Germany Laura Gioia Passione Laura Gioia Passione 1 Center for Biomolecular Nanotechnologies @unile, Arnesano (LE), Italy 3 University of Salento, Lecce, Italy 5 National Nanotechnology Laboratory of Consiglio Nazionale Delle Ricerche, Arnesano (LE), Italy Andrea Camposeo Andrea Camposeo 1 Center for Biomolecular Nanotechnologies @unile, Arnesano (LE), Italy 5 National Nanotechnology Laboratory of Consiglio Nazionale Delle Ricerche, Arnesano (LE), Italy Elisa Mele Elisa Mele 1 Center for Biomolecular Nanotechnologies @unile, Arnesano (LE), Italy Mirella Di Lorenzo Mirella Di Lorenzo 5 National Nanotechnology Laboratory of Consiglio Nazionale Delle Ricerche, Arnesano (LE), Italy 7 Istituto Italiano Di Tecnologia, Genoa, Italy Vincenzo Costantino Vincenzo Costantino 2 University of Bari, Bari, Italy Francesco Paolo Schena Francesco Paolo Schena 2 University of Bari, Bari, Italy 4 Consorzio Carso, Valenzano (Bari), Italy Dario Pisignano Dario Pisignano 1 Center for Biomolecular Nanotechnologies @unile, Arnesano (LE), Italy 3 University of Salento, Lecce, Italy 5 National Nanotechnology Laboratory of Consiglio Nazionale Delle Ricerche, Arnesano (LE), Italy Abstract Introduction and Aims: Different types of cells have been used for the development of potential bioartificial kidney devices. Recently, the reprogramming of adult cells to embryonic nephron progenitors (C.E.Hendry et al JASN 2013) and human embryonic stem cells differentiated to renal proximal tubular cells (K.Narayan et al KI 2013) have been used as potential building blocks for a bioartificial kidney. Here we propose the combination of adult renal progenitor/stem cells with different microfabrication and nanofabrication technologies to develop miniaturized, bioartificial proximal tubule-like platforms, which are very promising tools for next-generation bio-analytic assays and for studying the nephrotoxicity of drugs. The potentialities of these interdisciplinary, cross-cutting platforms for in-vitro testing of drugs are presented and discussed. Methods: Our class of devices is composed of overlapped elastomeric layers, embedding microfluidic connections, porous and functionalized membranes, and polymeric valves, as well as suitable pumps to control all the involved flows, besides living cells. All the tested experimental geometries are designed and realized to mimic the in vivo kidney structures, and specifically renal tubules. Employed microtechnologies include optical and soft lithography, and particular care is paid to ensure the biocompatibility of all the involved device surfaces. In the devices, living cells are placed in contact with functionalized membranes to tailor and control the transport of solutes. Results: The basement membrane of tubules is composed by several extracellular matrix proteins, we generally find that fibronectin promoted an enhanced proliferation of stem cells compared to other proteins. Various kinds of renal cells were used to test our devices. Then, the culture conditions and initial seeding concentration on-chip were optimized up to reaching confluence of cells. Working conditions, operating fluxes as well as fluidic connections were optimized to obtain functional bio-chips with polarized ARPCs. Solute transport across membranes was studied in detail, and found to be modulated by the embedded cells up to permeability values of the order of 0.5 µm/s. Conclusions: Bioartificial proximal-tubule like device platforms represent an interesting model for studying the nephrotoxicity of drugs by microfluidic approaches. The combination of cross-cutting technologies derived from complementary disciplines will certainly constitute a strategic pathway to implement novel bio-assays of remarkable nephrologic interest in the near future. SP411 STARTING DIALYSIS ON ONCE-WEEKLY SCHEDULE WITH SOFT, PRE-DILUTION HF OR HDF CAN PRESERVE RESIDUAL RENAL FUNCTION AND ALLOW LESS FREQUENT TREATMENT FOR YEARS, IN MANY ESRD PATIENTS Francesco Gaetano Casino Francesco Gaetano Casino 1 Nephrology Unit, Matera, Italy Salvatore Domenico Mostacci Salvatore Domenico Mostacci 1 Nephrology Unit, Matera, Italy Maria Di Carlo Maria Di Carlo 1 Nephrology Unit, Matera, Italy Andrea Sabato Andrea Sabato 1 Nephrology Unit, Matera, Italy Clelia Procida Clelia Procida 1 Nephrology Unit, Matera, Italy Abstract Introduction and Aims: Based on empirical observations, we hypothesized that less frequent Haemodialysis (HD) could preserve residual renal function (RRF). Accordingly, for decades, we have been trying to start maintenance HD on once-weekly schedule in almost every patient with significant RRF, soon increasing the frequency of treatment in the case of deterioration of RRF and Urinary Output (UO) or clinical status. More recently we have decided to start all new patients on once-weekly predilution HDF or HF. The aim of this study was to evaluate the impact of different initial dialysis schedules and/or modalities on RRF survival. Methods: We retrieved data of all ESRD patients started on HD at our Unit from January, 2000 to June, 2013, and followed-up for at least 6 months. The patients were divided into 3 groups (G), based on the initial schedule (the one present 2 months after the start) and/or modality of treatment: standard HD, 3 sessions per week (3HD/w, G1); HD once or twice weekly, (1HD/w, G2), and pre-dilution HDF or HF once weekly (1HDF/w, G3). For the sake of simplicity, 500 mL/day was arbitrarily set as the critical level of UO, so that, the RRF survival time, to be used with Kaplan-Meyer (KM) analysis, was computed as the time interval between the date of the 1st dialysis and that of the last measured UO equal or greater than 500 mL/day. Results: We found a total of 150 patients fulfilling the inclusion criteria. As shown in table 1, the main baseline patients' characteristics were similar for the 3 groups. The KM analysis showed a significant (Log Rank, p<0.001) difference among groups, with an impressive 2-year cumulative RRF survival of 89% for G3, vs 27% for G1, and 63% for G2 patients. The 3-year survival rate for G3 patients remained stable at 89%. Conclusions: Due to the observational nature of the study, the above results only suggest that starting HD on a less frequent schedule could allow a long RRF survival time, further prolonged by using HDF or HF. Interestingly, similar data showing a beneficial effect of twice-weekly HD on RRF survival have recently been published for a large group of Chineese patients. Such an effect is usually explained by less hypotensive episodes on 2HD/w vs 3HD/w patients. However, it is also possible that less frequent dialysis could be more biocompatible. Moreover, the associated higher BUN levels could maintain a beneficial osmotic diuresis. A soft HDF or HF, using low volume flows, ultrapure diialysate and very compatible membranes, would both avoid too low BUN levels and increase biocompatibility. While waiting for evidence-based new guide lines for dialysis start, we believe that everyone could safely test our approach by starting a few suitable patients on 1HDF or HF/w, being careful to increase the frequency on the basis of the observed GFR and UO (or interdialysis weight gain) values as well as clinical status, paying a particular attention to the control of biochemistries, ECF volume and blood pressure. We would stress that using the UKM-based incremental approach is not recommended because, due to the the erroneous assumption of equivalency between renal and dialytic clearance, it overestimates the dialysis needs, so that 1 HD/w would be nearly impossible. Moreover, as hypothesised above, a high efficient treatment could increase the RRF loss rate. Baseline patients characteristics and RRF survival by group  Age years Weight kg baseline GFR mL/min baseline Kt/V per session deltaGFR ml/min/y mean RRF survival months 2-y cum surv % G1 N=48 67±17 68±17 5.1±2.2 1.6±0.3 9±15 17±2 27±7 G2 N=80 69±15 63±12 6.0±2.0 1.5±0.3 3±5 49±5 63±6 G3 N=22 67±13 68±16 5.0±1.5 1.3±0.4 1±3 54±3 89±7   Age years Weight kg baseline GFR mL/min baseline Kt/V per session deltaGFR ml/min/y mean RRF survival months 2-y cum surv % G1 N=48 67±17 68±17 5.1±2.2 1.6±0.3 9±15 17±2 27±7 G2 N=80 69±15 63±12 6.0±2.0 1.5±0.3 3±5 49±5 63±6 G3 N=22 67±13 68±16 5.0±1.5 1.3±0.4 1±3 54±3 89±7  Baseline patients characteristics and RRF survival by group  Age years Weight kg baseline GFR mL/min baseline Kt/V per session deltaGFR ml/min/y mean RRF survival months 2-y cum surv % G1 N=48 67±17 68±17 5.1±2.2 1.6±0.3 9±15 17±2 27±7 G2 N=80 69±15 63±12 6.0±2.0 1.5±0.3 3±5 49±5 63±6 G3 N=22 67±13 68±16 5.0±1.5 1.3±0.4 1±3 54±3 89±7   Age years Weight kg baseline GFR mL/min baseline Kt/V per session deltaGFR ml/min/y mean RRF survival months 2-y cum surv % G1 N=48 67±17 68±17 5.1±2.2 1.6±0.3 9±15 17±2 27±7 G2 N=80 69±15 63±12 6.0±2.0 1.5±0.3 3±5 49±5 63±6 G3 N=22 67±13 68±16 5.0±1.5 1.3±0.4 1±3 54±3 89±7  SP412 MIDDLE MOLECULE REMOVAL IN HDF COMPARISON OF MID- VERSUS POST-DILUTION (MIDEMM STUDY) Caroline Créput Caroline Créput 1 AURA Centre Hemod Henri Kuntziger, Paris, France Raymond Vanholder Raymond Vanholder 2 University Hospital, Gent, Belgium Jean Claude Stolear Jean Claude Stolear 3 CHWaPi, Tournai, Belgium Gaëlle Lefrancois Gaëlle Lefrancois 4 ECHO, Nantes, France Melanie Hanoy Melanie Hanoy 5 CHU, Rouen, France Joelle Nortier Joelle Nortier 6 CUB Erasme, Bruxelles, Belgium Jacky Potier Jacky Potier 7 CH Public du Cotentin, Cherbourg, France Luisa Sereni Luisa Sereni 8 Bellco srl, Mirandola, Italy For The Midemm Study Group. For The Midemm Study Group. Abstract Introduction and Aims: Online hemodiafiltration (HDF) with high-volume substitution fluid is an optimal way to remove uremic substances ranging widely in molecular size from small to low molecular weight (MW). Post-dilution HDF is the most efficient infusion mode to obtain maximum clearance.Mid-dilution infusion is an interesting alternative that represents simultaneous pre- and post- dilution infusion modes and could be a highly effective technique to remove uremic toxins, avoiding the disadvantages of pre- and post-dilutional modes.The aim of this multicentric study was to compare mid-dilution (MID) with post-dilution HDF (POST) by evaluating their efficiency in removing different middle MW (MMW) and protein bound uremic toxins. Methods: We performed a cross-over study including 158 Patients from 21 centres. All patients were randomized in two different groups for three months: group A (1 month MID - 1 month POST -1 month MID) and group B (1 month POST- 1 month MID -1 month POST). 64 patients were excluded from the final analysis because of incomplete data. The reduction rate (RR) of middle and protein bound molecules were centrally determined from serum samples as well as the second generation Daugirdas Kt/Vd. Albumin loss was carried out for both groups.Unpaired t student test was performed using GraphPad prism version 4.00 for Windows. Results: The data of 94 (48 from group A and 46 from group B) patients (53M and 41F) were fully analysed. The median age was 70 (27-92) years and dialysis vintage was 47,2 (7,5÷454,6) months. No difference was found in the demographic characteristics and treatment parameters. 164 MID sessions and 161 POST sessions were analysed. A statistically significant difference in RR (%) was found for three MMW molecules: β-2 Microglobulin (β2M), Complement Factor D (CFD) and Retinol Binding protein (RBP). Values were 80,1±0,4 in POST vs 81,6±0,4 in MID (p=0,01) for β2M; 72,8±0,8 in POST vs 76,4±0,6 in MID (p=0,0003) for CFD and 24,1±0,9 in POST vs 30,0±0,8 in MID (p=0,003) for RBPThe other investigated molecules, ADMA, Homocystein, Leptin and Myoglobin, shown a better MID RR but it is not statistically significant.The reinfused volume was significantly higher in MID than in POST (average total volume of 43,63 L in MID vs 20,96 L in POST), but also the amount of reinfused volume in MID exchanged in its post dilution stage (estimated around the 2/3 as shown in Maduell publication) is significantly higher (28,8 L in MID vs 20,96 L in POST); this could explain the depuration capability of MID respect POST for the MMW molecules, indeed, was found a linear correlation (R2 0.83) between the delta differences in RR (RR Mid - RR Post) and MW of molecules (Figure 1). View largeDownload slide View largeDownload slide No significant differences between MID - and POST-dilution were observed for small MW molecules depuration (assessed by second generation daugirdas Kt/vd), neither for Albumin loss. Conclusions: MID is superior to remove MMW molecules as compared to POST. This very likely can be related to an higher total amount and efficiency of substituted volume obtained in the MID group as compared to the POST group. SP413 ECODIALYSIS: IS IT POSSIBLE TO DESIGN AN ECO-FRIENDLY SYSTEM? Martina Ferraresi Martina Ferraresi 1 University of Torino, Turin, Italy Amina Pereno Amina Pereno 2 Politecnico of Turin, Turin, Italy Marta Nazha Marta Nazha 1 University of Torino, Turin, Italy Silvia Barbero Silvia Barbero 2 Politecnico of Turin, Turin, Italy Giorgina B Piccoli Giorgina B Piccoli 1 University of Torino, Turin, Italy Abstract Introduction and Aims: Attention to the environmental impact is still limited in medicine. Chronic Hemodialysis produces about 600000 tons of plastic wastes per year. The economic crisis and the awareness of the ecosystem induced to focus attention on the lifespan of disposables,“from cradle to grave”. A new outlook is presently focussed on recycle, that is the subsequent start of new cycles leading to a “from cradle to cradle” model: a “new life” for the waste products (Fig 1). Aim of the study is an analysis of the disposables employed in chronic hemodialysis, for identifying strategies limiting the environmental impact and containing the costs. Methods: An analysis of the disposables employed on dialysis and of their "final destiny" (the grave) was performed in 3 subsequent bicarbonate dialysis sessions with 3 different dialysis machines. All disposables and packagings were photographed, classified, weighted and analyzed as for type of materials, possibility to recycle, contamination with blood or biological fluids. Results: Each dialysis session produces between 4 and 6 kg of wastes; it may be divided into about 2 Kg of residual fluids (to be discharged); 2 Kg of "contaminated" wastes (i.e. in contact with blood or fluids) and 2 kg of "non contaminated" wastes. The differentiation is crucial, as the weight of contaminated waste products is the main determinant of disposal cost (approximately 2 Euro/kg in Italy). Furthermore, each dialysis session produces between 0.9 and 1.4 kg of packaging (cardboard and plastic); this is usually discharged separately, but where this procedure is not followed, it adds considerably to the volume and weight of the final wastes.Therefore, a undifferentiated waste collection may produce over 6 kg of waste products per session; the cost (up to 12-14 Euros) corresponds to 20-40% of the cost of the disposables. While all the cardboard and paper wastes are readily recyclable, the plastic wastes (non contaminated) can theoretically enter a dedicated recycle process. In this regard, the wastes may be classified into "families" of different plastic materials, with different compatibility for joint recycling. However, in most of the cases the types of plastic components are not identifiable and separable.Further problems are related with:-Packaging oversize: the content of most of the packaging of dialysis materials occupies between 50 and 75% of the space, increasing costs (production, wastes, transportation).-Emptying: there are no automated systems for emptying residual fluids after the dialysis session.-Difficult separation of materials: many packages are laminated made of different components.-Difficult separation of contaminated material: there is no clear definition of "contaminated". Conclusions: Attention to the life cycle of the dialysis disposables may conjugate the attention to our planet, reducing the "mountain" of wastes produced every year; simple tasks, as careful emptying and differentiating between "contaminated" and "non contaminated" wastes may lead to a 20% saving of the costs of a dialysis session. Cooperation with the Industry is needed for designing recycling strategies in keeping with the modern "cradle to cradle" approach. View largeDownload slide View largeDownload slide SP414 SURFACE, A PARAMETER TO CONSIDER IN HIGH CONVECTION VOLUME HDF Alain Ficheux Alain Ficheux 1 RD – Néphrologie and Université Montpellier 1, EA7288, Montpellier, France Nathalie Gayrard Nathalie Gayrard 1 RD – Néphrologie and Université Montpellier 1, EA7288, Montpellier, France Flore Duranton Flore Duranton 1 RD – Néphrologie and Université Montpellier 1, EA7288, Montpellier, France Caroline Guzman Caroline Guzman 1 RD – Néphrologie and Université Montpellier 1, EA7288, Montpellier, France Ilan Szwarc Ilan Szwarc 2 Néphrologie Dialyse St Guilhem, Centre de Dialyse de Sète, Sète, France Johanna Bismuth -Mondolfo Johanna Bismuth -Mondolfo 2 Néphrologie Dialyse St Guilhem, Centre de Dialyse de Sète, Sète, France Philippe Brunet Philippe Brunet 3 Service de Néphrologie, Hôpital de La Conception – Université Aix-Marseille, Marseille, France Marie Françoise Servel Marie Françoise Servel 2 Néphrologie Dialyse St Guilhem, Centre de Dialyse de Sète, Sète, France Angel Argilés Angel Argilés 1 RD – Néphrologie and Université Montpellier 1, EA7288, Montpellier, France 2 Néphrologie Dialyse St Guilhem, Centre de Dialyse de Sète, Sète, France Abstract Introduction and Aims: Convection volume seems to be crucial to the survival benefits proposed for HDF. However, high convection requires increasing transmembrane pressure (TMP) which in turn may change the membrane's behaviour and dialyser's performances.We wanted to characterise the influence of membrane surface area on the physics and on the removal performances of high convection volume on-line post-dilutional HDF. Methods: Twelve stable dialysis patients were successively treated with Amembris® 1.8 m² and 2.3 m² dialysers, and two high convection flows, one (QUF-optimal) obtained while maintaining the dialysis setting at the maximum in vivo global ultrafiltration coefficient (GKD-UF max) and the other one at the maximum convection flow (QUF-max) limited only by the European Best Practice Guidelines (EBPG) (<30% blood flow / 300 mmHg of TMP) for 1 week each. Continuous sampling of spent dialysate was performed in all dialysis sessions and total mass of urea, creatinine, and total proteins were measured. SDS-PAGE scanning of the removed proteins and ELISA measurements of β-2-microglobulin (B2M), retinol binding protein, lambda light chains of immunoglobulins, α1-antitrypsin and albumin, were performed. Results: Increasing from QUF-optimal to QUF-max using the 1.8 m² dialyser resulted in frequent TMP alarms and only 33% of the sessions reached the prescribed convection volume. Increasing the dialyser's surface to 2.3 m² significantly decreased the number of alarms and increased the number of sessions reaching the aimed convection volume (100% at QUF-optimal and 79% at QUF-max). The total amount of urea removed was 545±43, 473±32 and 491±44,471±38 mmol/session in HDF with QUF-optimal and QUF-max respectively for the 1.8 and 2.3 m2 surface (NS). The corresponding Kt/V values were 1.77±0.05, 1.78±0.05 and 1.75±0.04, 1.75±0.05, (NS). Removal of low mol wt proteins (observed on SDS-PAGE pattern analysis) and particularly B2M did not change in the 4 different conditions (274±35, 290±35, 266±24 and 283±35 mg/session (NS)). High molecular weight proteins removal increased with convection, notably for albumin (from 386±57 to 793±158 with 1.8 m² and from 559±69 to 1052±178 mg/session with 2.3 m² (p<0.001). The highest albumin loss was observed with the larger dialyser at QUF-max (figure 2). View largeDownload slide View largeDownload slide View largeDownload slide View largeDownload slide Conclusions: Increasing membrane surface area diminished the number of alarms allowing a more frequent accomplishment of the prescribed convection volumes. However, the use of larger dialysers in a QUF-max situation, results in an increased albumin loss suggesting that when large dialysers are used a QUF-optimal setting seems more appropriate. SP415 SAFETY AND PERFORMANCE OF A HOME HAEMODIALYSIS DEVICE: RESULTS FROM THE FIRST IN-HUMAN STUDY WITH A NOVEL HOME HD SYSTEM Angelito Bernardo Angelito Bernardo 1 Baxter Healthcare, Deerfield, IL Jason Demers Jason Demers 2 Deka R & D Corp, Manchester, NH Audrey Hutchcraft Audrey Hutchcraft 1 Baxter Healthcare, Deerfield, IL Thomas C Marbury Thomas C Marbury 3 Orlando Clinical Research Center, Orlando, FL Marc Minkus Marc Minkus 1 Baxter Healthcare, Deerfield, IL Matthew Muller Matthew Muller 1 Baxter Healthcare, Deerfield, IL Ruth Stallard Ruth Stallard 1 Baxter Healthcare, Deerfield, IL Bruce Culleton Bruce Culleton 1 Baxter Healthcare, Deerfield, IL Abstract Introduction and Aims: Despite the clinical and humanistic benefits associated with high dose haemodialysis (short daily or frequent nocturnal HD), relatively few patients receive this therapy. Among the many stated barriers to the growth of high dose HD is the absence of a HD device designed for the patient as the user, a device with intrinsic safety features to mitigate risks associated with HD in the home environment, and a device with features that limit the burden on the patient when performing independent HD. Methods: We performed a first in-human, prospective, single arm clinical study with a novel HD device, Vivia (Baxter Healthcare, Deerfield, IL, USA). Unique features of the Vivia Haemodialysis System, including pneumatic blood pumps, infusion-quality dialysate, and extended use of the dialyser (2.1m2, polyethersulfone membrane) and blood set, were tested over 10 weeks (2-week stabilization period and 8-week evaluable period) at two clinical sites in the United States. Safety was assessed on all subjects who used Vivia at least once. Urea clearance was assessed using weekly standard Kt/V, values transformed from second generation estimates for single pool Kt/V. The association between fluid weight removed (as measured by the Vivia HD System) and weight change (determined using weigh scales) was measured for each treatment. Dialysate was sampled at a minimum of weekly for each subject throughout the study. Criteria for success was defined as a bacterial count of 0 CFU/mL and an endotoxin level of < 0.03 EU/mL, consistent with AAMI and ISO standards for dialysate for infusion. Results: Twenty-two subjects (mean age 51 years, 45% F) received 4 treatments per week for 10 weeks. Adverse events were similar to those expected for prevalent HD patients. Hypotension was the most common adverse event (2 events per 100 treatments). No deaths and no device-related serious adverse events occurred during the study. During the evaluable period, the mean (standard deviation) duration of each treatment was 3.8 (0.2) hours with a mean blood flow rate and dialysate flow rate of 357 (21) ml/min and 395 (9) ml/min, respectively. The mean weekly standard Kt/V urea was 2.97 (0.29). The association between fluid weight removed as measured by Vivia and weight change is shown in the figure (R2 0.97). The maximum number of uses from a single dialyser and blood set was 24. No decrement in urea clearance with multiple uses of a dialyser was observed. Of 272 dialysate samples obtained on Vivia devices in use during the study, endotoxin levels were less than 0.03 EU/ml and 72-hour culture results revealed no bacterial growth for all samples. Conclusions: This first in-human clinical study supports the safety and performance of a novel HD system. View largeDownload slide View largeDownload slide SP416 PILOT TRIAL ON IONIC STRENGTH HEMODIAFILTRATION, A NOVEL DIALYSIS TECHNIQUE FOR INCREASED PROTEIN BOUND TOXIN REMOVAL Detlef H Krieter Detlef H Krieter 1 University Hospital Würzburg, Würzburg, Germany Thomas Körner Thomas Körner 1 University Hospital Würzburg, Würzburg, Germany Eric Devine Eric Devine 2 Excorlab GmbH, Obernburg, Germany Marieke Rüth Marieke Rüth 2 Excorlab GmbH, Obernburg, Germany Joachim Jankowski Joachim Jankowski 3 Charité - Universitätsmedizin, Berlin, Germany Christoph Wanner Christoph Wanner 1 University Hospital Würzburg, Würzburg, Germany Horst-Dieter Lemke Horst-Dieter Lemke 2 Excorlab GmbH, Obernburg, Germany Abstract Introduction and Aims: Protein bound uremic toxins (PBT) are difficult to remove by conventional hemodialysis (HD). Aim of the present study was to demonstrate the clinical feasibility of a modified hemodiafiltration technique increasing the ionic strength in plasma to enhance the PBT removal. Methods: In a prospective, randomized, controlled trial enrolling 8 maintenance dialysis patients (NCT01923961), HD was compared with online predilution hemodiafiltration (HDF) and predilution HDF using an infusion fluid with increased NaCl concentration (HDFNaCl). Blood and dialysate flow rate (250 and 575 mL/min, resp.), treatment time (240 min), and high-flux dialyzer (PUREMA® H, 2.1 m²) were always identical. In both HDF modes, the infusion flow rate was 125 mL/min. In HDFNaCl, the infusate Na+ was adjusted to approach 240 mmol/L in blood before entering the dialyzer and dialysate Na+ was set at the technically feasible minimum of 130 mmol/L. Removal of free and total para-cresyl sulfate (pCS) and indoxyl sulfate (IS) was determined by plasma clearances (K), reduction ratio (RR), and mass in dialysate. Hemocompatibility was assessed by the time courses of white blood cells, platelets, hemolysis (free hemoglobin, LDH), complement C5a, and thrombin-antithrombin III (TAT). Na+ was monitored in both arterial and venous blood. Results: All treatments were well tolerated without any adverse event. Compared to HD and HDF, the RRs of free and total PBT were highest in HDFNaCl (free pCS, 66.5±14.4, 72.0±14.6 vs. 74.0±13.8 %; total pCS, 43.0±9.4, 42.9±14.3 vs. 46.0±12.9 %; free IS, 60.4±16.5, 68.4±8.2 vs. 72.6±6.1 %, (P=0.026); total IS, 47.8±10.3, 45.2±7.7 vs. 52.0±12.9 %). The same trend was seen for the PBT mass detected in dialysate (total pCS 352±234, 415±299 vs. 419±228 µmol; total IS 302±172, 280±145 vs. 350±171 µmol). The values for K were highly variable. No differences between the treatment modes were observed for the hemocompatibility parameters. In HDFNaCl, Na+ in blood entering the dialyzer was 232±7 mmol/L. In arterial blood, it slightly increased over time (0 min, 132±2 to 240 min, 136±3 mmol/L; P<0.001). Compared with HD, at 240 min, arterial (133±2 vs.136±3 mmol/L; P=0.032) and venous (136±3 vs. 140±3 mmol/L; P=0.01) Na+ was higher in HDFNaCl. Conclusions: Increased ionic strength HDF may enhance the removal of PBT without clinically and biochemically overt adverse effects. As the Na+ balance during dialysis is crucial, implementing effective HDFNaCl will require adjustment of the minimum dialysate Na+ setting, which was limited to 130 mmol/L with the standard online HDF equipment deployed. SP417 THE CLOSED LOOP CONTROL OF BLOOD VOLUME (BV) IN ON-LINE HEMODIAFILTRATION (OL-HDF) Alessandro Surace Alessandro Surace 1 Gambro Dasco SpA, Modena, Italy Paolo Rovatti Paolo Rovatti 1 Gambro Dasco SpA, Modena, Italy Denis Steckiph Denis Steckiph 2 Gambro Hospal SpA, Bologna, Italy Elena Mancini Elena Mancini 3 Policlinico Sant'Orsola-Malpighi, Bologna, Italy Antonio Santoro Antonio Santoro 3 Policlinico Sant'Orsola-Malpighi, Bologna, Italy Abstract Introduction and Aims: The closed loop control of BV (Hemocontrol) is a recognized strategy for reducing intradialysis hypotension. This system, till now, has been only used in conventional hemodialysis (HD). On the other hand many recent studies suggest that Hemodiafiltration (HDF) may have additive advantages in term of hemodynamic tolerance in comparison to HD. Thus the implementation of HC in post-dilution OL-HDF (HDF+HC) could combine the benefits of HC with those of the high-volume convective treatments. In the present study we were aimed at verifying performance and safety of HDF+HC in terms of dialysis efficiency and sodium balance. Methods: The integration of HC system in OL-HDF treatments was tested from May 2012 to May 2013 in a prospective randomized cross-over pilot study (SOCRATHE, NCT01582867). Six patients (4 male, 2 female, mean age 73 ± 12 years) were treated on 2 different modalities, HD+HC (control) and HDF+HC (intervention). For each modality 6 Run-In treatments without HC were executed, followed by 12 treatments with HC. Each patient acted as his/her own control. Pre and post session plasma Na+ concentrations (Nap, measured by ion selective sodium electrode), inter-dialytic weight gain (IDWG), blood pressures (BPs), dialysis dose (KT/V), relative BV changes (ΔBV%) and reported thirst scores (TS, Likert type scales from 5=never to 25=always thirsty) were collected. Eventual detrimental effects on treatment efficacy, due to the mutual interaction of HC system with OL-HDF therapy have been assessed. Results: The main results are summarized in Table 1. The infusion volume achieved in HDF+HC was comparable with the OL-HDF one (20.6±2.8 vs 20.2±3.9 l, p=0.845). Conclusions: HDF+HC therapy resulted safe and at least with the same performances of conventional HD+HC as concerns IDWG, BP values and ΔBV% (Figure 1). The HC system in HDF reached the desired final targets (ΔBV%, Total Weight Loss and patient sodium) with the same accuracy showed in HD. Dialysis dose was higher in HDF+HC treatments.Plasma sodium concentration resulted slightly higher in HDF+HC treatments (about 1 mmol/l for both initial and final Nap): however, this sodium difference is widely within the instrumentation accuracy and can be compensated modifying the HC equivalent conductivity (left unchanged during the study in both the modality). Hence, there are no sufficient evidences to suppose sodium retention effect when combining HC and OL-HDF. Further studies will be needed in order to: • Better investigate the genesis of an eventual Na+ increment separating the effects of HC and OL-HDF on sodium balance. • Define the correct prescription set-up for HDF+HC treatments basing on patients clinical conditions. • Demonstrate if such a system is able to produce relevant clinical benefits in the long term. Table 1  IDWG [Kg] Initial Nap[mmol/L] Final Nap [mmol/L] Pre- dialysis BP [mmHg] Post-dialysis BP [mmHg] KT/V Thirst Score HD+HC 3,02 ± 0,47 134,8 ± 4,2 135,4 ± 2,2 Systolic (S): 130 ± 23 Diastolic (D): 67 ± 18 S: 121 ± 13 D: 67 ± 17 1.29 ± 0.20 7,3 ± 2,5 HDF+HC 3,07 ± 0,56 135,8 ± 3,9 136,5 ± 2,1 S: 128 D: 67 ± 17 S: 122 D: 65 ± 13 1.37 ± 0.25 9,0 ± 2,5 p-value (Paired t) p=0,503 p=0,114 p=0,028 S: p=0,580 D: p=0,768 S: p=0,936 D: p=0,489 p=0.020 p=0,049   IDWG [Kg] Initial Nap[mmol/L] Final Nap [mmol/L] Pre- dialysis BP [mmHg] Post-dialysis BP [mmHg] KT/V Thirst Score HD+HC 3,02 ± 0,47 134,8 ± 4,2 135,4 ± 2,2 Systolic (S): 130 ± 23 Diastolic (D): 67 ± 18 S: 121 ± 13 D: 67 ± 17 1.29 ± 0.20 7,3 ± 2,5 HDF+HC 3,07 ± 0,56 135,8 ± 3,9 136,5 ± 2,1 S: 128 D: 67 ± 17 S: 122 D: 65 ± 13 1.37 ± 0.25 9,0 ± 2,5 p-value (Paired t) p=0,503 p=0,114 p=0,028 S: p=0,580 D: p=0,768 S: p=0,936 D: p=0,489 p=0.020 p=0,049  Table 1  IDWG [Kg] Initial Nap[mmol/L] Final Nap [mmol/L] Pre- dialysis BP [mmHg] Post-dialysis BP [mmHg] KT/V Thirst Score HD+HC 3,02 ± 0,47 134,8 ± 4,2 135,4 ± 2,2 Systolic (S): 130 ± 23 Diastolic (D): 67 ± 18 S: 121 ± 13 D: 67 ± 17 1.29 ± 0.20 7,3 ± 2,5 HDF+HC 3,07 ± 0,56 135,8 ± 3,9 136,5 ± 2,1 S: 128 D: 67 ± 17 S: 122 D: 65 ± 13 1.37 ± 0.25 9,0 ± 2,5 p-value (Paired t) p=0,503 p=0,114 p=0,028 S: p=0,580 D: p=0,768 S: p=0,936 D: p=0,489 p=0.020 p=0,049   IDWG [Kg] Initial Nap[mmol/L] Final Nap [mmol/L] Pre- dialysis BP [mmHg] Post-dialysis BP [mmHg] KT/V Thirst Score HD+HC 3,02 ± 0,47 134,8 ± 4,2 135,4 ± 2,2 Systolic (S): 130 ± 23 Diastolic (D): 67 ± 18 S: 121 ± 13 D: 67 ± 17 1.29 ± 0.20 7,3 ± 2,5 HDF+HC 3,07 ± 0,56 135,8 ± 3,9 136,5 ± 2,1 S: 128 D: 67 ± 17 S: 122 D: 65 ± 13 1.37 ± 0.25 9,0 ± 2,5 p-value (Paired t) p=0,503 p=0,114 p=0,028 S: p=0,580 D: p=0,768 S: p=0,936 D: p=0,489 p=0.020 p=0,049  View largeDownload slide View largeDownload slide SP418 PRESCRIPTIONS OF DIALYSATE POTASSIUM CONCENTRATIONS DURING SHORT DAILY AND LONG NOCTURNAL (HIGH DOSE) HAEMODIALYSIS John K Leypoldt John K Leypoldt 1 Baxter Healthcare Corporation, Deerfield, IL Baris U Agar Baris U Agar 2 Baxter Healthcare Corporation, Round Lake, IL Angelito Bernardo Angelito Bernardo 1 Baxter Healthcare Corporation, Deerfield, IL Bruce F Culleton Bruce F Culleton 1 Baxter Healthcare Corporation, Deerfield, IL Abstract Introduction and Aims: Dialysate potassium concentrations are prescribed to provide adequate dialytic removal while maintaining serum potassium levels within normal limits, and such prescriptions during thrice weekly haemodialysis (HD) are based largely on clinical experience. The prescription of dialysate potassium concentrations during short daily and long nocturnal (high dose) HD are challenging due to limited clinical experience with such modalities. Our aim was to provide a quantitative approach for prescribing dialysate potassium concentrations based on a model of potassium kinetics. Methods: Potassium kinetic parameters based on a pseudo one-compartment model were first determined during kinetic modeling sessions in 547 patients participating in the HEMO Study. Those patients had a predialysis serum potassium concentration of 5.25±0.95 mEq/L and were treated thrice weekly with blood flow rates of 343±61 mL/min, dialysate flow rates of 688±129 mL/min, dialyser potassium dialysances of 179±27 mL/min, and treatment times of 206±29 min. Patients were then categorized based on the prescribed dialysate potassium concentration as 1K (1.02±0.05 mEq/L, N=60), 2K (2.01±0.05 mEq/L, N=437) or 3K (3.01±0.07 mEq/L, N=50) with measured intradialytic decreases in serum potassium concentration (ΔK) of 1.89±0.71 mEq/L for 1K, 1.58±0.83 mEq/L for 2K, and 1.02±0.55 mEq/L for 3K patients. Dialysate potassium concentrations were then prescribed for each patient during short daily and long nocturnal HD based on the kinetic model to maintain the identical predialysis serum potassium level and dialytic removal of potassium as during thrice weekly HD. Short daily HD was assumed to be performed 6 times per week with treatment times one-half those during thrice weekly HD (103±15 min), all other conditions identical. Long nocturnal HD was assumed to be performed 5 times per week with a treatment time of 420 min and reduced blood and dialysate flow rates, achieving a dialyser potassium dialysance of 148±5 mL/min. Results: Prescribed dialysate potassium concentrations (Dialysate K in mEq/L) and ΔK in mEq/L for high dose HD are tabulated:  Short Daily HD Long Nocturnal HD Patient Category Dialysate K ΔK Dialysate K ΔK 1K 1.46±0.23 0.81±0.47 3.72±0.56 0.54±0.22 2K 2.37±0.24 0.75±0.46 4.10±0.68 0.44±0.23 3K 3.19±0.17 0.49±0.28 4.26±0.48 0.25±0.15   Short Daily HD Long Nocturnal HD Patient Category Dialysate K ΔK Dialysate K ΔK 1K 1.46±0.23 0.81±0.47 3.72±0.56 0.54±0.22 2K 2.37±0.24 0.75±0.46 4.10±0.68 0.44±0.23 3K 3.19±0.17 0.49±0.28 4.26±0.48 0.25±0.15   Short Daily HD Long Nocturnal HD Patient Category Dialysate K ΔK Dialysate K ΔK 1K 1.46±0.23 0.81±0.47 3.72±0.56 0.54±0.22 2K 2.37±0.24 0.75±0.46 4.10±0.68 0.44±0.23 3K 3.19±0.17 0.49±0.28 4.26±0.48 0.25±0.15   Short Daily HD Long Nocturnal HD Patient Category Dialysate K ΔK Dialysate K ΔK 1K 1.46±0.23 0.81±0.47 3.72±0.56 0.54±0.22 2K 2.37±0.24 0.75±0.46 4.10±0.68 0.44±0.23 3K 3.19±0.17 0.49±0.28 4.26±0.48 0.25±0.15  These results suggest that dialysate potassium concentrations during short daily HD should be 0.2-0.5 mEq/L higher than during thrice weekly HD and approximately equal to 4 mEq/L during long nocturnal HD. Under such conditions, the intradialytic decrease in serum potassium concentration will be reduced by more than one-half during short daily and by approximately three-quarters during long nocturnal HD of that during thrice weekly HD. Conclusions: We conclude that dialysate potassium concentrations during high dose HD modalities can be quantitatively predicted using a potassium kinetic model. High dose HD modalities may improve clinical outcomes by reducing intradialytic decreases in serum potassium concentration. SP419 EFFECT OF THE DIALYSATE BICARBONATE CONCENTRATION ON CALCIUM MASS BALANCE USING CONVENTIONAL HAEMODIALYSIS Svetlana Vankova Svetlana Vankova 1 BBraun Avitum, Prague 4, Czech Republic Jan Havlin Jan Havlin 1 BBraun Avitum, Prague 4, Czech Republic Abstract Introduction and Aims: The calcium mass balance (CMB) in haemodialysis (HD) patients is related to extraosseal calcifications. The diffusion gradient between ionized calcium in inflow of dialysate and serum is considered to be the main driving force of intradialytic CMB. However, the influence of pH and intradialytic alkalinisation, important factors affecting the level of ionized calcium, has not been studied with respect to intradialytic calcium flux. The aim of this study is to evaluate the effect of various dialysate bicarbonate and calcium concentrations on CMB. Methods: We measured CMB in 9 stable patients on HD with a mean age of 74.4 years. All patients underwent 4 HD treatments using a different dialysate concentration of calcium (DCa) 1.25 vs. 1.5 mmol/L and bicarbonate (DHCO3) 26 vs 32 mmol/L. Blood was sampled before and after the HD for total (tCa) and ionized (iCa) serum calcium, pH and bicarbonate. The CMB (calcium mass from the dialysate to the patient, without effect of ultrafiltration) was determined from the tCa levels in the dialyzer inlet and from the continuous partial waste dialysate collection (150ml/h) samples. We calculated the difference between post and pre-dialysis values (ΔtCa, ΔiCa and ΔHCO3 ) and the differences between inflow dialysate and pre-dialysis serum concentrations (diffusion gradients of total calcium (Diff_tCa), ionized calcium (Diff_iCa) and bicarbonate (Diff_HC03)). Other parameters were set as follows: session duration - 4 hours, the filter - low-permeability polysulfone 1,5m2, the blood flow - 350 ml/min, the dialysate flow - 600 ml/min, the mean URR - 70.8% (± 5.7). Results: The mean diffusive CMB was positive with 1.5_DCa and it increased non-significantly with higher DHCO3 (57.7 ± 262 vs 153.9 ± 232.6 mg), with 1.25_DCa/32_HCO3 it was almost neutral (-12.8 ± 165.2 mg) and it was negative with 1.25_DCa/26_HCO3 (-147.5 ± 191.7 mg). According to repeated measures ANOVA there was not a significant effect of DHCO3 on CMB (p = 0.23) and there was a significant effect of DCa on CMB (p = 0.01). Serum tCa levels increased significantly when 1.5_DCa was used, while they remained stable when 1.25_DCa was used. Serum iCa levels increased significantly for all combinations of DCa/DHCO3, except for the combination 1.25_DCa/32_DHC03 (Table 1). We found no significant correlation between CMB and ΔtCa or ΔiCa, but there was a significant correlation between CMB and ΔHCO3 (p = 0,04, r = 0,344). Both, Diff_Ca and Diff_iCa, significantly correlated with CMB (p = 0,01, r = 0,415, resp. p = 0,026, r = 0,372), however we found the strongest correlation for Diff_HCO3 (p = 0,004, r = 0,469). Conclusions: The diffusive CMB had a positive correlation with the bicarbonate gradient between the inflow of the dialysate and the predialysis blood concentration, as well as with the tCa and iCa diffusion gradient. Furthermore, we observed a significant positive correlation between CMB and serum HCO3 change during HD, but not between intradialytic changes of tCa or iCa. Therefore, the alkalinisation effect on a higher intradialytic calcium gain should always be considered when selecting dialysate concentration of bicarbonate. CMB was not found to depend on the intradialytic tCa or iCa changes. Table 1 N 9 1.5_DCa/32_DHCO3 1.5_DCa/26_DHCO3 1.25_DCa/32_DHCO3 1.25_DCa/26_HCO3 CMB (mg) 153.9 (± 232.6) 57.7 (± 262.9) -12.8 (± 165.2 -147.5 (± 191.7) ΔtCa (mmol/L) 0.350 (± 0.097) 0.352 (± 0.094) 0.023 (± 0.140) 0.077 (± 0.104) ΔiCa (mmol/L) 0.148 (± 0.045) 0.178 (± 0.028) -0.005 (± 0.072) 0.038 (± 0.038) ΔHCO3 (mmol/L) 5.67 (± 1.79) 1.98 (± 1.66) 6.01 (± 1.91) 1.78 (± 1.32)  N 9 1.5_DCa/32_DHCO3 1.5_DCa/26_DHCO3 1.25_DCa/32_DHCO3 1.25_DCa/26_HCO3 CMB (mg) 153.9 (± 232.6) 57.7 (± 262.9) -12.8 (± 165.2 -147.5 (± 191.7) ΔtCa (mmol/L) 0.350 (± 0.097) 0.352 (± 0.094) 0.023 (± 0.140) 0.077 (± 0.104) ΔiCa (mmol/L) 0.148 (± 0.045) 0.178 (± 0.028) -0.005 (± 0.072) 0.038 (± 0.038) ΔHCO3 (mmol/L) 5.67 (± 1.79) 1.98 (± 1.66) 6.01 (± 1.91) 1.78 (± 1.32)  Table 1 N 9 1.5_DCa/32_DHCO3 1.5_DCa/26_DHCO3 1.25_DCa/32_DHCO3 1.25_DCa/26_HCO3 CMB (mg) 153.9 (± 232.6) 57.7 (± 262.9) -12.8 (± 165.2 -147.5 (± 191.7) ΔtCa (mmol/L) 0.350 (± 0.097) 0.352 (± 0.094) 0.023 (± 0.140) 0.077 (± 0.104) ΔiCa (mmol/L) 0.148 (± 0.045) 0.178 (± 0.028) -0.005 (± 0.072) 0.038 (± 0.038) ΔHCO3 (mmol/L) 5.67 (± 1.79) 1.98 (± 1.66) 6.01 (± 1.91) 1.78 (± 1.32)  N 9 1.5_DCa/32_DHCO3 1.5_DCa/26_DHCO3 1.25_DCa/32_DHCO3 1.25_DCa/26_HCO3 CMB (mg) 153.9 (± 232.6) 57.7 (± 262.9) -12.8 (± 165.2 -147.5 (± 191.7) ΔtCa (mmol/L) 0.350 (± 0.097) 0.352 (± 0.094) 0.023 (± 0.140) 0.077 (± 0.104) ΔiCa (mmol/L) 0.148 (± 0.045) 0.178 (± 0.028) -0.005 (± 0.072) 0.038 (± 0.038) ΔHCO3 (mmol/L) 5.67 (± 1.79) 1.98 (± 1.66) 6.01 (± 1.91) 1.78 (± 1.32)  SP420 SELECTIVE ION MEASUREMENT IN SPENT DIALYSATE WITH LASER INDUCED BREAKDOWN SPECTROSCOPY D J Klomp D J Klomp 1 TNO, Eindhoven, Netherlands F Van Beijnum F Van Beijnum 2 TNO, Delft, Netherlands J P.R. Day J P.R. Day 2 TNO, Delft, Netherlands F P Wieringa F P Wieringa 1 TNO, Eindhoven, Netherlands J P Kooman J P Kooman 3 Maastricht University Medical Center, Maastricht, Netherlands Abstract Introduction and Aims: Correct electrolyte balancing is imperative for optimal long-term haemodialysis process. Numerous complications can occur due to electrolyte derangements. To avoid or minimize the effects of this unbalance in patients, it is necessary to be able to monitor and adjust these individual ion balances, furthermore in-line monitoring would also facilitate patient specific treatment. Besides non-ion selective overall conductivity measurements in dialysate, no stable, in-line ion-selective measurement tool is currently commercially available. For in-line measurement of K+, Na+ and Ca2+, a LIBS system (Laser Induced Breakdown Spectroscopy) was developed to enable the measurement of these electrolytes in the spent dialysate flow. LIBS is an optical modality that resembles flame photometry. Instead of a flame, a short tightly focused laser pulse excites the atoms by inducing a micro-plasma in a sample. The characteristic atomic emission spectrum is measured making the components clearly distinguishable. The optical nature of LIBS enables non-contact “through a window” sensing, thus offering inherent electrical and microbiological safety. The method also has good perspectives for miniaturization and continuous real time monitoring. Methods: A LIBS setup was developed capable of creating a plasma discharge with a diameter of 200 micrometer in flowing dialysate (500 ml/min) at a repetition rate of 20 Hz by the application of 20 mJ laser pulses (1W optical power injection). The atomic emission spectra emitted by the formed plasma was measured with an echelle spectrometer combined with a gated iCCD camera. Each measurement point consisted of 400 pulses (8 s sample rate with running average). The setup was calibrated with a concentration series of individual electrolytes in water. Results: Accurate atomic spectra were measured with sharp and well-separated peaks for K+ and Ca2+ and broad self-reversed peaks for Na+ at the expected wavelengths (see figure). The significant parameters from each concentration series had a linear response with respect to the concentrations of the electrolytes. Measurements on two different clean dialysates had good correlations with the calibration lines. Conclusions: The LIBS system was shown to be capable of in-line measurement of individual K+, Na+ and Ca2+ concentrations. For future work, a mobile setup has been constructed to facilitate measurements in the haemodialysis clinic. These measurements are planned in 2014. Knowledge of the exact concentrations of electrolytes in spent dialysate opens perspectives for real-time, patient-specific treatment. Further development towards a miniaturized version is being pursued for incorporation in a portable artificial kidney using sorbent-based dialysate reconditioning. SP421 DIALYSATE REGENERATION BY ELECTRO-OXIDATION COMBINED WITH ACTIVATED CARBON DOES NOT INCREASE OXIDATIVE STRESS OR ENDOTHELIAL CYTOTOXICITY H Gremmels H Gremmels 1 UMC Utrecht, Utrecht, Netherlands D H Hazenbrink D H Hazenbrink 1 UMC Utrecht, Utrecht, Netherlands F Simonis F Simonis 2 Nanodialysis BV, Oirschot, Netherlands M L Otten M L Otten 1 UMC Utrecht, Utrecht, Netherlands M Wester M Wester 1 UMC Utrecht, Utrecht, Netherlands W H Boer W H Boer 1 UMC Utrecht, Utrecht, Netherlands J A Joles J A Joles 1 UMC Utrecht, Utrecht, Netherlands K G Gerritsen K G Gerritsen 1 UMC Utrecht, Utrecht, Netherlands Abstract Introduction and Aims: Major challenge in the design of a wearable dialysis device is the removal of urea, since the daily urea production is very high and removal by adsorption has proved difficult. Electro-oxidation (EO) seems attractive since electrodes are durable, small and inexpensive. We achieved clinically relevant urea degradation in blood (9.5±1.0mmol/h) using an EO unit in series with activated carbon (AC) for removal of chlorine by-products [submitted]. Major concern of EO is that toxic, in particular oxidative, by-products are generated that are not removed by AC. Therefore we investigated the effect of EO in combination with AC on oxidative status and endothelial cytotoxicity of dialysate and dialyzed uremic plasma. Methods: The EO-unit contains 10 graphite electrodes (70g, 585cm2). Uremic plasma (1L, urea 24-43mM), obtained from plasmapheresis of patients with kidney failure, was dialyzed for 1h and dialysate was recirculated in counter current direction through the EO-unit in series with a degasser (containing 15g of AC) and an AC filter (50g). Three series of experiments were performed, in which recirculation with and without EO were compared. Oxygen radical adsorbance capacity (ORAC) of EO-treated fluids was assessed using fluorescein as probe, 2,2-azobis-2-methyl-propanimidamide, dihydrochloride as free radical generator and Trolox for calibration. Endothelial colony forming cells isolated from umbilical cord blood from 3 donors were exposed to EO and AC-treated fluids. Induction of intracellular reactive oxygen species (ROS) was evaluated using chloromethyl-dichlorodihydrofluorescein diacetate (CM-H2DCFDA). PrestoBlue, a resazurin-based reagent, and neutral red were used to assess cell viability. CM-H2DCFDA and viability data were normalized to PBS-treated controls. Electric cell-substrate impedance sensing (xCELLigence) was used to monitor real-time cell proliferation. Results: Urea degradation by EO was 7.2±1.2mmol/h. Treatment by EO plus AC had no influence on the total anti-oxidant capacity of dialysate and uremic plasma as compared to treatment by AC alone (Fig. 1A). No effects of EO and/or AC treated dialysate and plasma were observed on intracellular generation of ROS, cell viability and cell proliferation (Fig. 1B-E). Conclusions: Biocompatibility studies suggest that dialysate regeneration by EO combined with AC does not increase oxidative status or endothelial cytotoxicity of dialysate and dialyzed uremic plasma as compared to AC without EO. Extensive biocompatibility studies and analysis of oxidation products are now warranted. View largeDownload slide View largeDownload slide SP422 SPECTRAL MEASUREMENT OF POLYVINYLPYROLIDONE ELUTED FROM POLYSULFONE MEMBRANES Koichi Umimoto Koichi Umimoto 1 Osaka Electro-Communication University, Shijonawate, Japan Yoshimasa Shimamoto Yoshimasa Shimamoto 1 Osaka Electro-Communication University, Shijonawate, Japan Kohei Mastushima Kohei Mastushima 1 Osaka Electro-Communication University, Shijonawate, Japan Masahiro Miyata Masahiro Miyata 1 Osaka Electro-Communication University, Shijonawate, Japan Abstract Introduction and Aims: Polysulfone (PS) dialysis membranes are made hydrophilic by blending polyvinylpyrolidone (PVP) and are well known to have excellent biocompatibility in clinical use. However, PS membranes have some side effects, such as anaphylaxis and skin lesions, which are supposedly caused by PVP. In recent years, it has been reported that PS dialysis membranes elute high levels of PVP after being stored for long periods.A colorimetric assay called the Muller method is generally used for measuring PVP eluted from dialysis membranes. However, ultraviolet (UV) spectroscopy offers an alternative approach for clinical analysis. UV spectroscopy does not use reagents, thereby permitting real-time analysis. In this study, we investigated direct measurement of PVP by an optical method and assessed the relation between the storage period of PS membranes and the quantity of PVP eluted. Methods: The concentration of PVP·K-90 (Wako chemicals, Ltd.) was determined by spectral analysis from the absorption measured at 203 nm based on its spectral peak. The actual concentration of PVP·K-90 was also determined by the Muller method. Then 1.0 L of physiological saline was passed through the blood side of a PS dialysis membrane (PS1.6UW Fresenius) and the concentration of PVP was measured by the optical method and the Muller method. Subsequently, PS dialysis membranes (RENAK-PS1.6 Kawasumi) stored for 6 months to 34 months were examined and PVP eluted from the membranes was measured. Results: The predicted concentrations of PVP·K90 closely matched the actual concentrations and there was a significant correlation between the actual and predicted concentrations of PVP·K90 (r=0.993, P<0.001). The spectrum of PVP eluted from the PS membrane was similar to that of PVP·K-90. There was a significant correlation between the predicted and actual concentrations of eluted PVP (r=0.965, P<0.01). The amount of PVP eluted from dialysis membranes stored for long periods ranged from 28.6 mg to 91.8 mg. There was a strong positive correlation between the storage period and the amount of PVP eluted (n=6, rs=0.886). Conclusions: Although the precision of measurement decreases slightly at low concentrations, it is possible to determine the concentration of PVP eluted from a PS dialysis membrane based on the spectral data obtained by using a UV spectrophotometer. This indicates that optical measurement can be employed as a method for real-time monitoring of PVP eluted during priming of the dialyzer. In addition, the quantity of PVP eluted from PS membranes increases in proportion to the storage period. SP423 CHARACTERIZATION OF PLATELET ACTIVATION AND COAGULATION INDICES IN AN IN VITRO DIALYSIS MODEL Matthew Muller Matthew Muller 1 Baxter Healthcare Corporation, Round Lake, IL Avinash Naik Avinash Naik 1 Baxter Healthcare Corporation, Round Lake, IL Sharon Pokropinski Sharon Pokropinski 1 Baxter Healthcare Corporation, Round Lake, IL Shawn Bairstow Shawn Bairstow 1 Baxter Healthcare Corporation, Round Lake, IL Jessica Svatek Jessica Svatek 1 Baxter Healthcare Corporation, Round Lake, IL Susan Young Susan Young 1 Baxter Healthcare Corporation, Round Lake, IL Richard Johnson Richard Johnson 1 Baxter Healthcare Corporation, Round Lake, IL Angelito Bernardo Angelito Bernardo 2 Baxter Healthcare Corporation, Deerfield, IL Abstract Introduction and Aims: The Vivia Haemodialysis System differs from traditional haemodialysis equipment in that it uses a pneumatically controlled diaphragm blood pump and a rigid cassette in the blood flow path. During haemodialysis, blood is chronically exposed to the extracorporeal circuit (ECC) consisting of the blood flow path and the dialyser. Blood components interact with the ECC potentially eliciting changes in platelets and coagulation factors. Platelet activation has been identified as a risk factor for cardiovascular events. Therefore, it is of clinical relevance to characterize the biocompatibility characteristics of the Vivia ECC. Methods:In vitro studies using the Vivia ECC were performed to analyze biocompatibility during simulated dialysis in a perfusion model. Treatments were performed using freshly donated heparin-anti-coagulated human blood at a blood flow of 400 ml/min for 2 hours. Blood incubated in a polypropylene tube on a rocker at 37°C served as a control. Blood samples were removed, mixed with NaCitrate or EDTA at 15, 30, 60, 90 and 120 minutes and processed for analysis of platelet activation (CD62) and counts, thrombin activation (prothrombin fragment F1+2) and heparin concentration. Results: Platelet CD62 expression increased from an initial 1.4% to a modest 4.8% at two hours, a level comparable to control values, which increased to 5.7%. Soluble CD62 (sCD62) levels (mean ± standard deviation) also increased during the runs (from 26 ± 8 to 52 ± 23 ng/ml) but did not differ from control values (26 ± 8 to 48 ± 7 ng/ml) either. As expected for an in vitro model test system with a large surface to volume ratio (Frank et al Kidney International (2001) 60:1972), there was a decrease in platelet count during the perfusion runs. Thrombin activation (F1+2 levels) was minimal for the first 45 minutes of perfusion, but then increased over control values at subsequent time points. The magnitude of the increase in F1+2 was consistent with the literature when corrected for the higher surface to volume ratio of this model system. The elevation in F1+2 values was also heparin-dependent since increasing heparin levels resulted in a 73% and 82% reduction in F1+2 values at 2 and 3 U/ml, respectively. Contact activation was investigated as a possible mechanism for thrombin activation, but no evidence for FXIIa production was found in the plasma samples. Conclusions: Platelet activation remained low and stable throughout the treatment as assessed by CD62 expression. Thrombin activation was low initially, but increased after an hour of perfusion to levels comparable to other published studies, an effect that could be largely reversed by increasing heparin levels. Therefore, the Vivia ECC showed excellent biocompatibility with respect to platelet activation and coagulation indices. SP424 COMPARISON OF UREA KINETIC MODELS WITH ON-LINE CLEARANCE MONITOR. WHAT IS THE BEST TARGET VALUE? Csaba Rikker Csaba Rikker 1 Péterfy Hospital, Budapest, Hungary Edina Juhász Edina Juhász 1 Péterfy Hospital, Budapest, Hungary Renáta Gáspár Renáta Gáspár 1 Péterfy Hospital, Budapest, Hungary László Rosivall László Rosivall 2 Institute of Pathophysiology, Hungarian Academy of Sciences, Semmelweis University, Budapest, Hungary Abstract Introduction and Aims: Since the secondary analysis of National Cooperative Dialysis Study data (1985) Kt/V has been used for the assessment of the adequacy of dialysis. For three treatments per week, the 2006 Kidney Disease Outcomes Quality Initiative (KDOQI) adequacy guidelines recommend a minimum single-pool Kt/V (spKt/V) of 1.2. The European Best Practice Guidelines (EBPG) 2002 recommend a minimum equilibrated Kt/V (eKt/V) value of 1.2, corresponding to a minimum spKt/Vof 1.40. Besides several calculations of Kt/V using pre- and postdialysis urea, in the last decades ionic dialysance (ID) appeared as a method of the on-line monitoring of delivered dialysis in every treatment without blood sampling. The aim of our study is to compare ID to three other calculations of Kt/V and determine the minimal value equivalent with eKt/V prescribed by EBPG. Methods: We measured in one online haemodiafiltration of 127 not selected patients the adequacy of treatment by spKt/V using Fresenius 5008 online clearance monitor (OCM). Simultaneously we determined spKt/V using the Lowrie and adjusted Daugirdas equation. The eKt/V was calculated from the latter equation. In accordance with EBPG we considered the value eKt/V ≥1.2 as reference. We evaluated the correlation of OCM with the above mentioned mathematical methods of urea kinetic model, dry weight, ultrafiltration (UF), ratio of true- and false positive cases below the reference value as well as the sensitivity, specificity, positive and negative predictive values at OCM spKt/V target 1.4, 1.3 and 1.2. Results: Lowrie spKt/V; OCM spKt/V ; Daugirdas spKt/V and Daugirdas eKt/V (mean±SD) were: 1.36±0.18, 1.52±0.22, 1.58±0.21 and 1,38±0.18, below the target value (spKt/V <1.4, eKt/V <1.2) were: 54.33%, 26.77%, 14.96% and 11.81% of the cases respectively. Correlation of OCM spKt/V with Lowrie spKt/V, Daugirdas spKt/V and Daugirdas eKt/V are: 0.61, 0.61 and 0.60. OCM spKt/V showed slightly but significantly lower values compared to Daugirdas spKt/V (p= 0.0004). We could not find any statistical correlation between OCM spKt/V and UF, dry weight, as well as UF expressed by percent of dry weight. At target value of OCM spKt/V 1.4, 1.3 and 1.2 below the reference value (eKt/V <1,2) expressed in % we have found true positive cases: 9.4, 8.7 and 5.5; false positive cases: 17.3, 6.3 and 1.6, true negative cases: 70.1, 81.1 and 86.6 and false negative cases: 3.1, 3.9 and 6.3, sensitivity: 0.75, 0.69 and 0.47, specificity: 0.80, 0.93 and 0.98, positive predictive value: 0.35, 0.58 and 0.78, negative predictive value: 0.96, 0.95 and 0.93 respectively. Conclusions: OCM is an excellent tool for following the adequacy of dialysis in every treatment. In accordance with several studies it slightly but significantly underestimates the value of Kt/V. Decreasing cut-off of OCM spKt/V from 1.4 to 1.3 the number of false positive cases diminishes by 11%, while the number of false negative cases rises only by 0.8 %. We suggest OCM spKt/V 1.4 as target value, nevertheless ≥1.3 can be enough for adequate dialysis. Further measurements are planned to verify the findings in other settings as well. SP425 ALBUMIN DIALYSIS USING MOLECULAR ADSORBENTS RECIRCULATING SYSTEM IN SEVERE LIVER FAILURE: PREDICTIVE FACTORS FOR CLINICAL OUTCOME - A SINGLE CENTER EXPERIENCE Elena Rusu Elena Rusu 1 “Carol Davila” University of Medicine and Pharmacy Bucharest, Bucharest, Romania Diana Zilisteanu Diana Zilisteanu 1 “Carol Davila” University of Medicine and Pharmacy Bucharest, Bucharest, Romania Sonia Balanica Sonia Balanica 2 Fundeni Clinical Institute, Bucharest, Romania Camelia Achim Camelia Achim 1 “Carol Davila” University of Medicine and Pharmacy Bucharest, Bucharest, Romania Teodora Atasie Teodora Atasie 2 Fundeni Clinical Institute, Bucharest, Romania Flavia Carstea Flavia Carstea 2 Fundeni Clinical Institute, Bucharest, Romania Mihai Voiculescu Mihai Voiculescu 1 “Carol Davila” University of Medicine and Pharmacy Bucharest, Bucharest, Romania Abstract Introduction and Aims: The Molecular Adsorbents Recirculating System (MARS) is an artificial liver support system that removes albumin-bound and water-soluble toxins that accumulate in liver failure, providing better conditions for liver recovery.We analyzed the prognostic factors for clinical outcome of patients with AoCLF treated with MARS in the Clinic of Internal Medicine and Nephrology in order to improve the MARS procedure indication and the selection of patients for therapy. Methods: Between January 2001 and August 2013 we treated 48 liver failure patients, to whom we performed 88 MARS sessions. The etiology of severe liver failure was: acute liver failure (n=11), acute on chronic liver failure (n=25), post liver transplantation graft failure (n=8), and post-hepatectomy liver failure (n=2). The mean age of the patients was 41.6 ± 18.2 years (interval 3-66 years). Results: Before starting MARS therapy 8 patients had sepsis, 19 patients presented renal impairment (9 patients with hepatorenal syndrome), 26 patients presented hepatic encephalopathy grade II or higher.MARS therapy was safe and well tolerated. We noticed favorable clinical effects: improvement in general condition, neurological status, regression of jaundice and pruritus, improvement in renal function and hemodynamic status. We obtained statistically significant improvement of serum total and direct bilirubin, serum creatinine, urea lactate. We also obtain a significant decrease of TNF-alpha after MARS. Regarding the outcome of the patients, in ALF group, 6 patients (54.5%) completely recovered the hepatic function. In the AoCLF group 3 patients were bridged with liver transplantation and 7 patients recovered their pre-decompensation status. The mean survival of the AoCLF patients (n=15) on the liver transplantation waiting list was 23.0 ± 6.9 days. The Kaplan-Meier and survival modeler analisys showed that the unfavorable prognosis factors for survival were: the presence of sepsis and multiple organ failure, hepatic encephalopathy grade 2 or higher, and renal dysfunction. We hadn’t found a relationship between age, etiology of liver failure or the bilirubin level and the patient’survival. Conclusions: The most promising results were observed among ALF patients. For acute on chronic liver failure patients MARS therapy could be an efficient solution for prolonging patient survival and a bridging method until liver transplantation will be achieved. We concluded that the predictive factors for patient survival are: sepsis, multiple organ failure, hepatic encephalopathy grade 2 or higher, and renal dysfunction. SP426 STUDY COSTS ANTICOAGULATION SYSTEMIC CHANGE IN HEMODIALISIS UNIT Tania Monzon Vazquez Tania Monzon Vazquez 1 Hospital Quiron Tenerife, Santa Cruz de Tenerife, Spain Sandra Saiz Garcia Sandra Saiz Garcia 2 Hospital Quiron Tenerife, Santa Cruz De Tenerife, Spain Vijay Mathani Vijay Mathani 2 Hospital Quiron Tenerife, Santa Cruz De Tenerife, Spain Beatriz Escamilla Cabrera Beatriz Escamilla Cabrera 2 Hospital Quiron Tenerife, Santa Cruz De Tenerife, Spain Abstract Introduction and Aims: Currently in Spain anticoagulation in haemodialysis situated about 50% use of each unfractionated heparin (UFH) and low molecular weight heparin (LMWH). A recent meta-analysis found no differences in efficacy between the two kinds of heparins. Use of LMWH has the advantage of the safe handling and the biggest drawback was its high cost.The aims of this study is analyze the economic benefits of systematic change in anticoagulation in our haemodialysis unit, from UFH to LMWH. Methods: Costs 6 months before and after the change in anticoagulation on August 2012, with an average over the whole period of 63 patients were analyzed. Then the economic cost of the products is detailed.The use of sodium heparin, implies a cost overrun from the use of 10cc and 20cc syringe, 2 needles 18G and two sodium heparin vials per haemodialysis session. Results: In the first study period, 41.3% of patients were treated with LMWH (enoxaparin 20 mg were 12.7% and enoxaparin 40 mg were 28.6%) and 55.6% with UFH. In the second period, all patients were treated with LMWH with following distribution: 44.5% enoxaparin 20 mg and 55.6% enoxaparin 40mg.We analized the costs for each product by an average of 63 patients, with 3 sessions per week during 6 months. Total cost of haemodialysis circuit anticoagulation was in the first period was 6344,64€ in the first period (UFH 5115,6€ + enoxaparin 1229,04€) vs. 2870,64€ in the second period (enoxaparin 20 mg: 1315,44€ + enoxaparin 40 mg: 1555,2€).This change saved € 3474 by semester. Conclusions: Main disadvantage of using LMWH was at its high cost, however in last years has increased the market price of the UFH. According to our study, LMWH use is less expensive than using UFH, without any evidence of increased thrombotic or hemorrhagic processes. MATERIAL COST ANTICOAGULATION KIND OF HEPARIN COST (€/UNIT) ENOXAPARIN 20 MG 0,63 € ENOXAPARIN 40 MG 0,60 € SODIUM HEPARIN 1% 0,95 € NEEDLE 18G 0,04 € SYRINGE 5CC 0,02 € SYRINGE 20CC 0,04 €  KIND OF HEPARIN COST (€/UNIT) ENOXAPARIN 20 MG 0,63 € ENOXAPARIN 40 MG 0,60 € SODIUM HEPARIN 1% 0,95 € NEEDLE 18G 0,04 € SYRINGE 5CC 0,02 € SYRINGE 20CC 0,04 €  MATERIAL COST ANTICOAGULATION KIND OF HEPARIN COST (€/UNIT) ENOXAPARIN 20 MG 0,63 € ENOXAPARIN 40 MG 0,60 € SODIUM HEPARIN 1% 0,95 € NEEDLE 18G 0,04 € SYRINGE 5CC 0,02 € SYRINGE 20CC 0,04 €  KIND OF HEPARIN COST (€/UNIT) ENOXAPARIN 20 MG 0,63 € ENOXAPARIN 40 MG 0,60 € SODIUM HEPARIN 1% 0,95 € NEEDLE 18G 0,04 € SYRINGE 5CC 0,02 € SYRINGE 20CC 0,04 €  TOTAL COST STUDY PERIOD  SEMESTER COST PERIOD 1 SEMESTER COST PERIOD 2 ENOXAPARIN 20 MG 408,24 € 1315,44 € ENOXAPARIN 40 MG 820,8 € 1555,2 € SODIUM HEPARIN (MATERIAL INCLUDED) 5115,6 € 0 € TOTAL COST 6344,64 € 2870,64 €   SEMESTER COST PERIOD 1 SEMESTER COST PERIOD 2 ENOXAPARIN 20 MG 408,24 € 1315,44 € ENOXAPARIN 40 MG 820,8 € 1555,2 € SODIUM HEPARIN (MATERIAL INCLUDED) 5115,6 € 0 € TOTAL COST 6344,64 € 2870,64 €  TOTAL COST STUDY PERIOD  SEMESTER COST PERIOD 1 SEMESTER COST PERIOD 2 ENOXAPARIN 20 MG 408,24 € 1315,44 € ENOXAPARIN 40 MG 820,8 € 1555,2 € SODIUM HEPARIN (MATERIAL INCLUDED) 5115,6 € 0 € TOTAL COST 6344,64 € 2870,64 €   SEMESTER COST PERIOD 1 SEMESTER COST PERIOD 2 ENOXAPARIN 20 MG 408,24 € 1315,44 € ENOXAPARIN 40 MG 820,8 € 1555,2 € SODIUM HEPARIN (MATERIAL INCLUDED) 5115,6 € 0 € TOTAL COST 6344,64 € 2870,64 €  SP427 ACUTE HEMODYNAMIC RESPONSE AND UREMIC TOXIN REMOVAL IN CONVENTIONAL AND EXTENDED HEMODIALYSIS AND HEMODIAFILTRATION: A RANDOMIZED CROSSOVER STUDY Tom Cornelis Tom Cornelis 1 Maastricht University Medical Centre, Maastricht, The Netherlands Frank M Van Der Sande Frank M Van Der Sande 1 Maastricht University Medical Centre, Maastricht, The Netherlands Sunny Eloot Sunny Eloot 2 Ghent University Hospital, Ghent, Belgium Eline Cardinaels Eline Cardinaels 1 Maastricht University Medical Centre, Maastricht, The Netherlands Otto Bekers Otto Bekers 1 Maastricht University Medical Centre, Maastricht, The Netherlands Jan Damoiseaux Jan Damoiseaux 1 Maastricht University Medical Centre, Maastricht, The Netherlands Karel M Leunissen Karel M Leunissen 1 Maastricht University Medical Centre, Maastricht, The Netherlands Jeroen Kooman Jeroen Kooman 1 Maastricht University Medical Centre, Maastricht, The Netherlands Abstract Introduction and Aims: Intensive hemodialysis (HD) has significant benefits. Aim of this study was to evaluate the acute effects of extended HD and hemodiafiltration (HDF) on hemodynamic response and solute removal. Methods: Thirteen conventional HD patients randomly completed a single study of 4-hour HD (HD4), 4-hour HDF (HDF4), 8-hour HD (HD8) and 8-hour HDF (HDF8). Blood pressure (BP) and heart rate (HR), pulse wave analysis, cardiac output (CO), microvascular density by sublingual capillaroscopy, as well as relative blood volume (RBV) and thermal variables were measured. Clearance and removal of uremic toxins were also studied. Results: Long treatments showed more stability of peripheral systolic BP (mmHg) (drop during HD4 -21.7±15.6; HDF4 -23.3±20.8; HD8 -6.7±15.2, p=0.037 versus HD4 and p=0.077 versus HDF4; HDF8 -0.5±14.4; p=0.004 versus HD4 and p=0.008 versus HDF4). A similar observation was found for peripheral diastolic BP and central BP. CO (L/min) remained more stable in extended sessions (drop in HD4 -1.4±1.5; HDF4 -1.6±1.0; HD8 -0.4±0.9, p=0.022 versus HDF4; HDF8 -0.5±0.8; p=0.062 versus HD4 and p=0.025 versus HDF4), in line with decreased RBV slope in long dialysis. No differences in microvascular density were found. Energy transfer rates (W) were comparable (HD4 13.3±4.7, HDF4 16.2±5.6, HD8 14.2±6.0, HDF8 14.5±4.3). Small molecule and phosphate removal were superior during long treatments. Beta2 microglobulin and FGF23 reduction ratios were highest in HDF8. Conclusions: Treatment time, and not modality was the determinant for the hemodynamic response. HDF significantly improved removal of middle molecules, with superior results in extended HDF. SP428 PREDIALYSIS SODIUM LEVELS AND CARDIOVASCULAR STABILITY IN HEMODIALYSIS Eduardo Baamonde Laborda Eduardo Baamonde Laborda 1 Avericum, Telde, Spain Elvira Bosch Benitez-Parodi Elvira Bosch Benitez-Parodi 1 Avericum, Telde, Spain German Perez Suarez German Perez Suarez 1 Avericum, Telde, Spain Gloria Anton Perez Gloria Anton Perez 1 Avericum, Telde, Spain Fatima Batista Garcia Fatima Batista Garcia 1 Avericum, Telde, Spain Mar Lago Alonso Mar Lago Alonso 2 Hospital Insular Gran Canaria, Las Palmas, Spain Cesar Garcia Canton Cesar Garcia Canton 2 Hospital Insular Gran Canaria, Las Palmas, Spain Abstract Introduction and Aims: A relationship between pre-hemodialysis plasma sodium and mortality has been described. Lower sodium levels are associated with higher mortality.One of the hypothesized reasons for this finding is based on intra-hemodialysis cardiovascular stability.AIMS:to analyze the relationship between pre-dialysis plasma sodium levels and intra-hemodialysis hemodynamic stability in a group of patients on standard hemodialysis and constant sodium bath. Methods: Retrospective analysis of 231 prevalent patients in HD (59.7% male; average age 61.36 ± 13.8 years; time in HD 33.41 ± 17.7 months; 54.1% diabetic). Patients were classified into tertile groups according to their pre-HD sodium levels (average of 12 determinations): Group 0 (G0) with pre-HD Na &lt 137,58 mEq/L (n=77); Group 1 (G1) with pre-HD Na from 137,59 to139.15 mEq/L (n=77); Group 2 (G2) with pre-HD Na &gt 139,16 mEq/L (n=77). Plasma sodium was corrected for glucose according to:Corrected-Na (cNa) = Na(mEq/L)+0.016*(serum glucose (mg/dl)-100). Patients were followed up for two years or until they left the program (median number of sessions 269). Maximum and minimum mean blood pressure (MBP) was measured in every session, as well as inter-dialysis weigth gain, ultrafiltration rate (UF), duration of session, dry weight and body mass index (BMI).A session was considered to be a session with hypotension when the difference between maximum and minimum MBP was higher than 30% and the value of MBP fell below 70 mmHg.Parameters of laboratory tests (hemoglobin, creatinine, albumin, calcium, phosphorus, ferritin and PTHi), HD adequacy: (Kt/V and URR) and antihypertensive treatment were analyzed. Results: View largeDownload slide View largeDownload slide HD sodium level was negatively correlated with UF rate (r: 0.325; p:0.000), percent weight gain (r: 0.279; p: 0.000) and percent of sessions with hypotension: (r: 0.146; p: 0.027) Conclusions: Pre-dialysis plasma sodium was inversely related with cardiovascular stability. Patients with lower levels showed higher tendency to hypotension. Patients with lower sodium levels showed higher percent inter-dialysis weight gain and higher UF rates, which could account for their higher tendency to intra-HD hypotension. SP429 AN EVALUATION OF BIOELECTRICAL IMPEDANCE SPECTROSCOPY, IN ORDER TO MEASURE AND COMPARE BODY WATER DISTRIBUTION IN BOTH HEALTHY PREGNANT WOMEN AND PREGNANT WOMEN ON DIALYSIS Seiji Hashimoto Seiji Hashimoto 1 NTT East Japan Sapporo Hospital, Sapporo, Japan Masahide Seki Masahide Seki 1 NTT East Japan Sapporo Hospital, Sapporo, Japan Maoka Tomochika Maoka Tomochika 1 NTT East Japan Sapporo Hospital, Sapporo, Japan Rie Yamamoto Rie Yamamoto 1 NTT East Japan Sapporo Hospital, Sapporo, Japan Nobuhiko Okamoto Nobuhiko Okamoto 1 NTT East Japan Sapporo Hospital, Sapporo, Japan Akira Nishikawa Akira Nishikawa 1 NTT East Japan Sapporo Hospital, Sapporo, Japan Takao Koike Takao Koike 1 NTT East Japan Sapporo Hospital, Sapporo, Japan Abstract Introduction and Aims: Pregnant women on dialysis face great difficulty carrying a baby to term. Some of those challenges include but are not limited to miscarriages and stillbirths. One of the major factors complicating prenatal care is the difficulty for them to properly manage body fluids. In this study we examine and compared fluid volume using Bioelectrical Impedance Spectroscopy (BIA) in healthy pregnant women and two of our successful pregnancies of women on dialysis. Methods: In our study we subjected 52 healthy pregnant women to test at various stages of their respected pregnancies. We did this in order to get enough results and or information, so we could compare our results with our two successful dialysis pregnancies. In both respective groups we measured fluid volume using BIA. In the cases of our dialysis patients we measured them before and after dialysis every week. In addition we also measured the hANP before and after dialysis. Results: In the case of our two dialysis subjects both the TBW (Total Body Water) and ICW (Intracellular Water) ware measured pre-dialysis. Moreover, neither case showed any significant changes throughout both respective pregnancies. However pre-dialysis the ECW (Extracellular Water) increased moderately during the course of both successful pregnancies.In comparison, with our healthy pregnant subjects, our pre-dialysis subjects TBW/FFM (body water rate) measurements showed a tendency to be lower pre-dialysis. However the difference was not that significant. Furthermore, measurements of the ECW/FFM (the cell external solution rate) also showed same tendency to be lower than that of their healthy counterparts. However, in the latter half of the dialysis subjects pregnancy terms, the ECW/FFM showed a value close to our healthy pregnant subjects. Furthermore according to the ICW/ECW (the intracellular and extracellular water ratio), the value post-dialysis also showed no significant difference to that of their respective healthy subjects. As for the ECW/TBW (the edematous rate), there were also no significant differences found. In addition, the hANP in our post-dialysis cases remained almost unchanged regardless of the gestational age of about 50. Conclusions: The BIA is regarded as a very useful testing method during pregnancy. Moreover it is even effective in the case of pregnant women with dialysis. SP430 CORRELATION BETWEEN SERUM SODIUM CONCENTRATION AND PLASMA CONDUCTIVITY AT DIFFERENT STAGES OF THE HEMODIALYSIS SESSION Enrico Ravagli Enrico Ravagli 1 University of Bologna, Cesena, Italy Laura Maldini Laura Maldini 2 “Degli Infermi” Hospital, Rimini, Italy Fabio Badiali Fabio Badiali 2 “Degli Infermi” Hospital, Rimini, Italy Claudia Perazzini Claudia Perazzini 1 University of Bologna, Cesena, Italy Giulia Lanciotti Giulia Lanciotti 1 University of Bologna, Cesena, Italy Denis Steckiph Denis Steckiph 3 Gambro Hospal S.p.A, Bologna, Italy Alessandro Surace Alessandro Surace 4 Gambro Dasco S.p.A, Medolla, Italy Paolo Rovatti Paolo Rovatti 4 Gambro Dasco S.p.A, Medolla, Italy Stefano Severi Stefano Severi 1 University of Bologna, Cesena, Italy Angelo Rigotti Angelo Rigotti 2 “Degli Infermi” Hospital, Rimini, Italy Abstract Introduction and Aims: Monitoring changes in the body sodium pool during hemodialysis (HD) sessions would be very useful and clinically relevant. Because a continuous and non-invasive measurement of sodium concentration in blood during HD is not currently possible, kinetic models for plasma conductivity (Cpl) estimation are used, based on the relationship between conductivity and ionic concentrations in plasma.The aim of the study was to investigate the correlation between the patient’s serum sodium concentration ([Na]) and Cpl estimated by the Diascan biosensor, for the purpose of non-invasive estimation of [Na], at different stages during the HD session. Methods: 24 dialysis patients were selected and a total of 152 sessions were studied.Arterial blood samples were taken for the determination of [Na] by blood gas analysis (direct potentiometry with an ion-selective electrode). Within 10 minutes after every sampling, Cpl was estimated by the Diascan biosensor and recorded by the dialysis machine. The timing of the blood sampling was 5’, 35’, 95’, 155’ from session start (SS) and 25’ before session end (SE).Recorded data was processed as follows: linear regression between [Na] and Cpl was calculated with the least-squares method for the whole dataset at each sampling time. Correlation coefficients were also calculated. The 95% confidence interval was calculated on the difference between the measured [Na] and the value estimated by linear regression. Results: The correlation between [Na] and Cpl for the whole dataset was R=0.54 (p<0.001). The time-specific correlations are reported in Fig. 1. All regression coefficients are significant with p<0.001 except for SE (p=0.003). Since the correlation of SE data was largely lower than the correlation at any other time during the session, the global correlation was recalculated excluding data from the last measurement, resulting in a value of R=0.60 (p<0.001, Fig. 1, bottom right).The 95% confidence interval of the difference between measured and estimated [Na] (calculated using the parameters for linear regression estimated from the whole dataset) was ±5 mmol/l. Conclusions: Our results show that the global correlation between [Na] and Cpl is comparable with that reported in previous studies.The evaluation of correlation at different times during the session shows that this relationship is valid for the whole treatment time, except at SE. This lower correlation is not clearly explained, but it could be related to the variability in measurement timing due to the variability in session duration.Since correlation is maintained up to SE, Diascan measurements could be used for non-invasive [Na] estimation. Moreover, estimation at SS (where correlation is high) could also be used for individualization of dialysis prescription. View largeDownload slide View largeDownload slide SP431 NOCTURNAL HAEMODIALYSIS WITH THE VIVIA HAEMODIALYSIS SYSTEM Phil McFarlane Phil McFarlane 1 St. Michael's Hospital, Toronto, ON, Canada Rosa Marticorena Rosa Marticorena 1 St. Michael's Hospital, Toronto, ON, Canada Niki Dacouris Niki Dacouris 1 St. Michael's Hospital, Toronto, ON, Canada Robert Pauly Robert Pauly 2 University of Alberta Hospital, Edmonton, AB, Canada Sergey Nikitin Sergey Nikitin 2 University of Alberta Hospital, Edmonton, AB, Canada Michael Amdahl Michael Amdahl 3 Baxter Healthcare, Deerfield, IL Angelito Bernardo Angelito Bernardo 3 Baxter Healthcare, Deerfield, IL Bruce Culleton Bruce Culleton 3 Baxter Healthcare, Deerfield, IL Abstract Introduction and Aims: The Vivia Haemodialysis System (Baxter Healthcare, Deerfield, IL, USA) was designed for the patient as the primary operator in a home environment. To reduce the burden associated with performing frequent and / or long haemodialysis (HD) in the home, the Vivia HD System includes features not typically available in traditional HD devices. These unique features include (1) extended use of the dialyser (2.1m2 polyethersulfone membrane) and blood set, facilitated by in-situ hot water disinfection between treatments; (2) generation of on-line infusible quality dialysate to allow automated priming, rinseback, and hemodynamic support during hypotensive episodes; and (3) a fully integrated access disconnect system to mitigate the risk associated with venous access disconnections. Given these unique features, we sought to determine the safety and efficacy of the Vivia HD System in a controlled clinical environment. Methods: Prevalent in-centre nocturnal HD patients were enrolled in this prospective, single arm clinical study at two clinical sites in Canada. All subjects received nocturnal HD, three times per week, for six weeks. Safety was assessed in all subjects who used the Vivia HD System at least once. Urea clearance was assessed using second generation estimates for single pool Kt/V. Anticoagulation was obtained with unfractionated heparin with adjustments to maintain intra-dialysis activated partial thromboplastin times (aPTT) levels between 1.5x and 2.0x pre-dialysis values. The association between fluid weight removed (as measured by Vivia) and weight change (determined using weigh scales) was calculated for each treatment. Dialysate was sampled at a minimum of three times per subject throughout the study. Dialysate criteria for success was defined as a bacterial count of 0 CFU/mL and an endotoxin level of < 0.03 EU/mL, consistent with AAMI and ISO standards for dialysate for infusion. Results: Seventeen subjects (mean age 55 years, 35% F) were enrolled. Sixteen subjects experienced at least one adverse event. The adverse event profile was similar to the event profile expected for prevalent HD patients. Hypotension was the most common adverse event (5 events per 100 treatments). There were no device related serious adverse events (i.e. hospitalizations or deaths) during the study. During the evaluable period, the mean (standard deviation) duration of each treatment was 7.0 (0.6) hours with a blood flow rate and dialysate flow rate of 293 (23) ml/min and 318 (27) ml/min, respectively. The mean single pool Kt/V was 2.49 (95% confidence interval 2.02 to 2.96). The association between fluid weight removed as measured by Vivia and weight change was high (R2 0.97). The maximum number of uses from a single dialyser and blood set was 17; 10 subjects (59%) achieved 10 or more uses from the same dialyser. Heparin bolus and infusion rates were increased from baseline in the majority of subjects by ~ 50%. Of 90 dialysate samples obtained, two samples showed bacterial counts of 0.002 CFU/mL, both secondary to environmental contamination. Three dialysate samples had endotoxin results out of range: (0.03 EU/mL, 0.035 EU/mL and 0.035 EU/mL). All positive endotoxin samples were retested in quadruplicate and all measured less than 0.03 EU/mL. The positive samples were due to known variability of the testing method at the acceptance limit. Conclusions: This study confirms the safety and expected performance of the Vivia HD System for extended duration HD treatments. SP432 MID-TERM EVALUATION OF CITRATE DIALYSATE-REINFUSATE IN ON-LINE POSTDILUTIONAL HEMODIAFILTRATION Giovanni Calabrese Giovanni Calabrese 1 Nephrology and Dialysis Unit ASL AL, Casale Monferrato, Italy Domenico Mancuso Domenico Mancuso 1 Nephrology and Dialysis Unit ASL AL, Casale Monferrato, Italy Antonio Mazzotta Antonio Mazzotta 1 Nephrology and Dialysis Unit ASL AL, Casale Monferrato, Italy Giuseppe Vagelli Giuseppe Vagelli 1 Nephrology and Dialysis Unit ASL AL, Casale Monferrato, Italy Chiara Balenzano Chiara Balenzano 1 Nephrology and Dialysis Unit ASL AL, Casale Monferrato, Italy Denis Steckiph Denis Steckiph 2 Gambro-Hospal SpA, Bologna, Italy Andrea Bertucci Andrea Bertucci 2 Gambro-Hospal SpA, Bologna, Italy Mario Della Volpe Mario Della Volpe 1 Nephrology and Dialysis Unit ASL AL, Casale Monferrato, Italy Marco Gonella Marco Gonella 1 Nephrology and Dialysis Unit ASL AL, Casale Monferrato, Italy Abstract Introduction and Aims: During HDF even low acetate concentrations in the dialysate-reinfusate (dAC) result in a sharp increase of serum AC, which induces the release of proinflammatory mediators. A citrate-based concentrate (dCIT) was recently marketed, but, since CIT binds Ca++and can change Ca mass balance, this concentrate is not yet widely used. The aim of the present study was to evaluate the effect of replacing dAC with dCIT upon Ca and PTH level during high-volume HDF online. A secondary end point was to evaluate the best strategy aimed to avoid undesirable changes on pre-dialysis PTH value. Methods: In 16 patients (pts) on long-term HDF (Polyamide m. 2.1 m2, Qb 400 and UF 94±10 ml/min), dAC (3.0 mmol/l) was substituted with dCIT (1 mmol/l, Selectbag Citrate, Gambro) on acid concentrate for one week, keeping unchanged for each pt the oral therapy and dCa (1.5 mmol/l) (Period 1). During the following 6 months of follow-up on CIT-HDF, the mean dose of CaCO3 and Calcitriol was increased (25 and 46%, respectively) (Period 2). During the last 6 months (Period 3), dCa was kept unchanged in 3 pts and was increased in 13 (1.65 mmol/l) and oral therapy returned to baseline prescription. The HD monitor (ARTIS, Gambro) as well as the other hemodialysis prescriptions (Session length, Blood flow, Dialyzer) were kept constant through all the periods.At the baseline and at the end of each period, PTH, total and ionized Calcium (tCa, iCa) were measured at pre and post-dialysis in the mid-week session. Moreover, in the same sessions, total convective volume was recorded. Results: At baseline (AC-HDF) the tCa level increased during the session (from 2.31±0.12 to 2.63±0.16 mM, p<0.0001), while it was stable during Period 1, but it increased again in Period 2 and 3 (Period 1: from 2.37±0.14 to 2.42±0.11 mM, p=0.12; Period 2: from 2.31±0.15 to 2.47±0.11 mM, p<0.01; Period 3: from 2.23±0.08 to 2.60±0.10 mM, p<0.0001). The iCa increased in Ac-HDF (from 1.13±0.05 to 1.22±0.03 mM, p<0.0001) and decreased during the Cit-HDF treatments, except the Period 3 (Period 1: from 1.12±0.07 to 1.07±0.03 mM, p<0.01; Period 2: from 1.09±0.07 to 1.05±0.03 mM, p<0.03; Period 3: from 1.14±0.07 to 1.12±0.09 mM, p<0.55). The PTH consistently followed the iCa, decreasing in Ac-HDF (273±196 to 141±99 pg/ml, p<0.0001) and decreased during the other Cit-HDF treatments, except during Period 3 (Period 1: from 298±174 to 358±178 pg/ml, p<0.01; Period 2: from 337±207 to 409±204 pg/ml, p<0.005; Period 3: from 246±223 to 189±130 pg/ml, p<0.01).Finally, the convective volume, set automatically by TMP biofeedback (UltraControl, Gambro), increased by citrate introduction, although not significantly (Baseline: 24.7±2.6 L, Period 1: 26.0±2.6 L, Period 2: 26.1±3.9 L, Period 3: 26.0±2.6 L, p=0.06). Conclusions: The adequate dialysate Ca in extracorporeal dialysis is still debated and should be chosen on the basis of clinical factors. If a negative Ca balance is unwanted on CIT-HDF, the increase of dCa of 0.15 mmol/l can be taken into account as first approach and the increase of oral therapy (Calcium an/or Vit. D derivates) as a second step. SP433 USEFULNESS OF TOXINOMETER MINI TO MONITOR DIALYSATE PURIFICATION IN CENTRAL DIALYSATE DELIVERY SYSTEM Takayuki Uchida Takayuki Uchida 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Katsunobu Ando Katsunobu Ando 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Masaya Kofuji Masaya Kofuji 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Tsukasa Higuchi Tsukasa Higuchi 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Naoki Momose Naoki Momose 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Kiyonori Ito Kiyonori Ito 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Yuichirou Ueda Yuichirou Ueda 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Haruhisa Miyazawa Haruhisa Miyazawa 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Yoshio Kaku Yoshio Kaku 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Aoi Nabata Aoi Nabata 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Taro Hoshino Taro Hoshino 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Honami Mori Honami Mori 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Izumi Yoshida Izumi Yoshida 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Susumu Ookawara Susumu Ookawara 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Kaoru Tabei Kaoru Tabei 1 Saitama Medical Center Jichi Medical University, Saitama, Japan Abstract Introduction and Aims: Central dialysate delivery system (CDDS), which produces dialysate at a central supply equipment, and distributes it from central to dialysis machines, was major system for supplying dialysate in hemodialysis (HD) treatment in Japan. Dialysate purification is essential to use the high performance dialyzers in Japan. Therefore, we routinely measured endotoxin (ET) activity and cultivated bacteria into dialysate in our dialysis center to evaluate dialysate purification. In this study, we aimed to evaluate the usefulness of Toxinometer Mini (WAKO Pure Chemical Industries Ltd), which is automated instrument that measures ET activity by simple, easy and cost-benefit operation. Methods: To confirm the accuracy of Toxinometer Mini measurement, the data of ET measured by Toxinometer Mini was compared with authorized clinicalexamination laboratory (SRL, Tokyo, Japan). Thereafter, we measured ET by Toxinometer Mini every months for 18 months. For evaluating the count of bacteria, membrane filtration method (37mm Quality Monitor Nihon Pall Ltd) was applied for cultivating bacteria. Samples were collected every month at reverse osmosis system, central supply equipment and on-line hemodiafiltration (HDF) machines, every six months at powder dissolution machine, and once a year at each HD machines. Results: There was a significant and positive linear correlation between ET concentrations measured by Toxinometer Mini and authorized clinical examination laboratory (r=0.99, p<0.001).The Bland-Altman plots for the comparative analysis showed good agreements between the two methods for both Toxinometer Mini and authorized clinical examination laboratory(N=82). Lower limit of ET measurement reached 0.001EU/mL for both instruments,and these values were satisfied the sensitivity of ET measurement recommended by Japanese Society for Dialysis Therapy (JSDT) guideline. We had measured ET concentrations and bacterial cultures for 18 months in CDDS and single patient dialysis machine (SPDM) (N=199). Only once of these samples was positive in ET measurement at SPDM , and also ,several times of bacterial cultures were positive in CDDS and SPDM , however detected ET concentrations and colonization of cultivated bacteria were below the standard recommended by JSDT guideline. In comparison between costs in ET measurement using Toxinometer Mini and using authorized clinical examination laboratory, the former required only 8.5 euro whereas the latter required about 20 euro per sample. Conclusions: The present study indicated that the ET measurement using Toxinometer Mini would be effective for monitoring dialysate purification. Sufficient management to dialysate purification could be performed by ET measurement using Toxinometer Mini and cultivation of bacteria in dialysate. SP434 DETECTION OF ALBUMIN FRAGMENTS ON DIALYZER MEMBRANES Koichi Umimoto Koichi Umimoto 1 Osaka Electro-Communication University, Shijonawate, Japan Miyuki Suyama Miyuki Suyama 1 Osaka Electro-Communication University, Shijonawate, Japan Yoshimasa Shimamoto Yoshimasa Shimamoto 1 Osaka Electro-Communication University, Shijonawate, Japan Masahiro Miyata Masahiro Miyata 1 Osaka Electro-Communication University, Shijonawate, Japan Aki Kamada Aki Kamada 1 Osaka Electro-Communication University, Shijonawate, Japan Abstract Introduction and Aims: In recent years, albumin fragments (Af) have been found in the urine of patients with diabetic nephropathy and the clinical significance of Af has been noted. When hemodialysis (HD) is performed, albumin is known to be adsorbed to the dialyzer membrane and it leaks into the dialysate with high-flux dialyzers. We have previously reported about analysis of protein adsorbed to dialyzer membranes. This time, we investigated adsorbed Af on dialyzer membranes and Af in the ultrafiltration (UF) fluid after dialysis with high-flux dialyzers. Methods: After standard HD with a cellulose triacetate (CTA) membrane or polymethylmethacrylate (PMMA) membrane, the dialyzers were rinsed with 0.9% NaCl solution. Then the membranes were cut into small fibers and the proteins were eluted from each membrane. At 30 minutes after starting HD with a PMMA membrane or a polyester polymer alloy (PEPA) membrane, UF fluid was collected. Then the samples were analyzed by dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and proteins were identified by western blotting (WB) using antihuman serum. In addition, quantitative image analysis was performed with a Gel Doc EZ (Bio Rad, Ltd.). Results: SDS-PAGE and WB showed the main band at 66 kilodaltons (KDa) after HD with both CTA and PMMA membranes, and this was identified as albumin. Thin bands were also found in the vicinity of 20 KDa and 40 KDa after HD with both membranes and these were identified as Af. In the UF fluid, albumin was detected at 66 KDa with both PMMA and PEPA membranes, and its quantity was 16.25×105and 20.69×105 signal intensity·mm2, respectively. There was no other band with the PMMA membrane except the band of albumin at 66 KDa, but thin bands of AF were found in the vicinity of 20 KDa with the PEPA membrane and the quantity of Af was 0.13×105 signal intensity·mm2. Conclusions: It is already known that serum proteins are adsorbed to dialyzer membranes and that albumin leaks into the dialysate with high-flux membranes. These results confirm that Af is also adsorbed to dialyzer membranes and that a small amount of Af leaks into the dialysate as well as albumin with PEPA membranes. SP435 EVALUATION OF VOLUME OVERLOAD IN HEMODIALYSIS PATIENTS USING BIOIMPEDANCE DEVICE Rika Sakai Rika Sakai 1 Koga General Hospital, Miyazaki, Japan Akihiro Minakawa Akihiro Minakawa 1 Koga General Hospital, Miyazaki, Japan Keiichi Fukudome Keiichi Fukudome 1 Koga General Hospital, Miyazaki, Japan Shuichi Hisanaga Shuichi Hisanaga 1 Koga General Hospital, Miyazaki, Japan Tabito Ishihara Tabito Ishihara 2 Fujimoto Central Hospital, Miyazaki, Japan Kazuhiro Yamada Kazuhiro Yamada 3 Social Insurance Miyazaki Konan Hospital, Miyazaki, Japan Shin Fukunaga Shin Fukunaga 3 Social Insurance Miyazaki Konan Hospital, Miyazaki, Japan Hiroko Inagaki Hiroko Inagaki 4 Chiyoda Hospital, Miyazaki, Japan Chihiro Tanaka Chihiro Tanaka 4 Chiyoda Hospital, Miyazaki, Japan Yuji Sato Yuji Sato 5 Dialysis Division, University of Miyazaki Hospital, Miyazaki, Japan Shoichi Fujimoto Shoichi Fujimoto 6 Department of Hemovascular Medicine and Artificial Organs, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan, Miyazaki, Japan Abstract Introduction and Aims: Assessment of body fluid overload in hemodialysis patients is clinically important. However, objective methods that evaluate fluid over load are limited. Methods: This was cross-sectional study assessing the usefulness of a new bioimpedance spectroscopy device to evaluate over hydration (OH) just before and just after hemodialysis session in Japan. 147 patients (mean age 65.9 years, 57.8% men, 31.3% diabetes was basal kidney disease, 19.7% comorbid with congestive heart failure, ischemic heart disease and valvular heart disease) were enrolled. Results: Pre-hemodialysis (HD) OH was ranged from +1.08 to +4.22 and post-HD OH from -1.02 to +2.10 (10thand 90th percentile, p<0.001 by Wilcoxon signed-rank test). Patients number was increased from 9.5% of pre-HD patients to 61.9% of post-HD patients who were within normal range of OH (-1.1 to +1.1 L). Amount of ultrafiltration was significantly correlated with absolute change of OH between pre-HD and post-HD (r=0.508, p<0.01). Post-HD OH was positively correlated with post-HD plasma atrial natriuretic peptide(ANP) levels (r=0.505, p<0.01). By multivariate logistic regression analysis, higher ANP level (over than 100 pg/ml) was significantly associated with post-HD OH, age and CHF or valvular heart disease, and higher post-HD OH level (over than +1.1 L) was significantly associated with pre-HD OH and plasma ANP. Conclusions: In conclusion, new bioimpedance spectroscopy device is useful to evaluate over hydration in dialysis patients. These OH data suggested that a certain level of our patients might not be set ideal dry weight. SP436 ON-LINE HEMODIAFILTRATION (OL-HDF): WHICH MODALITY FOR WHICH BLOOD FLOW RATE? Jacky Potier Jacky Potier 1 CHPC, Cherbourg, France Julien Bouet Julien Bouet 1 CHPC, Cherbourg, France Guillaume Queffeulou Guillaume Queffeulou 1 CHPC, Cherbourg, France Abstract Introduction and Aims: Even if Post-HDF (POST) has become the reference, other ol-HDF modalities (HDF) differentiated by their infusion site (PRE, MIXED and MID) permit Middle Molecules (MM) to be optimally removed. Then, the absence of volumetric recommendation - as with POST- and generalization of HDF, whatever vascular access and blood flow rate (Qb) have led us to compare HDF from their MM removal efficiency and to find the best match between Qb and HDF. Methods: 10 patients (pts); M=7; F=3; Age 74±10.9y; dialysed since 55.2±70m underwent 4 hours PRE, POST MIXED and ol-HDF sessions with 5008Cordiax (Fresenius), AutoSub+ and FXCordiax1000 dialyser. MID 4 hours sessions were performed with an OLPURMD220 (Bellco) dialyser and Total Convective Volume (Vconv) in MID was fixed to be equal to the one obtained in MIXED in the same conditions. MM removal efficiency of beta2-microglobulin (β2m; 11.8kDa), myoglobin (Myo; 17.2kDa), Prolactin (PLT; 23kDa) and Orosomucoïd (ORO; 42kDa) were evaluated by Reduction Ratios (RR(%) = (Cpre-CPost) / Cpre with Cpost corrected for hemoconcentration).Each pt was dialysed with each one of the 4 HDF modalities, but was allocated to only one Qb Group (Qb): 250mL/min (Qb250) for 4 pts (3/4 with a chronic jugular catheter); Qb300 for 3 pts and Qb350 for 3pts. Each pt was dialysed with each one of the 4 HDF. Statistical analysis (StatView) was performed with Student's unpaired test. Data are expressed by mean +/- SD and P<0.05 is considered as significant. Results: For POST and MIXED modalities, the lower Vconv (L) were obtained in Qb250 group (Vconv POST = 16.3±1.7; p=0.001, Vconv MIXED = 28.7±2.6 (NS)), versus Qb300 (V Conv POST: 24.7±1.3, Vconv MIXED: 34.3±5.6) or Qb350 (Vconv POST: 25.6±1.7, Vconv MIXED: 34.9±2.3). Mean Vconv PRE was 57.2±9.8 with no influence of the Qb.RRβ2m: Qb250 :79.2±2.8 ;Qb300 :81.7±3.3 ;Qb350 :82.3±5.9 . No significant difference between Qb or between HDF modalities in each Qb groupRRmyo: Qb250 :62.0±8.6 ;Qb300 :70.0±10.1 ;Qb350 :67.8±12.2 , p=0.032 between Qb250 and Qb300 . In Qb300 group, MIXED and POST were more efficient for myoglobin removal (RR = 76.2±5.9 and 77.8±0.8) vs PRE(56.3±7.5).RRPLT: Qb250 :65.1±10.1 ;Qb300 :67.8±15.9 ;Qb350 :63.7±14.6 - No significant difference between Qb or between HDF modalities in each Qb group.RRORO: Qb250 :6.0±5.4 ;Qb300 :6.3±8.6 ;Qb350 :9.4±4.0 - No significant difference between Qb. In Qb350 group, MIXED and POST were more efficient than PRE for orosomucoid removal (RR MIXED = 11.5±1.6; p=0.01, RR POST = 10.31±3.2; p=0.049, RR PRE= 4.1±2.03) Conclusions: Vconv seemed optimal from Qb300. Globally, in terms of MM removal, there was no difference between Qb, each one including all HDF modalities. This finding argues for a universal use of HDF whatever Qb. In each Qb, there was only minor differences between HDF and always between POST or MIXED versus PRE. For Qb250 and Qb300 MIXED was always the more efficient and proportionally to the MW of the molecule. Finally we recommend all HDF modalities, but especially those with a Post-dilution participation if removal of toxins with a MW above the β2m one is wished, as often actually recommended. SP437 EFFICACY AND SAFETY OF TINZAPARIN ANTICOAGULATION OF THE EXTRACORPOREAL CIRCUIT WITH A SINGLE BOLUS ADMINISTRATION IN NOCTURNAL HOME HEMODIALYSIS Robert Bell Robert Bell 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Linda Nolin Linda Nolin 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Vincent Pichette Vincent Pichette 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Helene Provencher Helene Provencher 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Caroline Lamarche Caroline Lamarche 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Annie-Claire Nadeau-Fredette Annie-Claire Nadeau-Fredette 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Georges Ouellet Georges Ouellet 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Martine Leblanc Martine Leblanc 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Sarah Bezzaoucha Sarah Bezzaoucha 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Yasmina Kouidmir Yasmina Kouidmir 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Jeannine Kassis Jeannine Kassis 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Marie-Louise Alonso Marie-Louise Alonso 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Jean-Philippe Lafrance Jean-Philippe Lafrance 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Michel Vallee Michel Vallee 1 Hopital Maisonneuve-Rosemont, Montreal, QC, Canada Abstract Introduction and Aims: Tinzaparin, a low molecular weight heparin, has shown practical benefits over unfractionated heparin for extracorporeal circuit (ECC) anticoagulation during in-center hemodialysis treatment. However, efficacy and safety of anticoagulation with tinzaparin has not been substantiated in patients with extended dialysis sessions, as in nocturnal home hemodialysis (NHD). In this regard, we present our experience with tinzaparin, administrated as a single bolus injection into the arterial line of the ECC for patients requiring 8 hours of anticoagulation. Methods: Fifteen chronic dialysis patients admitted to our NHD program between 2009 and 2012 had their first 8-hour in-center dialysis session receiving twice the tinzaparin dose that gave adequate anticoagulation for their usual 4-hour dialysis treatment. This represented a mean tinzaparin dose of 54± 12 and 110± 19 anti-Xa units/kg for a 4-hour and 8-hour dialysis session, respectively. Safety and dose/response were assessed by measuring anti-Xa levels at time 0 and at 15, 30, 60, 120, 240, 360 and 480 min after administration. Anticoagulation efficacy was evaluated visually, in 14 of the 15 patients, by assessing clot formation in both the dialyzer and the venous bubble trap through a simple scoring system. Results: A mean peak plasma anti-Xa level of 1,35 ± 0,52 U/ml was reached within 15 min and averaged 0,32 ± 0,16 U/ml by the end of the 8-hour session. Although the relationship between anti-Xa levels and clinical outcomes is unclear, usual recommended therapeutic anti-Xa levels for once-daily treatment ranges from 1.0 and 2.0 U/ml. There was no complete coagulation of the ECC in either the dialyzer or the venous bubble trap. There were 7 moderate coagulation events: 1 in the dialyzer and 6 in the venous bubble trap. There were no episodes of minor or major bleeding in any of the patients. Subsequent doses were adjusted to prevent further clotting. The mean tinzaparin dose was 111± 20 anti-Xa units/kg before and 113±15 anti-Xa units/kg after dose adjustment, p > 0,05. Conclusions: Our experience is the first to demonstrate that a single weight-based intravenous bolus administration of tinzaparin in NHD is effective and safe. SP438 MULTIPARAMETRIC ONLINE SENSORS FOR DIALYSIS DEVICE Julien Fils Julien Fils 1 Metemis, Moirans, France Pascal Mailley Pascal Mailley 2 CEA-LETI, Grenoble, France Abstract Introduction and Aims: Monitoring system for dialysis machine. To improve the quality of the dialysis treatment and to follow the health status of the patient during this treatment, the continuous monitoring of the blood composition in terms of ion contains provides accurate information. Indeed, away from the patient staus, this monitoring gives a clear view of the efficiency of the machine and allows anticipating adjustments in the device setup. Methods: In the framework of the European FP7 project Nephron+, the partner developed a sensing platform (multisensory system and associated electronic management) for the monitoring of endogenous ions including H+ (pH) calcium, sodium, potassium and chloride. It is worth to notice that this platform is not limited to the aforementioned species and may include if required sensors dedicated to small organic species such as urea or glucose. The plateform sensors are embedded into the Wearable Artificial Kidney Device developed within this NEPHRON+ project to monitor the status of the device and the health parameters of the dialysate patient. Each of these sensors works on the potentiometry mode: briefly, the difference of potential between a reference electrode and a selective sensitive electrode is measured, its amplitude being proportional to the concentration of the target ion. The potetiometric electrodes, so called Ion Selective Electrodes (ISE) are designed in three layers. The first one is a metallic electrode which is connected to the electronic board, then a liquid layer which acts as internal electrolyte (that contains a reference concentration of the target ion) between the metallic electrode and the sensitive membrane used as third layer. The latter is chemically designed to be specific for one ion without interferences from the ionic fauna of the dialysate.These electrodes are designed to be low cost in order to allow their integration in one-shot systems. Their small size, less than one 1mm square, enables their positioning in direct contact with the dialysate within the fluidic sensing chamber which is placed directly on the main dialysate fluidic line. These sensors can be implemented in several part of the device due to their small form factor. Furthermore, the sensors have been proved to be mechanically stable (no leakage or drilling of the membrane) for at least one month under function. In addition, the membrane and the inner solution are biocompatible according to the ISO standards (13995) and can be sterilized thanks to manufacturing conditions (sterile environment) or beta sterilization.The sensors deliver real time monitoring of ion concentrations with a response time of few seconds. Thereby, the potential measurements are sampling every second or more (according to the required dynamic) and sent to the display or the main board of the device in real time. Results: The sensor platform has been tested by the company Nanodialysis and validated after more than one week of use in continuous within artificial dialysate. Each sensor shown long lifetime (more than 2 months), and provided the required accuracy and precision. The sensors show good performances against interferences. At now, owing to their simple and efficient architecture, the sensors can be implemented within an industrial process to produce them in a large scale. Conclusions: The potentiometric sensor platform, designed for the monitoring of dialysis, has demonstrated its ability to provide continuous real time multiparametric information about the state of the patient and of the dialysis machine efficacy. The design of the sensors, especially the constitutive materials, provides biocompatibility and ability to be sterilized. The transfer to an industrial company will allow providing these sensor platforms or unitary sensors in large quantity to perform their CE marking. SP439 COUPLED PLASMA-FILTRATION ADSORPTION (CPFA) REDUCES TUBULAR INJURY IN BILE-ASSOCIATED CAST NEPHROPATHY THROUGH DIRECT ADSORPTION OF BILIRUBIN AND LIVER-TYPE FATTY ACID BINDING PROTEIN Vincenzo Cantaluppi Vincenzo Cantaluppi 1 University of Torino, Torino, Italy Davide Medica Davide Medica 2 Nephrology, Dialysis and Kidney Transplantation Unit, Torino, Italy Alessandro D Quercia Alessandro D Quercia 2 Nephrology, Dialysis and Kidney Transplantation Unit, Torino, Italy Sergio Dellepiane Sergio Dellepiane 2 Nephrology, Dialysis and Kidney Transplantation Unit, Torino, Italy Silvia Ferrario Silvia Ferrario 2 Nephrology, Dialysis and Kidney Transplantation Unit, Torino, Italy Massimo Gai Massimo Gai 2 Nephrology, Dialysis and Kidney Transplantation Unit, Torino, Italy Gianluca Leonardi Gianluca Leonardi 2 Nephrology, Dialysis and Kidney Transplantation Unit, Torino, Italy Cesare Guarena Cesare Guarena 2 Nephrology, Dialysis and Kidney Transplantation Unit, Torino, Italy Marialuisa Caiazzo Marialuisa Caiazzo 3 Scientific Affairs, Bellco Srl, Mirandola (MO), Italy, Italy Luigi Biancone Luigi Biancone 2 Nephrology, Dialysis and Kidney Transplantation Unit, Torino, Italy Abstract Introduction and Aims: Bile-associated deposition of intraluminal casts and proximal tubular epithelial cell (TEC) apoptosis are possible causes of acute kidney injury (AKI) in the course of severe liver dysfunction. TEC injury is mediated by bilirubin adsorption through a mechanism dependent on the activity of the endocytic receptor megalin. Liver-type Fatty Acid Binding Protein (L-FABP) is a 15 KDa peptide belonging to the free fatty acid family able to bind hydrophobic molecules including bilirubin. During liver failure, the increase of L-FABP plasma levels is known to enhance bilirubin uptake with consequent damage of tubular cells. Indeed, L-FABP is able to bind to megalin mediating bilirubin uptake in TEC. The aim of this study was to investigate the protective role of Coupled Plasma Filtration Adsorption (CPFA) on bile cast nephropathy through direct L-FABP and bilirubin resin adsorption. Methods: We reported the case of a kidney transplant patient who developed sepsis, AKI and liver dysfunction treated by CPFA. We evaluated plasma levels of bilirubin and L-FABP. Renal biopsies, urine sediment and NGAL were performed at different time points. In vitro, we tested: 1) static and dynamic adsorption of L-FABP to polystyrene resin; 2) pro-apoptotic effect (TUNEL) of patient’s plasma drawn before and after CPFA on human tubular epithelial cells (TEC): the role of L-FABP was further confirmed in tubular cells engineered to knock-down megalin, the L-FABP receptor, by small interfering RNA (siRNA). Results: A 50-year-old man was subjected to kidney transplantation with slow recovery of graft function. Kidney biopsy revealed acute tubulo-interstitial and vascular rejection treated with thymoglobulin. He then developed septic shock for Legionella infection with multiple organ failures (serum creatinine 5.2 mg/dl and oliguria requiring dialysis; bilirubin 42 mg/dl with liver biopsy showing marked cholestasis; plasma L-FABP 52 ng/ml). Urine analysis showed the presence of tubular cells, casts and intense positivity for bilirubin: urine NGAL level was 356 ng/ml. A new kidney biopsy showing bile cast nephropathy was performed. After CPFA was started, we observed an increase of urine output, a decrease of bilirubin (<15 mg/dl), L-FABP (9 ng/ml) and urine NGAL (82 ng/ml).In vitro, we observed that the polystyrene resin efficiently adsorbed L-FABP in static and dynamic condition. When we incubated TEC with patient’s plasma, we observed a cytotoxic and pro-apoptotic effect with activation of caspases. After CPFA treatment, the pro-apoptotic activity of patient's plasma on TEC was significantly reduced. In addition, plasma-induced TEC apoptosis was dependent on the presence of megalin, the L-FABP receptor: indeed, the pro-apoptotic effect of plasma was significantly reduced in TEC engineered to knock-down megalin by siRNA. Conclusions: CPFA may have a protective role in bile-associated cast nephropathy and TEC apoptosis through the direct adsorption of bilirubin and L-FABP to the synthetic polystyrene resin. CPFA may be exploited as therapeutic option to limit AKI during sepsis and in bridge to transplantation of patients with end stage liver failure. SP440 CARBON FOOTPRINTS OF AN IN-CENTRE HAEMODIALYSIS DEVICE, THE NXSTAGE SYSTEM ONE AND THE VIVIA HAEMODIALYSIS SYSTEM Margaret Enos Margaret Enos 1 Baxter Healthcare Corporation, Deerfield, IL Bruce Culleton Bruce Culleton 1 Baxter Healthcare Corporation, Deerfield, IL Derek Wiebenson Derek Wiebenson 2 Baxter Healthcare SA, Zurich, Switzerland Abstract Introduction and Aims: Increasing haemodialysis (HD) duration and / or frequency is gaining popularity and has been shown to improve clinical and humanistic outcomes. Furthermore, there is an increasing interest to create a more sustainable therapy for this growing patient population, as demonstrated by initiatives such as the National Health Service’s carbon reduction strategy in the United Kingdom, the Green Nephrology Programme for sustainable kidney care, and Environmentally Preferable Purchasing policies adopted by hospitals and purchasing organizations. In order to further understand the potential environmental impact of a growing home HD patient population, this study assessed the carbon footprints of a conventional HD (CHD) device (Arena, Baxter Healthcare, Deerfield, IL), used both in-centre and in the home setting, and two Home HD machines (Vivia, Baxter Healthcare, Deerfield, IL and System One, NxStage, Lawrence, MA), including regimens of nocturnal HD, short daily HD and CHD for six countries (Canada, France, Germany, Sweden, the United Kingdom, and the United States). Methods: This study utilized the life cycle assessment method to calculate the cradle-to-grave greenhouse gas emissions including consumable supplies, energy and water used during treatment, people transportation, and waste disposal. The frequency and duration of the treatments assessed were 5 times a week, 7 hours per treatment for nocturnal HD; 6 times a week, 3 hours per treatment for short daily HD; and 3 times a week, 4 hours per treatment for CHD. Results: The overall carbon footprint was greatest for the System One device when used for short daily HD, followed by the same device when used for frequent nocturnal HD. Averaging the results across all six countries, the carbon footprint was most dependent on the quantity and types of consumables used for each therapy (see Table). Consumables represented 83-87% of the carbon footprint for System One, 66-68% for Arena in the home setting, and 43-51% for Vivia. Comparing the same therapy, the Vivia HD System, in which the dialyser and blood set can be used multiple times, had a 50-56% smaller carbon footprint than NxStage System One and a 42% smaller carbon footprint than the Arena device. Either patient travel for a monthly doctor’s visit or water usage during treatment made the smallest contribution (30%) after treatment consumables (>40%). Conclusions: These results suggest that maximizing the use of consumables or producing consumables in a more environmentally responsible manner will have the greatest impact in delivering sustainable HD therapies. Although high dose HD has more weekly treatment sessions, performing this therapy in the home with Vivia generates fewer emissions than CHD performed less frequently in-centre. View largeDownload slide View largeDownload slide SP441 IS THERE A RECOMMENDED CONVECTIVE VOLUME FOR MIXED HEMODIFILTRATION? Jacky Potier Jacky Potier 1 CHPC, Cherbourg, France Mélanie Hanoy Mélanie Hanoy 2 CHU, Rouen, France Simon Duquennoy Simon Duquennoy 3 CHU, Caen, France Abstract Introduction and Aims: Since ESHOL study, one considers a Convective Volume (Vconv) >= 23.1L as an objective but this goal is restricted to Post ol-HDF (POST). MIXED is currently proposed on 5008 Cordiax (Fresenius) with a complete automated mode. The delivered Substitution Volume (VSubs) is then shared between Pre and Post-Dilution modalities. Observational data showed high consistency between delivered Vconv in POST - managed with AutoSub+ - and its corresponding Post Vconv (= Post VSubs + UF) in MIXED.We tried to determine if this Volume equivalence is correlated to a similar Middle Molecule (MM) solute removal, the aim being to find a volumetric recommendation also for MIXED. Methods: 21 patients (pts) from 3 centers; M=12; F=9; Age = 72.1±13.9 years; Weight = 73.1±14.5 Kg, dialyzed since 84.2±83.6 months, underwent one 4 hours dialysis session with POST (AutoSub+) and one MIXED session. All sessions were performed on 5008 Cordiax with FX Cordiax 1000 hemodiafilter. MM removal efficiency of beta2-microglobulin (β2m; 11.8kDa), Myoglobin (Myo; 17.2kDa), Prolactin (PLT;23kDa) and Orosomucoïd (ORO; 42kDa) was evaluated by Reduction Ratios (RR = (Cpre-CPost) / Cpre with Cpost corrected for hemoconcentration.)Each patient was treated with only one of the 4 Qb groups (Qb): 250mL/min (Qb250) for 6 pts (1 catheter); Qb300 for 5 pts (2 catheters), Qb350 for 5pts and Qb400 for 5pts. Statistical analysis (StatView) was performed with Student's unpaired test. Data are expressed by mean +/- SD. P<0.05 is considered as significant. Results: (Cf Table 1) Total Vconv (L) was proportional to Qb. It was higher in MIXED: 34.5±5.1 (from 29.1±3.4 with Qb250 to 39.5±1.7 with Qb400). Post infusion ratio in MIXED reached 66 to 69%. and there was no significant difference between Post Vconv in the two modalities: Mean Post Vconv in MIXED = 24.4±3.5 (from 20.0±1.2 with Qb250 to 28.7±1.3 with Qb400) and Mean Post VConv in POST = 25.2±3.6 (from 21.3±0.9 with Qb250 to 29.9±1.6 with Qb400), For each Qb, RR were not significantly different between POST and MIXED, whatever the solute, even if Qb250 RR values were lower for β2M and Myo. For higher MW solutes, MIXED appeared better (but NS) and for PLT, RR was even inversely correlated to Qb in POST. Conclusions: 5008 Cordiax system delivers similar Post VConv - whatever Qb - in MIXED and POST modalities, probably linked to the new AutoSub+. This similarity allows us to compare the MM removal efficiency of two equivalent Post Vconv, the first pre-diluted with MIXED and the second considered as the reference in terms of morbidity and mortality. As the MM removal is consistently identical, we suggest the volumetric recommendations for MIXED should be similar to those of the POST (Post Vconv>= 23.1L). Otherwise, the Pre-D contribution with MIXED could explain the tendency toward a better removal of the highest MW solutes that should be confirmed by a study with a greater number of patients. Table 1 RR Results (MIXED in the top line of each cell of the table) RR% β2m Myo PLT ORO Qb250 80.4±4.7 81.3±2.9 71.0±8.7 74.3±6.6 72.9±7.8 73.0±7.1 14.4±7.2 12.8±10.6 Qb300 84.3±1.4 84.1±2.5 80.1±3.4 78.2±6.3 78.9±7.9 74.72±7.0 16.6±11.0 11.7±10.1 Qb350 84.5±6.2 84.8±6.2 78.9±7.9 74.72±7.0 75.7±12.9 70.0±18.9 16.0±4.0 16.9±7.6 Qb400 84.2±5.8 85.6±3.6 77.4±3.1 76.4±5.1 76.0±7.7 67.3±15.7 17.6±4.0 12.03±9.6  RR% β2m Myo PLT ORO Qb250 80.4±4.7 81.3±2.9 71.0±8.7 74.3±6.6 72.9±7.8 73.0±7.1 14.4±7.2 12.8±10.6 Qb300 84.3±1.4 84.1±2.5 80.1±3.4 78.2±6.3 78.9±7.9 74.72±7.0 16.6±11.0 11.7±10.1 Qb350 84.5±6.2 84.8±6.2 78.9±7.9 74.72±7.0 75.7±12.9 70.0±18.9 16.0±4.0 16.9±7.6 Qb400 84.2±5.8 85.6±3.6 77.4±3.1 76.4±5.1 76.0±7.7 67.3±15.7 17.6±4.0 12.03±9.6  Table 1 RR Results (MIXED in the top line of each cell of the table) RR% β2m Myo PLT ORO Qb250 80.4±4.7 81.3±2.9 71.0±8.7 74.3±6.6 72.9±7.8 73.0±7.1 14.4±7.2 12.8±10.6 Qb300 84.3±1.4 84.1±2.5 80.1±3.4 78.2±6.3 78.9±7.9 74.72±7.0 16.6±11.0 11.7±10.1 Qb350 84.5±6.2 84.8±6.2 78.9±7.9 74.72±7.0 75.7±12.9 70.0±18.9 16.0±4.0 16.9±7.6 Qb400 84.2±5.8 85.6±3.6 77.4±3.1 76.4±5.1 76.0±7.7 67.3±15.7 17.6±4.0 12.03±9.6  RR% β2m Myo PLT ORO Qb250 80.4±4.7 81.3±2.9 71.0±8.7 74.3±6.6 72.9±7.8 73.0±7.1 14.4±7.2 12.8±10.6 Qb300 84.3±1.4 84.1±2.5 80.1±3.4 78.2±6.3 78.9±7.9 74.72±7.0 16.6±11.0 11.7±10.1 Qb350 84.5±6.2 84.8±6.2 78.9±7.9 74.72±7.0 75.7±12.9 70.0±18.9 16.0±4.0 16.9±7.6 Qb400 84.2±5.8 85.6±3.6 77.4±3.1 76.4±5.1 76.0±7.7 67.3±15.7 17.6±4.0 12.03±9.6  SP442 SAFETY AND EFFICACY OF REGIONAL CITRATE ANTICOAGULATION IN SUSTAINED LOW EFFICIENCY DIALYSIS Wang Tingli Wang Tingli 1 West China Hospital of Sichuan University, Chengdu, China Zhang Ling Zhang Ling 1 West China Hospital of Sichuan University, Chengdu, China Shi Yunying Shi Yunying 1 West China Hospital of Sichuan University, Chengdu, China Fu Ping Fu Ping 1 West China Hospital of Sichuan University, Chengdu, China Abstract Introduction and Aims: Regional citrate anticoagulation,which has been widely used in CRRT, can reduce bleeding complications.However, the application of regional citrate anticoagulation and heparin has not been compared in SLED. In order to provide evidence for clinical practice, this study evaluated the safety and efficiency of regional citrate anticoagulation in SLED, and comparedits application with heparin. Methods: We prospectively enrolled 63 patients with AKI or ESRD in nephrology division, West China Hospital, Sichuan University, between November 2011 and October 2013. These patients were randomized to receive citrate with calcium-free dialysate or heparin with conventionaldialysate. All of the patients received SLED treatment by Fresenius4008sARrTplus dialyzer through either femoral or internal jugular venous catheter, with each session of treatment lasting for 8 hours.In the citrate group, we pumped in 4% tri-sodium citrate solution through the arterial line at 130ml/h and 10% calcium gluconate through the venous line at 40ml/h. We recorded systemic citrate concentration at 2h and 5h, peripheral and post filter ionized calcium level at 0h, 2h and 5h respectively. In the heparin group, we injected 2000-2500 IU heparin in vein and followed with 200-250 IU per hour pumped in through the arterial line.The blood flow was at 150ml/min and the conventional dialysate at 200ml/min. PT and APTT was monitored at 0h and 2h in all of the patients. Results: Thirty patients in the citrate group underwent 56 sessions of SLED while thirty three patients in the heparin group underwent 62 sessions. The average age of the two groups was 71.7 ± 10.0 and 70.1 ± 12.8 years old. Both groups contained patients with heart failure and/or respiratory failure, septic shock, uremic encephalopathyand poor volume control. A total of 4 patients died during hospitalizationof multiple organ failure, and the death was not related to SLED and its anticoagulation. The other 59 patients (93.7%) was discharged after treatment or converted to outpatient IHD.A patient in the heparin group had hematoma and bleeding at femoral vein catheter. In heparin group, PT and APTT at 2h was significantly higher than that in the citrate group(PT: 15.5 ± 2.0 vs. 12.3 ± 2.7s, P <0.001; APTT:56.0 ± 10.9 vs. 32.8 ± 6.1s, P<0.001). The Citrate group received calcium gluconate pump through the venous side, so there was no significant effect on ionized calcium in peripheral blood.Ionized calcium levels in peripheral blood at 0h, 2h, 5h were1.22 ± 0.15 mmol / L, 1.21 ± 0.11 mmol / L and 1.25 ± 0.11 mmol / L(P = 0.76). Post-dialyzer ionized calcium at 2h and 5h was significantly lower than that in the peripheral blood (0.29 ± 0.05mmol / L vs. 0.31 ± 0.06 mmol / L, P<0.001). Through clearance by the dialyzerand the body's own metabolism,citrate level in peripheral blood was significantly lower than the post-dialyzer level (P<0.001).Transmembrane pressure 2h and 5h were 105.1 ± 14.8mmHg and 107.1± 15.5mmHgrespectively (P= 0.68). Conclusions: SLED under regional citrate anticoagulation is safe and effective. Citrate achieves satisfying regional anticoagulation effect without interfering systemic clotting function, and shows the similar anticoagulant effect to heparin without causing the riskof bleeding. There is no significant metabolic alkalosis and disturbance of electrolyte during and after SLED.It is more safe for the patients with high risk of bleeding, and also provides clinicians with an alternative anticoagulant approach for SLED. SP443 CITRIC ACID AND ACETATE FREE BASED DIALYSATE IN ONLINE HEMODIAFILTRATION POST-DILUTION ALLOWS HEPARIN FREE SESSIONS Thibault Dolley-Hitze Thibault Dolley-Hitze 1 AUB Santé, Saint-Malo, France Didier Hamel Didier Hamel 1 AUB Santé, Saint-Malo, France Marie-Laure Lombart Marie-Laure Lombart 1 AUB Santé, Saint-Malo, France Abstract Introduction and Aims: Up to now, heparin is the simplest mean to realise OnLine HemoDiaFiltration Post-Dilution (OL-HDF) without clotting however it induces several adverse events (increased bleeding risk, bone metabolism disorders, dyslipidemia) and exposes nurses to patients’ blood. Citric acid based concentrate has been yet studied in order to stop heparin injection during dialysis sessions (J. Aniort, Blood purif. 2012) but this dialysate contains a small proportion of acetate (citric acid 0.8mM, acetate 0.3mM) with its own side effects (per-dialytic hypotension, cramps, inflammation). The aim of our study is to determine if citric acid and acetate free fluid (citric acid 1mM, acetate 0mM) is safe in HDF-OL PostD and can allow heparin removal. Methods: All stable patients treated by OL-HDF with 3mM acetate on machines accepting the studied concentrate (Select Bag Citrate®, Gambro) were included. They all received citrate concentrate and have been randomly assigned to either the control group (fraxiparin as usual) or study group (fraxiparin slow withdrawal, 0.1ml per week until discontinuation) for a 3 months period. Dialysis Fluids contained 0.10 or 0.15mEq/l calcium more than usual (1.60 or1.65mEq/l) in order to avoid hypocalcemia but other dialysis parameters didn’t change. The blood calcium concentration (total or ionized) has been checked weekly for 4 weeks. All the hemorrhagic or clotting events were thorough noted as well as online dialysance and convection volumes at each session. Statistical analyses were performed with Statview® software and non parametric tests were applied. Results: 17 patients were enrolled in the study, 9 were randomly assigned to the control group and 8 to the study group (fraxiparin discontinuation). 589 sessions were analyzed, 306 in the control group and 283 in the study group. Total and ionized calcium concentration remained stable during the study period. In the study group, no more clotting events were observed (13 in each group, p=0.94). Fraxiparin was discontinued by 5 out 8 patients in the study group and 0 out 9 in the control group (p=0.009) with 0.075ml mean dose in study group vs 0.41 ml in control group (p=0.018). The dialysis dose did not differ among the two groups (Kt/V Daugirdas 2: control group 1.81 vs 1.72 study group, p=0.68 and On-line Kt 51.64 vs 50.53, p=0.40) as well as total convective volumes (26.45 l in control group vs 26.50 l in study group, p=0.94). Conclusions: Heparin free OL-HDF is achievable with the use of citrate based and acetate free concentrates. Dialysis parameters and performances remain stable. Nevertheless, not all the patients can benefit from this technique and the reasons should be determined by a larger trial. SP444 EFFECT OF HOT WATER DISINFECTION ON DIALYSER SOLUTE CLEARANCES WITH EXTENDED USE IN A NEW HAEMODIALYSIS DEVICE John K Leypoldt John K Leypoldt 1 Baxter Healthcare Corporation, Deerfield, IL Angelito Bernardo Angelito Bernardo 1 Baxter Healthcare Corporation, Deerfield, IL Audrey M Hutchcraft Audrey M Hutchcraft 2 Baxter Healthcare Corporation, Round Lake, IL Raymond Vanholder Raymond Vanholder 3 University Hospital, Ghent, Belgium Bruce F Culleton Bruce F Culleton 1 Baxter Healthcare Corporation, Deerfield, IL Abstract Introduction and Aims: Conventional reuse of dialysers creates potential exposure to the toxic effects of chemicals, and some chemical-based reuse methods do not maintain dialyser solute clearances, depending on membrane and chemical. A new haemodialysis (HD) device, Vivia (Baxter Healthcare, Deerfield, IL, USA), was designed to permit extended or multiple use of the dialyser and blood tubing set by in-situ, non-chemical hot water disinfection, thereby eliminating chemical exposure and the risk of infections due to blood circuit disconnections. We aimed to evaluate the effects of hot water disinfection on dialyser solute clearances by performing a clinical study with Vivia to assess the effects of extended use on urea and β2-microglobulin (β2-M) clearances. Methods: A prospective, single arm clinical study was performed on 22 chronic HD patients (12 M, 10F). Mean ± SD age of the patients was 50.9 ± 9.5 years; 16 patients were black, 5 were white and 1 was a Taino Indian. Hot water disinfection (exposure to 85ºC for 1 hour) was performed prior to every use of the dialyser, including first use. Over the course of this 8-week evaluation, HD treatments were performed with a 2.1 m2 polyethersulfone membrane dialyser for 3.9 ± 0.2 hours, 4 times per week. Dialysers were replaced if in-situ dialyser sodium clearance was <90% of the initial dialyser sodium clearance or if there were abnormalities in physical appearance. Pre-dialysis and post-dialysis blood samples were obtained at first use, second use and then weekly; the urea reduction ratio (URR) and dialyser β2-M clearance were calculated to assess extended use dialyzer performance. Results: Dialyser performance was assessed in 207 dialysers across 648 treatments. Thirty-nine percent of dialysers were used multiple times and 41% of treatments were delivered by dialysers that achieved 5 or more uses. Abnormalities in physical appearance, primarily residual clots in the venous header of the dialyser or the blood set, most often terminated extended use. Overall, dialyser performance was evaluated at a blood flow rate of 357 ± 21 mL/min and a dialysate flow rate of 395 ± 9 mL/min. Performance results are tabulated as mean ± SD (Number of determinations): Dialyser Use Counts URR β2-M Clearance (mL/min) 1 69 ± 8 (171) 77 ± 31 (171) 2-4 70 ± 7 (71) 79 ± 27 (73) 5-10 73 ± 6 (34) 77 ± 20 (33) >10 74 ± 7 (21) 72 ± 15 (20)  Dialyser Use Counts URR β2-M Clearance (mL/min) 1 69 ± 8 (171) 77 ± 31 (171) 2-4 70 ± 7 (71) 79 ± 27 (73) 5-10 73 ± 6 (34) 77 ± 20 (33) >10 74 ± 7 (21) 72 ± 15 (20)  Dialyser Use Counts URR β2-M Clearance (mL/min) 1 69 ± 8 (171) 77 ± 31 (171) 2-4 70 ± 7 (71) 79 ± 27 (73) 5-10 73 ± 6 (34) 77 ± 20 (33) >10 74 ± 7 (21) 72 ± 15 (20)  Dialyser Use Counts URR β2-M Clearance (mL/min) 1 69 ± 8 (171) 77 ± 31 (171) 2-4 70 ± 7 (71) 79 ± 27 (73) 5-10 73 ± 6 (34) 77 ± 20 (33) >10 74 ± 7 (21) 72 ± 15 (20)  Post-hoc repeated measures analysis of URR and β2-M clearance on dialyser use count for dialysers used at least 10 times in 12 patients was also performed. In this analysis, URR was independent of dialyser use count (P=0.7), but the estimated β2-M clearance decreased (P=0.02) by 0.74 (standard error of 0.27) mL/min for each dialyser use. Conclusions: Hot water disinfection during extended use of large surface area polyethersulfone dialysers in the Vivia device has no effect on dialysis adequacy as assessed by URR. Extended use decreases dialyser β2-M clearance; however, these effects are small and likely not clinically significant given the high baseline β2-M clearance rates. SP445 THE ROLE OF CONVECTION ON THE LONG-TERM VARIATIONS (Δ)OF SERUM BETA 2 MYCROGLOBULIN (B2M), C-REACTIVE PROTEIN (CRP) CONCENTRATIONS, AND ESA REQUIREMENT (ΔESA) IN UREMIC PATIENTS TREATED BY POST DILUTIONAL ON-LINE HDF Ezio Movilli Ezio Movilli 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Corrado Camerini Corrado Camerini 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Paola Gaggia Paola Gaggia 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Roberto Zubani Roberto Zubani 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Paolo Feller Paolo Feller 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Alessandra Pola Alessandra Pola 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Orsola Carli Orsola Carli 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Chiara Salviani Chiara Salviani 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Chiara Manenti Chiara Manenti 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Giovanni Cancarini Giovanni Cancarini 1 U.O. Nephrology, Spedali Civili and University of Brescia, Brescia, Italy Abstract Introduction and Aims: Inflammation and increased ESA requirement are frequently associated in patients on dialysis treatment. On-line Hemodiafiltration (Ol-HDF), putting together high levels of diffusion and convection could improve both conditions. However, it is still not known which depurative component predominate in determining this result. Aim of the study: to evaluate the role of convection and diffusion on ΔB2M, ΔhsCRP, and ΔESA in Ol-HDF. Methods: 30 patients, 26 men, age 57±13 years, dialytic vintage 12-108 months, were switched from conventional HD to post dilutional Ol-HDF. At 12 months the effect of Ol-HDF on ΔhsCRP, ΔB2M, and ΔESA (U/Kg/sett) were evaluated. Other variables considered: Body weight (BW), serum albumin (sAlb), Hemoglobin (Hb), Kt/V. Iron therapy and ESA were administered IV according to the K/DOQI guidelines in order to maintain TSAT between 20-40%, serum ferritin between 150-500 ng/ml, Hb between 11-12 g/dL. Qb, treatment time and Qd remained constant. Ol-HDF was performed utilizing High-flux membranes 1.9-2.1 sqm. Ultrapure dialysate and substitution fluid was employed in both HDF and HD treatments. Data are expressed as mean±SD. Paired t test, Mann-Whitney U test, simple and multiple regression analysis were employed for statistical evaluation. Results: Total convective volume (TCV) was 21.8±1.7 l/session Significant reduction of hsCRP: (from 5.3±7.5 to 2.1±2.7 mg/dl; p<0.01), B2M (from 29.0±14.4 to 21.3±12.3 mg/dl; p<0.0001) and ESA (from 92±6 to 57±35 U/Kg/week; p<0.008). No significant variations of Kt/V, Hb, BW, sAlb. A significant inverse correlation was found between TCV and ΔB2M (r: 0.74; p<0.0001), and TCV and ΔhsCRP (r: 0.41; p<0.02), no correlation between TCV and ΔESA. No correlation was found between Kt/V and ΔB2M, ΔhsCRP, and ΔESA. Multiple regression analysis with ΔESA as dependent variable showed ΔhsCRP as the only significantly associated independent factor (p<0.008). Conclusions: Ol-HDF induces a long-term significant reduction of B2M and hsCRP concentrations.The entity of reduction is directly correlated to the amount of TCV. The observed reduction in ESA requirement is associated to the reduction of inflammation and seems to be independent from convection. SP446 THE ROLE OF LUNG ULTRASOUNDS, BIOIMPEDANCE ANALYSES AND NATRIURETIC PEPTIDES IN THE ASSESSMENT OF EXTRAVASCULAR LUNG WATER IN HEMODIALYSIS PATIENTS Laura Bozzoli Laura Bozzoli 1 University of Pisa, Pisa, Italy Elisa Colombini Elisa Colombini 1 University of Pisa, Pisa, Italy Guido Ricchiuti Guido Ricchiuti 1 University of Pisa, Pisa, Italy Giovanna Pisanu Giovanna Pisanu 1 University of Pisa, Pisa, Italy Luna Gargani Luna Gargani 2 CNR, Pisa, Italy Carlo Donadio Carlo Donadio 1 University of Pisa, Pisa, Italy Abstract Introduction and Aims: Background: Lung ultrasound (LUS) allows a non-invasive evaluation of extravascular lung water (EVLW) through the analysis of B-lines in heart failure patients. Natriuretic peptides are also measured to evaluate heart failure. More recently LUS has been proposed to assess EVLW in maintenance hemodialysis (MHD) patients. Total body (TB) and segmental thoracic impedance analysis (BIA) can estimate TB and lung water compartments.Objectives: 1) To evaluate the correlation between B-lines and TB and segmental thoracic hydration estimated by means of BIA; 2) To compare LUS and BIA data with natriuretic peptides dynamic changes, echocardiographic findings and inferior vena cava (IVC) diameters; 3) To evaluate the usefulness of a comprehensive antero-lateral and posterior LUS scanning. Methods: Thirty-three adults MHD patients (24 M and 9F), were examined. LUS (Fig.1), TB and thoracic BIA, natriuretic peptides and physical examination were performed immediately before and after a dialytic session. Echocardiography and IVC analysis were performed in the interdialytic period. Results: A higher number of B-lines was found in lateral and posterior lung segments (Fig.2). Also the dynamic changes in B-lines were not homogeneous. The number of B-lines, and their decrease with HD, were correlated with TB and thoracic BIA. Thoracic and TB fluid compartments and their variations were correlated, suggesting that the increase in lung fluids was driven by the increase in TB fluids. BNP and NT-proBNP, which were markedly increased due to severe renal dysfunction, were still correlated with LVEF and with thoracic BIA. The residual number of B-lines after HD was correlated with LVEF and with BNP. No correlation was found between IVC, left atrium dimensions, diastolic dysfunction, physical examination and B-lines. Conclusions: A comprehensive LUS examination is advisable. LUS together with BIA and BNP, at the end of dialysis, may have a complementary role in the assessment of pulmonary congestion and allow to unravel the pathogenesis of EVLW increase in MHD patients. View largeDownload slide View largeDownload slide View largeDownload slide View largeDownload slide SP447 CLINICAL EVALUATION OF NEW HIGH CUT OFF MEMBRANE Antonino Sidoti Antonino Sidoti 1 Nephrology Unit, Poggibonsi, Italy Maria L Lusini Maria L Lusini 1 Nephrology Unit, Poggibonsi, Italy Marina Biagioli Marina Biagioli 1 Nephrology Unit, Poggibonsi, Italy Paolo M Ghezzi Paolo M Ghezzi 2 Bellco srl, Mirandola, Italy Luisa Sereni Luisa Sereni 2 Bellco srl, Mirandola, Italy Marialuisa Caiazzo Marialuisa Caiazzo 2 Bellco srl, Mirandola, Italy Giuseppe Palladino Giuseppe Palladino 2 Bellco srl, Mirandola, Italy Abstract Introduction and Aims: The uremic syndrome is characterized by the retention of various solutes that would normally be excreted by the kidneys. Uremic toxins represent an heterogeneous group of substances that includes organic compounds and peptides both in their “native” and modified form, the latter by post-translational changes.Standard HD membranes are unable to depurate solutes with MW greater than 18 kDa;. The aim of the study was to evaluate the performance of a new, more permeable dialytic membrane (Synclear 05) in terms of extraction capability of middle-high MW molecule useful for uremic toxin removal. Methods: Twenty ESRD patients (11 M), were enrolled for a prospective, crossover study in order to compare the extraction capability of two membranes used in SUPRA (Synclear 02) and KIDNEY (Synclear 05) therapies.Serum samples and pre-cartridge ultrafiltrate (UF) were collected at the beginning and at the end of each middle week session Plasma and UF samples were used to determine, β-2 microglobulin (β2M), free light chain (FLCs) κ and λ, Interleukin-6 (IL-6), α-1 acid glycoprotein (A1AG1), Albumin and Immunoglobulins G (IgG) levels. β2M, FLC κ, FLC λ, A1AG1, Albumin and IgG were determined by nephelometric assays (BNII, Siemens Healthcare Diagnostics, Tarrytown, NY, USA); IL-6, were evaluated by Solid Phase Sandwich ELISA (Quantikine ELISA kit, R&D System, Minneapolis, MN, USA). Results: Plasma and UF levels were evaluated both at the start and at the end of each treatment. Pre dialysis levels were not statistically different (data not shown). The extraction capability was determined as percentage ratio between UF and plasma concentrations both at the start that at the end of session and then averaged.In order to compare the extraction capability and, consequently, the Molecular weight Cut off (MWCO) of the two membranes, a wide range of MW molecules were tested.Statistically significant differences between SUPRA and KIDNEY extraction capabilities were found for FLCs κ [23 KDa] (40 ± 11 vs 65 ± 23%, p<0,0001), IL-6 [24 KDa](49 ± 10 vs 57 ± 12 %, p<0,05, FLCs λ [46 KDa] (19 ± 5 vs 28 ± 8 %, p<0,0001), A1AG1 [43 KDa] (6 ± 2 vs 12 ± 5 %, p<0,0001), Albumin [66 KDa] (3 ± 1 vs 7 ± 3 %, p<0,0001) and IgG [150 KDa] (0 vs 2 ± 1, p<0,0001). In the figure are reported the sieving curves of the two membranes calculated with the above data, compared with a standard High Flux membrane. View largeDownload slide View largeDownload slide Conclusions: The results of this study demonstrate that, compared to Sync 02, Sync 05 membrane offers a higher permeability to middle MW molecules, and possess a MWCO higher than Sync 02 and the other standard HDF membranes. SP448 EXAMINATION OF NEUTROPHIL INTERACTION ON NEW POLYSULFONE (PS) MEMBRANE NV Tadashi Tomo Tadashi Tomo 1 Oita University Hospital, Yufu, Japan Kaede Ishida Kaede Ishida 1 Oita University Hospital, Yufu, Japan Takeshi Nakata Takeshi Nakata 1 Oita University Hospital, Yufu, Japan Abstract Introduction and Aims: In hemodialysis, the platelet is thought to be activated by the contact of an artificial material and blood, various factors including PDMP are produced, and it leads to the arteriosclerosis progress through the interaction of the activation of the white blood cell and the vascular endothelical cell. It has been reported that The new PS membrane “NV” has been reported to clinically control the platelet activation by introducing new hydrophile polymer, and to have a high anti-thrombus. We examined radical generation of neutrophle and the stimulation of cytokine production by the NV membrane in vitro. Methods: The conventional type of PS membrane “CX” made by Toray was assumed to be a contrast. New blood from healthy volunteer person was circulated for one hour at 37C by taking out the hollow fiber of CX or NV and making the pencil type dialyzer. After circulated, the radical generation of the neutrophilic leukocyte or the plasma was measured by the chemiluminescence method. IL-6 and pentraxin3 of the plasma were measured with ELISA. Results: The amount of the radical production in NV (11±11 RLU) was significantly lower than in CX (22±22 RLU)(p=0.999). IL-6 production in NV (33±33 pg/mL) was also significantly lower than in CX (44±44 pg/mL) (p=0.04). The production of pentraxin3 in NV (55±55 ng/mL) was also significantly lower than in CX (66±66 ng/mL) (p=0.03). Conclusions: The new membrane NV decreased the radical production of the neutrophilic leukocyte, and had the possibility that dialysis patient's inflammation can be controlled by suppressing the cytokine production. SP449 COMPARISON OF CONVECTIVE VOLUMES AND DIALYSIS DOSE GENERATED BY DIFFERENT AUTOMATED DEVICES IN ONLINE HEMODIAFILTRATION POST-DILUTION Didier Hamel Didier Hamel 1 AUB Santé, Saint-Malo, France Thibault Dolley-Hitze Thibault Dolley-Hitze 1 AUB Santé, Saint-Malo, France Abstract Introduction and Aims: Since ESHOL study (Maduell F., JASN 2013) was published, OnLine HemoDialFiltration Post-Dilution (OL-HDF) has become the gold standard to perform chronic hemodialysis. Due to this study, total convective volume (= ultrafiltration rate + substitution volume) is also wished to reach 25L or more per session to improve patients’ survival. In our dialysis center, above 90% of the patients benefit from HDF realized with 4 types of HDF machines (AK-200 ULTRA, ARTIS, 5008 and 5008-CORDIAX) for which automatic devices control substitution volumes (Ultra-control® for AK200-Ultra and ARTIS, Autosub® for 5008 and Autosub plus® for 5008 CORDIAX). We wondered if these machines and devices could deliver the same performances, consequently we decided to conduct a retrospective and monocentric study to compare total convective volume and also dialysis dose. Methods: Univariate and multivariate analyses were conducted on patients who had undergone at least ten 4-hour OL-HDF post-dilution sessions during the first 9 months in 2013 and models used only the first 70 sessions. All patients had complete data for all covariates that were designated as either case-mix factors (age, gender) or dialysis-specific factors (weight, biological and dialysis parameters: substitution volume, ultra-filtration rate, on line dialysance (K and Kt) and biological Kt/V recorded on DIALOG7 Software) that hence were time-dependent. Associations between total convective volumes or Kt parameters and device type were estimated by using generalized linear regression (SAS PROC Mixed; SAS Institute, Cary, NC) with an unstructured covariance structure. Before model development, we verified Gaussian distributions of continuous variables. To verify model assumptions, we performed routine regression diagnostics that assessed normality, linearity, homogeneity of variance, and influence. Model results are summarized by using parameter estimates and 95% CIs. All P reported are 2 sided, and statistical significance is defined as P less than 0.05. All statistical analyses were performed using SAS (version 9.3). Results: 3446 sessions from 62 patients (40 male) aged 74 ± 13 years were analyzed (1997 sessions with 5008, 542 with 5008 CORDIAX, 707 with AK200 and 200 with ARTIS); 4 different hemodiafilters have been used during the study period (Elisio®, TS SL®, VitaPES® and FX100®). The choice of filters did not depend on dialysis machine. Total convective volumes (least squared mean ± SEM) were 27.02 ± 0.24, 27.26 ± 0.25, 26.58 ± 0.25 and 26.45 ± 0.29 for 5008, 5008 CORDIAX, AK200 and ARTIS respectively; Hochberg’s adjusted p-values were all statistically significant for pair-wise comparisons except between AK200 UC ARTIS (p = 0.9889) and between CORDIAX and G5008 (p = 0.1252). Online Kt figures were quite similar with least squared mean ± SEM being 58.61 ± 0.45, 58.08 ± 0.47, 52.86 ± 0.48 and 51.41 ± 0.54 for 5008, 5008 CORDIAX, AK200 and ARTIS, respectively; all p-values statistically significant for pair-wise comparisons. Multivariate analyses confirmed these results when comparing 5008 or 5008 CORDIAX to AK200 or ARTIS. Conclusions: These retrospective and monocentric datas show lower total convective volume for patients treated with Artis dialysis machine® AK-200 ultra® compared to 5008® and 5008® Cordiax but all the convective volumes obtained were above 25 l. Dialysis dose were also worse when treatment is delivered by Artis® or by AK-200® but remain above current recommendations. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved


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HAEMODIALYSIS TECHNIQUES AND ADEQUACY 1, Nephrology Dialysis Transplantation, 2014, iii209-iii222, DOI: 10.1093/ndt/gfu153