From the Guidelines
Thromboelastography (TEG) measures the viscoelastic properties of blood clot formation and lysis.
Mechanism of TEG
- TEG uses a sample of whole blood incubated in an oscillating cup with a free-floating pin to sense changes in blood as it goes through the various stages of clot formation and breakdown 1.
- The test provides quantitative data in the form of a real-time two-dimensional graph called a TEMogram, which includes parameters such as R, MA, and alpha angles 1.
- TEG assesses blood coagulation from initial clot formation to clot lysis at the patient's bedside, making it a point-of-care technology 1.
- The mechanism of TEG involves the activation of coagulation, bypassing primary hemostasis, which makes it insensitive to antiplatelet agents or any kind of platelet inhibition 1.
Limitations of TEG
- TEG has limitations, including the inability to assess the contribution of endothelium to coagulation, detect von Willebrand disease, or detect disorders of primary hemostasis 1.
- TEG results can be influenced by factors such as hematocrit, which can lead to inaccurate interpretations in patients with anemia or other conditions with variable hematocrit 1.
- The test also has variable precision, with coefficients of variance ranging from 7.1% to 39.9% for TEG parameters, which highlights the need for sufficient quality control measures and adequate user training 1.
From the Research
Mechanism of Thromboelastography (TEG)
The mechanism of Thromboelastography (TEG) involves recording the continuous profiles of whole blood coagulation by measurement of the viscoelastic changes associated with fibrin polymerization, providing a global assessment of haemostatic function 2.
Key Aspects of TEG
- TEG is a whole-blood viscoelastic coagulation test used in clinical laboratories and at the point of care 3
- It provides information on coagulation defects that are often difficult to detect using routine laboratory tests such as activated partial prothrombin time or prothrombin time 3
- TEG evaluates hemostatic properties of blood, identifies coagulopathy, and guides blood product administration 4
- The test assesses dynamic clot formation, allowing for the determination of specific deficiencies present in whole blood that are otherwise undetectable with traditional coagulation studies 5
Technical Aspects of TEG
- TEG measures the viscoelastic changes associated with fibrin polymerization 2
- The test is easy to perform and can provide information on a patient's coagulation status within 30 min 6
- TEG has been proven to reduce blood product use as well as improve patient outcomes in a variety of medical settings, including trauma and surgery 5