Application of thrombelastography/thromboelastometry to veterinary medicine

Abstract

Thrombelastograph analyzers are point-of-care hemostatic analyzers that provide global assessment of the hemostatic process. Thrombelastography (TEG) detects and provides a continuous recording of the changes in the viscoelastic properties of whole blood from initial clot formation through fibinolysis. TEG has been validated for use in dogs, horses, and cats. Hemostasis research using TEG has focused on test validation, alterations of TEG tracings in animals with naturally occurring diseases, and the use of TEG for monitoring various therapeutic modalities. This article reviews TEG methodology and terminology, including potential sources of preanalytical and analytical errors, the correlation between TEG and other routine hemostatic assays, and current clinical applications of TEG, with emphasis on veterinary medical practice. Data suggest that TEG may be a sensitive and useful adjunctive tool for evaluating an animal with an underlying coagulopathy, including hypercoagulability and hypocoagulability. Additional prospective studies are needed to (1) correlate TEG tracing patterns with a clinical predisposition for bleeding or thrombosis in various disease states and (2) determine whether monitoring and treating hemostatic disorders based on TEG tracings improve clinical outcome.

Canine idiopathic immune-mediated haemolytic anaemia: a review with recommendations for future research

“…Risk factors inherent to IMHA are thrombocytopenia, increases in serum bilirubin concentrations, and hypoalbuminaemia, but treatment-related factors, such as glucocorticoid therapy, blood transfusion, and intravenous catheterization, may contribute as well (Klein et al 1989;McManus et al 2001;Carr et al 2002). Many dogs with IMHA can be considered hypercoagulable, based on thromboelastography recordings (Sinnott and Otto 2009;Kol and Borjesson 2010;Fenty et al 2011). P-selectin expression is considered to be a marker of activated platelets and is increased in dogs with IMHA (Weiss and Brazzell 2006;Ridyard et al 2010).…”

Thromboelastometric evaluation of horses submitted to experimental thrombosis and jugular thrombectomy

“…Through thromboelastometry, we can evaluate the effect of heparin and control its therapy by graphic indicators of the interval of clotting time and clot formation, which is more judicious managed with the availability of specific reagents, such as Heptem ® -a heparinase that is inactive, thus facilitating the identification of anomalous effects from the therapy and the immediate correction of the dose or suspension of medication (Donahue & Otto 2005, Epstein et al 2009, Kol & Borjesson 2010, Mendez--Angulo et al 2010.…”

“…TEG ® and ROTEM ® , both apparatuses of thromboelastography, furnish a graphic representation of the formation and subsequent lysis of the coagulum, but differ in their system of detection and collection of data, utilizing a torsion wire and optical detector, respectively (Reikvam et al 2009, Kol & Borjesson 2010, Mendez-Angulo et al 2010, Wiinberg & Kristensen 2010. The interest in their use in equine medicine is focused primarily on distinguishing states of hypo-and hypercoagulability, in addition to evaluating coagulation and fibrinolysis (Dias & De Lacerda Neto 2013).…”

“…These disturbances are frequently monitored by means of a coagulogram -exams that analyze specific factors in the plasma (platelet count, fibrinogen, bleeding time, platelet function, activated clot time, thrombin time [TT], prothrombin time [PT] and activated partial thromboplastin time [aPTT]), responsible for the clotting system (Reikvam et al 2009, Mendez--Angulo et al 2010. These routine tests provide fragmented pieces of information on the clotting process while, for the diagnosis of coagulopathies, many of them need to be performed jointly (Kol & Borjesson 2010).…”

Laboratory evaluation and interpretation of haemostasis in small animals

“…These include simple tests such as the whole blood clotting time or the activated clotting time (ACT) (Bateman et al, 1999) and automatic viscoelastic point-of-care haemostatic assays, which undergo a revival (kol and Borjesson, 2010). These methods are easily to perform and can be used as bedside tests.…”