Total Laboratory Automation of Routine Hemostasis Testing

Abstract

The aim of this study was to assess whether preanalytical management of coagulation samples through an open total laboratory automation system may impair the reliability of routine hemostasis tests as compared with loading of centrifuged plasma specimens directly into the coagulation analyzer for routine testing. Forty inpatient samples were divided into two aliquots. The former was centrifuged and directly loaded in a hemostasis analyzer, whereas the latter was entered into a 16.5 m long track-line system (FlexLab), where it was automatically centrifuged and conveyed to the same coagulation analyzer. An analytically significant difference was found between values of samples directly loaded in the coagulation analyzer and those entered in the track-line system for prothombin time (19.6 ± 1.7 versus 19.2 ± 1.6 s; p < 0.001) and activated partial thromboplastin time (38.0 ± 1.4 versus 37.5 ± 1.3 s; p = 0.021) but not for fibrinogen (305 ± 12 versus 304 ± 12 mg/dL; p = 0.97). Nevertheless, the mean percentage bias of prothombin time (-1.8%), activated partial thromboplastin time (-1.0%), and fibrinogen (0.4%) was modest and always lower than the total allowable error and was thereby considered not clinically significant. The results of this study confirm that connection of coagulation analyzers to track-line systems is a viable solution for modern clinical laboratories.

Keywords: automation; coagulation; hemostasis; preanalytical variability; sample quality.