La variabilità preanalitica dei test coagulativi

The approach to diagnosis, therapy and monitoring of bleeding and thrombotic disorders requires appropriate and discretionary use of laboratory resources. The total quality in coagulation testing is a prerequisite for achieving clinically reliable results. Although there is widespread perception that the preanalytical variability can adversely impact on results of coagulation tests, only a few studies have addressed this issue in detail. The major issues, extraordinarily magnified for the peculiarity of the tests, include the procedures used for collecting samples (venous stasis, devices, needle gauge, the type of the primary tube, the blood to anticoagulant ratio), the management of the tube after collection (mixing, time and mode of transport, spinning, storage) and other miscellanea variables which might variably result from inappropriate collection and handling of the specimen (eg hemolysis, lipemia, jaundice, contamination with heparin or other liquids). All these variables can affect the integrity of the specimen and affect the reliability of test results, thereby producing negative clinical and economic consequences.