Evaluation of coagulation stages of hemorrhaged swine: comparison of thromboelastography and rotational elastometry

Abstract

Thromboelastography (TEG) or rotational thromboelastometry (ROTEM) assesses blood viscoelastic properties and clotting kinetics that can be measured by Haemoscope TEG and Pentapharm ROTEM devices using slightly different methodologies. These devices were compared by measuring blood samples associated with various degrees of coagulopathy. Blood samples, collected from swine undergoing three types of severe injury and resuscitation protocol resulting in normal, hypercoagulopathy, and hypocoagulopathy, were assessed with TEG or ROTEM before the surgical procedures, and after injury, fluid resuscitation, and simulated hospital phase. Standard clotting parameters were compared by Student's t-test at a significance of a P value less than 0.05. Regression analysis indicated a positive correlation between TEG and ROTEM for reaction time (R), clotting rate (K), and maximum amplitude (Ma) parameters. With samples of normal coagulation, R (440 +/- 136 vs. 391 +/- 73 s), K (99 +/- 39 vs. 81 +/- 20 s), and Ma (74 +/- 4 vs. 69 +/- 5 mm) were higher, whereas (alpha) (68 +/- 8 vs. 75 +/- 3 mm) was lower with TEG than ROTEM, respectively; a P value is less than 0.05. The magnitude of changes from baseline in hypercoagulable or hypocoagulable samples due to level of injury was equivalent with TEG and ROTEM indicating comparable use of the instruments. However, when samples were extremely hypocoagulopathic due to resuscitation fluid, the TEG values could not be readily determined. Overall, TEG readings were higher than ROTEM readings; this disparity between the two instruments was attenuated with hypercoaguable samples. Both devices yielded similar information regarding the status of coagulation related to trauma. Because of operating characteristics, the same instrument should be used for monitoring the same patient or study.

Effects of Hyperbaric and Decompression Stress on Blood Coagulation and Fibrinolysis

“…In summary, our study confirmed that TEG R and ROTEM CT were a sensitive parameter to detect a hypercoagulable state, as observed in trauma 18 and healthy populations exposed to stress. 30 The differences between the 2 systems in the postdiving time, when hypercoagulation was observed by the reduced onset time to start coagulation and in the hypofibrinolysis only detected by EXTEM, may be due to activation methods (kaolin/ellagic acid vs tissue factor) leading to different coagulation pathways (intrinsic vs extrinsic).…”

Evaluation of Encapsulated Liver Cell Spheroids in a Fluidised-Bed Bioartificial Liver for Treatment of Ischaemic Acute Liver Failure in Pigs in a Translational Setting

“…Fibrinogen and prothrombin are likely contributing to the improvement of clotting function, which we measured by Thromboelastography (TEG), assessed to be a better measure of clotting dysfunction than prothrombin time and aPTT in a model of hypothermia and haemorrhagic shock in swine [25]. TEG measures several parameters of clotting function, reflecting viscoelastic properties of blood, platelet activation, fibrin formation and retraction of the clot [26], [27]. The R-time reflects fibrin formation rate, functionally dependent on clotting factors, and particularly fibrinogen; for their derivation see Fig 4.…”

The simultaneous occurrence of both hypercoagulability and hypofibrinolysis in blood and serum during systemic inflammation, and the roles of iron and fibrin(ogen)

“…We show how this provides insight into hypofibrinolysis associated with inflammation (6) and how fibrinogen packaging (7) is changed during inflammation. Here we also discuss various substances and molecules (8) that may influence clot structure and also the relationship between hypercoagulability and fibrosis (9 106,109,[112][113][114][120][121][122][123][124] to the effect that results can be reasonably comparable in some circumstances but for detailed studies of specific effects it is probably wise to standardise on a particular instrument or technique.…”