How Is Thromboelastography Currently Used?
Typically, TEG is used by a variety of medical subspecialties, including pathology, general surgery, and anesthesiology.[3,4,8–11] The use of TEG in general surgery has revolutionized the acute care of traumatically injured patients because of the test's comprehensive ability to rapidly evaluate traumatic coagulopathy.[7,12–17] By having a detailed picture of the coagulation profile, trauma surgeons are able to offer a more patient-specific delivery of blood products outside the generic 1:1:1 ratio (Packed Red Blood Cell [PRBC]:FFP:Platelets) for transfusion.[4,16,18–20] Patient-specific delivery of blood products allows physicians to more effectively adapt to any changes that may occur throughout resuscitation. Figueiredo et al found that patient-specific blood transfusion protocols were not only safe but also reduced the overall amount of blood products used. Because of these findings, multiple studies that examine traumatically injured patients support increased TEG testing availability, especially during massive transfusion protocols.[21–23]
In addition to blood transfusion protocols, TEG has also been used to predict the risk of death in trauma patients.[8,24] Kane et al showed that TEG R > 6 was associated with a 52% mortality rate and was an independent risk factor for death. Cuffolo et al noted that LY-30 was an independent risk factor for death within 24 hours in trauma patients.
Outside the trauma arena, TEG has growing musculoskeletal appeal related to its ability to detect and monitor the use of anticoagulation therapies. For example, Dias et al showed that oral anticoagulants can be detected and monitored using the rapid TEG's activation clot time and kaolin test. Furthermore, a rapid TEG can be used to differentiate between Xa inhibitors (eg, enoxaparin) and direction thrombin inhibitors (eg, fondaparinux), which can be invaluable for patients who are unsure of which and how much anticoagulant they are taking. Tekkesin et al demonstrated that enoxaparin therapy can be monitored postoperatively with the coagulation index from rotational thromboelastometry (ROTEM), which is another brand name for a test similar to TEG. Connelly et al proved that enoxaparin doses can be tailored to a patient's coagulation profile; however, this did not result in a difference in the incidence of venous thromboembolism (VTE) between the groups studied.
TEG has also been investigated for its potential in predicting VTE. Reports by both Park and Gary showed that TEG can be used to predict a hypercoagulable state.[7,28] Gary et al showed that elevated admission rapid TEG MA values could predict patients at risk for sustaining a VTE. Furthermore, the Park study proved that TEG is better at predicting hypercoagulability than the traditional coagulation tests. However, Parameswaran et al did not establish a correlation between a hypercoagulable state on TEG and postoperative VTE.
Anesthesiologists presently use TEG to monitor patient resuscitation in cardiothoracic and hepatic surgery,[29–34] to evaluate the safety of neuroaxial anesthesia, and to mitigate the risk of epidural hematoma. In a case report, Mauritz was able to safely use TEG to direct platelet therapy in a patient with medical comorbidities causing coagulopathies, who required a caesarian section with neuroaxial anesthesia.
J Am Acad Orthop Surg. 2019;27(14):503-508. © 2019 American Academy of Orthopaedic Surgeons