Interpreting TEG Studies for Managing Bleeding
Thromboelastography (TEG)-guided transfusion strategies should be used to manage bleeding as they provide a more comprehensive assessment of coagulation than conventional tests and lead to reduced blood product usage without increasing bleeding complications. 1
Understanding TEG/ROTEM Basics
TEG and rotational thromboelastometry (ROTEM) are viscoelastic tests that measure the entire clotting process in real-time, providing information on:
- Clot initiation (R-time/CT): Prolonged times indicate coagulation factor deficiencies
- Clot formation rate (K-time/α-angle/CFT): Reflects fibrinogen function and platelet contribution
- Maximum clot strength (MA/MCF): Indicates platelet function and fibrinogen contribution
- Clot stability/lysis (LY30/CLI): Measures fibrinolysis
TEG-Guided Bleeding Management Algorithm
Step 1: Initial Assessment
- Obtain baseline TEG/ROTEM alongside conventional coagulation tests (PT/INR, aPTT, fibrinogen, platelet count) 1
- Control obvious bleeding points through direct pressure, tourniquets, or hemostatic dressings 1
- Establish large-bore IV access and begin fluid resuscitation 1
Step 2: Interpret TEG Parameters and Treat Accordingly
| TEG Parameter | Abnormality | Treatment |
|---|---|---|
| R-time > 10 min | Prolonged clot initiation | Fresh Frozen Plasma (FFP) or Prothrombin Complex Concentrate (PCC) [1] |
| K-time > 3 min or α-angle < 53° | Poor clot formation | Cryoprecipitate or Fibrinogen concentrate [1] |
| MA < 50 mm | Weak clot strength | Platelet transfusion [1] |
| LY30 > 3% | Hyperfibrinolysis | Consider tranexamic acid (except in variceal bleeding) [1] |
Step 3: Specific Clinical Scenarios
Trauma-Induced Coagulopathy
- Initially deliver blood products empirically (1:1 RBC:FFP ratio) 1
- Give tranexamic acid 1g immediately if within 3 hours of injury 1
- Transition to TEG-guided therapy as soon as available 1
- Consider cryoprecipitate (two pools) and platelets (one adult dose) until test results available 1
Cardiac Surgery
- TEG/ROTEM is strongly recommended to guide transfusion 1
- Target higher platelet counts (>75 × 10⁹/L) after cardiopulmonary bypass 1
- Use local transfusion protocols guided by TEG/ROTEM results 1
Liver Disease/Cirrhosis
- Standard coagulation tests (INR, platelet count) often overestimate bleeding risk 1
- TEG-guided transfusion in cirrhotic patients leads to significantly lower blood product use (16.7% vs 100%) without increased bleeding complications 2, 3
- Do not routinely correct coagulation parameters before procedures in cirrhosis unless TEG indicates need 1
Advantages of TEG-Guided Approach
- Reduced blood product usage: Multiple studies show significant reduction in transfusion requirements 2, 3, 4
- Potential mortality benefit: Evidence suggests reduced mortality (3.9% vs 7.4%) 4
- Faster results: Point-of-care testing provides quicker turnaround than conventional lab tests 1
- More comprehensive: Assesses entire coagulation process rather than isolated factors 1
Common Pitfalls and Caveats
- Standardization issues: There are concerns about standardization between centers and devices 1
- Device differences: Limited interchangeability between TEG and ROTEM requires separate treatment algorithms 1
- Interpretation challenges: Requires training and experience to properly interpret results
- Sensitivity limitations: May be less sensitive to certain coagulation defects, particularly in TBI patients 1
- Clinical context: Always interpret TEG results in the context of the clinical scenario 1
- Timing matters: TEG parameters can change rapidly in actively bleeding patients, requiring repeat testing 1
Conclusion
TEG/ROTEM-guided transfusion strategies provide significant advantages over conventional coagulation test-guided approaches in bleeding patients. They allow for targeted blood component therapy, reducing unnecessary transfusions while maintaining or improving clinical outcomes. The evidence is strongest in cardiac surgery and trauma settings, with growing evidence in liver disease. Implementation requires proper training and protocol development specific to your institution's available devices.