Topic 13: TEG

Question 1

Clot strength - platelet to fibrin ratio

Answer 1

• Platelets 80%-90%

* Fibrin 10%-20%

Question 2

Tests that are Component Measurements of clots?

Answer 2

• PT/INR:
• PTT:
• Fibrinogen concentration
• Platelet Count

Question 3

•PT/INR: measures what?

Answer 3

measures extrinsic clotting (VIIa, Xa, IIa)

Question 4

•PTT:

Answer 4

measures intrinsic clotting (XIIa, Xia, IXa, IIa)

Question 5

Test that Measures component interactions

Answer 5

• TEG

* Shows net effect “whole picture” of hemostasis

Question 6

TEG is ?

Answer 6

• A whole blood hemostasis analyzer

* Point of care test

Question 7

How does TEG work?

Answer 7

Cup oscillates
•Pin is attached to torsion wire
•Clot binds pin to cup
•Degree and magnitude of pin motion are functions of the clot kinetics and mechanical properties
•System generates a hemostasis profile

Question 8

R

Answer 8

is the time of latency from the time that the blood was placed in the TEG until the fibrin formation

Question 9

R

likely variable?

Answer 9

Reaction time (time to clot formation)
is the time of latency from the time that the blood was placed in the TEG until the fibrin formation
(coagulation factors)

Question 10

alpha - α

likely variable?

Answer 10

Speed of fibrin accumulation
measure the rapidity of the fibrin build up and cross linking, that is, the speed of clot strengthening
(Fibrinogen)

Question 11

K

likely variable?

Answer 11

Time elapsed until clot reaches a fixed strength
K time is a measure of the rapidity to reach a certain level of clot strength
(Fibrinogen)

Question 12

MA

likely variable?

Answer 12

max amplitude, is a direct function of the max dynamic properties of fibrin and platelet bonding via GPIIb/GPIIIa and represents the ultimate strength of the fibrin clot
Highest vertical amplitude of TEG tracing
(Platelets)

Question 13

CI

Answer 13

coagulation index is a linear combination of MA, K, Alpha, R

Question 14

LY30

likely variable?

Answer 14

measures the rate of amplitude reduction every 30 minutes after MA. gives an indication of stability of the clot
% of amplitude reduction 30 minutes after its maximum
(Fibrinolysis)

Question 15

LY30

likely variable?

Answer 15

measures the rate of amplitude reduction every 30 minutes after MA. gives an indication of stability of the clot
% of amplitude reduction 30 minutes after its maximum
(Fibrinolysis)

Question 16

Standard (kaolin)

Answer 16

•Uses normal parameters

uses CI, MA, LY30, K, R alpha

Question 17

Rapid TEG

Answer 17

• Uses tissue factor in place of kaolin to speed up the reaction
• R-value is replaced by TEG-ACT value
• Other parameters the same

Question 18

Heparinase

Answer 18

•Used on bypass or post bypass alongside a standard TEG

Question 19

Platelet Mapping

Answer 19

• Determines to what degree platelet function is inhibited due to pharmacological inhibition of either the arachidonic acid (AA) or adenosine diphosphate (ADP) pathways
• AA: Aspirin
• ADP: Clopidogrel
• Run alongside a standard TEG and a TEG with added AA or ADP.
• Calculates platelet inhibition as a percentage

Question 20

Elongated R-Thrombin Formation Abnormalities:

Possible cause of imbalance:

Answer 20

•Slow enzymatic reaction

Question 21

Elongated R-Thrombin Formation Abnormalities:

Possible Etiologies

Answer 21

• Factor deficiency/dysfunction

* Residual heparin

Question 22

Elongated R-Thrombin Formation Abnormalities:

Common Treatments:

Answer 22

• FFP

* Protamine

Question 23

Low alpha angle - Fibrin formation

Possible cause of imbalance

Answer 23

slow rate of fibrin formation

Question 24

Low alpha angle - Fibrin formation

possible etiologies

Answer 24

Low fibrinogen levels or function
•Insufficient rate/amount of thrombin generation
•Platelet deficiency/dysfunction

Question 25

Low alpha angle - Fibrin formation | Common treatments

Answer 25

* FFP | * Cryoprecipitate

Question 26

Low MA - possible causes?

Answer 26

Insufficient platelet-clot formation

Question 27

Low MA - possible etiologies

Answer 27

Poor platelet function •Low platelet count •Low fibrinogen levels or function

Question 28

Low MA - common treatments?

Answer 28

Platlets

Question 29

High MA - possible causes?

Answer 29

Excessive platelet activity

Question 30

High MA - possible etiologies?

Answer 30

Platelet | hypercoagulability

Question 31

High MA - common treatments

Answer 31

antiplatelet agents

Question 32

Platelet mapping measures what??

Answer 32

Measures the effect of antiplatelet agents on platelet function •Measures the pt’s maximum platelet function as a reference point •Measures the percentage of inhibition relative to the patient’s reference point

Question 33

Platelet mapping -- what drugs are monitored?

Answer 33

Antiplatelet Drugs •ADP receptor inhibitors •Examples: clopidogrel, ticlopidine * Arachidonic acid pathway inhibitors * Example: aspirin * GPIIb/IIIa inhibitors * Examples: abciximab, tirofiban, eptifibatide

Question 34

Why platelet mapping?

Answer 34

Individual response to antiplatelet drugs determines clinical outcome •Knowing percent of platelet inhibition is insufficient to determine therapeutic efficacy •Knowledge of maximum platelet function is also required as a reference point

Question 35

Rotational Elastometry (ROTEM)

Answer 35

Stationary cup, rotating spindle •Clot impedes rotation of the pin •Additional tests available

Question 36

R time between 7-10 min clinical cause? suggested treatment?

Answer 36

decrease clotting factors 1 FFP or 4 ml/kg

Question 37

R time between 11-14 min clinical cause? suggested treatment?

Answer 37

decrease clotting factors x2 2 FFP or 8 ml/kg

Question 38

R time greater than 14 clinical cause? suggested treatment?

Answer 38

decrease clotting factors x3 4 FFP or 16 ml/kg

Question 39

MA between 49 - 54mm clinical cause? suggested treatment?

Answer 39

decrease platelet function .3mcg/kg DDAVP

Question 40

MA between 41-58mm clinical cause? suggested treatment?

Answer 40

decrease platelet function x5 platelet units

Question 41

MA 40 mm or less clinical cause? suggested treatment?

Answer 41

decrease platelet function x2 x10 platelets units

Question 42

LY30 7.5% or greater, CI less than 3.0 clinical cause? suggested treatment?

Answer 42

primary fibrinolysis antifibrinolytic

Question 43

LY30 7.5% or greater, CI greater than 3.0 clinical cause? suggested treatment?

Answer 43

secondary fibrinolysis anticoagulant of choice

Question 44

LY30 less than 7.5%, CI greater than 3.0 clinical cause? suggested treatment?

Answer 44

prothrombotic state anticoagulant of choice

Question 45

Antiplatelet Drugs •ADP receptor inhibitors •Examples:

Answer 45

Clopidogrel | Ticlopidine

Question 46

Antiplatelet Drugs •Arachidonic acid pathway inhibitors | •examples

Answer 46

Aspirin

Question 47

Antiplatelet Drugs •GPIIb/IIIa inhibitors | •Examples:

Answer 47

abciximab, tirofiban, eptifibatide