Pre-analytical phase management: a review of the procedures from patient preparation to laboratory analysis

Abstract

The pre-analytical phase encompasses all the procedures before the start of laboratory testing. This phase of the testing process is responsible for the majority of the laboratory errors, since the related procedures involve many sorts of non-laboratory professionals working outside the laboratory setting, thus without direct supervision by the laboratory staff. Therefore, either correct organization or management of both personnel and procedures that regard blood specimen collection by venipuncture are of fundamental importance, since the various steps for performing blood collection represent per se sources of laboratory variability. The aim of this (non-systematic) review addressed to healthcare professionals is to highlight the importance of blood specimen management (from patient preparation to laboratory analyses), as a tool to prevent laboratory errors, with the concept that laboratory results from inappropriate blood specimens are inconsistent and do not allow proper treatment nor monitoring of the patient.

Patient posture for blood collection by venipuncture: recall for standardization after 28 years

“…It is now clearly acknowledged that the vast majority of laboratory errors occur in the pre-analytical phase and are primarily attributable to a lack of standardized protocols during venous blood sampling 7, 8. The influence of posture on the CBC was investigated nearly 30 years ago by Leppanen and Grasbeck, 9 who manually measured white blood cell (WBC) differential counts in 22 healthy women after 2 h fasting 9 .…”

Fases Pré-Analítica, Analítica E Pós-Analítica No Monitoramento Laboratorial Da Anticoagulação Com Antagonistas Da Vitamina K

“…A fase pré-analítica é a etapa que concentra o maior número de erros que podem afetar o diagnóstico 15,18,19 . A explicação consiste na inexistência de automação e na dificuldade de controle do processo, incluindo a variabilidade da condição de jejum do paciente ou a omissão do paciente a respeito de questionamentos que são essenciais para garantir a qualidade do exame 18,[20][21][22][23] .…”

“…A explicação consiste na inexistência de automação e na dificuldade de controle do processo, incluindo a variabilidade da condição de jejum do paciente ou a omissão do paciente a respeito de questionamentos que são essenciais para garantir a qualidade do exame 18,[20][21][22][23] . Causas de erros pré-analíticos, como tempo de armazenamento (78,6%), tempo de torniquete (78,6%), metodologia de flebotomia (64,3%), falta de informação do paciente (64,3%), incorreta relação sangue/anticoagulante (57,0%) e tubos inadequados (50%), são reportados por diferentes estudos [24][25][26][27] .…”

“…A frequência de fatores que afetam o processo analítico, como amostras contaminadas (43,0%), interferência medicamentosa (29,0%) e variações laboratoriais (29,0%), foram evidenciadas por distintas pesquisas 18,[23][24][25][26][27] . Nos ensaios laboratoriais de coagulação, a realização de testes laboratoriais tem relevância para excluir eventuais interferentes ou possibilitar a identificação da provável fonte de comprometimento dos resultados 15 .…”

The EFLM strategy for harmonization of the preanalytical phase

“…There is now solid evidence that diagnostic errors are mostly attributable to the lack of standardization or harmonization of many manually intensive activities belonging to the preanalytical phase [4][5][6]. Unlike mistake in other parts of the total testing cycle, the identification of preanalytical errors remains challenging because the vast majority of these activities are performed outside the physical boundaries of clinical laboratories, with insufficient guidance, or often without the direct supervision of laboratory professionals [7].…”