2011-06-14

INCERTIDUMBRE EN MI INFORME DE LABORATORIO

Spanish and english version

Los avances tecnológicos registrados en los últimos años han permitido aumentar la capacidad operativa de los laboratorios de análisis clínicos.

Los sistemas automatizados que se fueron incorporando, dieron lugar a la creación de mega laboratorios donde se atienden   de 500 a 1000 pacientes por día.

Cuando se analizan los resultados de estos sistemas automatizados en forma comparativa para una misma muestra, se concluye que, si bien la variabilidad intra-laboratorio ha disminuido respecto a los métodos manuales, la variabilidad entre- laboratorios sigue siendo alta, aún para resultados comparados con equipos similares de un mismo fabricante.

Esto, en mi condición de paciente, me sigue preocupando por cuanto sigo sin saber aún con sistemas que se suponia iban a mejorar la exactitud de los resultados, si los cambios numéricos en mis análisis se deben a cambios de origen analítico o a cambios de origen bioquímico.

Por otra parte, pese a que la comunidad internacional supone que la fase analítica ha quedado resuelta, hecho que es cuestionable en base al análisis de los programas de control de calidad externo, se acepta que la etapa que introduce mayor error en los resultados es la etapa pre- analítica.

No es de sorprender que si un laboratorio tiene que lidiar con muestras derivadas de 500 a 1000 pacientes por día, se cometan errores que son estadísticamente difíciles de mensurar  y que pueden  falsear la interpretación del informe de laboratorio con las consecuencias que esto conlleva para mi como paciente.

Asimismo llama la atención cómo resultados obtenidos con métodos que arrojan resultados  distintos, se informan con el mismo rango de referencia.

Está claro que la interpretación de un análisis clínico se hace comparando el resultado numérico frente a ese rango sugerido por el laboratorio.
Este rango de referencia incorrecto seria la principal fuente de los errores post-analíticos, que no son de origen accidental.

En la actualidad el profesional responsable del laboratorio de análisis clínicos comparte la responsabilidad de los resultados que informa con el ingeniero a cargo del correcto uso de los aparatos automatizados. El profesional responsable se ha convertido en mero espectador del sistema y no participa activamente como deberia hacerlo en beneficio de un mejor diagnóstico.

Con este panorama, como paciente, creo conveniente revisar los procedimientos que se utilizan  actualmente para estudiar mi verdadero estado bioquímico para lograr que la información volcada en mi protocolo así lo refleje.

“Lo que no sirve para  su madre,  tampoco sirve para  su paciente”.
                                                                                      Dr.Samy Cembal

English version:

Uncertainty in my clinical laboratory report


Over the past years, the latest “state to the art” automated analytical technology allowed clinical laboratories to, amazingly, increase their operational capacity.  These automated systems had promoted the creation of Mega laboratories, which are able to evaluate about 500 to 1000 patients daily.

Based on the comparison of results obtained for the same sample, either using the automated or manual systems, it can be concluded that, even though the intra-laboratory variation has noticeably decreased by using automated systems, inter-laboratory variation is still high for results obtained from even same manufacturer analyzers.


This particular scenario, as a PATIENT, worries me lots, since I still cannot determine (even with these sophisticated systems with which the results, theoretically,  are more accurate), if the numeric differences  obtained in the result are due to analytical or biochemical changes.

On the other hand, even though the international community assumes, already, that the analytical phase is resolved, (controversial fact based on External Quality Programs results), it is worldwide accepted that the pre-analytical stage is the one which introduces more error.

 
It is not unexpected, for a laboratory dealing with samples from 500 to 1000 patients a day, to have random mistakes, statistically complex to measure, which can modify the laboratory report information with the consequences to me as a PATIENT.

Another interesting point is to observe that methods giving different results, are reported using the same normal reference range. It is well known that the interpretation of a biochemical report is done by the contrast of the analytical values obtained with the reference range values suggested by the laboratory.

 
This incorrect or inappropriate reference range values could be the principal source of non accidental errors for the post analytical phase.
Nowadays, the laboratory professional shares the responsibility of the reported results with the engineer in charge of the automated analyzers suitability. The biochemical professional is becoming a passive analytical system watcher rather than an active actor for a better diagnostic.  

With this scenario, as a PATIENT, I consider the urge to review the current procedures to study my actual biochemical state base on the appropriate information that will show in the laboratory report.

"What is not usefull for your mother, is not usefull for your patient either."
                                                                                              Dr.Samy Cembal
2 Comments:

English version:

Cecifenili said :

Results validation by the biochemical professional, with vast experience in immunoassays, based on the patient clinical situation plus the appropriateness of the automated analyzers, is what makes a difference in the quality of results between different laboratories.

But it is essential to have into consideration the pre-analytical conditions for sampling. Whenever these requirements are not met, it is very difficult to evaluate the results even though the other stages (analytical and post-analytical) are highly optimized.

Silvana Roveto said…

I totally agree with Dr Fenilli. I must also include the biochemist-physician relationship for the appropriate end result analysis, where the patient physiological, pharmacological, biochemical and historical background must be taken in consideration. For laboratories, with about 1000 patients daily, many biochemists would be necessary for that analysis.

19 jun 2011 21:06