Preanalytiske

Preanalytiske, or the pre-analytical phase, encompasses all steps from test ordering and patient preparation to the moment a sample begins analysis in the laboratory. It covers patient identification, consent where relevant, collection procedures, labeling, the choice of specimen type and collection tubes, volume adequacy, and the initial handling, transport, and processing of specimens (such as centrifugation or aliquoting) before analytical measurement.

The goal is to preserve sample integrity and ensure that the specimen reflects the patient's condition at collection. Factors in this phase include patient-related variables (fasting status, diurnal variation, medications), collection technique (venipuncture vs capillary, use of tourniquet), sample type, and proper avoidance of contamination or mix-ups.

Common preanalytical errors include mislabeling or specimen mix-ups, incorrect tube type or additives, insufficient volume, excessive delays in transport, temperature excursions, contamination, hemolysis, and clotting of serum samples. Such errors can lead to inaccurate results, need for redraws, delayed diagnosis, or inappropriate treatment.

Quality assurance in the preanalytical phase relies on standardized procedures, training and competency assessment, specimen handling protocols, barcode-based labeling, and robust specimen tracking. Organizations follow guidelines from bodies such as CLSI and standards such as ISO 15189 to minimize errors and improve patient safety.

Improving preanalytical processes reduces rework, lowers costs, and shortens turnaround times, while enhancing the reliability of laboratory testing. In practice, laboratories implement checklists, preanalytical error reporting, and root-cause analysis to continually improve this foundational phase.