The pre-analytical phase is essential for the analysis result quality. This phase take place between medical prescription and analysis, and involves the sampler and his patient. Pre-analytical phase comprises all the factors that can influence sample results before its analysis.
This is a major step for measuring the quantities of the consituents of biological fluids, as well as for the diagnostic and the monitoring of some diseases. This phase is considered as the most error prone part, Indeed, 2/3 of laboratory diagnostic nonconformities are attributable to pre-analytic errors.
Nonconformities biological samples require to redo and engender additional costs of personnel, equipment, time and energy.
Any not detected or reported error during pre-analytic phase may falsify the analysis results and deacresad patient satifsfaction by doing new tests.
It is fundamental to master pre-analytical phase.

What is the extent of the pre-analytical phase ?

Pre-analytical phase starts with the reception of the patient until the analytical phase.
Pre analytical phase encompasses:
From prescription to analysis, traceability is crucial and all the actors must be involved.

Which are the procedures and operating methods involved in this phase ?

Laboratory must have written, dated and validated procedures and operatinf methods concerning:
  • Patient preparation instructions
  • Choosing appropriate products
  • Sampling methods
  • Patient and specimen identification: surname, first name, marital name, sex and date of birth
  • sample transmportation
  • Pre-treatement of the sample (centrifugation)
  • Sample storage before and after analysis

When samples are send to a laboratory, healthcare professionals must include a sampling sheet (Arrêté du 20 juin 2003, JORF du 3 juillet 2003), it allow to verify compliance with the transmission time and temperature indacated in the procedure, as well as tje conformity of the sample when it is receive. the respect of the delay and temper.

In a future article, you will discover how patient preparation, reception and comfort can influence the quality of the pre-analytical phase, which are the responsabilities of the clinician, which are home sampling specificities ans how to identify samples. Finally, we will see factors that can disturb the results of the analysis, before discussing the results report.

To minimize the risk, products and equipments you use are important. LABELIANS stand by you to choose and use them well.