TEG (Thromboelastogram) Flashcards
True or False:
Particularly in post bypass bleeding, you can have bleeding with abnormal labs (TEG, fibrinogen, platelets) or bleeding with normal labs (TEG, fibrinogen, platelets).
True
When evaluating the TEG, what is the sequence of evaluation of TEG values that can be used?
Reaction Time (R)
Kinetics (K)
Alpha Angle (A)
Maximum Amplitude (MA)
Lysis at 30 minutes (LY30)
What do you do if the TEG R>9%?
Transfuse 1-2 units FFP
What do you do if TEG Angle < 57 or
Fibrinogen < 150-200 mg/dl?
Transfuse 5-10 units Cryoprecipitate
What do you do if TEG MA = 52 and/or
Platelets < 100,000?
Transfuse 1 unit platelets
If uremia or VW, then give DDAVP 0.3 mcg/kg
What do you do if TEG LY30 > 10%?
Additional Amicar 1.5 g bolus and continue infusion. May administer loading dose over 15-60 minutes.
(Usual dose and range: IV: Loading dose of 5 to 10 g (or 75 to 150 mg/kg), followed by 1 g/hour (or 10 to 15 mg/kg/hour) until the end of the procedure or up to 8 hours after the procedure (Berenholtz 2009; Gravlee 2008; Li 2017; Verma 2020).
What do you do if there is bleeding with normal labs?
First, rule out surgical bleeding
Second, if known or suspected treatment with antiplatelet drugs, then transfuse 1-unit of platelets.
What do you do if bleeding persists after addressing TEG and possible surgical bleeding/antiplatelet actions?
IF BLEEDING PERSISTS:
1.optimize temperature
2. repeat TEG, platelets, fibrinogen, coags
What do you do if Post-protamine TEG R
<10% (Regular TEG R) and bleeding persists?
Repeat Protamine 25-50 mg
What products would be needed to treat the following TEG?
R (reaction time): Elevated
K (kinetics): Increased
α Angle: Decreased
MA (maximum amplitude): Decreased
LY30 (clot lysis): Elevated
An elevated reaction time indicates the clot is taking longer than normal to form – which is a problem with coagulation factors, so it requires FFP.
An increased K indicates the clot takes longer to reach a fixed strength – which indicates a fibrinogen deficiency and is thus treated with cryoprecipitate.
A decreased Alpha angle indicates an elevated time of fibrin accumulation – which is a function of fibrinogen and platelet number, and is treated with cryoprecipitate and platelet transfusion.
The MA is decreased, indicating a decreased clot strength owing to platelet dysfunction, which can be addressed with platelet transfusion.
An elevated LY30 indicates hyperfibrinolysis, which is reversed with TXA.
Define Reaction time.
What produces a prolonged R?
What produces a shortened R?
The time in minutes elapsed from the start of the test until the clot moves the pin enough to produce a 2-mm amplitude on the tracing is defined as the reaction time (R).
R reflects the activity of the coagulation cascade; a coagulation factor deficiency produces a prolonged R and hypercoagulability yields a shortened R time.
Define Apha Angle
The alpha angle (α) is a measure in degrees of the speed of clot formation.
It is defined as the angle between the horizontal axis of the tracing and the tangent to the tracing at 20-mm amplitude. Decreased angles indicate a slower rate of clot strengthening, as seen with low fibrinogen levels. Normal values are in the range of 45°–55°.
Define Coagulation Time
The coagulation time (K) is measured in minutes from the end of R to when the tracing amplitude reaches 20 mm.
Like the alpha angle, K is determined by the rate at which the clot strengthens and is a factor of thrombin’s cleaving of available fibrinogen into fibrin. Low fibrinogen levels produce greater K values.
Define Maximum Amplitude
Maximum amplitude (MA) is the point of maximum clot strength in millimeters.
The amplitude of MA is determined primarily by the functional contribution of platelets to the clotting process, reflecting the end result of platelet–fibrin interaction. Normal values are in the range of 50–60 mm.
Define Lysis Index 30
The lysis index at 30 minutes (Ly30) is the percentage reduction in MA after 30 minutes. Higher fibrinolytic activity produces a greater Ly30. Normal values are not higher than 7.5%–8%.
Coagulation factor deficiency, whether innate or due to anticoagulants such as heparin or warfarin, gives a tracing with a prolonged R time.
Hypercoagulable states yield a tracing with decreased R and K times along with an increased alpha angle and MA, reflecting an increased speed of clotting (R, K, α) and increased clot strength (MA).
Platelet dysfunction or severe thrombocytopenia produces a tracing with a decreased MA, indicating reduced clot strength.
Excess fibrinolysis is noted by a tracing with an increased clot lysis (Ly30).
What are the five parameters evaluated by TEG?
Draw a thromboelastograph (TEG).
