Main TEG variables
| TEG variable . | ROTEM equivalent . | Interpretation . | Derivation . | Main determinants . | Main corrective component . |
|---|---|---|---|---|---|
| R time | Clotting time | Initiation of clot | Time from start of sample placement in cup to the first detectable fibrin strands (amplitude 2 mm) | Activity of coagulation factors | FFP |
| K time | Clot formation time | Amplification of clot | Time taken to achieve a certain level of clot strength (amplitude 20 mm) | Activity of coagulation factors | FFP |
| α angle | Clot formation time | Thrombin burst: the speed at which the fibrin builds up and crosslinking takes place | Formed by the slope of the TEG tracing from the horizontal line | Presence and interactions of fibrinogen | Fibrinogen |
| Maximum amplitude | Maximum clot firmness | Ultimate strength of the clot | Height of the TEG tracing from the horizontal line | Platelets (predominantly) and fibrin | Platelets |
| Clot lysis at 30 and 60 min (LY30 and LY60) | LY30, LY45, LY60 | Degree of fibrinolysis | Amount of clot lysis at specific time points, by percent decrease in amplitude | Activity of fibrinolytic factors | TXA |
| TEG variable . | ROTEM equivalent . | Interpretation . | Derivation . | Main determinants . | Main corrective component . |
|---|---|---|---|---|---|
| R time | Clotting time | Initiation of clot | Time from start of sample placement in cup to the first detectable fibrin strands (amplitude 2 mm) | Activity of coagulation factors | FFP |
| K time | Clot formation time | Amplification of clot | Time taken to achieve a certain level of clot strength (amplitude 20 mm) | Activity of coagulation factors | FFP |
| α angle | Clot formation time | Thrombin burst: the speed at which the fibrin builds up and crosslinking takes place | Formed by the slope of the TEG tracing from the horizontal line | Presence and interactions of fibrinogen | Fibrinogen |
| Maximum amplitude | Maximum clot firmness | Ultimate strength of the clot | Height of the TEG tracing from the horizontal line | Platelets (predominantly) and fibrin | Platelets |
| Clot lysis at 30 and 60 min (LY30 and LY60) | LY30, LY45, LY60 | Degree of fibrinolysis | Amount of clot lysis at specific time points, by percent decrease in amplitude | Activity of fibrinolytic factors | TXA |
Other useful parameters are derived from these variables. The shape of the waveform is also important.