Alta prevalencia de covid19 asintomático en hemodiálisis. Aprendiendo dia a dia el primer mes de pandemia de covid19 / High prevalence of asymptomatic COVID-19 in haemodialysis: learning day by day in the first month of the COVID-19 pandemic

Los pacientes en diálisis son un grupo de riesgo de sufrir la infección por el SARS-CoV2 y posiblemente de tener más complicaciones, pero la información con la que contamos es escasa. El objetivo de este trabajo es describir la experiencia del primer mes de pandemia por SARS-Cov2 en una unidad hospitalaria de hemodiálisis (HD) que atiende al 2º distrito madrileño con más en incidencia de COVID19 (casi 1000 pacientes en 100000 h). Se presenta mediante un diario las acciones llevadas a cabo, la incidencia de COVID19 en pacientes y en el personal sanitario, algunas características clínicas y el resultado de un cribado entre todos los pacientes de la unidad. Al inicio, teníamos 90 pacientes en HD: 37(41,1%) han tenido COVID19, de los que 17 (45,9%) fueron diagnosticado spor síntomas detectados en el triaje o durante la sesión y 15 (40,5%) en un cribado realizado a posteriori en los que no se había hecho test diagnóstico por PCR-SARS-Cov2 hasta ese momento. El síntoma más frecuente fue la fiebre, el 50% presentó linfopenia y el 18,4% saturación de O2 < 95%. Precisaron ingreso hospitalario 16 (43,2%) y 6 fallecieron (16,2%). Encontramos un agrupamiento de contagio por turnos y también en aquellos que usaban transporte colectivo. En cuanto al personal, de las 44 personas involucradas, 15 (34%) presentaron sintomatología compatible y 4 (9%) tuvieron PCR SARS-Cov-2 positiva determinada por Salud Laboral y 9 (20%) precisaron algún periodo de Incapacidad Laboral Transitoria (ILT), y 5 fueron considerados casos probables

Dialysis patients are a risk group for SARS-CoV2 infection and possibly further complications, but we have little information. The aim of this paper is to describe the experience of the first month of the SARS-Cov2 pandemic in a hospital haemodialysis (HD) unit serving the district of Madrid with the second highest incidence of COVID19 (almost 1000 patients in 100000 h). In the form of a diary, we present the actions undertaken, the incidence of COVID19 in patients and health staff, some clinical characteristics and the results of screening all the patients in the unit.We started with 90 patients on HD: 37 (41.1%) had COVID19, of whom 17 (45.9%) were diagnosed through symptoms detected in triage or during the session, and 15 (40.5%) through subsequent screening of those who, until that time, had not undergone SARS-CoV2 PCR testing. Fever was the most frequent symptom, 50% had lymphopenia and 18.4% < 95% O2 saturation. Sixteen (43.2%) patients required hospital admission and 6 (16.2%) died. We found a cluster of infection per shift and also among those using public transport. In terms of staff, of the 44 people involved, 15 (34%) had compatible symptoms, 4 (9%) were confirmed as SARS-Cov2 PCR cases by occupational health,9 (20%) required some period of sick leave, temporary disability to work (ILT), and 5 were considered likely cases. CONCLUSIONS: We detected a high prevalence of COVID19 with a high percentage detected byscreening; hence the need for proactive diagnosis to stop the pandemic. Most cases are managed as outpatients, however severe symptoms are also appearing and mortality to date is 16.2%. In terms of staff, 20% have required sick leave in relation to COVID19

Risk in dosing regimens for 25-OH vitamin D supplementation in chronic haemodialysis patients.

INTRODUCTION: 25-OH vitamin D (25-OHvitD) insufficiency or deficiency should be treated in haemodialysis (HD) patients, although the 25-OHvitD target, drug or dosing regimens are unclear. AIMS: To describe factors associated with 25-OHvitD levels in HD patients and to assess the effect of three dosing regimens to supplement 25-OHvitD (calcifediol) on serum calcium (Ca), phosphate (P), parathyroid hormone (PTH), 25-OHvitD and 1,25-OHvitD. METHODS: Two hundred and seventeen patients from three HD units were studied. Demographic and biochemical data were collected at baseline. Two different 25-OHvitD assays were used. One hundred and sixty-seven patients were treated with various calcifediol dosing regimens. The same biochemical determinations were repeated after 3 months of treatment. RESULTS: At baseline, 12.9% of patients had 25-OHvitD <10 ng/ml. In multivariate linear regression, the season (lower in winter) and the assay method were determinants of 25-OHvitD concentration. Following calcifediol supplementation, 25-OHvitD, calcium and phosphate increased, while PTH diminished with statistical significance. After treatment, there were positive correlations between 25-OHvitD and Ca (r = 0.28, p < 0.0001) or 1,25-OHvitD (r = 0.75, p < 0.0001) that were not observed in the baseline dataset. High concentrations of post-treatment 25-OHvitD were associated with higher 1,25-OHvitD levels. Calcemia increased more in those treated with concomitant active vitamin D or those having suppressed baseline PTH, while PTH decreased more in those having above-target PTH levels. CONCLUSIONS: Standardisation of methods to determine 25-OHvitD blood levels is needed. In HD patients, calcifediol increased 25-OHvitD, calcemia and phosphatemia and lowered PTH. Caution should be exercised with the higher calcifediol dosing regimens, especially in patients with suppressed PTH or on vitamin D receptor activators.

¿Hemos olvidado lo más importante para prevenir las bacteriemias en pacientes portadores de catéteres para hemodiálisis? / Have we forgotten the most important thing to prevent bacteremias associated with tunneled hemodialysis catheters?

La bacteriemia relacionada con el catéter (BRC) en pacientes en hemodiálisis (HD) es una complicación grave. Existen múltiples publicaciones que abogan por el uso de diferentes medidas farmacológicas para su prevención, pero muy pocas sobre la importancia de las medidas de precaución universal . El objetivo de este trabajo es mostrar la baja tasa de incidencia de BRC obtenida con la aplicación estricta de un protocolo de cuidados de catéter tunelizado (CT) por un personal bien entrenado en una nueva unidad de HD. Durante20 meses se aplicó un protocolo de manejo de CT por personal de enfermería cual i f i cado. Se ut i l izaron un total de 42 CT en 32 pacientes . El tiempo total de seguimiento fue de 8.372 días en los que ocurrieron dos episodios de BRC: 0,24 eventos /1.000 días - catéter. El trabajo muestra cómo sólo con medidas de precaución universal pueden lograr se tasas de BRC dentro de la excelencia (AU)

Bacteremia associated with tunneled central venous catheters (CVC) is a major complication in hemodialysis patients. Strategies that aim to prevent catheter-related bacteremia (CRB),ranging from the application of topical antibiotics to the use of different catheter-lock solutions, have been studied, but limited interest has been shown about following standardization of aseptic care and maintenance of CVC by experienced staff. This study reports CRB incidence obtained with astrict infection prophylaxis protocol based on universal precautions against infection adopted in our Unit by qualified nursing hemodialysis staff. During a period of 20 months, 32 patients received 42 CVC. There were 2 CRB, with an incidence of 0.24CRB/1000 days-catheter. This study shows that an optimal catheter-use management reduces the incidence of CRB to excellent rates. The use of a protocol directed to vigorously protect the catheter at the time of usage by specialized teams is critically important and is highly recommended (AU)

[Vascular access models cause heterogeneous results in the centres of one community]. / Los modelos de atención al acceso vascular condicionan resultados heterogéneos en los centros de una misma comunidad.

INTRODUCTION: Vascular access (VA) is the main difficulty in our hemodialysis Units and there is not adequate update data in our area. PURPOSE: To describe the vascular access management models of the Autonomous Community of Madrid and to analyze the influence of the structured models in the final results. MATERIAL AND METHODS: Autonomous multicenter retrospective study. Models of VA monitoring, VA distribution 2007-2008, thrombosis rate, salvage surgery and preventive repair are reviewed. The centers are classified in three levels by the evaluation the Nephrology Departments make of their Surgery and Radiology Departments and the existence of protocols, and the ends are compared. MAIN VARIABLES: Type distribution of VA. VA thrombosis rate, preventive repair and salvage surgery. RESULTS: Data of 2.332 patients were reported from 35 out of 36 centers. Only 19 centers demonstrate database and annual evaluation of the results. Seventeen centers have multidisciplinary structured protocols. Forty-four point eight percent of the patients started dialysis by tunneled catheter (TC). Twenty-nine point five percent received dialysis by TC in December-08 vs 24.7% in December-07. Forty-four point seven percent of TC were considered final VA due to non-viable surgery, 27% are waiting for review or surgery more than 3 months. For rates study data from 27 centers (1.844 patients) were available. Native AVF and graft-AVF thrombosis rates were 10.13 and 39.91 respectively. Centers with better valued models confirmed better results in all markers: TC rates, 24.2 vs 34.1 %, p: 0.002; native AVF thrombosis rate 5.3 vs 10.7 %; native AVF preventive repair 14.5 vs 10.2%, p: 0.17; Graft- AVF thrombosis rate 19.8 vs 44.4%, p: 0.001; Graft-AVF preventive repair 83.2 vs 26.2, p < 0.001.They also have less patients with TC as a final option (32.2 vs 45.3) and less patients with TC waiting for review or surgery more than 3 months (2.8 vs 0). LIMITS: Seventy-five percent of patients were reached for the analysis of thrombosis rate. Results are not necessarily extrapolated. CONCLUSIONS: For the first time detailed data are available. TC use is elevated and increasing. Guidelines objectives are not achieved. The difference of results observed in different centers of the same public health area; make it necessary to reevaluate the various models of care and TC follow-up.

Nuevas fórmulas para estimar el filtrado glomerular. Hacia una mayor precisión en el diagnóstico de la enfermedad renal crónica / No disponible

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Insuficiencia renal por enfermedad de depósito de cadenas ligeras / Renal failure due to light chain deposition disease

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Vigencia de la acetazolamida en la terapéutica diurética actual: aplicaciones en el edema refractario y la hiperpotasemia relacionada al bloqueo aldosterónico / Actuality of the use of acetazolamide as a diuretic: usefulness in refractory edema and in aldosteroneantagonist- related hyperkalemia

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[Fluid therapy in surgical patients: composition and influences on the internal milieu]. / Sueros empleados en enfermos quirúrgicos: composición y efectos sobre el medio interno.

UNLABELLED: Intravenous fluids administration is the usual practice in the postoperative period. Nonetheless, consensus about the more appropriate fluid reposition recipe is still insufficient. OBJECTIVE: To study the type of intravenous reposition used in Surgical Units and its impact on the internal milieu. DESIGN: prospective study of 112 patients with scheduled surgery, receiving only intravenous fluids. METHODS: biochemical study on postoperative fluids management in uncomplicated surgery. Principal variables: 1. Water and electrolytes administrated. 2. Differences in sodium/water balances before surgery vs first day after surgery. 3. Symptoms related to hyponatremia. RESULTS: Median P[Na] before and after surgery was 139.9+/-2.9 and 137.7+/-3.7, respectively (p<0.01). Fourteen patients (12.5%) had P[Na]<135, and 12 of them had a reduction of more than 6 mmol/L; accordingly, twenty-six patients (23.2%) had an increased free-water retention (p<0.05). Relevantly, they did not receive a higher amount of free-water and the proportion of isotonic saline/free water varied from <1 to >3. As possible mechanism of free-water accumulation: the postoperative P[Na] was lower in the patients who had a negative free-water clearance >or= -1 L (136.7+/-4.1 vs 138.5+/-3.2 mmol/L, p 0.015). CONCLUSION: The present study provides new information about the intravenous fluids prescribed in postoperative patients, ie, different proportions saline/water are basically equivalent with respect to inducing symptomatic hyponatremia. The mean value of the relation saline/water is 2:1. Hypotonic fluids input is not clearly related to more intense hyponatremia; the latter appears to depend more on a reduced capacity of the kidney to generate sufficient free water output.

Sueros empleados en enfermos quirúrgicos: composición y efectos sobre el medio interno / Fluid therapy in surgical patients: composition and influences on the internal milieu

La prescripción de sueros en el postoperatorio es una práctica rutinaria, pero sobre la que no existe un consenso basado en la evidencia. Objetivo: Examinar sistemáticamente el tipo de reposición hidroelectrolítica empleado por los Servicios Quirúrgicos y sus consecuencias sobre el medio interno. Pacientes y métodos: Diseño: estudio prospectivo en 112 pacientes con cirugías programadas. Método: estudio bioquímico del manejo hidroelectrolítico en postoperatorios no complicados tratados solo con sueros intravenosos. Variables principales: 1. agua y electrolitos administrados; 2. Diferencias de equilibrio hidrosalino entre pre- y post-operatorio;3. alteraciones clínicas atribuíbles a hiponatremia. Resultados: La [Na]P media pre y postoperatoria fue 139,9± 2,9 y 137,7 ± 3,7, respectivamente (p < 0,01) Catorce pacientes(12,5%) alcanzaron [Na]P < 135 mmol/L, y 12 presentaron un descenso de [Na]P ≥ 6 mmol/L, vg, 26 sujetos(23,2%) tuvieron un incremento significativo de agua libre(p < 0,05) Estos pacientes no habían recibido mayor cantidad de agua libre que el resto, siendo la proporción sueros isotónicos/agua libre desde < 1 a > 3. Como posible mecanismo de la retención hídrica, la [Na]P postoperatoria en los pacientes con aclaramiento de agua libre negativo ≥ -1litro/24 h fue más baja (136,7 ± 4,1 vs 138,5 ± 3,2 mmol/L,p 0,015). Conclusiones: Se aporta información previamente no disponible: a) diversas proporciones de suero isotónico: agua libre resultaron equivalentes frente al desarrollo de hiponatremia sintomática; b) la relación media suero isotónico: agua libre es 2:1, y c) las soluciones de reposición más hipotónicas no aparecen relacionadas con más hiponatremias. Éstas en cambio dependen de la respuesta renal de retención de agua (AU)

Intravenous fluids administration is the usual practice in the post operative period. Nonetheless, consensus about the more appropriate fluid reposition recipe is still insufficient. Objective: To study the type of intravenous reposition used in Surgical Units and its impacton the internal milieu. Patients and methods: Design: prospective study of 112 patients with scheduled surgery, receiving only intravenous fluids. Methods: biochemical study on postoperative fluids management in uncomplicated surgery. Principal variables: 1. Water and electrolytes administrated. 2. Differences in sodium/water balances before surgery vs first day after surgery. 3. Symptoms related to hyponatremia. Results: Median P[Na] before and after surgery was 139.9 ± 2.9 and 137.7 ± 3.7, respectively (p< 0.01). Fourteen patients (12.5%) had P[Na] < 135, and 12 ofthem had a reduction of more than 6 mmol/L; accordingly, twentysix patients (23.2%) had an increased free-water retention (p <0.05). Relevantly, they did not receive a higher amount of freewater and the proportion of isotonic saline/free water varied from< 1 to > 3. As possible mechanism of free-water accumulation: the postoperative P[Na] was lower in the patients who had a negative free-water clearance ≥ -1 L (136,7 ± 4,1 vs 138,5 ± 3,2 mmol/L, p0,015). Conclusion: The present study provides new information about the intravenous fluids prescribed in postoperative patients, ie, different proportions saline/water are basically equivalent with respect to inducing symptomatic hyponatremia. The mean value of the relation saline/water is 2:1. Hypotonic fluids input is not clearly related to more intense hyponatremia; the latter appears to depend more on a reduced capacity of the kidney to generate sufficient free water output (AU)

[Spanish extrahospitalary hemodialysis centers survey]. / Encuesta sobre los centros de hemodiálisis extrahospitalaria en España.

BACKGROUND: Many guides and scientific recommendations about hemodialysis (HD) treatment have been developed. However, its impact and application is unknown. The aim of this study is to describe how Spanish Extrahospitalary Hemodialysis Centers work. METHODS: A transversal, descriptive study was conducted by means of a survey. An 83-items questionnaire tackled different aspects involving patients and HD characteristics, Dialysis Unit organization and anemia management. RESULTS: One hundred surveys were distributed and 91% were answered, corresponding to 6599 patients (M 4015/F 2584). Fifteen % were younger of 50 years and 45.2% older of 70 years. Seventy seven % had arteriovenous fistulas, 8.1% had polytetrafluoroethylene grafts and 14.8% had catheters. The mean number of patients per center was 72.3 (11-212). Seventy eight % were divided in 3 shifts, with a mean relationship of 38.9 patients/physician, 4.7 patients/nurse and 9 patients/auxiliary personnel. HD characteristics were: 60.1% of the HD sessions were longer than 4 hours, 97.2% were on a 3 days/week schedule; 95.4% used a conventional technique; 49.1% were performed with high-flux membranes, 89.6% with synthetic membranes, and 11.7% used Qb higher than 400 mL/min: On the other hand, 8.8% of the patients were HVC +, 0.68% were AgHBs +, and 0.09 were HIV +. There were HCV + patients in 79% of Dialysis Units, 50% of them with complete isolation, while patients with hepatitis B were attended in 13.8%, and VIH + in 3.4% of the Units, the latter always with complete isolation. Water treatment was done with simple osmosis in 46.6% of the cases, with water collection in 86.8% with pyrogen filter in the monitors in 48.9%. Surveillance of the controls was performed by the physician in 94.3% of the cases, and by technicians or nurses in the rest. Mean Hb was 11.9(1.4) g/dL, being higher of 11 g/dL in 80.2% of the patients. Ferritin higher than 100 microg/L was found in 92.4% and transferrin saturation higher than 20% in 81.9% of patients. The percentage treated with erithropoyetic stimulant agents was 90.6%. CONCLUSIONS: All information collected is relevant in order to know what is done and how to improve it.. It will be useful to evaluate the impact of the publication of the new Guides of HD Centers of SEN on medical practice in this area.

Centros de diálisis extrahospitalaria: ¿de dónde venimos, a dónde vamos? / No disponible

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Encuesta sobre los centros de hemodiálisis extrahospitalaria en España / Spanish extrahospitalary hemodialysis centers survey

Introducción: Existen múltiples guías y recomendaciones científicas sobre el tratamiento de HD, pero se desconoce su grado de aplicación y repercusión. El Grupo de Trabajo de Hemodiálisis Extrahospitalaria se planteó describir una serie de puntos relevantes de la forma de trabajo de los centros extrahospitalarios. Material y métodos: Se realizó un estudio transversal y descriptivo, mediante un cuestionario de 83 preguntas en forma de encuesta, que abordaba distintos aspectos de los pacientes (pac), de características la HD (pauta, tratamiento de agua, medidas de aislamiento de virus), de la organización y el manejo de la anemia. Resultados: Se distribuyeron encuestas a 100 centros, de los que respondieron el 91%. El número total de pacientes fue 6.599 (H 4.015 vs M 2584). El 15,7% eran menores de 50 y el 45,2% mayores de 70 años. Los accesos vasculares prevalentes eran: 77% fístulas nativas, 8,1% prótesis y el 14,8% catéteres. La media de pacientes por centro fue 72,3 (rango 11-212), en el 78% divididos 3 turnos, con una media 38,9 pac/médico, 4,7 pac/enfermera y 9 pac/auxiliar. El 60,1% se dializaban más de 4 horas, con una frecuencia de 3 días/semana en el 97,2%, por una técnica convencional el 95,4%, con membranas de alta permeabilidad el 49,1% y sintéticas el 89,6%, el 11.7% utilizaban Qb superiores a 400 mL/min. El 8,8% de los pacientes eran VHC+, 0,68% virus B + y 0,09 VIH +. El 79% de los centros dializaban pacientes portadores del virus C (con aislamiento completo el 50%), mientras que los individuos virus B + se atendían en el 13,8% y los HIV + en el 3,4% de los centros, siempre con aislamiento completo. El tratamiento de agua fue ósmosis simple en el 46,6%, con almacenamiento de agua, 86,8% y filtro de pirógenos en los monitores, 48,9%. La supervisión de los controles la realizaba el médico en el 94,3% y en el resto sólo lo supervisaban el técnico o el personal de enfermería. La hemoglobina media fue 11,9 (1,4) g/L, siendo superior a 11 g/L en el 80,2% de los pacientes, con una ferritina > 100 μg/L el 92,4% y una saturación > 20% el 81,9%. El % de tratados con agentes estimuladores de la eritropoyesis era el 90,6%. Conclusiones: Toda la información obtenida es relevante para conocer qué se hace y cómo mejorarlo. Además, proporciona una herramienta para evaluar el impacto de la publicación de la Guía de Centros de HD de la SEN sobre la práctica médica en este sector

Background: Many guides and scientific recommendations about hemodialysis (HD) treatment have been developed. However, its impact and application is unknown. The aim of this study is to describe how Spanish Extrahospitalary Hemodialysis Centers work. Methods: A transversal, descriptive study was conducted by means of a survey. An 83-items questionnaire tackled different aspects involving patients and HD characteristics, Dialysis Unit organization and anemia management. Results: One hundred surveys were distributed and 91% were answered, corresponding to 6,599 patients (M 4,015/F 2,584). Fifteen % were younger of 50 years and 45.2% older of 70 years. Seventy seven % had arteriovenous fistulas, 8.1% had polytetrafluoroethylene grafts and 14.8% had catheters. The mean number of patients per center was 72.3 (11-212). Seventy eight % were divided in 3 shifts, with a mean relationship of 38.9 patients/physician, 4.7 patients/nurse and 9 patients/auxiliary personnel. HD characteristics were: 60.1% of the HD sessions were longer than 4 hours, 97.2% were on a 3 days/week schedule; 95.4% used a conventional technique; 49.1% were performed with high-flux membranes, 89.6% with synthetic membranes, and 11.7% used Qb higher than 400 mL/min: On the other hand, 8.8% of the patients were HVC +, 0.68% were AgHBs +, and 0.09 were HIV +. There were HCV + patients in 79% of Dialysis Units, 50% of them with complete isolation, while patients with hepatitis B were attended in 13.8%, and VIH + in 3.4% of the Units, the latter always with complete isolation. Water treatment was done with simple osmosis in 46.6% of the cases, with water collection in 86.8% with pyrogen filter in the monitors in 48.9%. Surveillance of the controls was performed by the physician in 94.3% of the cases, and by technicians or nurses in the rest. Mean Hb was 11.9(1.4) g/dL, being higher of 11 g/dL in 80.2% of the patients. Ferritin higher than 100 μg/L was found in 92.4% and transferrin saturation higher than 20% in 81.9% of patients. The percentage treated with erithropoyetic stimulant agents was 90.6%. Conclusions: All information collected is relevant in order to know what is done and how to improve it. It will be useful to evaluate the impact of the publication of the new Guides of HD Centers of SEN on medical practice in this area

[Reticulocyte response after immediate withdrawal of recombinant human erythropoietin in chronic hemodialysis patients]. / Respuesta reticulocitaria tras cese inmediato de administración de eritropoyetina recombinante humana en enfermos en hemodiálisis crónica. Implicaciones en la terapia de la anemia.

UNLABELLED: The sudden interruption of recombinant human erythropoietin (rHuEPO) in end-stage renal disease (ESRD) patients leads to rapid anemization. The mechanisms of this phenomenon are, however, insufficiently understood. The present study examined the response to immediate rHuEPO withdrawal in dialysis patients. METHODS: 10 chronic hemodialysis (HD) patients regularly receiving rHuEPO were studied. rHuEPO was stopped and reinitiated after 7 days. Reticulocyte profile, haemoglobin and haematocrit were measured at 0, 7 and 15 days. As a complementary study, and with the purpose of analyzying whether uremia was a relevant factor, 10 non-uremic male Wistar rats were treated with rHuEPO. After two weeks, rHuEPO was withdrawn in 5 animals, and continued for 7 additional days in the remainder. The same variables than in the human study were determined. RESULTS: Changes in reticulocyte subtypes from baseline to day 7 were: total 18.2 +/- 0.9 vs 14.3 +/- 1.8% (p < 0.06); high-fluorescence (HFR): 2.6 +/- 0.4 vs 0.75 +/- 0.2 (p < 0.001); medium-fluorescence (MFR): 13.0 +/- 1.1 vs 6.6 +/- 0.9% (p < 0.02); and low-fluorescence (LFR): 84.2 +/- 1.4 vs 92.7 +/- 1% (p NS). The baseline pattern was recovered upon 7 days of rHuEPO reinitiation (p NS). Mean hemoglobin and hematocrit decreased by day 14 (p < 0.02) in spite of rHuEPO reinitiation at day 7. In non-uremic rats, changes were similar to that in the ESRD patients. CONCLUSION: rHuEPO induces changes in the reticulocyte pattern, consisting in a reduction of immature reticulocytes. These changes appear to be independent of the presence of uremia. Accordingly, complete rHuEPO withdrawal in HD patients will cause a rapidly-developing anaemia due to an alteration in the reticulocyte maturation series; therefore, sudden rHuEPO interruption should be avoided whenever is possible. As a collateral application, the specific changes described herein have potential use for detecting illegal administration of rHuEPO.

[Hypophosphatemia in dialysis units]. / Hipofosforemia en unidades de diálisis crónica.

Hypophosphatemia (Hf) is infrequently reported in chronic hemodialysis patients. The objective of this report is to describe the incidence, etiology, symptoms and treatment of Hf in a Dialysis Unit (defined as phosphorus < 2.5 mg/dL). In a retrospective study over a period of three years, we identified 22 cases of Hf, occurring on 11 among 149 patients. A two-groups distribution was made: Group A, patients with more than one episode (n = 3, 14 episodes of Hf) and Group B, patients with only one isolated episode of Hf (n = 8, 8 episodes of Hf). Plasma Ca, P, Albumin and nPCR were significant lower in group A (p < 0.05). Only two patients of group B had symptoms. Cases of Hf were: Group A: low-protein diet and alcoholism, Group B: decreased dietary intake due to non-digestive problems (n = 2) or due to digestive problems plus antacids (n = 4), phos-phate binders (n = 1) and dietary phosphorus restriction (n = 1). Three patients had secondary hyperparathyroidism. Treatment consisted on oral supplementarion by diet and changes in oral calcium salts. Intravenous supplementation was required acutely to raise serum P in a patient with auricular fibrilation. Two group A patients who has plasma 1.25 vitamin D < 5 pg/mL received vitamin D, and the third oral supplements of P. In all the cases, Hf resolved with these measures. We concluded that Hf is not so infrequent in hemodialysis. In patients with low-protein diet and low vitamin D concentration, Hf can be sustained. On the other hand, a decreased dietary intake maintaining similar phosphate binder's supplementation is the most frequent cause of occasional and symptomatic Hf, even in patients with secondary hyperparathyroidism.

Hipofosforemia en unidades de diálisis crónica / Hypophosphatemia in dialysis units

La hipofosforemia (Hf) se describe raramente en los pacientes en hemodiálisis (HD) crónica. Hemos recogido retrospectivamente los casos de Hf ocurridos durante 3 años en un mismo centro. Revisamos todas las determinaciones de P realizadas (n = 2.201), considerándose Hf una concentración de P plasmático menor de 2,5 mg/dL. Posteriormente, se recogieron los datos clínicos y bioquímicos de cada caso para analizar las causas, síntomas y el tratamiento aplicado. Recogimos 22 episodios de Hf (0,9% del total de mediciones de P) en 11 pacientes sobre un total de 149 enfermos (7,3%) en tratamiento con HD convencional. Separamos dos grupos según presentaran Hf repetida (grupo A, n = 3) o aislada (grupo B, n = 8). Las concentraciones de P y albúmina y la nPCR, fueron menores en el grupo A, mientras que el B presentaba un calcio plasmático significativamente mayor (p 3 mg/dL. Concluimos que la Hf en HD no es tan infrecuente como se suele considerar, pudiendo aparecer de forma mantenida en pacientes con baja ingesta. La disminución aguda de la ingesta manteniendo los ligantes habituales, unida a la administración de antiácidos es la causa más frecuente de Hf esporádica en pacientes con buen control del P, que pueden tener incluso un hiperparatiroidismo secundario

Hypophosphatemia (Hf) is infrequently reported in chronic hemodialysis patients. The objective of this report is to describe the incidence, etiology, symptoms and treatment of Hf in a Dialysis Unit (defined as phosphorus < 2,5 mg/dL). In a retrospective study over a period of three years, we identified 22 cases of Hf, ocurring on 11 among 149 patients. A two-groups distribution was made: Group A, patients with more than one episode (n = 3, 14 episodes of Hf) and Group B, patients with only one isolated episode of Hf (n = 8, 8 episodes of Hf). Plasma Ca, P, Albumin and nPCR were significant lower in group A (p < 0,05). Only two patients of group B had symptoms. Cases of Hf were: Group A: lowprotein diet and alcoholism, Group B: decreased dietary intake due to non-digestive problems (n = 2) or due to digestive problems plus antacids (n = 4), phosphate binders (n = 1) and dietary phosphorus restriction (n = 1). Three patients had secondary hyperparathyroidism. Treatment consisted on oral supplementarion by diet and changes in oral calcium salts. Intravenous supplementation was requiered acutely to raise serum P in a patient with auricular fibrilation. Two group A patients who has plasma 1,25 vitamin D < 5 pg/mL received vitamin D, and the third oral supplements of P. In all the cases, Hf resolved with these measures. We concluded that Hf is not so infrequent in hemodialysis. In patients with lowprotein diet and low vitamin D concentration, Hf can be sustained. On the other hand, a decreased dietary intake maintaining similar phosphate binder’s supplementation is the most frequent cause of occasional and symptomatic Hf, even in patients with secondary hyperparathyroidism

[Can we increase phosphate removal with conventional hemodialysis?]. / Se puede aumentar la eliminación de fósforo con la hemodiálisis convencional?

BACKGROUND: The aim of the present study was to investigate the effect of different dialysate buffer and glucose concentrations, membrane surface (S) bigger than 2 m2 and increased dialysate flow (Qd) in phosphate (P) removal. METHODS: A. First phase (5 patients): the following variations in dialysate composition were introduced. A: glucose 1.60 g/L, bicarbonate: 39 mEq/L, acetate 4 mEq/L, B: glucose 1.5 g/L bicarbonate 17 mEq/L, acetate 10 mEq/L; C: glucose 0, bicarbonate: 39 mEq/L, acetate 4 mEq/L; and D: glucose 0, bicarbonate 17 mEq/L, acetate 10 mEq/L. B. Second phase (14 patients): variations in S and Qd were: 1. Qd: 500 mL/min + Hemophan 2 m2, 2. Qd: 500 mL/min + Hemophan 2.6 m2, 3. Qd: 750 mL/min + Hemophan 2 m2, 4. Qd: 750 mL/min + Hemophan 2.6 m2. RESULTS: Comparing HDs performed with low bicarbonate (B and D) respect to current buffer formulations (A and C), total P removal was 997.3 (+/- 237.3) vs 882 (+/- 216.1) mg (p NS). No differences were found by grouping the sessions according to glucose concentration. There were no significant differences in total phosphate removal between the two different S or Qd. The most important predictive factor of total P removal was the initial P and 2 hours serum P concentration, and PTH concentration. CONCLUSIONS: i) Removal of P is better predicted by pre-dialysis P serum concentration; ii) P removal was not affected by the changes in bicarbonate and glucose concentration in the dialysate; iii) the increase of the dialyzer area between 2 and 2.6 m2 augments Kt/V, but without influencing P elimination; iv) a higher Qd does not determine significant differences in P removal and v) higher PTH is associated with a higher P elimination.