Ensuring the quality of thrombodynamics test performance: Influence of preanalytical stage factors

BACKGROUND: Quality assurance in coagulation testing is crucial for effective diagnostics. In addition to the direct control of the analytical procedure, the collection and preparation of samples must be standardized and controlled during the preanalytical phase.

AIM: To assess the effect of preanalytical factors, such as freezing and transportation via laboratory pneumatic tube system, on the thrombodynamics parameters.

MATERIALS AND METHODS: Citrated plasma samples from 30 volunteers were analyzed. These plasma samples were transported from the treatment room to the laboratory in two ways: manually in a container or by pneumatic mail. Test preparations were performed as follows: samples were centrifuged at 1600 g for 15 min, and ¾ of the plasma volume was then taken into a plastic tube and centrifuged again at 10 000 g for 5 min. Thereafter, 90% of the volume was transferred into a plastic tube and tested for thrombodynamics parameters. Ten plasma samples were deep-frozen after centrifugation, defrosted using a water bath, centrifuged again, and subjected to thrombodynamics studies.

RESULTS: Delivery by pneumatic mail triggers processes that cause false hypercoagulation in plasma samples. In addition, defrosted plasma samples show increased velocity parameters of hypercoagulability compared with fresh plasma.

CONCLUSION: For thrombodynamics studies, plasma freezing and transportation by pneumatic mail are not recommended.