Evaluation of urinalysis pre-analytical phase in a private laboratory of Maringá city, Paraná, Brazil / Avaliação da fase pré-analítica do exame de urina de rotina em laboratório privado da cidade de Maringá, Paraná, Brasil

ABSTRACT Introduction: Routine urinalysis is among the most requested exams in the clinical laboratory, assisting in the diagnosis of various diseases and treatment follow-up. In this case, the pre-analytical phase is extremely important because the quality of the sample directly influences the analysis and interpretation of the result. Objective: The aim of this study was to identify the main errors in the pre-analytical phase of routine urine examination in a private laboratory and their frequency of occurrence. Material and method: Data were collected from 2014 to 2018. In all, 107,277 urine samples were registered and 98 (0.09%) were sent for recollection. Results: Recollect requests were higher among females (81.6%), and the most affected age groups were 51 to 60 years old and 21 to 30 years old. The most common justification for recollection was insufficient material (48.0%), followed by confirmation of results in 24.5% of cases. The predominance of urine recollection in women was due to their having urine tests more often since they are more prone to urinary tract infections, especially in the sexually active and postmenopausal life stages. Conclusion: In general, the urine recollection rate obtained in the research was lower than the goal set by the laboratory; however, the main reasons that led to recollection request could be avoided or minimized if patients had been well educated on the correct collection procedures, indicating the need for constant training and training programs of the work team.

RESUMEN Introdución: El análisis de orina de rutina es una de las pruebas más solicitadas en el laboratorio clínico, pues ayuda en el diagnóstico de diversas enfermedades y en el seguimiento del tratamiento de los pacientes. En este caso, la fase preanalítica es fundamental, puesto que la calidad de la muestra influye directamente en el análisis y en la interpretación del resultado. Objetivo: El objetivo de este estudio fue identificar los principales errores en la fase preanalítica en la prueba de orina rutinaria de un laboratorio privado y su frecuencia de ocurrencia. Material y método: Se recopilaron datos entre 2014 y 2018. En total, se registraron 107.277 muestras de orina; 98 (0,09%) fueron enviadas para nueva extracción. Resultados: La solicitud de nueva extracción fue mayor entre las mujeres (81,6%); los grupos de edad más afectados fueron de 51 a 60 años y de 21 a 30 años. La justificación más común para la toma repetida fue cantidad insuficiente (48%), seguida de confirmación de resultado, en el 24,5% de los casos. El predominio de las muestras de orina en las mujeres ocurrió debido a la frecuencia de los análisis de orina en las mujeres, porque ellas son más propensas a las infecciones urinarias, especialmente en las etapas de la vida sexualmente activa y posmenopáusica. Conclusión: En general, la tasa de toma repetida de orina obtenida en la investigación fue menor que el objetivo estipulado por el laboratorio, pero las principales razones que llevaron a la solicitud de nueva extracción podrían evitarse o minimizarse si los pacientes hubieran sido bien instruidos sobre los procedimientos correctos de recolección, lo que indica la necesidad de programas de capacitación y entrenamiento constante para el equipo de trabajo.

RESUMO Introdução: O exame de urina de rotina está entre os exames mais solicitados no laboratório clínico, pois auxilia no diagnóstico de várias doenças e no acompanhamento do tratamento dos pacientes. Nesse caso, a fase pré-analítica é fundamental, uma vez que a qualidade da amostra influencia diretamente a análise e a interpretação do resultado. Objetivo: O objetivo deste estudo foi identificar os principais erros na fase pré-analítica no exame de urina de rotina de um laboratório privado e sua frequência de ocorrência. Material e método: Dados entre 2014 e 2018 foram coletados. Ao todo, 107.277 amostras de urinas foram cadastradas; 98 (0,09%) foram encaminhadas para recoleta. Resultados: A solicitação de recoletas foi maior no sexo feminino (81,6%); as faixas etárias mais acometidas foram de 51 a 60 anos e de 21 a 30 anos. A justificativa mais comum para recoleta foi material insuficiente (48%), seguida por confirmação de resultado, em 24,5% dos casos. O predomínio de recoletas de urina no sexo feminino ocorreu devido à frequência da realização dos exames de urina em mulheres, pois elas estão mais propensas a infecções urinárias, principalmente na fase de vida sexualmente ativa e na pós-menopausa. Conclusão: De forma geral, o índice de recoletas de urinas obtido na pesquisa foi menor que a meta estipulada pelo laboratório, mas os principais motivos que levaram à solicitação de recoleta poderiam ser evitados ou minimizados se os pacientes tivessem sido bem instruídos quanto aos corretos procedimentos de coleta, o que indica a necessidade de programas de capacitação e treinamento constantes da equipe de trabalho.

The hemodynamic effects of ATP in retrograde perfusion of the bivascularly perfused rat liver.

AIMS/BACKGROUND: In the sinusoidal bed the distribution of water is flow-limited, but it becomes partly barrier-limited when adenosine triphosphate (ATP) is introduced. This effect could be exerted either directly by ATP or by substances released from presinusoidal regions. Furthermore, portally infused ATP seems to be able to diffuse in the direction of the arterial bed. It is not known if this diffusion route is specific. Answers to these questions can be obtained from indicator-dilution experiments in retrograde perfusion. METHODS: Indicator-dilution experiments, using [14C]sucrose and [3H]water, were conducted. Rat livers were perfused in the retrograde mode (hepatic vein+hepatic artery --> portal vein). RESULTS: When ATP was infused into the hepatic vein, the distribution of [3H]water remained essentially flow-limited. The infusion of ATP into the hepatic artery increased the sucrose and extra-sucrose spaces of the arterial bed, but infusion into the hepatic vein was without effect. CONCLUSIONS: The results indicate that the induction of barrier-limited distribution of [3H]water is not a direct effect of ATP. Furthermore, if the transhepatic diffusion of ATP can occur from presinusoidal regions to the arterial bed, as shown by previous work, a similar diffusion does not occur from postsinusoidal regions.

Inhibition by extracellular ATP of organic anion transport in the perfused rat liver.

The action of extracellular ATP on organic anion transport in the bivascularly perfused rat liver was investigated, using bromosulfophthalein as a model substance. Transport was measured by means of the multiple-indicator dilution technique. The action of portal 100 microM ATP presented the following characteristics: (a) inhibition of bromosulfophthalein single pass extraction; the inhibition degree decreased with increasing bromosulfophthalein doses; (b) diminution of the influx rate coefficients; (c) 86.7% decrease of the maximal activity of the saturable component for bromosulfophthalein transport, but 100% increase of the non-saturable component; (d) diminution of the bromosulfophthalein flow-limited distribution space; (e) no significant alteration of the rate coefficients for metabolic sequestration. The action of ATP on organic anion transport in the intact liver occurred at much lower concentrations (10x) than those previously reported for isolated hepatocytes. This reinforces the suggestion that inhibition of organic anion transport could be a physiologically relevant effect of extracellular ATP.