Table 2.

Comparison of the Three Viscoelastic Point-of-Care Tests.

Step of Clot Formation	Factors Affecting Clot Stability	TEG	Sonoclot	ROTEM	Therapeutic Options
Initial clot formation/fibrin formation	Factors XII and XI of the intrinsic pathway or factors VII and VIII if a tissue factor activator is used	R	SonACT	CT	Administration of plasma, coagulation factors
Clot kinetics	Factor II and VIII activity, platelet, and fibrinogen function	Kinetics (K) and angle α	CR	Clot formation time (CFT) and angle α	Fresh frozen plasma (FFP) Cryoprecipitate
Maximum clot strength	Platelet functionand number, thrombin generation, fibrinogen	Maximum amplitude (MA)	Peak amplitude	Maximum clot firmness (MCF)	Cryoprecipitate/platelet concentrate
Maximum lysis	Fibrinolysis	LY30, LY45, LY60	R3 curve	CL30, CL45, CL60	Antifibrinolytic drugs Assessment of disseminated intravascular coagulation
Advantages		Rapid interpretation at 30 min; rapid TEG yields results even earlier and is useful in transplantation	Rapid results in 15–20 min, decision for FFP and platelet concentrate use can be taken early.	Stable system as movement does not impair the graphical output. Can clearly differentiate between fibrinogen defects and platelet dysfunction.	All 3 systems provide good guidance for FFP usage.
Disadvantages		Decision pathways for platelet dysfunction and fibrinogen defects show overlap. (K time, α angle, and maximum amplitude). Movement of the system impairs results	Differentiation of the contribution by platelets and fibrinogen defects to clot rate is difficult to assess. Movement of the system impairs results	Expensive as multiple tests are run simultaneously	All 3 systems are validated for use in liver transplantation with increasing evidence for restricted use in intensive care practice in acute variceal bleeding.

Abbreviations: TEG, thromboelastography; ROTEM, rotational thromboelastometry; Ly, lysis; ACT, activated clotting time; CT, clotting time; CL, clot lysis.