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.

[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.

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.

[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.

[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.

[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.

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.

[Estimation of the cost in the farmacologic treatment of chronic renal failure]. / El coste del tratamiento farmacológico en la enfermedad renal crónica.

The prevalence and incidence of end stage renal disease has increased considerably in the past years. We know that the cost of treatment of these patients is high. Limited information exists on care resource utilization for maintenance of patients before the initiation of replacement therapy. The purpose of this study is determine the cost of pharmaceutic treatment during the predialysis phase. Pharmacy cost was analyzed for 200 patients controlled on outpatient nephrology department. The mean age was 72.4 years, 59% were males, and the comorbidity distribution was: hypertension 87%, hyperlipidemia 56% and diabetes 35%. The per-patient-per-month charges were 215.45 Euro, with a continous increase from 84.64 Euro on stage 1 to 352.59 Euro on stage 5 of chronic kidney disease. Erythropoiesis stimulants were reponsible of 46.5% of these cost. The most frequent prescribed medications were antihypertensive drugs, statins and iron preparations. Patients with end stage renal disease generate significant cost during the predialysis period. The limited resources, and the growth of health care expeditures, particulary the spending for prescriptions drugs, are two of the major problems for Health Care Systems. A better knowledge of the associated costs to the treatment of these patients will help us to increase our efficiency.

[Middle molecules removal. Beyond beta2-microglobulin]. / Depuración de grandes moléculas. Más allá de la beta2-microglobulina.

The uremic toxin removal capacity mainly depends on dialyzer and hemodialysis modes. The low-flux hemodialysis only removes solutes having molecular weights less than 5.000 Da. High-flux hemodyalisis represents a form of low-volume hemodiafiltration because of the internal filtration and back-filtration that can take place within a dialyzer. Hemodiafiltration with large volumes of replacement fluid seems to be the best technique for removing all small, medium-sized and large molecules. The objective of our study was to evaluate the large molecules removal bigger than beta2-microglobuline on high flux haemodialysis and on-line hemodiafiltration with postdilutional infusion, in patients with three times a week dialysis and on short daily dialysis. We studied 24 patients, 15 males and 9 females stable on haemodialysis programme, twelve on standard four to five hours three times a week dialysis and twelve on 2 to 2 1/2 hours six times a week dialysis. All patients were dialysed with Fresenius 4008 monitor, three sessions on high flux haemodialysis (HD) and three sessions on on-line hemodiafiltration (OL-HDF). Two sessions with each filter were performed (polisulfone HF80, polyethersulfone Arylane H9 and new polisulfone APS 900). Pre and postdialysis concentrations of urea, creatinine, (beta2-microglobulin (beta2-m), myoglobin, prolactin and alpha1 microglobulin (alpha1-m) were measured. There was no difference in urea and creatinine small molecules removal. beta2m removal was 68% on HD and 81% on OL-HDF. Myoglobin and prolactin present a similar removal pattern, a higher removal with new filters (60% with Arylane and 59% with APS) in comparison with clasical polisulfone (22% with HF80). The mean alpha1-m reduction rate on HD was 6% and on OL-HDF 22%. OL-HDF with APS 900 filter was the most remove technique (35.4%), significatively higher than the other modes and filters. We can conclude that the new filters generation reach a better uremic toxins removal, specially in large molecules higher than beta2-m and on HD modality.

[Depurative efficiency of intermediate and large molecules with different hemodialysis modalities]. / Eficacia depurativa de medianas y grandes moléculas en diferentes modalidades de hemodiálisis.

An accumulation of uremic toxins occurs in renal failure, interfering with different biological functions. Low-flux hemodialysis only clears solutes with a molecular weight lower than 5000 Da. High-flux hemodialysis improves this clearance, being limited from 15,000 Da up. Hemodiafiltration techniques, mid-dilutional, post-dilutional or both, with high reinfusion volumes, are the most efficacious cleaning either large, middle or small uremic toxins. Protein-bound small-size mole cules are not properly removed by any technique. Research in technology and new therapeutic schemes are still needed in order to achieve more physiological depuration methods with better future results.

[Monitoring hemodialysis dose with ionic dialisance in on-line hemodiafiltration]. / Valoración de la medición de la dosis de diálisis con dialisancia iónica en hemodiafiltración on-line.

Until now, with the ionic dialysance measurement, it has been possible to determine hemodialysis dose in each session of hemodialysis (HD) and in the conventional hemofiltration (HDF) but not in the modality of on-line HDF. Recently it is possible with a new biosensor that allows to measure the dose in on-line HDF. The aim of this study was to evaluate the value of this biosensor in different dialysis situations comparing the dialysis dose measured in blood in comparison with the values obtained from the sensor. We have analysed 192 hemodialysis sessions performed in 24 patients, 15 male and 9 female, mean age of 70.2 +/- 12 years, included in on-line HDF. All treatments were done using 4008H (Fresenius) monitor equipped with on-line clearance monitoring (OCM), that measure, with non invasive monitoring, the effective ionic dialysance equivalent to urea clearance. Every patient received eight dialysis sessions: one with dialysate flow (Qd) 500 ml/min, two with HD and Qd 800 ml/min and five with on-line HDF. Other habitual haemodialysis parameters were no changed, dialysis time 200 +/- 63 min (135-300) and blood flow 421 +/- 29 ml/min (350-450). Initial and final ionic dialysance values (K), final Kt, Kt/V measured with OCM using V of Watson, and Kt/V determined in blood pre and postdialysis concentrations of urea (Daugirdas second generation), were measured. The mean of initial K was 251 +/- 21 ml/min and the final K was 234 +/- 24 ml/min. The Kt measured with OCM was 50.6 +/- 17 L, 51.2 +/- 17 in men and 49.7 +/- 16 in women. The V (Watson) was 34.5 +/- 6 L. The Kt/V measured with the Kt of OCM and V was 1,499 +/- 0.54 and Kt/V measured in blood samples was 1,742 +/- 0.58. The correlation between both values was 0.956. The Kt was different according to dialysis modality used: in HD and Qd 500 was 44.7 +/- 15 L, in HD and Qd 800 was 50.7 +/- 17 and in on-line HDF (22.1 +/- 7 L of reposition volume), was 51.8 +/- 17 L. The Kt/V from blood samples also shows variation: in HD and QD 500 was 1.60 +/- 0.55, in HD and Qd 800 was 1,726 +/- 0.56 and in on-line HDF was 1,776 +/- 0.59. In this study has been observed a close correlation between the new biosensor OCM with the measures obtained from the blood samples. For this reason this sensor it is useful in all modalities of dialysis treatment, included on-line HDF. The sensor was able to discriminate the efficacy of different dialysis modalities used in this study.

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.

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.

[Assessment of salt intake in hemodialysis]. / Valoración de la ingesta de sal en hemodiálisis.

One of the main goals of dialysis is to reach a correct sodium balance. Dietary sodium restriction facilitates control of thirst, water overload, hypertension and cardiac failure. Nowadays, it is possible to estimate sodium mass transfer and known interdialytic salt intake, by means of non-invasive methods. The use of dialysate sodium profiles improves dialysis tolerance but it has been reported that interdialytic thirst may increase because of an inappropriate sodium balance. The aim of this study was to evaluate the usual salt intake in hemodialysis patients, the effects on interdialytic gain weight, arterial pressure, blood volume preservation and dialysis tolerance of two different profiles of dialysate sodium and an additional session with salt restriction. Seventeen dialysis patients, 12 male and 5 females, were studied. Each patient underwent seven hemodialysis treatments: three consecutives sessions (a week) with constant sodium and ultrafiltration hemodialysis; three consecutive sessions with exponential decrease of conductivity (Initial 15.5-16.0, mid-session 14.3 and at the end 13.9-14 mS/cm) and ultrafiltration (1.6 l/h initial and 0.1 at the end) profiled hemodialysis; and an additional session which had a special dietary salt restriction. Dialysis parameters and dry weight were kept constant. Integra monitor with Diascan and Hemoscan biosensors (Hospal) were used in all sessions. We measured pre- and postdialytic plasma conductivity, sodium mass transfer, interdialytic weight gain, mean arterial pressure (MAP), percent reductions of blood volume (%R-BV) and hypotensive episodes during dialysis. Mean sodium mass transfer was 1,144 +/- 356 mmol (no profile week) vs 1,242 +/- 349 mmol (week with profiles), NS. It was equivalent to a salt ingestion of 9.6 +/- 3 and 10.4 +/- 3 g/day respectively. End plasma conductivity was 14.04 +/- 0.14 (no profile) versus 14.21 +/- 0.08 mS/cm (profiled), p < 0.001. Interdialytic weight gain was 2.49 +/- 0.76 (no profile) vs 2.32 +/- 0.56 kg (profiled), NS. MAP was 101 +/- 11 (no profile) vs 99 +/- 10 mmHg (profiled), NS. The %R-BV was -7.73 +/- 3 (no profile) vs -6.46 +/- 3% (profiled), p < 0.01. Hypotensive episodes/session were 0.66 +/- 0.75 (no profiles) vs 0.41 +/- 0.57 (profiled), NS. Mean sodium mass transfer was 356 +/- 125 mmol with usual salt intake and 240 +/- 81 mmol with salt restriction, p < 0.001. It was equivalent to a salt ingestion of 10.47 +/- 3 versus 7.06 +/- 2 g per day respectively, p < 0.001. Initial plasma conductivity was 14.31 +/- 0.21 (usually sodium intake) versus 14.16 +/- 0.17 mS/cm (salt restriction), p < 0.01. Predialysis blood pressures were decreased with dietary salt restriction, MAP was 99.1 +/- 11 vs 94.4 +/- 12 mmHg (p < 0.01). Interdialytic weight gain decreased with salt restriction, 2.32 +/- 0.76 vs 1.78 +/- 0.49 kg (p < 0.001). The %R-BV was -7.25 +/- 2 (usual sodium intake) vs -5.91 +/- 2% (salt restriction), p < 0.01. Hypotensive episodes/session were 0.71 +/- 0.8 (usual sodium intake) vs 0.18 +/- 0.5 (salt restriction), p < 0.05. In conclusion, automatic measurement of sodium mass transfer is a practical tool to follow dietary salt ingestion in hemodialysis patients. It allows us accurate, individualised and continual dietary interventions. The use of exponential decrease sodium profiles improve dialysis tolerance without changes in sodium balance, interdialytic weight gain or arterial pressure. A reduction of three g in salt intake observed in this study was beneficial in interdialytic weight gain, dialysis tolerance and blood pressure control.

[Comparison of dialyzers in on-line hemodiafiltration]. / Comparación de dializadores en hemodiafiltración en línea.

UNLABELLED: At present we have a great variety of high-flux dialyzers whose characteristics in vitro seem similar. On-line HDF is a technique which combines diffusion with elevated convection and uses dialysate as replacement fluid. On-line HDF provides the highest clearances for small, medium-sized and large molecules and gives the best performance from the dialyzers. Conscious of this wide choice of dialyzers we evaluated the performance of different dialyzers in renowing small and medium-large molecules. Eleven patients were included in this study, 7 males and 4 females. Every patient received 11 on-line HDF sessions with Fresenius 4008B machine, Qi 100 ml/min or 6 L/h, QB 400 ml/min, QB 800 ml/min, UF 0.5 L/h and Td 60 min. Only the dialyzer was changed: 1.9 m2 cellulose triacetate (Tricea 190G), 2.1 m2 poly methyl methacrylate of PMMA (BK-2.1P), 1.8 m2 polyester-polymer Allol or PEPA (FLX-18GWS), 2.05 m2 acrylonitrile (Filtral 20), 2.1 m2 polyamide (Poliflux 2.1) and 1.8-2.4 m2 polysulfones (HF 80, BS-1.8S, APS-900, Arylane H9, Idemsa 2000, HdF 100). Arterial pressure, venous pressure and transmembrane pressure (TMP) were monitored. Plasma, urea, creatinine, phosphate, uric acid and beta 2m concentrations were measured at the beginning and at the end dialysis from arterial and venous blood lines, and arterial blood line with the slow flow method. Recirculation, dialyzer solutes clearance and solute reduction rates were calculated. No significant differences were found in arterial pressure, venous pressure and recirculation. Small molecule removal was similar except in BK-2.1P and HdF 100 dialyzers which were lower and higher respectively. There were differences in TMP and beta 2m removal among dialyzers employed. Mean TMP, beta 2m clearance and beta 2m reduction ratio were: Tricea 190G (TMP 336 mmHg, beta 2m K 79 ml/min and beta 2m reduction ratio 44.9%), BK-2.1P (TMP 485, beta 2m K 102 and beta 2mRR 48.3%), FLX-18 GWS (TMP 195, beta 2m K 140 and beta 2mRR 54.6%), Filtral 20 (TMP 245, beta 2m K 132 and beta 2mRR 54.1%), Poliflux 2.1 (TMP 209, beta 2m K 158 and beta 2mRR 56.0%), HF 80 (TMP 208, beta 2m K 160 and beta 2mRR 57.4%), BS-1.8S (TMP 186, beta 2m K 179 and beta 2mRR 59.6%), APS-900 (TMP 174, beta 2m K 176 and beta 2mRR 64.8%), Arylane H9 (TMP 206, beta 2m K 171 and beta 2mRR 59.9%), Idemsa 2000 (TMP 203, beta 2m K 169 and beta 2mRR 60.4%), HdF 100 (TMP 152, beta 2m K 186 and beta 2mRR 64.6%). CONCLUSIONS: Of the dialyzers evaluated in on-line HDF, cellulose triacetate and PMMA have a smaller beta 2m removal and their use is limited by an elevated TMP. The polysulfones provide greater beta 2m removal with lower TMP, particularly the APS-900 and HdF 100 dialyzers. The acrylonitrile, PEPA and polyamide are intermediate.

[Evaluation of methods to calculate dialysis dose in daily hemodialysis]. / Cuantificación de la dosis de diálisis en hemodiálisis diaria.

UNLABELLED: Daily dialysis has shown excellent clinical results because a higher frequency of dialysis is more physiological. Different methods have been described to calculate dialysis dose which take into consideration change in frequency. The aim of this study was to calculate all dialysis dose possibilities and evaluate the better and practical options. Eight patients, 6 males and 2 females, on standard 4 to 5 hours thrice weekly on-line hemodiafiltration (S-OL-HDF) were switched to daily on-line hemodiafiltration (D-OL-HDF) 2 to 2.5 hours six times per week. Dialysis parameters were identical during both periods and only frequency and dialysis time of each session were changed. Time average concentration (TAC), time average deviation (TAD), normalized protein catabolic rate (nPCR), Kt/V, equilibrated Kt/V (eKt/V), equivalent renal urea clearance (EKR), standard Kt/V (stdKt/V), urea reduction ratio (URR), hemodialysis product and time off dialysis were measured. Daily on-line hemodiafiltration was well accepted and tolerated. Patients maintained the same TAC although TAD decreased from 9.7 +/- 2 in baseline to a 6.2 +/- 2 mg/dl after six months, p < 0.01. No significant changes were observed in weekly Kt/V and eKt/V throughout the study. However EKR, stdKt/V and weekly URR were increased during D-OL-HDF in 24-34%, 46% and 50%, respectively. Hemodialysis product was raised in a 95% and time off dialysis was reduced to half. CONCLUSION: Dialysis frequency is an important urea kinetic parameter which there are to take in consideration. It's necessary to use EKR, stdKt/V or weekly URR to calculate dialysis dose for an adequate comparison between different frequency dialysis schedules.

[Acute interstitial nephritis associated with omeprazole therapy]. / Nefritis intersticial aguda por omeprazol.

From 1 to 3% of acute renal failures are due to acute interstitial nephritis (AIN). Most of them are due to drugs. Nonsteroidal antiinflammatory drugs, penicillins and sulfonamides are the most frequently reported. Clinical presentation of drug-induced AIN has changed over time and with the use of new drugs. In fact actually the classic triad of fever, rash and eosinophilia is uncommon. Omeprazole is a drug widely used in the treatment of gastroesophageal reflux disease and peptic ulcer disease. Serious side effects are rare with this drug, but despite of its safety we can see serious adverse effects such as acute renal failure. We describe two cases of acute interstitial nephritis after use of omeprazole and a review of all the cases published in the last years.

[Interaction of the mechanisms of beta 2-microglobulin convection, diffusion, and adsorption in line hemodiafiltration]. / Interacción de los mecanismos de convección, difusión y adsorción de beta 2-microglobulina en la hemodiafiltración en línea.

The in vivo contribution of diffusion, convection ad adsorption to beta 2-microglobulin (beta 2-m) elimination by hemodiafiltration (HDF) was investigated. 11 patients (8M/3W), with a mean age of 59 +/- 10 years and weighing 62.7 +/- 8.7 kg were studied. A 1.89 m2 polysulphone membrane was used in 180 min postdilution HDF. Samples at blood inlet (bi), blood autlet (bo), dialysate outlet (do) and ultrafiltrate (uf) were taken to determine beta 2-m concentrations at 30 and 150 min. Rates of flow (Q, ml(min) prescribed were: infusion, Qinf = 103.6 +/- 12.3, Quf = 14.6 +/- 4.0 y Qb = 465 +/- 5.0. Effective Qbi was automatically measured by the machine and Qdo = 800 + Quf. The removed beta 2-m mass (M, mg/min) was obtained by multiplying rates of flow (Q, L/min) by beta 2-m concentrations (mg/L) at each sampling point. From mass balance, we calculated the mass of beta 2-m removed (mg/min) by adsorption 0.23 +/- 0.2, by convection 0.7 +/- 0.3 and by diffusion 1.0 +/- 0.4, at 30 min. At 150 min, the beta 2-m mass removed was -0.06 +/- 0.1 by adsorption 0.4 +/- 0.1 by convection and 0.3 +/- 0.1 by diffusion. In HDF, these beta 2-m eliminating mechanisms play a variable role throughout the session. The more significant conclusion is that diffusion of beta 2-m with a synthetic "open" membrane is an important method of removing beta 2-m, comparable to convection over the whole procedure. That result explain the relative efficacy of beta 2-m clearance by HDF convection, and also explain why isolated diffusion is an efficient mechanism for beta 2-m removal by high-flux hemodialysis.