SNF472, a novel inhibitor of vascular calcification, could be administered during hemodialysis to attain potentially therapeutic phytate levels.

BACKGROUND: Cardiovascular calcification (CVC) is a major concern in hemodialysis (HD) and the loss of endogenous modulators of calcification seems involved in the process. Phytate is an endogenous crystallization inhibitor and its low molecular mass and high water solubility make it potentially dialyzable. SNF472 (the hexasodium salt of phytate) is being developed for the treatment of calciphylaxis and CVC in HD patients. We aimed to verify if phytate is lost during dialysis, and evaluate SNF472's behaviour during dialysis. METHODS: Dialyzability was assessed in vitro using online-hemodiafiltration and high-flux HD systems in blood and saline. SNF472 was infused for 20 min and quantified at different time points. RESULTS: Phytate completely dialyzed in 1 h at low concentrations (10 mg/l) but not when added at 30 or 66.67 mg/l SNF472. In bypass conditions, calcium was slightly chelated during SNF472 infusion but when the system was switched to dialysis mode the calcium in the bath compensated this chelation. CONCLUSION: Phytate dialyses with a low clearance. The administration of SNF472 as an exogenous source of phytate allows to attain supra-physiological levels required for its potential therapeutic properties. As SNF472 is infused during the whole dialysis session, the low clearance would not affect the drug's systemic exposure.

Optimization of the convection volume in online post-dilution haemodiafiltration: practical and technical issues.

In post-dilution online haemodiafiltration (ol-HDF), a relationship has been demonstrated between the magnitude of the convection volume and survival. However, to achieve high convection volumes (>22 L per session) detailed notion of its determining factors is highly desirable. This manuscript summarizes practical problems and pitfalls that were encountered during the quest for high convection volumes. Specifically, it addresses issues such as type of vascular access, needles, blood flow rate, recirculation, filtration fraction, anticoagulation and dialysers. Finally, five of the main HDF systems in Europe are briefly described as far as HDF prescription and optimization of the convection volume is concerned.

Cumulative iron dose and resistance to erythropoietin.

INTRODUCTION: Optimizing anemia treatment in hemodialysis (HD) patients remains a priority worldwide as it has significant health and financial implications. Our aim was to evaluate in a large cohort of chronic HD patients in Fresenius Medical Care centers in Spain the value of cumulative iron (Fe) dose monitoring for the management of iron therapy in erythropoiesis-stimulating agent (ESA)-treated patients, and the relationship between cumulative iron dose and risk of hospitalization. METHODS: Demographic, clinical and laboratory parameters from EuCliD(®) (European Clinical Dialysis Database) on 3,591 patients were recorded including ESA dose (UI/kg/week), erythropoietin resistance index (ERI) [U.I weekly/kg/gr hemoglobin (Hb)] and hospitalizations. Moreover the cumulative Fe dose (mg/kg of bodyweight) administered over the last 2 years was calculated. Univariate and multivariate analyses were performed to identify the main predictors of ESA resistance and risk of hospitalization. Patients belonging to the 4th quartile of ERI were defined as hypo-responders. RESULTS: The 2-year iron cumulative dose was significantly higher in the 4th quartile of ERI. In hypo-responders, 2-year cumulative iron dose was the only iron marker associated with ESA resistance. At case-mix adjusted multivariate analysis, 2-year iron cumulative dose was an independent predictor of hospitalization risk. DISCUSSION: In ESA-treated patients cumulative Fe dose could be a useful tool to monitor the appropriateness of Fe therapy and to prevent iron overload. To establish whether the associations between cumulative iron dose, ERI and hospitalization risk are causal or attributable to selection bias by indication, clinical trials are necessary.

Elimination of large uremic toxins by a dialyzer specifically designed for high-volume convective therapies.

BACKGROUND: Unlike conventional hemodialysis treatments, which rely almost solely on diffusion-related mechanisms for solute removal, hemodiafiltration (HDF) allows more efficient removal of higher molecular weight toxins due to convective transport mechanisms. To facilitate the removal of these toxins in HDF treatment modalities, dialyzers with highly efficient high-flux membranes are necessary. This study assessed the large uremic toxin removal ability of a high-flux dialyzer (FX CorDiax 60) specifically designed to facilitate convective therapies compared with a standard high-flux dialyzer (FX 60). METHODS: In an open, randomized, cross-over, single-center, controlled, prospective clinical study, 30 adult chronic hemodialysis patients were treated by post-dilution online HDF with the FX 60 or the FX CorDiax 60 dialyzer. All other dialysis parameters were kept constant in both study arms. The reduction rate (RR) of blood urea nitrogen, phosphate, ß2-microglobulin (ß2-m), myoglobin, prolactin, α1-microglobulin, α1-acid glycoprotein, albumin and total protein as well as the elimination into dialysate was intraindividually compared for the two dialyzer types. RESULTS: For FX CorDiax 60 versus FX 60, the RR was significantly higher for blood urea nitrogen (86.23 ± 4.14 vs. 84.89 ± 4.59%, p = 0.015), ß2-m (84.67 ± 3.79 vs. 81.30 ± 4.82%, p < 0.0001), myoglobin (75.23 ± 10.48 vs. 58.60 ± 12.1%, p < 0.0001), prolactin (72.96 ± 9.68 vs. 56.91 ± 13.01%, p < 0.0001) and α1-microglobulin (20.89 ± 18.27 vs. 13.60 ± 12.50%, p = 0.016). There were no significant differences in the RR for phosphate, α1-acid glycoprotein, albumin and total protein. Mass removal was significantly higher with the FX CorDiax 60 than with the FX 60 for ß2-m (0.26 ± 0.09 vs. 0.24 ± 0.09 g, p = 0.0006), myoglobin (1.83 ± 0.89 vs. 1.51 ± 0.76 mg, p = 0.0017), prolactin (0.17 ± 0.13 vs. 0.14 ± 0.08 mg, p = 0.02) and albumin (4.25 ± 3.49 vs. 3.01 ± 2.37 g, p = 0.03). CONCLUSIONS: This study demonstrates that treating patients with an FX CorDiax 60 instead of an FX 60 dialyzer in post-dilution HDF mode significantly increases the elimination of middle molecules.

Exploring the opinion of CKD patients on dialysis regarding end-of-life and Advance Care Planning.

Advance care planning (ACP) and the subsequent advance directive document (ADD), previously known as "living wills", have not been widely used in Spain. The Ethics Group from the Spanish Society of Nephrology has developed a survey in order to investigate the opinion of dialysis patients regarding the ADD and end-of-life care. Patients received documentation explaining ACP and filled out a survey about their familiarity with and approval of the ADD. Seven hospital dialysis centres participated in the study for a total of 416 active dialysis patients. Questionnaires were distributed to 263 patients, 154 of which answered (69.2% completed them without assistance). The rates for ADD implementation (7.9%) and designation of a representative person (6.6%) were very low. Most of the patients clearly expressed their wishes about irreversible coma, vegetative state, dementia and untreatable disease. More than 65% did not want mechanical ventilation, chronic dialysis, tube feeding or resuscitation if cardiorespiratory arrest occurred. They reported that an ADD could be done before starting dialysis but most thought that it should be offered only to those who requested it (65% vs 34%). In conclusion, patients have clear wishes about end-of-life care, although these desires had not been documented due to the very low implementation of the ADD.

[Guidelines for automated manual infusion: a practical way of prescribing postdilution on-line hemodiafiltration]. / Pauta de infusión manual automatizada: una forma práctica de prescribir la hemodiafiltración on-line posdilucional.

Post-dilution on-line hemodiafiltration (OL-HDF) is the most efficient infusion mode to obtain maximum clearances of uremic toxins, with a recommended manual infusion flow (Qi) of 25% of the blood flow with the main limitation that causes alarms by hemoconcentration throughout the session. Recent technical advances allow automatic prescription of Qi if hematocrit and total protein (TP) values are specified. As these analytical results are not possible to obtain in each dialysis session, a practical way to prescribe Qi is to make an automatic prescription adjusting the hematocrit and total protein values at the beginning of the session to obtain the manual prescription required and we will call it automatic-manual prescription. The aim of this study was to compare manual Qi with automatic-manual Qi in postdilution OL-HDF. 30 patients (16 men and 14 women), 59.9 +/- 15 years old, in hemodialysis program for 50.1 +/- 67 months were included. Every patient underwent four OL-HDF sessions, two with manual Qi (4008-S and 5008 monitors) and two with automatic-manual Qi (A-M), one with the same Qi and one with manual Qi +20 (A-M+20). The same usual dialysis parameters were maintained: helixone dialyzer, dialysis time of 266 +/- 39 minutes, blood flow of 420 +/- 36. Recirculation, Kt and intradialysis alarms were measured at each session. No significant differences in the fistula recirculation or dialysis dose measured using Kt. Total infusion volume was 24.9 +/- 4 (4008 S), 23.4 +/- 4 L (5008) with manual Qi, 23.6 +/- 4 L (A-M) Qi (NS) and 25.8 +/- 5 L (A-M+20). Only 14% of patients had no incidents. The number of alarms was significantly higher with manual prescription 55 alarms with 4008 and 40 with 5008 vs. AM (11) p < 0.01) and A-M+20 (16 alarms) We concluded that automatic-manual Qi is a practical way for post-dilutional OL-HDF prescription where the same efficiency and total reinfusion volume with an important reduction of intradialysis alarms are obtained, allowing to rise Qi by 20% without increasing intradialysis alarms.

Pauta de infusión manual automatizada: una forma práctica de prescribir la hemodiafiltración on-line posdilucional / Guidelines for Automated Manual Infusion: A Practical Way of Prescribing Postdilution On-line Haemodiafiltration

La hemodiafiltración on-line (HDF-OL) posdilucional es la modalidad más eficaz para obtener la máxima depuración de toxinas urémicas, con un flujo de infusión (Qi) recomendable del 25% del flujo sanguíneo y con el principal inconveniente de provocar alarmas por hemoconcentración a lo largo de la sesión. Recientes avances técnicos permiten la prescripción automática del Qi si se especifican los valores del hematocrito y de las proteínas totales. Como no es posible disponer en cada sesión de estos valores, una forma práctica de pautar la HDF-OL posdilucional es realizar una prescripción automática ajustando el hematocrito y las proteínas totales para obtener al inicio de la sesión la prescripción manual prescrita, a la que llamaremos prescripción manual automatizada. El objetivo del estudio fue comparar la pauta convencional de Qi manual respecto a la manual automatizada. Se incluyeron 30 pacientes (16 varones y 14 mujeres), de 59,9 ± 15 años de edad, en programa de hemodiálisis durante 50,1 ± 67 meses. Cada paciente recibió cuatro sesiones de HDF-OL, dos con Qi manual (monitores 4008-S y 5008) y dos con Qi manual automatizada (M-A), una con Qi igual a la manual y otra incrementando el Qi 20 ml/min (M-A+20). El resto de parámetros de diálisis no variaron: filtro de helixona, tiempo de diálisis 266 ± 39 minutos, flujo de sangre 420 ± 36 ml/min. En cada sesión se recogieron el Kt, la recirculación y las alarmas. No se observaron diferencias significativas en el índice de recirculación ni en la dosis de diálisis medida con el Kt. El volumen total de infusión fue de 24,9 ± 4 l (4008S), 23,4 ± 4 l (5008) con Qi manual, 23,6 ± 4 l (M-A) y 25,8 ± 5 l (M-A+20). En sólo el 14% de los pacientes no hubo incidencias. El número de alarmas fue significativamente superior con la prescripción manual, 55 alarmas con 4008 y 40 con 5008, respecto a la M-A (11, p <0,01) y M-A+20 (16 alarmas). Concluimos que la prescripción del Qi manual automatizada es una forma práctica de prescribir la HDF-OL posdilucional consiguiendo el mismo volumen convectivo y la misma eficacia, con una importante reducción de las alarmas intradiálisis, lo que permite un incremento del Qi un 20% sin aumento del número de alarmas (AU)

Post-dilution on-line hemodiafiltration (OL-HDF) is the most efficient infusion mode to obtain maximum clearances of uremic toxins, with a recommended manual infusion flow (Qi) of 25% of the blood flow with the main limitation that causes alarms by hemoconcentration throughout the session. Recent technical advances allow automatic prescription of Qi if hematocrit and total protein (TP) values are specified. As these analytical results are not possible to obtain in each dialysis session, a practical way to prescribe Qi is to make an automatic prescription adjusting the hematocrit and total protein values at the beginning of the session to obtain the manual prescription required and we will call it automatic-manual prescription. The aim of this study was to compare manual Qi with automatic- manual Qi in postdilution OL-HDF. 30 patients (16 men and 14 women), 59.9 ± 15 years old, in hemodialysis program for 50.1 ± 67 months were included. Every patient underwent four OL-HDF sessions, two with manual Qi (4008-S and 5008 monitors) and two with automatic- manual Qi (A-M), one with the same Qi and one with manual Qi +20 (A-M+20). The same usual dialysis parameters were maintained: helixone dialyzer, dialysis time of 266 ± 39 minutes, blood flow of 420 ± 36. Recirculation, Kt and intradialysis alarms were measured at each session. No significant differences in the fistula recirculation or dialysis dose measured using Kt. Total infusion volume was 24.9 ± 4 (4008S), 23.4 ± 4 L (5008) with manual Qi, 23.6 ± 4 L (A-M) Qi (NS) and 25.8 ± 5 L (A-M+20). Only 14% of patients had no incidents. The number of alarms was significantly higher with manual prescription 55 alarms with 4008 and 40 with 5008 vs. AM (11) p <0.01) and A-M+20 (16 alarms) We concluded that automatic-manual Qi is a practical way for post-dilutional OL-HDF prescription where the same efficiency and total reinfusion volume with an important reduction of intradialysis alarms are obtained, allowing to rise Qi by 20% without increasing intradialysis alarms (AU)

Convección versus difusión: ¿ha llegado el momento del cambio? / No disponible

No disponible

Short daily versus conventional hemodialysis quality of life: a cross-sectional multicentric study in Spain.

BACKGROUND: End-stage renal disease is a major health problem worldwide nowadays. Although conventional hemodialysis is the most widely used modality, short daily hemodialysis has been proposed as a more physiologic treatment. The objective of this article is to compare the quality of life of patients on each hemodialysis modality. METHODS: A multicentric cross-sectional study was performed in 9 Spanish hospitals. Patients treated for at least 3 months with conventional or short daily hemodialysis were included and quality of life measured using the Euroqol-5D quality of life questionnaire. Bayesian models were used for analyzing quality of life results. RESULTS: Ninety-three patients were included, 27 were on daily hemodialysis and 66 on conventional hemodialysis. All models demonstrated a better quality of life for daily hemodialysis versus conventional hemodialysis. Only 14% of the patients on conventional hemodialysis were willing to change to a daily schedule. CONCLUSIONS: Short daily hemodialysis shows a better quality of life than conventional hemodialysis with all Bayesian approaches considered.

Resultados del proyecto de mejora de la calidad de la asistencia en hemodiálisis: estudio multicéntrico de indicadores de calidad de la Sociedad Española de Nefrología (SEN) / No disponible

Introducción: En el año 2002 se creó el grupo de trabajo sobre Calidad en Nefrología de la SEN (CNSEN). Los objetivos de este grupo han sido la identificación, difusión, implantación y consolidación de una herramienta de Gestión de la Calidad en Hemodiálisis, sistemática, objetiva y global, basada en la recopilación de Indicadores de Calidad, las estrategias de retroalimentación (Feedback) y Benchmarking,y el diseño de Planes de Mejora y Evaluación Global. El objetivo de este estudio es presentar los primeros resultados de los indicadores de calidad obtenidos en un grupo de centros españoles, así como evaluar la repercusión de la aplicación de las mencionadas técnicas en los resultados obtenidos. Métodos: Durante 2007 se ha ido incorporando al estudio un total de 28 unidades de hemodiálisis de todo el ámbito nacional. El número total de pacientes evaluados a lo largo del estudio ha sido 2516. Los indicadores han sido recogidos mediante un software informático específico de calidad, que permite calcularlos con facilidad. Los indicadores de cumplimiento se refieren a las siguientes áreas: adecuación de diálisis, anemia, metabolismo mineral y óseo, nutrición, enfermedades víricas, accesos vasculares, mortalidad, morbilidad (ingresos hospitalarios) y trasplante. Cada tres meses los centros reciben sus datos comparados con los del resto del grupo. Resultados: Se detectó una mejora de los resultados a nivel global, excepto en los niveles de hemoglobina. El porcentaje de centros que alcanzaron los estándares definidos por el CNSEN pasó del 65% al 90,9% en el caso del estándar de Kt/V Daugirdas II (> 1,3 en > del 80% de sus pacientes); del 71,4 % al 77,2 % en el caso del estándar de PTH (> 30% de sus pacientes con PTH entre 150 y 300 pg/ml); y del 42,8% al 63,5% en el caso del estándar de fósforo (> 75% de sus pacientes con fósforo < 5,5 mg/dl). Más del 50% de los centros mejoraron sus resultados con respecto al inicio del estudio en todas las áreas analizadas. Los centros que no obtuvieron una mejora en sus resultados partían de porcentajes de cumplimiento de los indicadores significativamente más altos que aquellos que si lograron mejorarlos (80,6 ± 15,4 versus 71,8 ± 16,6 respectivamente; p < 0,001). Conclusiones: Estamos avanzando en lo referente al conocimiento de los resultados de la hemodiálisis, aunque el trabajo pendiente todavía es extenso. La monitorización de indicadores de calidad respecto a un estándar, y su puesta en común con otros centros puede contribuir a la mejora de resultados y a la disminución en la variabilidad entre centros (AU)

Introduction: The Spanish Society of Nephrology «Quality in Nephrology Working Group» (QNWG) was created in 2002. The aims of this group are the identification, diffusion, implementation and consolidation of a systematic, objective and comprehensive set of quality performance measures (QPMs) to help along the improvement of patient care and outcomes on hemodialysis, by means of strategies of feedback and benchmarking, and the design of quality improvement projects. The objective of this study is to present the preliminary results of a set of quality performance measures obtained in a group of Spanish hemodialysis centers, as well as to evaluate the repercussion of the application of the aforementioned thecniques on the observed results. Methods: During 2007 a total of 28 hemodialysis units participated in the study; 2,516 patients were evaluated. A specific software was designed and used to facilitate the calculation of CPMs in each unit. The clinical indicators used refered to dialysis adequacy; anemia; mineral metabolisme; nutrition; viral infections; vascular access; mortality, morbidity (number and days of hospital admissions); and renal transplant. Every three months each center received its own data and its comparison with the rest of the group. Results: Except for hemoglobin levels we observed a global improvement. The percentage of centers reaching the stablished standards defined by the QNWG passed from 65% to 90.9% for Kt/V Daugirdas II (> 1.3 in > that 80% of the patients); from 71.4% to 77.2% for PTH (> 30% of patients with serum PTH between 150 and 300 pg/ml); and from 42.8% to 63.5% for phosphate (> 75% of patients with a serum phsphate < 5.5 mg/dl). More than 50% of centers showed an improvement in their final results as compared with their own initial results in all analyzed CPMs. Those centers that did not obtained an improvement in their results started the study with better percentages of acomplishment than those that showed a significant improvement in QPMs. (80.6 ± 15.4 versus 71.8 ± 16.6 respectively; p < 0.001). Conclusions: We are starting to make progresses in our knowledge of clinical results in our hemodialysis units, although there is still a long way to go over. To monitor and share CPMs results within hemodialysis centers might help to improve their results as well as to reduce intecenters variability (AU)

¿Cuánto tiempo es necesario aumentar la prescripción de hemodiálisis con la utilización de catéteres? / No disponible

En los últimos años hemos observado un aumento progresivo en el porcentaje de pacientes de hemodiálisis que utilizan catéteres centrales tunelizados como acceso vascular permanente, situándose las tasas de prevalencia e incidencia entorno al 7 y 25%, respectivamente. A pesar de que los catéteres actuales permiten la obtención de mayores flujos sanguíneos y menores complicaciones infecciosas, las dosis de diálisis obtenidas resultan inferiores a las alcanzadas mediante la utilización de fístulas arterio-venosas nativas (FAV) y prótesis vasculares. El objetivo principal del presente estudio fue valorar el tiempo adicional para obtener una dosis óptima de diálisis mediante la utilización de catéteres centrales venosos tunelizados. Dicha premisa se basa en la obtención de menores flujos sanguíneos (Qb) así como de posibles disfunciones vasculares que en diferentes ocasiones obligan a invertir las líneas arterio-venosas. Se analizaron un total de 48 pacientes (31 varones/17 mujeres) con una edad media de 61,6 ± 14 años (rango: 28-83); 20 con catéteres centrales tunelizados y 28 con FAV nativas. Todos los pacientes incluidos en el estudio se dializaron con la modalidad de hemodiálisis de alto flujo, con polisulfona de 1,9 m2, con una duración de 240 minutos, con flujo baño a 500 ml/min y monitores equipados con dialisancia iónica (DI). El objetivo principal de análisis fue la obtención de un Kt de 45 litros con cada uno de los diferentes accesos vasculares. Los pacientes portadores de una FAV recibieron 3 sesiones con variaciones de Qb a 300, 350 y 400 ml/min. Los pacientes con catéteres tunelizados recibieron dos sesiones de diálisis al máximo Qb, una con conexión de líneas normales y otra con líneas invertidas. Entre los resultados obtenidos cabe destacar que sólo los pacientes portadores de una FAV con un Qb de 400 ml/min alcanzaron el objetivo de Kt de 45 litros. Los sujetos con FAV precisaron incrementar 12 minutos de hemodiálisis con Qb de 350 ml/min y 28 minutos con Qb de 300 ml/min; los catéteres tunelizados en posición normal 24 minutos y los invertidos un total de 59 minutos. Concluimos que los pacientes dializados con catéteres centrales venosos tunelizados necesitan para alcanzar una dosis mínima de diálisis (Kt de 45 litros), incrementar por término medio 30 minutos el tiempo de la sesión si funciona en posición normal y 60 minutos en posición invertida de líneas arterio-venosas (AU)

The use of central catheters in hemodialysis patients as a permanent vascular access has increased during the last years, reaching numbers of around 7% of prevalent patients and between 25% of incident patients. Although the current catheters allow higher sanguineous flows with smaller incidence of infectious complications and dysfunction, the dose of dialysis that is reached is still inferior to that obtained with native arterio-venous fistula (AVF) and grafts. The aim of the present study was to evaluate the possible additional time supposed by dialysis using central venous catheters with respect to habitual vascular access as a consequence of the lesser blood flow (Qb) and the irregularity of its function (frequent lowering of the Qb and necessity of inverting the lines on many occasions). A total of 48 patients (31 men/17 women) with an average age of 61.6 ± 14 years old (rank: 28-83), 20 with tunnelled catheter and the remaining with AVF, were included in the study. All the patients were dialyzed in the modality of high flux hemodialysis with a polisulphone of 1.9 m2 dialyzer, dialysis time of 240 minutes, dialysate flow 500 ml/min and monitors equipped with ionic dialysance (ID) with the objective of obtaining a Kt of 45 litres with each one of the different vascular accesses. The patients with AVF received 3 sessions, with variations of Qb to 300, 350 and 400 ml/min. The patients with tunnelled catheter received two sessions, to the maximum Qb, one with normal connection and other with inverted one. In the results obtained it is possible to emphasize that only the patients with AVF and 400 ml/min reached the objective of 45 L of Kt. The patients with AVF needed to increase 12 minutes of hemodialysis with a Qb of 350 ml/min and 28 minutes with a Qb of 300 ml/min; the catheters on normal position needed to increase 24 minutes and finally in the inverted catheters an increase of 59 minutes was necessary to reach the same Kt objective. We concluded that the patients dialyzed with central catheters on average needed to increase by 30 minutes the time of dialysis if the catheter worked in a normal position but 60 minutes if the arterio-venous lines were inverted so as to reach the minimum dose of dialysis (AU)

[Preliminary results of the Spanish Society of Nephrology multicenter study of quality performance measures: hemodialysis outcomes can be improved]. / Resultados del proyecto de mejora de la calidad de la asistencia en hemodiálisis: estudio multicéntrico de indicadores de calidad de la Sociedad Española de Nefrología (SEN).

INTRODUCTION: The Spanish Society of Nephrology "Quality in Nephrology Working Group" (QNWG) was created in 2002. The aims of this group are the identification, diffusion, implementation and consolidation of a systematic, objective and comprehensive set of quality performance measures (QPMs) to help along the improvement of patient care and outcomes on hemodialysis, by means of strategies of feedback and benchmarking, and the design of quality improvement projects. The objective of this study is to present the preliminary results of a set of quality performance measures obtained in a group of Spanish hemodialysis centers, as well as to evaluate the repercussion of the application of the aforementioned thecniques on the observed results. METHODS: During 2007 a total of 28 hemodialysis units participated in the study; 2516 patients were evaluated. A specific software was designed and used to facilitate the calculation of CPMs in each unit. The clinical indicators used refered to dialysis adequacy; anemia; mineral metabolisme; nutrition; viral infections; vascular access; mortality, morbidity (number and days of hospital admissions); and renal transplant. Every three months each center received its own data and its comparison with the rest of the group. RESULTS: Except for hemoglobin levels we observed a global improvement. The percentage of centers reaching the stablished standards defined by the QNWG passed from 65% to 90,9% for Kt/V Daugirdas II (> 1,3 in > that 80% of the patients); from 71,4 % to 77,2 % for PTH (> 30 % of patients with serum PTH between 150 and 300 pg/ml); and from 42,8 % to 63,5 % for phosphate (> 75 % of patients with a serum phsphate < 5,5 mg/dl). More than 50% of centers showed an improvement in their final results as compared with their own initial results in all analyzed CPMs. Those centers that did not obtained an improvement in their results started the study with better percentages of acomplishment than those that showed a significant improvement in QPMs. (80,6+/-15,4 versus 71,8+/-16,6 respectively; p<0,001) CONCLUSIONS: We are starting to make progresses in our knowledge of clinical results in our hemodialysis units, although there is still a long way to go over. To monitor and share CPMs results within hemodialysis centers might help to improve their results as well as to reduce intecenters variability.

[How much should dialysis time be increased when catheters are used?]. / ¿Cuánto tiempo es necesario aumentar la prescripción de hemodiálisis con la utilización de catéteres?

SUMMARY: The use of central catheters in hemodialysis patients as a permanent vascular access has increased during the last years, reaching numbers of around 7% of prevalent patients and between 25% of incident patients. Although the current catheters allow higher sanguineous flows with smaller incidence of infectious complications and dysfunction, the dose of dialysis that is reached is still inferior to that obtained with native arterio-venous fistula (AVF) and grafts. The aim of the present study was to evaluate the possible additional time supposed by dialysis using central venous catheters with respect to habitual vascular access as a consequence of the lesser blood flow (Qb) and the irregularity of its function (frequent lowering of the Qb and necessity of inverting the lines on many occasions). A total of 48 patients (31 men/17 women) with an average age of 61,6 +/- 14 years old (rank: 28-83), 20 with tunnelled catheter and the remaining with AVF, were included in the study. All the patients were dialyzed in the modality of high flux hemodialysis with a polisulphone of 1,9 m2 dialyzer, dialysis time of 240 minutes, dialysate flow 500 ml/min and monitors equipped with ionic dialysance (ID) with the objective of obtaining a Kt of 45 litres with each one of the different vascular accesses. The patients with AVF received 3 sessions, with variations of Qb to 300, 350 and 400 ml/min. The patients with tunnelled catheter received two sessions, to the maximum Qb, one with normal connection and other with inverted one. In the results obtained it is possible to emphasize that only the patients with AVF and 400 ml/min reached the objective of 45 L of Kt. The patients with AVF needed to increase 12 minutes of hemodialysis with a Qb of 350 ml/min and 28 minutes with a Qb of 300 ml/min; the catheters on normal position needed to increase 24 minutes and finally in the inverted catheters an increase of 59 minutes was necessary to reach the same Kt objective. We concluded that the patients dialyzed with central catheters on average needed to increase by 30 minutes the time of dialysis if the catheter worked in a normal position but 60 minutes if the arterio-venous lines were inverted so as to reach the minimum dose of dialysis.

[Kt as control and follow-up of the dose at a hemodialysis unit]. / Kt como control y seguimiento de la dosis en una unidad de hemodiálisis.

To ensure our patients are receiving an adequate dose in every dialysis session there must be a target to achieve this in the short or medium term. The incorporation during the last years of the ionic dialysance (ID) in the monitors, has provided monitoring of the dialysis dose in real time and in every dialysis session. Lowrie y cols., recommend monitoring the dose with Kt, recommending at least 40 L in women and 45 L in men or individualizing the dose according to the body surface area. The target of this study was to monitor the dose with Kt in every dialysis session for 3 months, and to compare it with the monthly blood test. 51 patients (58% of our hemodialysis unit), 32 men and 19 women, 60.7+/-14 years old, in the hemodialysis programme for 37.7+/-52 months, were dialysed with a monitor with IC. The etiology of their chronic renal failure was: 3 tubulo-interstitial nephropathy, 9 glomerulonephritis, 12 vascular disease, 7 polycystic kidney disease, 7 diabetic nephropathy and 13 unknown. 1,606 sessions were analysed during a 3 month period. Every patient was treated with the usual parameters of dialysis with 2.1 m2 cellulose diacetate (33.3%), 1.9 m2 polisulfone (33.3%) or 1.8 m2 helixone, dialysis time of 263+/-32 minutes, blood flow of 405+/-66, with dialysate flow of 712+/-138 and body weight of 66.7+/-14 kg. Initial ID, final ID and Kt were measured in each session. URR and Kt/V were obtained by means of a monthly blood test. The initial ID was 232+/-41 ml/min, the final ID was 197+/-44 ml/min, the mean of Kt determinations was 56.6+/-14 L, the mean of Kt/V was 1.98+/-0.5 and the mean of URR was 79.2+/-7%. Although all patients were treated with a minimum recommended dose of Kt/V and URR when we used the Kt according to gender, we observed that 31% of patients do not get the minimum dose prescribed (48.1+/-2.4 L), 34.4% of the men and 26.3% of the women. If we use the Kt individualized for the body surface area, we observe that 43.1% of the patients do not get the minimum dose prescribed with 4.6+/-3.4 L less than the dose prescribed. We conclude that the monitoring of dialysis dose with the Kt provides a better discrimination detecting that between 30 and 40% of the patients perhaps do not get an adequate dose for their gender or body surface area.

[Control of hypertension refractory to medical management by means of short daily hemodialysis]. / Control de HTA refractaria a tratamiento médico con hemodiálisis corta diaria.

Hypertension is a very frequent complication in patients in hemodialysis. A high percentage of the patients on standard hemodialysis remain hypertense in spite of intensive pharmacologic treatment. We presented the case of a hypertense patient with difficult control in spite of antihypertensive treatment with five drugs and several secondary complications. The change to a short daily hemodialysis was successful to hypertension control and allowed a gradual suspension of drugs.

Kt como control y seguimiento de la dosis en una unidad de hemodiálisis / Kt as control and follow-up of the dose at a hemodialysis unit

Asegurar que el paciente recibe la dosis adecuada en cada sesión de diálisis debe ser un objetivo a conseguir a corto o medio plazo. La incorporación de la dialisancia iónica (DI) en los monitores durante los últimos años ha permitido monitorizar la dosis de hemodiálisis en tiempo real y en cada sesión. Lowrie y cols., recomiendan el seguimiento de la dosis con el Kt, recomendando un mínimo de 40 L en mujeres y 45 en hombres o individualizar la dosis por área de superficie corporal. El objetivo del presente estudio era hacer un seguimiento de la dosis con el Kt en cada sesión durante 3 meses, y comparar con la analítica mensual habitual. 51 pacientes (58% de la Unidad de hemodiálisis), 32 varones y 19 mujeres, de 60,7 ± 14 años de edad, en programa de hemodiálisis durante 37,7 ± 52 meses, se dializaron con monitor con DI de forma rutinaria. La etiología de su IRC era de 3 NTI, 9 GNC, 12 nefroangiosclerosis, 7 poliquistosis renal, 7 diabetes mellitus y 13 no filiada. Se analizaron 1.606 sesiones durante 3 meses. Cada paciente recibió la pauta habitual de HD, con dializadores de diacetato de celulosa de 2,1 m2 (33,3%), polisulfona de 1,9 m2 (33,3%) y helixona de 1,8 m2, con duración de 263 ± 32 minutos, con un flujo sanguíneo de 405 ± 66, con flujo baño a 712 ± 138 ml/min, peso seco de 66,7 ± 14 kg. Se valoró la DI inicial, la DI final y el Kt en cada sesión y el PRU y el Kt/V mediante la analítica mensual. La DI inicial fue de 232 ± 41 ml/min, la DI final de 197 ± 44 ml/min, la dosis media de Kt fue de 56,6 ± 14 L, el Kt/V medio de 1,98 ± 0,5 y el PRU de 79,2 ± 7%. Todos los pacientes recibieron una dosis mínima de Kt/V y PRU de 1,3 y 70%, respectivamente. No obstante, si utilizamos el Kt según el sexo, observamos que el 31% de los pacientes no alcanzaban la dosis mínima prescrita (48,1 ± 2,4 L), 34,4% de los hombres y el 26,3% de las mujeres. Si utilizamos el Kt individualizado por su superficie corporal, (49,1 ± 4 L), observamos que el 43.1% de los pacientes no alcanzaban la dosis mínima prescrita, con 4,6 ± 3,4 L menos de dosis. Concluimos que el seguimiento de la dosis de diálisis con el Kt, permite una mejor discriminación de la adecuación de diálisis, identificando entre el 30 y el 40% de pacientes que quizá no alcanzasen una dosis adecuada para su género o para su superficie corporal (AU)

To ensure our patients are receiving an adequate dose in every dialysis session there must be a target to achieve this in the short or medium term. The incorporation during the last years of the ionic dialysance (ID) in the monitors, has provided monitoring of the dialysis dose in real time and in every dialysis session. Lowrie y cols., recommend monitoring the dose with Kt, recommending at least 40 L in women and 45 L in men or individualizing the dose according to the body surface area. The target of this study was to monitor the dose with Kt in every dialysis session for 3 months,and to compare it with the monthly blood test. 51 patients (58%of our hemodialysis unit), 32 men and 19 women, 60.7 ± 14 years old, in the hemodialysis program me for 37.7 ± 52 months, were dialysed with a monitor with IC. The etiology of their chronic renalfailure was: 3 tubulo-interstitial nephropathy, 9 glomerulonephritis,12 vascular disease, 7 polycystic kidney disease, 7 diabetic nephropathy and 13 unknown. 1,606 sessions were analysed during a 3 month period. Every patient was treated with the usual parameters of dialysis with 2.1 m2 cellulose diacetate (33.3%), 1.9m2 polisulfone (33.3%) or 1.8 m2 helixone, dialysis time of 263 ±32 minutes, blood flow of 405 ± 66, with dialysate flow of 712 ±138 and body weight of 66.7 ± 14 kg. ITo ensure our patients are receiving an adequate dose in every dialysis session there must be a target to achieve this in the short or medium term. The incorporation during the last years of the ionic dialysance (ID) in the monitors, has provided monitoring of the dialysis dose in real time and in every dialysis session. Lowrie y cols., recommend monitoring the dose with Kt, recommending at least 40 L in women and 45 L in men or individualizing the dose according to the body surface area. The target of this study was to monitor the dose with Kt in every dialysis session for 3 months, and to compare it with the monthly blood test. 51 patients (58% of our hemodialysis unit), 32 men and 19 women, 60.7 ± 14 years old, in the hemodialysis programme for 37.7 ± 52 months, were dialysed with a monitor with IC. The etiology of their chronic renal failure was: 3 tubulo-interstitial nephropathy, 9 glomerulonephritis, 12 vascular disease, 7 polycystic kidney disease, 7 diabetic nephropathy and 13 unknown. 1,606 sessions were analysed during a 3 month period. Every patient was treated with the usual parameters of dialysis with 2.1 m2 cellulose diacetate (33.3%), 1.9 m2 polisulfone (33.3%) or 1.8 m2 helixone, dialysis time of 263 ± 32 minutes, blood flow of 405 ± 66, with dialysate flow of 712 ± 138 and body weight of 66.7 ± 14 kg. Initial ID, final ID and Kt were measured in each session. URR and Kt/V were obtained by means of a monthly blood test. The initial ID was 232 ± 41 ml/min, the final ID was 197 ± 44 ml/min, the mean of Kt determinations was 56.6 ± 14 L, the mean of Kt/V was 1.98 ± 0.5 and the mean of URR was 79.2 ± 7%. Although all patients were treated with a minimum recommended dose of Kt/V and URR when we used the Kt according to gender, we observed that 31% of patients do not get the minimum dose prescribed (48.1 ± 2.4 L), 34.4% of the men and 26.3% of the women. If we use the Kt individualized for the body surface area, we observe that 43.1% of the patients do not get the minimum dose prescribed with 4.6 ± 3.4 L less than the dose prescribed. We conclude that the monitoring of dialysis dose with the Kt provides a better discrimination detecting that between 30 and 40% of the patients perhaps do not get an adequate dose for their gender or body surface areanitial ID, final ID and Kt (..) (AU)

Control de HTA refractaria a tratamiento médico con hemodiálisis corta diaria / No disponible

La hipertensión arterial es una complicación muy frecuente en pacientes en hemodiálsis. Un elevado porcentaje de los pacientes tratados con hemodiálisis estándar permanecen hipertensos a pesar de tratamiento farmacológico intensivo. Presentamos el caso de una paciente hipertensa de difícil control con varios ingresos por complicaciones secundarias a pesar de tratamiento antihipertensivo con cinco fármacos. La HTA fue controlada con el cambio a un esquema de diálisis corta diaria con la progresiva suspensión del tratamiento farmacológico (AU)

Hypertension is a very frequent complication in patients in hemodialysis. A high percentage of the patients on standard hemodialysis remain hypertense in spite of intensive pharmacologic treatment. We presented the case of a hypertense patient with difficult control in spite of antihypertensive treatment with five drugs and several secondary complications. The change to a short daily hemodialysis was successful to hypertension control and allowed a gradual suspension of drugs (AU)

Membranas en el fracaso renal agudo / Membranes in acute renal failure

Las membranas de diálisis con las mejores propiedades biológicas deben ser biocompatibles, capaces de excluir las impurezas del baño de diálisis y tener grandes poros que permitan la eliminación de sustancias lo más parecido al riñón nativo sano, con pérdida casi nula de albúmina o moléculas de mayor tamaño. Los dializadores que mejor se ajustan a estas características son los dializadores de alto flujo o de alta permeabilidad. En la elección de la membrana de diálisis para el tratamiento del FRA se deben tener en cuenta la biocompatibilidad y la permeabilidad a pequeños solutos y a solutos de tamaño mediano-grande

When choosing the appropriate dialysis membrane in the acute setting, both biocompatibility and permeability should be considered. The parameters used when selecting a filter for acute dialysis are small solute removal, middle/large solute removal, and biocompatibility. With respect to small solute removal, membrane pore characteristics (pore size distribution and density) and surface area are important membrane-related determinants. Membrane characteristics define biocompatibility, although other factors, such as disinfectants may influence. Unlike in chronic hemodialysis, in which leukopenia and complement activation are well-accepted indicators of poor biocompatibility (i.e. bioincompatibility), the markers of inflammation in critically ill patients with acute renal failure are less clearly defined. In critical patients with acute renal failure activation of several inflammatory pathways preclude clear evaluation of the independent contribution of membrane biocompatibility. However, it has been demonstrated that in patients with acute renal failure, the use of cuprophan membranes can lead to complement activation and lipoxygenase stimulation. Despite initial studies demonstrated lower mortality with the use of biocompatible membranes in acute renal failure, subsequent studies casted doubts on these earlier findings. Most studies were undepowered and had randomization problems. Current evidence does not allow to recommend the unrestricted use of biocompatible membranes. However, bioincompatible membranes (grade B) and unsubstituted cellulose membranes (grade A) should be avoided. With respect to permeability, each membrane has intrinsic permeability characteristic that allow their classification according to their water and solute permeability. With respect to water permeability, membranes are classified according the ultrafiltration coefficient (CUF) expressed as mL/h/mmHg (ultrafiltered mL per hour per each mmHg of transmembrane pressure). Low permeability membranes are those with a CUF lower than 12 mL/h/mm Hg and high permeability membranes those with a CUF higher than 20 mL/h/mm Hg. With respect to solute permeability, membranes should resemble the native kidney, with a cut-off for albumin. Solute permeability is expressed by the sieving coefficient. Currently, it is not possible to recommend permeability characteristics for dislyzer membranes in the treatment of acute renal failure. However, it is plausible to recommend medium-high permeability membranes (grade C). The decision will be influenced by the dialysis modality in each particular patient