Thromboelastography as a tool to evaluate blood of healthy volunteers and blood component quality: a review

Thromboelastography is a technique to evaluate the overall coagulation behaviour of blood and blood components. First, we evaluated the literature concerning the use of thromboelastography for characterizing coagulation behaviour of healthy volunteers, such as blood donors. Overall coagulation is sensitive to gender, most likely caused by the difference in haematocrit and plasma content of male versus female blood. Smaller and less pronounced effects in thromboelastographic response are caused by differences in fibrinogen level or by use of oral contraceptives. Short-term hypercoagulable effects are observed after smoking or blood donation, while small effects of non-steroidal anti-inflammatory drugs on platelets are also present. Second, in whole blood donations, the thromboelastographic variables are also sensitive to storage time and temperature, but are less sensitive to levels of clotting factors. Platelet count and quality have little influence on thromboelastographic variables, and differences are mainly observed at counts <100x10⁹ /l, after extended storage time of platelet concentrates or storage under specific conditions, including freezing. Thromboelastographic profiles of plasma samples are mainly affected by residual cell counts, microparticles and fibrinogen levels, and less by levels of clotting factors. Taken together, publications have shown that as an overall clotting test, thromboelastography may support optimization of blood component preparation and storage with regard to temperature, time and secondary and tertiary treatments. Minimal deviations of in vitro quality are most reliable demonstrated when an appropriate assay is chosen.