Table 1.
Comparison of TEG® and ROTEM® parameters and relative physiological significance.
| TEG® Test Variable | Definition | ROTEM® Test Variable | Definition | Physiological Significance |
|---|---|---|---|---|
| Reaction time (R-time) |
Time until clot amplitude of 2 mm is reached | Clotting time (CT) | Time until clot amplitude of 2 mm is reached | Initiation phase of enzymatic clotting factor activation. It is a measure of time taken to initiate coagulation |
| Kinetics time (K-time) |
Time until clot amplitude of 20 mm is reached (from 2 mm amplitude) | Clot formation time (CFT) | Time until clot amplitude of 20 mm is reached (from 2 mm amplitude) | The amount of time it takes to reach a certain clot strength (amplitude of 20 mm) |
| Alpha angle (α) | Angle between central horizontal line and a tangent to the curve through the 20 mm amplitude point | Alpha angle (α) | Angle between central horizontal line and a tangent to the curve through the 20 mm amplitude point | Rate of clot formation and strengthening (kinetic measurement of fibrin–platelet interaction) |
| Amplitude 10 min after CT (A10) | Amplitude at 10 min after clotting time | Measure of clot strength (fibrin–platelet interaction) | ||
| Amplitude 30 min after CT (A30) | Amplitude at 30 min after clotting time | Measure of clot strength (fibrin–platelet interaction) | ||
| Maximum amplitude (MA) | Peak amplitude of clot | Maximum clot firmness (MCF) | Peak amplitude of clot | Measure of clot strength (fibrin–platelet interaction |
| Lysis at 30 min (LY30)Lysis at 60 min (LY60) | Percentage decrease in clot strength at 30 min after maximum amplitude (MA) Percentage decrease in clot strength at 60 min after maximum amplitude (MA) |
Maximum lysis (ML) | Maximum percentage reduction in maximum clot firmness (MCF) |
Measure of clot stability. Fibrinolytic-induced dissolution of the fibrin–platelet bond |