preanalytischen

Preanalytical is a term used in laboratory medicine to describe all activities that occur before a laboratory analysis and can influence test results. It covers patient preparation, specimen collection, labeling, transport, processing, storage, and handling from the moment a test is ordered until analysis begins.

The preanalytical phase depends on correct patient identification, appropriate specimen type and collection tube, adequate sample volume, and proper timing. Factors such as fasting status, exercise, or recent medication can also affect results. Key steps include proper collection technique, correct labeling, timely and appropriate transport, and prompt, correct processing in the laboratory. Some tests require specific handling, such as centrifugation, separation of plasma or serum, or refrigeration, to preserve analyte stability.

Specimen quality is critical. Common preanalytical issues include misidentification of the patient, incorrect tube type, insufficient or hemolyzed samples, clotting in anticoagulated tubes, contamination, delayed transport, and improper storage. These errors can lead to inaccurate results, repeat testing, and delayed diagnosis.

Quality management in the preanalytical phase relies on standardized procedures, staff training, and adherence to guidelines from bodies such as CLSI and ISO 15189. Laboratories implement checklists, process controls, and information systems to ensure correct patient data, specimen labeling, and traceability. Reducing preanalytical errors improves patient safety, shortens turnaround times, and lowers costs associated with repeat testing and misdiagnosis.