TEG Interpretation Lecture by Jim Bradley

Introduction

• Jim Bradley, Consultant Anaesthetist at NUH
• Lecture on TEG interpretation
• Traditionally in small group workshops, now presented virtually due to COVID
• Given to trainees during rotations (February & August) and sometimes haematologists
• Expansion of TEG usage in intensive care and obstetrics
• New TEG algorithm consolidating trauma and non-trauma algorithms
• Focus on a unifying algorithm for all bleeding patients (excluding cardiac cases)

Case Study: Trauma Patient

• 31-year-old woman, unrestrained rear seat passenger, high-speed RTC
• Cardiac arrest, return of circulation via needle thoracocentesis and blood given
• Arrival at Queen's, major haemorrhage activated, trauma pack 1 started
• CT scan and theatre
• TEG results to be used for demonstration

Understanding TEG Curves

• TEG machine displays four curves: Citrated Kaolin (CK), Citrated Rapid TEG (CRT), Citrated Kaolin with Heparinase (CKH), and Citrated Functional Fibrinogen (CFF)
• Importance of filling citrate tubes correctly for accurate results
• Cartridge-based system, browser-based TEG Manager for viewing results

Citrated Kaolin (CK) Curve

• Standard TEG curve
• Measures reaction time (R time) and maximum amplitude (MA)
• Normal R time: <9.1 minutes; longer R time indicates need for FFP (15ml/kg)
• Max amplitude (MA) indicates clot strength; MA < 52 mm indicates poor clot strength

Citrated Functional Fibrinogen (CFF) Curve

• Monitors fibrinogen concentration
• Normal CFF MA: >17 mm; lower values indicate need for cryoprecipitate

Citrated Rapid TEG (CRT) Curve

• Same reagents as CK but with added tissue factor for faster results
• CRT MA used instead of R time for quicker assessment

Citrated Kaolin with Heparinase (CKH) Curve

• Used to detect heparin presence by comparing CK and CKH R times
• Significant differences (>2 min) indicate excess heparin, treated with protamine

Additional Considerations and Limitations

• TEG results at 37°C; warm patients if hypothermic
• Some drugs (clopidogrel, warfarin, DOACs) do not show up in TEG
• Treat based on clinical context and evolving patient conditions
• TEG results are a snapshot and may not reflect ongoing bleeding

Treatment Algorithm

• Threshold for coagulopathy: ACT of 120 seconds
• R time >9.1: give FFP
• CK MA <52: check CFF MA
  • CFF MA <17: give cryoprecipitate
  • CFF MA normal but CK MA poor (<52): give platelets
  • CK MA <47: give platelets
• LY30 >3%: give tranexamic acid

Resources and Contact

• PowerPoint presentation and URL for TEG Manager available on anaesthesia homepage
• Accessible on any Trust browser system
• Feedback and questions to Jim Bradley via provided email
• Presentation to be available on Trust and Anesthesia YouTube channels

Conclusion

• Thank you for attention, open to questions