an introduction to thromboelastography

1. THROMBOELASTOGRAPHY
DR. VIGNESH KUMAR
SENIOR RESIDENT
JPN APEX TRAUMA CENTRE, AIIMS

2. TRAUMA INDUCED COAGULOPATHY
Brohi K, et al. "Acute traumatic coagulopathy." Journal of Trauma and Acute Care Surgery 54.6 (2003):
1127-1130.

3. ACIDOSIS
HYPOTHERMIA
HYPOTENSION
HIGH ISS
Impaired Clotting Factor Function
Impaired Platelet Function
CNS Injuries
Increased
TF Release DIC
Long Bone
Fxs
Fat Embolism
Increased
IVF & PRBCs
Dilution of Clotting
Factors & Platelets
C
O
A
G
U
L
O
P
A
T
H
Y
Hess J, Hoyt D, et al. J Trauma 2008; 65:748-54
Prot. C Activation
Hyper-
fibrinolysis
TRAUMA INDUCED COAGULOPATHY

5. ROUTINE TEST OF COAGULATION
LAB TEST COMPONENT MEASURED NORMAL VALUES
PROTHROMBIN TIME FACTOR 7 (1,2,5,10) 12-14 SECONDS
ACTIVATED PARTIAL
THROMBOPLASTIN TIME
FACTOR 8,9,11,12 (1,2,5,10) 24-35 SECONDS
BLEEDING TIME PLATELET FUNCTION 3-7 MINUTES
THROMBIN TIME FACTOR 1,2 12-20 SECONDS

6. Annals of surgery. 2012; 256(3):476-484

7. Annals of surgery. 2012; 256(3):476-484

9. THROMBOELASTOGRAPHY

10. THROMBOELASTOGRAPHY
• Dr Hellmut Hartert, found TEG in 1948, at the University of
Heidelburg
• Determines viscoelasticity during clot formation
• Overall coagulability of whole blood
• Interaction between platelets, fibrinogen, and coagulation factors
• “Hemostasis is a dynamic interplay between platelets, coagulation
factors and its inhibitors, and fibrinolytic proteins”

13. Interpretation of TEG tracing
TEG parameter
Correlations with phase
of coagulation
Reaction time (min)
Time between initiation of
coagulation cascade to initial
formation of fibrin
Kinetic time (min)
Time between initial formation of
fibrin to specific clot firmness (20
mm)
α-angle (degrees)
Rate of fibrin formation and
crosslinking
Maximum amplitude
(mm)
Maximum clot strength
Lysis-30 (%)
Fibrinolysis 30 minutes after
maximum amplitude

15. NORMAL TEG

20. Parameters Normal Value Abnormal values Treatment
‘r’ time 5-8 mins
7-10 mins 1 FFP or 4 ml/Kg
11-14 mins 2 FFP or 8 ml/Kg
>14 mins 4 FFP or 16 ml/Kg
α angle 450 -740 <450 0.6 u/Kg cryoprecipitate
MA 53-73 mm
41-50 mm 5 units Platelets
<40 mm 10 units Platelets
Lysis 30 <8% >7.5% Fibrinolytic of choice
TREATMENT FOR ABNORMALITIES IN TEG
Tapia NM, Mattox KL et al. J Trauma Acute Care Surg. 2013;74(2):378-386.

26. ADVANTAGES OF TEG
• The evaluation of the coagulation system in whole blood allows
assessment of the combined influence of platelets, RBC, leukocytes
on clot formation, including platelet function.
• The end-point is clinically relevant, i.e. clotting in whole blood (fibrin
formation, clot retraction and fibrinolysis).
• Third, the results are available within a short time frame making them
relevant to clinical decision-making.
• It analyses the blood at 37.C (body temperature)

27. LIMITATIONS OF TEG
• VHA is routinely performed at 37°C and therefore the effect of
hypothermia will not be recognised.
• Patients on anti-platelet drugs (inhibition of platelet function) can
have false TEG readings
• The endothelial contribution to haemostasis is not displayed in VHA
• Moreover it is to be used by trained personal, frequent calibration is
required.

28. ROTEM

29. TEG AND ROTEM

41. QUESTIONS

42. SUMMARY
• TEG helps in the evaluation of the coagulation system in whole blood
• TEG is a real time measure of coagulation and aids in clinical decision
making
• It helps in guiding blood transfusion better than routine test of
coagulation
• Helps in diagnosing patients who are in/prone for trauma induced
coagulopathy
• Few limitations do exist with TEG