Evaluating hemostatic potential of platelet concentrate by tromboelastography

Introduction. The thromboelastography method potentially can be used to assess the hemostatic potential of platelet concentrates (PC). Currently, in vitro thromboelastographic study of PC is not standardized. The aim of the work. To evaluate hemostatic quality of PC by thromboelastography in a medium, similar to whole blood. Materials and methods. We examined blood samples from donors, PC, harvested by apheresis, and PC, obtained by pooling platelet fractions, isolated from whole donor blood. To compare the data of thromboelastography and clinical efficacy, PC-doses were transfused to 11 patients for the relief or prevention of hemorrhagic syndrome. To assess the platelet′s hemostatic potential with thromboelastography, PC-samples were combined with filtered blood from donors (without platelets) in a 1:9 ratio, at the parallel we studied samples of whole blood and filtered blood from the same donors. We examined changes in thromboelastographic parameters (k and MA) under influence of PC-samples. Platelet morphofunctional analysis was performed using vital dyes and fluorescence microscopy. To assess the clinical effect of PC in patients after transfusion we evaluated the presence of complications and clinically pronounced hemorrhagic syndrome, corrected count increment of platelet after 24 hours. Results. High variability of MA and k was observed in apheresis and pooled PC. The addition of PC into the filtered blood induced noticeable shortening of the time k, what is more, we observed correlation between morphofunctional parameters of PC-platelets and values k and MA. We proposed the criterion for assessing the PC hemostatic potential (HR), which is determined by the restoration in% of the hemostatic activity of filtered donor blood after PC addition. The analysis of the clinical effect showed that PC-doses with HR values > 95% and k < 4 min are the most effective. At HR > 95% and k < 4 min the hemostatic potential of PC is considered high, at HR from 75% to 95% and k < 4 – acceptable, at HR < 75% or HR < 95% and k > 4 – low. PC with high hemostatic potential are recommended for therapeutic transfusions (relief of hemorrhagic syndrome), PC with acceptable hemostatic potential are recommended for preventive transfusions, CT scans with low hemostatic potential are not recommended for transfusions. Conclusions. The proposed method of thromboelastographic examination of platelet concentrates makes allows to select doses with high hemostatic potential of platelets and could be used in industrial and clinical transfusiology.