El cálculo de la creatinina sérica basal sobrestima el diagnóstico de alteración renal aguda en pacientes operados de cirugía cardíaca / The calculation of baseline serum creatinine overestimates the diagnosis of acute kidney injury in patients undergoing cardiac surgery

Introducción y objetivo: La definición y clasificación actual de insuficiencia renal aguda se basa en criterios de consenso (sistemas RIFLE y AKIN). De los parámetros recomendados (creatinina, tasa de filtración glomerular y diuresis), la creatinina es el más empleado. En ausencia de valor basal conocido se recomienda su estimación a partir de la ecuación MDRD simplificada, asumiendo en el cálculo una tasa de filtración de 75 ml/min/1,73 m2. El objetivo del presente trabajo fue evaluar la repercusión diagnóstica del empleo de la creatinina basal estimada frente al valor real medido en pacientes operados de cirugía cardíaca. Métodos: Análisis de pacientes operados de cirugía cardíaca mayor incluidos de forma prospectiva en una base de datos. Para cada paciente se calculó el estadio RIFLE máximo alcanzado usando la creatinina basal medida y la estimada. Se analizó la repercusión sobre el diagnóstico mediante coeficientes de correlación intraclase, análisis de concordancia y gráficas de Bland y Altman. Resultados: La incidencia de insuficiencia renal aguda postoperatoria en 2.103 casos operados entre 2002 y 2007 fue del 29,1% al utilizar la creatinina estimada (14,3% con la medida). Esto supone una sobrestimación del 104%, y la correlación intraclase es de 0,12. Excluyendo a los pacientes con insuficiencia renal crónica conocida (tasa de filtrado glomerular [TFG] <60 ml/min/1,73 m2), tanto la sobrestimación (2,4%) como la correlación (0,57) mejoraron. Conclusiones: El cálculo de la creatinina basal a partir de la ecuación MDRD sobrestima la incidencia de insuficiencia renal aguda tras la cirugía cardíaca, y es un método inadecuado para su detección cuando el valor basal se desconoce (AU)

Introduction and objectives: The current definition and classification of acute kidney injury is based on consensus criteria (RIFLE and AKIN systems). Creatinine is the most commonly used of the recommended parameters (creatinine, glomerular filtration rate and diuresis). If the baseline value is not known, it can be calculated based on the simplified MDRD equation, assuming a filtration rate of 75ml/min/1.73m2 for the calculation. The aim of this study was to evaluate the diagnostic impact of using estimated baseline creatinine compared to the actual value measured in patients undergoing cardiac surgery. Methods: Analysis of patients undergoing major cardiac surgery, who were prospectively included in a database. The maximum RIFLE stage reached was calculated for each patient using the measured and estimated baseline creatinine levels. The impact on the diagnosis was analysed using intraclass correlation coefficients, concordance analysis and Bland-Altman plots. Results: The incidence of postoperative acute kidney injury in 2103 cases between 2002 and 2007 was 29.1%, according to estimated creatinine (14.3% with the measure). This represents an overestimation of 104%, with an intraclass correlation of 0.12. By excluding patients with known chronic kidney disease (glomerular filtration rate [<60ml/min/1.73m2), both the overestimation (2.4%) and the correlation (0.57) improved. Conclusions: The calculation of baseline creatinine using the MDRD equation overestimates the incidence of acute kidney injury after cardiac surgery, and is an inadequate method for detection when the baseline value is unknown (AU)

The calculation of baseline serum creatinine overestimates the diagnosis of acute kidney injury in patients undergoing cardiac surgery.

INTRODUCTION AND OBJECTIVES: The current definition and classification of acute kidney injury is based on consensus criteria (RIFLE and AKIN systems). Creatinine is the most commonly used of the recommended parameters (creatinine, glomerular filtration rate and diuresis). If the baseline value is not known, it can be calculated based on the simplified MDRD equation, assuming a filtration rate of 75 ml/min/1.73 m2 for the calculation. The aim of this study was to evaluate the diagnostic impact of using estimated baseline creatinine compared to the actual value measured in patients undergoing cardiac surgery. METHODS: Analysis of patients undergoing major cardiac surgery, who were prospectively included in a database. The maximum RIFLE stage reached was calculated for each patient using the measured and estimated baseline creatinine levels. The impact on the diagnosis was analysed using intraclass correlation coefficients, concordance analysis and Bland-Altman plots. RESULTS: The incidence of postoperative acute kidney injury in 2103 cases between 2002 and 2007 was 29.1%, according to estimated creatinine (14.3% with the measure). This represents an overestimation of 104%, with an intraclass correlation of 0.12. By excluding patients with known chronic kidney disease (glomerular filtration rate [<60 ml/min/1.73 m2), both the overestimation (2.4%) and the correlation (0.57) improved. CONCLUSIONS: The calculation of baseline creatinine using the MDRD equation overestimates the incidence of acute kidney injury after cardiac surgery, and is an inadequate method for detection when the baseline value is unknown.

Acute kidney injury as a risk factor for chronic kidney diseases in disadvantaged populations.

Acute kidney injury (AKI) is considered to be a potential cause for developing chronic kidney disease (CKD); on the other hand, CKD predisposes to AKI. The lack of adequate epidemiological data makes it difficult to determine if AKI induces CKD in less developed countries. The etiology of AKI in rich populations, in whom sophisticated surgery, interventional radiology and oncology treatments are usually the cause of AKI, is very different from that of disadvantaged populations, where the origin of AKI is associated with endemic infections, obstetric problems, poisons, toxins and natural disasters. Any conclusions extrapolated from these two settings should be treated with caution. Moreover, people living in disadvantaged conditions are usually much younger than those in rich areas and this age factor could facilitate total recovery of renal function after AKI if treatment based on an adequate supply of water, rehydration and anti-infectious measures were provided. In the small segment of the population of less developed countries having an income per capita similar to that observed in the developed countries, the long-term outcome of AKI should also be expected to be similar. New data coming from two single centers analyzing only the long-term outcome of acute tubular necrosis (ATN) patients, with a normal or near normal renal function prior to the AKI episode, coincide in reporting a requirement for chronic dialysis among the surviving patients of 2%. If these data are confirmed, the importance of AKI as cause of CKD should be reconsidered, both in developed and less developed countries.

Biobancos: una nueva herramienta para la investigación clínica / No disponible

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Deterioro agudo de la función renal en una Unidad Coronaria en España / Acute renal function deterioration in a coronary unit in Spain

Objetivo. Valorar la incidencia y el valor pronóstico del deterioro agudo de la función renal (DAFR) en pacientes cardiológicos agudos. Ámbito. Unidad Coronaria de un hospital universitario terciario. Diseño. Estudio retrospectivo. Pacientes. Cien pacientes consecutivos ingresados durante 2004. Intervenciones. No hubo intervenciones aleatorizadas. Los procedimientos diagnósticos y terapéuticos se realizaron de acuerdo con protocolos locales y las Guías de Práctica Clínica en uso. Variables principales. El objetivo primario del estudio fue analizar la incidencia de DAFR y su relación con la mortalidad por cualquier causa durante el ingreso. Se definió DAFR como el aumento de la creatinina sérica respecto a la basal mayor de 0,5 mg/dl y/o mayor del 50%. Resultados. La incidencia de DAFR fue del 26%, con un incremento medio de la creatinina sérica de 1,5 ± 0,9 mg/dl. El DAFR se asoció de forma significativa con la edad y los antecedentes de hipertensión e insuficiencia renal crónica. Los pacientes con DAFR tuvieron un curso más complicado, mayores estancias hospitalarias y recibieron menos cateterismos. El empeoramiento agudo de la función renal se asoció con mayor mortalidad hospitalaria (33% frente a 6%, p = 0,002). Conclusiones. El DAFR es frecuente en el paciente cardiópata agudo y su presencia se asocia con alta mortalidad (AU)

Objective. To assess the incidence and prognostic value of acute renal function deterioration (ARFD) in patients with acute heart disease. Setting. Coronary Care Unit in a tertiary university hospital. Design. Retrospective study. Participants. One hundred consecutive patients admitted during 2004. Interventions. No randomized interventions were done. Diagnostic and therapeutic procedures were performed according to local protocols and current Clinical Practice Guidelines. Primary variables. The primary aim of the study was to analyze the incidence of acute renal function deterioration and its effect in mortality during hospitalization. ARFD was defined as the increase of serum creatinine by 0.5 mg/dl and/or by 50% over baseline. Results. Incidence of ARFD was 26%, with a mean increase of serum creatinine of 1.5 ± 0.9 mg/dl. ARFD was significantly associated with age, background of hypertension and chronic kidney disease. Patients with ARFD had a more complicated course, longer hospitalizations, and received fewer catheterisms. Acute renal function deterioration was associated with higher mortality during hospitalization (33% versus 6%, p = 0.002). Conclusions. Acute renal function deterioration is frequent in patients with acute heart disease and its presence is linked with higher mortality (AU)

[Acute renal function deterioration in a Coronary Unit in Spain]. / Deterioro agudo de la función renalen una Unidad Coronaria en España.

OBJECTIVE: To assess the incidence and prognostic value of acute renal function deterioration (ARFD) in patients with acute heart disease. SETTING: Coronary Care Unit in a tertiary university hospital. DESIGN: Retrospective study. PARTICIPANTS: One hundred consecutive patients admitted during 2004. INTERVENTIONS: No randomized interventions were done. Diagnostic and therapeutic procedures were performed according to local protocols and current Clinical Practice Guidelines. PRIMARY VARIABLES: The primary aim of the study was to analyze the incidence of acute renal function deterioration and its effect in mortality during hospitalization. ARFD was defined as the increase of serum creatinine by 0.5 mg/dl and/or by 50% over baseline. RESULTS: Incidence of ARFD was 26%, with a mean increase of serum creatinine of 1.5 +/- 0.9 mg/dl. ARFD was significantly associated with age, background of hypertension and chronic kidney disease. Patients with ARFD had a more complicated course, longer hospitalizations, and received fewer catheterisms. Acute renal function deterioration was associated with higher mortality during hospitalization (33% versus 6%, p = 0.002). CONCLUSIONS: Acute renal function deterioration is frequent in patients with acute heart disease and its presence is linked with higher mortality.

[Control of the dialysis dose by ionic dialysance and bioimpedance]. / Control de la dosis de diálisis mediante dialisancia iónica y bioimpedancia.

INTRODUCTION: The ionic dialysance monitor allows an automated measure of Kt in each dialysis session. Bioelectrical impedance analysis (BIA) determines the total body water which it is equivalent to the urea volume of distribution (V). If the Kt, determined by ionic dialysance, is divided by the V, estimated by bioelectrical impedance, a Kt/V at the end of dialysis session (Kt/VDiBi) is obtained. AIM OF THE STUDY: To evaluate the agreement between the Kt/VDiBi and the Kt/V obtained by two simplified formulas: the monocompartimental (Kt/Vm) and the equilibrated (Kt/Ve) Daugirdas equations. METHODS: The Kt/VDiBi, the Kt/Vm and the Kt/Ve were determined in 38 hemodialysis patients (27 males and 11 females) in the same hemodialysis session. The patients were on dialysis three times a week for 3.5 to 4 hours. The V was determined by monofrequency bioelectrical impedance (50 kHz) at the end of the dialysis session. RESULTS: The Kt/VDiBi, Kt/Vm and Kt/Ve were 1.29+/-0.26, 1.54+/-0.29 and 1.36+/-0.25, respectively (p<0.001 between the Kt/VDiBi and the KtVm, and p<0.001 between the KtV/DiBi and the Kt/Ve). The intraclass correlation coefficient showed better concordance between the KtV/DiBi and the Kt/Ve (coefficient 0.88) than between the Kt/VDiBi and the KtVm (coefficient 0.65). The relative difference of the Kt/VDiBi was 8.3+/-6.4% with respect to the Kt/Ve and 18.4+/-7.8 % with respect to the Kt/Vm (p<0.001). The relative difference between the Kt/VDiBi and the Kt/Ve was lower than 15% in the 84% of the patients and lower than 10% in the 64% of the patients. CONCLUSIONS: If the V obtained by bioelectrical impedance analysis is included in the ionic dialysance monitor, we can obtain a Kt/V for each patient in real time, which is similar to the equilibrated Kt/V obtained from the Daugirdas equation.

Long-term outcome of acute tubular necrosis: a contribution to its natural history.

As long-term outcome studies of acute renal failure (ARF) are scarce and non-homogeneous, we studied 187 consecutive acute tubular necrosis (ATN) patients without previous nephropathies, discharged alive from our hospital between October 77 and December 92 and followed-up until December 99 (range 7-22 years; median 7.2). Variables were analyzed at the time of the acute episode and during follow-up. In 2000-2001 a clinical evaluation was made in 58 of the 82 patients still alive. Ten patients were lost to follow-up and 95 died. In 59% death was related with the disease present when the ATN developed. Kaplan-Meir survival curve showed 89, 67, 50, and 40% at 1, 5, 10, and 15 years, respectively, after discharge. Survival curves were significantly better (log-rank P<0.001) among the youngest, those surviving a polytrauma, those without comorbidity and surprisingly those treated in intensive care units. The proportional Cox model showed that age (hazard ratio (HR) 1.04 per year of age; P=0.000), presence of comorbid factors (HR 4.29; P=0.006), surgical admission (HR 0.45; P=0.000), and male sex (HR 1.72; P=0.020) were the variables associated with long-term follow-up. In the evaluated patients renal function was normal in 81%. Long-term outcome after ARF depends on absence of co-morbid factors, cause of initial admission and age. Although the late mortality rate is high and related with the original disease, renal function is adequate in most patients.

Control de la dosis de diálisis mediante dialisancia iónica y bioimpedancia / Control of the dialysis dose by ionic dialysance and bioimpedance

Introducción: El monitor de dialisancia iónica permite obtener el Kt de cada sesión de diálisis de forma automática. La técnica de bioimpedancia proporciona el parámetro correspondiente al contenido corporal total de agua que es similar al volumen de distribución de la urea (V). Si dividimos el Kt de la dialisancia iónica entre el V calculado por la bioimpedancia conseguimos un Kt/V (Kt/VDiBi). Objetivo: El objetivo del presente trabajo es estudiar la concordancia existente entre el Kt/VDiBi y el Kt/V simplificado obtenido por las ecuaciones de Daugirdas correspondientes a los modelos monocompartimental (Kt/Vm) y equilibrado (Kt/Ve). Material y métodos: El estudio se realizó en 38 enfermos en los que se calculó en la misma sesión de hemodiálisis el Kt/VDiBi, el Kt/Vm y el Kt/Ve. Se trata de 27 varones y 11 mujeres que se dializaban 3 veces a la semana, en sesiones de 3,5 – 4 horas de duración. El V se calculó al finalizar la sesión de hemodiálisis con técnica de bioimpedancia vectorial de monofrecuencia. Resultados: Los resultados de Kt/VDiBi, Kt/Vm y Kt/Ve fueron: 1,29 ± 0,26, 1,54 ± 0,29 y 1,36 ± 0,25 respectivamente (p < 0,001 entre Kt/VDiBi y KtVm, y p < 0,001 entre KtV/DiBi y Kt/Ve). El coeficiente de correlación intraclase mostró una mejor concordancia entre Kt/VDiBi y Kt/Ve (coeficiente 0,88, concordancia excelente), que entre Kt/VDiBi y Kt/Vm (coeficiente 0,65, concordancia buena). La diferencia relativa del Kt/VDiBi fue 8,3 ± 6,4% con respecto al Kt/Ve, y 18,4 ± 7,8% con respecto al Kt/Vm (p < 0,001). La diferencia relativa entre Kt/VDiBi y Kt/Ve fue inferior a 15% en el 84% de los enfermos, e inferior a 10% en el 64% de los enfermos. Conclusiones: Si introducimos en el monitor de dialisancia iónica el V obtenido por bioimpedancia, podemos obtener en cada sesión de hemodiálisis un Kt/V para cada enfermo que es equiparable al Kt/V equilibrado de la ecuación de Daugirdas

Introduction: The ionic dialysance monitor allows an automated measure of Kt in each dialysis session. Bioelectrical impedance analysis (BIA) determines the total body water which it is equivalent to the urea volume of distribution (V). If the Kt, determined by ionic dialysance, is divided by the V, estimated by bioelectrical impedance, a Kt/V at the end of dialysis session (Kt/VDiBi) is obtained. Aim of the Study: To evaluate the agreement between the Kt/VDiBi and the Kt/V obtained by two simplified formulas: the monocompartimental (Kt/Vm) and the equilibrated (Kt/Ve) Daugirdas equations. Methods: The Kt/VDiBi, the Kt/Vm and the Kt/Ve were determined in 38 hemodialysis patients (27 males and 11 females) in the same hemodialysis session. The patients were on dialysis three times a week for 3.5 to 4 hours. The V was determined by monofrequency bioelectrical impedance (50 kHz) at the end of the dialysis session. Results: The Kt/VDiBi, Kt/Vm and Kt/Ve were 1.29 ± 0.26, 1.54 ± 0.29 and 1.36 ± 0.25, respectively (p < 0.001 between the Kt/VDiBi and the KtVm, and p < 0.001 between the KtV/DiBi and the Kt/Ve). The intraclass correlation coefficient showed better concordance between the KtV/DiBi and the Kt/Ve (coefficient 0.88) than between the Kt/VDiBi and the KtVm (coefficient 0.65). The relative difference of the Kt/VDiBi was 8.3 ± 6.4% with respect to the Kt/Ve and 18.4 ± 7.8% with respect to the Kt/Vm (p < 0.001). The relative difference between the Kt/VDiBi and the Kt/Ve was lower than 15% in the 84% of the patients and lower than 10% in the 64% of the patients. Conclusions: If the V obtained by bioelectrical impedance analysis is included in the ionic dialysance monitor, we can obtain a Kt/V for each patient in real time, which is similar to the equilibrated Kt/V obtained from the Daugirdas equation

Nefrología basada en investigación clínica: bases conceptuales para la constitución de un grupo de trabajo en Nefrología Basada en la Evidencia de la Sociedad Española de Nefrología / No disponible

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Cytomegalovirus infection after renal transplantation: selective prophylaxis and treatment.

We have reviewed our experience in selective cytomegalovirus (CMV) infection prophylaxis and treatment in our renal transplant population. Between 1996 and 2001, 263 cadaveric renal transplant recipients had at least 6 months follow up. Immunosuppression was based on cyclosporine Neoral (n=108) or tacrolimus (n=155). CMV infection prophylaxis (oral acyclovir or gancyclovir at half usual doses) was only prescribed in recipients receiving a CMV positive ve kidney and in recipients treated with OKT3. CMV infection was diagnosed by a positive pp65 antigenemia upon appearance of CMV-related symptoms, leading to specific treatment (IV ganciclovir) only if symptoms were intense or there was visceral involvement. Thus, no preemptive treatment or programmed or periodic antigenemia was performed in any case. Nineteen episodes of symptomatic CMV infection were diagnosed (prevalence 7.2%). The frequency was similar for all immunosuppressive regimens. Only 9 of 19 (47%) of patients were given IV ganciclovir; the others were not treated. All patients survived without apparent complications, relapses, or recurrences. No oral gancyclovir was delivered after IV treatment. Our CMV prophylaxis protocol was limited to high-risk patients, using lower gancyclovir dosages than those usually advocated. It does not include programmed or scheduled search for CMV antigenemia in asymptomatic renal transplant patients. Despite these factors, our CMV infection rate and severity were similar to those reported with more aggressive protocols, with extended prophylaxis, preemptive therapy, or intense surveillance.

A low incidence of new-onset insulin-dependent diabetes mellitus using tacrolimus in kidney recipients in Europe.

Employing tacrolimus (Tac) for routine immunosuppression in renal transplantation (RT), produced an incidence of new-onset, insulin-treated, diabetes mellitus (newDM) as high as 20%. More recently, several large multicenter kidney studies using Tac as the primary immunosuppressant have been reported in Europe. Between 1997 and 2001, we performed 155 RTs using Tac (0.2 mg/k/per day, targeting whole blood trough levels <15 ng/mL) with a rapid steroid taper. The acute rejection rate was 13%, and 89% of grafts are still functioning. Only 5 Tac-treated patients not previously requiring insulin needed insulin therapy for > or =30 days (3.2%). Eight separate studies employing Tac in at least one arm (N=2728) have been reported between 1997 and 2002. Tac was combined with azathioprine or MMF, and/or steroids. The incidence of new DM at study end ranged from 2.3% to 8.3%. The only trial with >6% incidence was the first one, using an initial dose of 0.3 mg/kg per day. The most recent studies utilized an initial dose of 0.2 mg/kg per day, targeting whole blood trough levels of <15 ng/mL and a steroid taper, with newDM at <6%. On the basis of these data, we confirm in that the use of Tac as a first-line immunosuppressant in renal transplant patients affords protection against acute rejection with a low level of newDM. The tendency to employ lower oral doses of Tac, lower blood target levels, and a reduced steroid dose appear to minimize glucose disturbances in RT.