TEG® and ROTEM® in trauma: similar test but different results?

INTRODUCTION Transfusion in trauma is often empiric or based on traditional lab tests. Viscoelastic tests such as thromboelastography (TEG®) and rotational thromboelastometry (ROTEM®) have been proposed as superior to traditional lab tests. Due to the similarities between the two tests, general opinion seems to consider them equivalent with interchangeable interpretations. However, it is not clear whether the results can be similarly interpreted. This review evaluates the comparability between TEG and ROTEM and performs a descriptive review of the parameters utilized in each test in adult trauma patients. METHODS PUBMED database was reviewed using the keywords "thromboelastography" and "compare", between 2000 and 2011. Original studies directly comparing TEG® with ROTEM® in any area were retrieved. To verify the individual test parameter used in studies involving trauma patients, we further performed a review using the keywords "thromboelastography" and "trauma" in the PUBMED database. RESULTS Only 4 studies directly compared TEG® with ROTEM®. One in liver transplantation found that transfusion practice could differ depending on the device in use. Another in cardiac surgery concluded that all measurements are not completely interchangeable. The third article using commercially available plasma detected clinically significant differences in the results from the two devices. The fourth one was a head-to-head comparison of the technical aspects. The 24 articles reporting the use of viscoelastic tests in trauma patients, presented considerable heterogeneity. CONCLUSION Both tests are potentially useful as means to rapidly diagnose coagulopathy, guide transfusion and determine outcome in trauma patients. Differences in the activators utilized in each device limit the direct comparability. Standardization and robust clinical trials comparing the two technologies are needed before these tests can be widely recommended for clinical use in trauma.