Dr. S. Parthasarathy
MD., DA., DNB, MD (Acu), Dip. Diab. DCA, Dip.
Software statistics PhD (physio)
Mahatma Gandhi medical college and research
institute , puducherry – India
What is it and when started
 Thromboelastography is a point-of-care global
hemostasis system used by anaesthetists largely to
monitor perioperative changes in coagulation in
surgical patients
 It was first developed by the German Dr. Hellmut
Hartert at University of Heidelberg School of
Medicine. in 1948
Thrombo elastography machine
Indications
 Cardiac Surgery
 Patient factors(aspirin,clopidogrel,heparin,




clotting disorders)
Vascular Surgery.
Major obs. Haemorrhage
Regional on heparin
liver transplantation
What does it test ??
 The visco elastic changes that occur during the





hemostatic process
TEG provides a real-time functional evaluation of the
coagulation cascade,
Platelet function
Clot formation
clot strengthening and fibrin cross-linkage
clot lysis
classical thromboelastography
 a small sample of blood is placed into a cuvette (cup)
rotated gently to imitate sluggish venous flow and
activate coagulation.
 When a sensor shaft is inserted into the sample a clot
forms between the cup and the sensor.
 The speed and strength of clot formation is measured
depends on the activity of the plasmatic coagulation
system, platelet function, fibrinolysis and other factors
Principle
Values
 the R value - time until the first evidence of a clot is




detected
The K value - the end of R until the clot reaches
20mm and this represents the speed of clot formation
The angle is the tangent of the curve made as the K is
reached and offers similar information to K
The MA is a reflection of clot strength.
Clot lysis time
R value
 R: R time is the period of latency from the time that the
blood was placed in the TEG analyzer until the initial
fibrin formation. This represents the enzymatic portion
of coagulation. (clotting factors ) 4 – 8 minutes
 R = 11 – 14 min – FFP 8 ml/kg
 R > 14 FFP 15 ml/Kg
 Prolonged R
 Shortened R
 Hypercoagulable state and early DIC
 K: K time is a measure of the speed to reach a certain
level of clot strength. This represents clot kinetics.
 1 – 4 minutes
 alpha : measures the rapidity of fibrin built up and
cross-linking (clot strengthening). This represents
fibrinogen level.
 45 – 75 deg
 R normal
 K prolonged
 Platelet defect
 MA: MA or maximum amplitude, is a direct function
of the maximum dynamic properties of the fibrin and
platelet bonding via GPIIb/IIIa and represents the
ultimate strength of the fibrin clot.
 55 – 70 mm
 80 % platelets
 20 % fibrinogen
Decrease and continuous decrease
 Platelet deficiency
 Primary fibrinolysis
 LY30: LY30 measures the rate of amplitude reduction
30 min after MA. This represents clot lysis.
 Normal = 7.5 %
Primary fibrinolysis
> 7.5 %
TO SUMMARIZE
 Cuvette pin 0.3 ml blood
 Visco elastic properties
 Full coagulation profile
 R, K ,MA , LY 30
 Disease s
TEG with heparinase
 heparinase (an enzyme breaking heparin)
 “heparinized” patients, prior to heparin reversal with
protamine.
 This test may prove particularly useful during long
pump runs, deep hypothermia, use of ventricular assist
devices or complicated major vascular cases
 The test will also detect if more protamine is needed to
fully reverse heparin.
To remove platelet effect
 Add recently FDA approved monoclonal antibody
which binds to the platelet GPIIb/IIIa receptors, to the
TEG sample
 eliminate platelet function from the
thromboelastogram
 The MA will become a function of fibrinogen activity
Various diseases – TEG
The Sonoclot
 provides an alternative visco elastic measure of
coagulation.
 In contrast to the TEG, Sonoclot immerses a rapidly
vibrating probe into a 0.4-mL sample of blood.
 As clot formation occurs, impedance to probe
movement through the blood increases and generates
an electrical signal and characteristic clot “signature.”
 The Sonoclot may be used to derive the ACT, as well as
to provide information regarding clot strength and
fibrinolysis.
Treat the patient than TEG
 Thank you all