Intercambiabilidad de resultados entre los diferentes laboratorios clínicos Catlab / Comparability study of analytical results between a group of clinical laboratories

Objetivo. Describir el estudio de la intercambiabilidad de los resultados de las magnitudes de bioquímica que se procesan indistintamente en los 4 laboratorios de Catlab. Material y métodos. Se establecieron requisitos de calidad de coeficiente de variación y error total (CV% y ET%). Se verificó, con materiales de control comercial, el cumplimiento del CV% en cada magnitud y para cada analizador de cada laboratorio y se estudió la intercambiabilidad con muestras recientes de suero. Se analizaron las diferencias con una aplicación en Microsoft Access® que genera gráficos de Bland-Altman modificados. Resultados. La intercomparación de las 32 magnitudes que se realizan en más de un laboratorio o analizador generó 306 gráficas de Bland-Altman: 101 (33,1%) cumplían directamente el requisito de ET% establecido a partir de la variabilidad biológica y 205 (66,9%) requirieron revisión. Se reprocesaron los datos según los requisitos mínimos de consenso de la Asociación Española de Farmacéuticos Analistas (AEFA), la Sociedad Española de Bioquímica Clínica y Enfermedad Molecular (SEQC), la Asociación Española de Biopatología Médica (AEBM) y de la Sociedad Española de Hematología y Hemoterapia (SEHH) de octubre del 2013. Aplicándolos, 170 comparaciones (56%) cumplían directamente los requisitos y 136 (44%) requerían revisión. Al valorar el número de puntos que excedían el requisito, los errores aleatorios, el intervalo de resultados en el que se detectaban discrepancias y el intervalo de decisión clínica se consideró que todos los resultados se podían aceptar y que las 32 magnitudes eran intercambiables en todos los centros y analizadores. Conclusiones. A partir del requisito de consenso de las 4 sociedades, los resultados de todas las magnitudes comparadas eran intercambiables. No obstante, cada uno de los laboratorios debe cumplir con criterios más estrictos de error total (AU)

Objective. To describe the study of the comparability of the measurements levels of biological tests processed in biochemistry in Catlab's 4 laboratories. Material and methods. Quality requirements, coefficients of variation and total error (CV% and TE %) were established. Controls were verified with the precision requirements (CV%) in each test and each individual laboratory analyser. Fresh serum samples were used for the comparability study. The differences were analysed using a Microsoft Access® application that produces modified Bland-Altman plots. Results. The comparison of 32 biological parameters that are performed in more than one laboratory and/or analyser generated 306 Bland-Altman graphs. Of these, 101 (33.1%) fell within the accepted range of values based on biological variability, and 205 (66.9%) required revision. Data were re-analysed based on consensus minimum specifications for analytical quality (consensus of the Asociación Española de Farmacéuticos Analistas (AEFA), the Sociedad Española de Bioquímica Clínica y Patología Molecular (SEQC), the Asociación Española de Biopatología Médica (AEBM) and the Sociedad Española de Hematología y Hemoterapia (SEHH), October 2013). With the new specifications, 170 comparisons (56%) fitted the requirements and 136 (44%) required additional review. Taking into account the number of points that exceeded the requirement, random errors, range of results in which discrepancies were detected, and range of clinical decision, it was shown that the 44% that required review were acceptable, and the 32 tests were comparable in all laboratories and analysers. Conclusions. The analysis of the results showed that the consensus requirements of the 4 scientific societies were met. However, each laboratory should aim to meet stricter criteria for total error (AU)

[Comparability study of analytical results between a group of clinical laboratories]. / Intercambiabilidad de resultados entre los diferentes laboratorios clínicos Catlab.

OBJECTIVE: To describe the study of the comparability of the measurements levels of biological tests processed in biochemistry in Catlab's 4 laboratories. MATERIAL AND METHODS: Quality requirements, coefficients of variation and total error (CV% and TE %) were established. Controls were verified with the precision requirements (CV%) in each test and each individual laboratory analyser. Fresh serum samples were used for the comparability study. The differences were analysed using a Microsoft Access® application that produces modified Bland-Altman plots. RESULTS: The comparison of 32 biological parameters that are performed in more than one laboratory and/or analyser generated 306 Bland-Altman graphs. Of these, 101 (33.1%) fell within the accepted range of values based on biological variability, and 205 (66.9%) required revision. Data were re-analysed based on consensus minimum specifications for analytical quality (consensus of the Asociación Española de Farmacéuticos Analistas (AEFA), the Sociedad Española de Bioquímica Clínica y Patología Molecular (SEQC), the Asociación Española de Biopatología Médica (AEBM) and the Sociedad Española de Hematología y Hemoterapia (SEHH), October 2013). With the new specifications, 170 comparisons (56%) fitted the requirements and 136 (44%) required additional review. Taking into account the number of points that exceeded the requirement, random errors, range of results in which discrepancies were detected, and range of clinical decision, it was shown that the 44% that required review were acceptable, and the 32 tests were comparable in all laboratories and analysers. CONCLUSIONS: The analysis of the results showed that the consensus requirements of the 4 scientific societies were met. However, each laboratory should aim to meet stricter criteria for total error.

Valor de la cistogammagrafía directa en el diagnóstico del reflujo vesicoureteral en pacientes con hidronefrosis prenatal / Value of the direct cystoscintigraphy in the diagnosis of vesicoureteral reflux in patients with prenatal hydronephrosis

Objetivo. Dado que la radiación recibida en una cistografía convencional, es del orden de 20 veces superior a la de una cistografía isotópica y que la sensibilidad de ésta última, es más alta en el diagnóstico del reflujo vésicoureteral, nos planteamos su utilización en el despistaje de este, en pacientes con hidronefrosis congénita. Material y métodos. En el periodo 2003-2009, se ha aplicado el siguiente protocolo a los neonatos con antecedentes de hidronefrosis prenatal con la finalidad de descartar reflujo. Profilaxis antibiótica si se confirma en ecografía a la semana de vida la dilatación de la vía excretora, a las 6 semanas de vida, se realiza nuevo control ecográfico, en el cual si la ectasia es superior a 8 mm, se practica cistogammagrafía directa. Si se trata de un niño de sexo masculino con dilatación o afectación parenquimatosa severa, o en casos en que se sospeche duplicidad, se practica cistografía convencional. Resultados. De los 65 casos estudiados, se ha detectado reflujo en 13 pacientes (20%) en 18 unidades renales (3 leve, 8 moderado y7 severo). El seguimiento se ha realizado en la mayoría de casos concistografía isotópica. Ninguno de los 13 pacientes con refl ujo a los que (..) (AU)

Objective. As the radiation received in conventional cystographyis about 20 times higher than radionuclide cystography and the sensitivity of the last is higher in order to diagnose vesicoureteral refl ux, we consider the use of radionuclide cystography in early detection of refluxin patients with prenatally detected hydronephrosis. Materials and methods. Between 2003 and 2009, a study of neonates with prenatal history of hydronephrosis was performed in order to rule out reflux. Our protocol was as follows: The diagnosis was confirmed by postnatal ultrasound at 1 week (in this case patient initiate antibiotic prophylaxis). A new ultrasound was repeated at 6 weeks, if the dilatation was larger than 8 mm at this time, direct radionuclide escintigraphy was performed. The patients were placed on prophylactic antibiotics until the screenining results were known. Conventional cystography was performed if a male infant showed (..) (AU)

[Value of the direct cystoscintigraphy in the diagnosis of vesicoureteral reflux in patients with prenatal hydronephrosis]. / Valor de la cistogammagrafía directa en el diagnóstico del reflujo vesicoureteral en pacientes con hidronefrosis prenatal.

OBJECTIVE: As the radiation received in conventional cystography is about 20 times higher than radionuclide cystography and the sensitivity of the last is higher in order to diagnose vesicoureteral reflux, we consider the use of radionuclide cystography in early detection of reflux in patients with prenatally detected hydronephrosis. MATERIALS AND METHODS: Between 2003 and 2009, a study of neonates with prenatal history of hydronephrosis was performed in order to rule out reflux. Our protocol was as follows: The diagnosis was confirmed by postnatal ultrasound at 1 week (in this case patient initiate antibiotic prophylaxis). A new ultrasound was repeated at 6 weeks, if the dilatation was larger than 8 mm at this time, direct radionuclide scintigraphy was performed. The patients were placed on prophylactic antibiotics until the screenining results were known. Conventional cystography was performed if a male infant showed severe dilatation, or in general in cases with parenchymatous atrophy or if a duplex system was suspected. RESULTS: In 13 (20%) of the 65 cases (18 kidneys) reflux was detected (3 minor, 8 moderate and 7 severe). In most cases, follow up was performed with radionuclide cystography. None of the patients with reflux placed on prophylactic antibiotics developed a febrile urinary tract infection during the first year of life. CONCLUSIONS: Direct radionuclide cystography is a useful diagnostic method in early detection of vesicoureteral reflux in patients with prenatal hydronephrosis with higher sensitivity than conventional cystography, and with an important advantage concerning radiation of the patient. Patients screened and placed on prophylactic antibiotics are probably going to present less episodes of pielonephrytis.