Correlación de determinaciones bioquímicas al usar dos tipos diferentes de tubos para muestras sanguíneas / Correlation of biochemical determinations when using two types different from tubes for blood samples

The impressive development of the clinical laboratory network of the HCUCH has forced a complete protocol revision, specially directed towards the procedures involved in way the biological samples are obtained. This includes the selection of the tubes used. In this sense, the use in the different centers of SS tubes, which stands for serum separating tubes, was evaluated. The SS tubes consist of a gel that which after centrifugation separates the thrombotic and serum phases, forming an impermeable barrier in between. Before its onset, is necessary to compare with the aid of the bio-statistical parameter of correlation coefficient both the biochemical and hormonal measurements obtained through the use of the typical tubes (containing heparin or without anticoagulant reactive) and those of the SS tubes. The determinations included 27parameters, consistent of biochemical, electrolytic and hormonal measurements. The data collected was tabulated and afterwards the statistical analysis was performed, considering correlation and concordance, and then the interclass Correlation coefficient (ICC) was applied. The concordance study concluded that 26 of the 27 evaluated parameters have a value of ICC between 0.858 and 1.0, Only the direct bilirrubin showed a low ICC (0.08), possibly, it must be considered the low values of it found in the samples, and therefore to make the result to significant the evaluation has to be made among a greater number of samples. In summary, the results supported the adoption of tubes SS for the clinical laboratories processes, since these threw equivalent and trustworthy results compared with the conventional tubes for the medical studied with advantages in operator protection and samples transport.

Experiencia del Hospital Clínico de la Universidad de Chile en el uso de tecnicas de laboratorio en el lugar de atención del paciente (point of care) / Experience of the Hospital Clínico de la Universidad de Chile in the use of techniques of laboratory in the place of attention of the patient

La tecnología de Point of Care o Near-patient testing, permite acercar el laboratorio a las áreas asistenciales críticas, las cuales requieren minimizar al máximo el tiempo de respuesta en la obtención del resultado para la toma de decisiones. En este trabajo se presenta la correlación entre los equipos de Point of Care (i-STAT y HemoCue), respecto de las técnicas habituales utilizadas en el Laboratorio Central del Hospital Clínico de la Universidad de Chile, para los parámetros pH, PO2, PCO2, sodio (Na+), potasio (K+), hematocrito y hemoglobina. Los resultados obtenidos en los equipos Point of Care evaluados muestran una adecuada confiabilidad respecto de los métodos tradicionales utilizados en el Hospital. La determinación de gases sanguíneos, evidenció una muy buena correlación entre los equipos i-STAT y AVL, como para la determinación de hemoglobina en equipo HemoCue y Celldyn 3700. Los resultados obtenidos de electrolitos en el equipo i-STAT e Hitachi 912 igualmente se relacionan bien, a pesar de que las mediciones de sodio y potasio en i-stat fueron realizadas en sangre completa y la técnica tradicional, Hitachi 912, utiliza suero. Las correlaciones en las determinaciones de hematocrito y hemoglobina al utilizar el equipo i-STAT, no fueron tan óptimas, debido probablemente a diferencias en las metódicas de detección. Los resultados obtenidos nos hace concluir que las técnicas de Point of Care constituyen herramientas útiles para los médicos de las unidades críticas, ya que entregan resultados de laboratorio confiables y oportunos.

Point of Care or Near-patient testing diagnostic techniques allow to approach the laboratory to critical care unit, with the goal of reducing the total response time of the analytical procedure. In this paper, we compare the results obtained in the Point of care equipment (i-STAT and Hemocue) with the common techniques used in the Central Laboratory of the University of Chile Hospital, for the determination of pH, PO2, PCO2, sodium, potassium, hematocrit and hemoglobin. In general, the results obtained in the point of care equipment showed a good correlation respect to the traditional techniques. The measurement of arterial blood gases showed a good correlation between i-STAT and AVL equipment and also for measurement of hemoglobin with Hemocue. The electrolyte analysis by i-STAT equipment also exhibited a good correlation with the traditional method, despite of the measurement of sodium and potassium were performed with whole blood instead of serum like the traditional method. The correlation in the hematocrit/hemoglobin levels by i-STAT were not that good, due probably to difference in the method of detection. The results obtained allow us to conclude that the Point of care techniques constitutes useful tools for physicians in critical care units since they give reliable and rapid results.