From the Guidelines
Thromboelastography (TEG) interpretation is complex and should be done with caution, considering the patient's clinical context and the limitations of the test.
Key Considerations
- TEG results can be influenced by various factors, such as hematocrit, and may not accurately reflect the patient's coagulation status in certain conditions, such as anemia 1.
- The test has high variability, with coefficients of variance ranging from 7.1% to 39.9% for TEG parameters, which can lead to inconsistent results 1.
- TEG measures similar parameters to ROTEM, but their results are not interchangeable due to differences in reagents and hardware 1.
- In patients on anticoagulant therapy, TEG can be used to detect coagulopathy, but its results should be interpreted in conjunction with clinical findings and other laboratory tests 1.
Clinical Applications
- TEG can be useful in guiding reversal therapies in patients on direct oral anticoagulants (DOACs) 1.
- Viscoelastic tests, including TEG, have been shown to decrease the requirement for prophylactic blood product transfusions in patients with cirrhosis undergoing invasive procedures 1.
- However, the use of TEG to predict post-procedural bleeding is still uncertain and requires further study 1.
Limitations
- TEG results should be interpreted with caution in patients with liver disease, as the test may not accurately reflect the patient's coagulation status 1.
- The test is not suitable for monitoring patients on anticoagulant therapy, as it can be influenced by various factors and may not accurately reflect the patient's coagulation status 1.
- TEG should not be used as the sole guide for anticoagulation reversal decisions in acute trauma patients 1.
From the Research
Interpretation of Thromboelastography (TEG)
Thromboelastography (TEG) is a laboratory assay utilized to evaluate hemostatic properties of blood, identify coagulopathy, and guide blood product administration 2. The interpretation of TEG involves assessing dynamic clot formation and evaluating the coagulation status of patients on an individual level 3.
Key Parameters
The key parameters in TEG include:
- Clot strength, which is associated with increased platelet content and plasma fibrinogen concentration 4
- Clot formation time, which is affected by the concentration of blood components such as platelets, fibrinogen, and red blood cells 4
- Maximum amplitude (MA), which is a measure of clot strength and is affected by platelet function and fibrinogen concentration 5
Limitations of TEG
The interpretation of TEG variables is limited without knowledge of the concentration of the blood components present 4. TEG does not provide a comprehensive or sensitive reflection of impaired platelet function, and should be supplemented by other methods of platelet function assessment wherever possible 5.
Clinical Applications
TEG has been used in various clinical settings, including trauma, surgery, and medical patients, to guide blood product administration and improve patient outcomes 3, 2, 6. The use of TEG has been shown to reduce blood product use and improve patient outcomes in certain clinical settings 3.
TEG Tracing Parameters
The normal TEG-tracing parameters and common hemodynamic abnormalities and their effect on the TEG tracing are illustrated in the literature 3. The TEG "functional fibrinogen" assay should be used only as a gross estimate of the fibrinogen concentration in whole blood 4.
Future Directions
Further research is needed to determine the value of TEG in the periprocedural setting and to explore its potential applications in various clinical states 3, 6. Critical care nurses and the multidisciplinary team must identify patients in whom the use of TEG is warranted, interpret the results, and provide appropriate interventions in response to the results and clinical status of the patient 6.