Thromboelastography - TEG coagulation test explained, interpretation of TEG Graph - Edusurg Clinics
Thromboelastography or TEG coagulation test is a diagnostic test used to assess the global function of the blood clotting process and the overall hemostatic balance. It provides a dynamic and comprehensive view of how blood clots form and break down in response to various physiological and pathological conditions. TEG is often used in surgical settings, trauma care, and critical care to guide decisions about blood transfusions, hemostatic interventions, and the management of bleeding disorders.
Here are the basic components of a TEG test and how to interpret its results:
Components of TEG:
R-time or Reaction Time: This measures the time taken for clot formation to begin after the initiation of the coagulation process. It reflects the interaction between clotting factors and platelets during the initial stages of coagulation.
K-time: This parameter represents the time it takes for the clot to achieve a certain level of strength. It is influenced by the rate of fibrin formation and cross-linking.
Alpha Angle: The alpha angle indicates the speed of clot formation and fibrin build-up. It reflects the kinetics of clot development.
MA or Maximum Amplitude: This parameter indicates the maximum clot strength and is often associated with platelet function and fibrinogen levels.
LY30: LY30 represents the percentage reduction in clot strength 30 minutes after reaching the maximum amplitude. It provides information about clot stability and fibrinolysis.
Fibrinolysis: TEG can also show signs of fibrinolysis by assessing the changes in clot strength over time. A prolonged or exaggerated drop in clot strength might suggest excessive fibrinolysis.
Interpretation:
TEG provides a graphical representation of these parameters over time, allowing clinicians to understand the complete coagulation process. Interpretation involves considering the interactions between the parameters and comparing them to established normal ranges or baseline values. Here are a few common interpretations:
Hypercoagulable State: If R-time and K-time are shortened, and the MA is increased, it might indicate a hypercoagulable state where clot formation and strength are accelerated.
Hypocoagulable State: Prolonged R-time and K-time, along with reduced MA, can indicate a hypocoagulable state, suggesting a deficiency in clotting factors or impaired platelet function.
Fibrinolysis: An exaggerated drop in clot strength might indicate hyperfibrinolysis, which could be associated with excessive bleeding risk.
Normal Coagulation: When the TEG parameters fall within normal ranges, it suggests a balanced and functional coagulation process.
It's important to note that TEG interpretation should be done in conjunction with a patient's clinical history, lab results, and overall condition. TEG is just one tool in the larger context of diagnosing and managing bleeding and clotting disorders. Interpretation can be complex, so it's essential for medical professionals with expertise in hemostasis to analyze the results and make informed decisions based on the patient's specific situation.