Thromboelastography/metry (TEG®; Haemoscope, Niles, IL/ROTEM®; Tem International GmbH, Munich, Germany) is increasingly used to guide transfusion therapy. This study investigated the diagnostic performance and therapeutic consequence of using kaolin-activated whole blood compared with a panel of specific TEM®-reagents to distinguish: dilutional coagulopathy, thrombocytopenia, hyperfibrinolysis, and heparinization.
Blood was drawn from 11 healthy volunteers. Dilutional coagulopathy was generated by 50% dilution with hydroxyethyl starch 130/0.4 whereas thrombocytopenia (mean platelet count 20 ×10⁹/l) was induced using a validated model. Hyperfibrinolysis and heparin contamination were generated by tissue plasminogen activator 2 nM and unfractionated heparin 0.1U/ml, respectively. Coagulation tests were run on ROTEM® delta.
Kaolin-activated whole blood showed no differences between dilutional coagulopathy and thrombocytopenia (mean clotting time 450 s vs. 516 s, α-angle 47.1° vs. 41.5°, maximum clot firmness 35.0 mm vs. 34.2 mm, all P values ≥0.14). Hyperfibrinolysis specifically disclosed an increased maximum lysis (median: 100%, all P values less than 0.001), and heparin induced a distinctly prolonged clotting time (2283 s, all P values less than 0.02). The coagulopathies were readily distinguishable using a panel of TEM-reagents. In particular, dilutional coagulopathy was separated from thrombocytopenia using FIBTEM (maximum clot firmness 1.9 mm vs. 11.2 mm, P < 0.001). The run time of analysis to achieve diagnostic data was shorter applying a panel of TEM-reagents. A transfusion algorithm based on kaolin suggested platelets in case of dilutional coagulopathy, whereas an algorithm applying TEM-reagents suggested fibrinogen.
Monoanalysis with kaolin was unable to distinguish coagulopathies caused by dilution from that of thrombocytopenia. Algorithms based on the use of kaolin may lead to unnecessary transfusion with platelets, whereas the application of TEM-reagents may result in goal-directed fibrinogen substitution.
"On the other hand, algorithms based on a panel of ROTEM ® reagents may avoid platelet transfusion when goal-directed fibrinogen substitution is more appropriate (Figs. 15.2 and 15.3a–h) (Larsen et al. 2011; Görlinger et al. 2010, 2011a, b). This is of special importance in liver transplantation since platelet transfusion is associated with a significant reduction in 1-year survival (74 % vs. 92 %; P < 0.001) in this clinical setting (Pereboom et al. 2009a, b). "
Perioperative Hemostasis: Coagulation for Anesthesiologists, Edited by Carlo E. Marcucci, Patrick Schoettker, 01/2015: chapter Perioperative Hemostasis in Hepatic Surgery: pages 267-283; Springer Verlag, Berlin, Heidelberg.
"Another criticism to TEG®-based algorithms is its mono-analysis with a single activator (Kaolin) compared to algorithms based on multiple assays (i.e. ROTEM®) with improved diagnostic efficacy . Harr  recently pointed out that TEG inability to differentiate between fibrinogen and platelet contribution to clot firmness resulted in two TEG®-based algorithms proposing different interventions to treat the same problem (low clot strength). "
[Show abstract][Hide abstract] ABSTRACT: Background
Thrombelastography is a laboratorial test that measures viscoelastic changes of the entire clotting process. There is growing interest in its clinical use in trauma resuscitation, particularly for managing acute coagulopathy of trauma and assisting decision making concerning transfusion. This review focuses on the clinical use of thrombelastography in trauma, with practical points to consider on its use in civilian and military settings.
A search in the literature using the terms “thrombelastography AND trauma” was performed in PUBMED database. We focused the review on the main clinical aspects of this viscoelastic method in diagnosing and treating patients with acute coagulopathy of trauma during initial resuscitation.
Thrombelastography is not a substitute for conventional laboratorial tests such as INR and aPTT but offers additional information and may guide blood transfusion. Thrombelastography can be used as a point of care test but requires multiple daily calibrations, should be performed by trained personnel and its technique requires standardization. While useful partial results may be available in minutes, the whole test may take as long as other conventional tests. The most important data provided by thrombelastography are clot strength and fibrinolysis. Clot strength measure can establish whether the bleeding is due to coagulopathy or not, and is the key information in thrombelastography-based transfusion algorithms. Thrombelastography is among the few tests that diagnose and quantify fibrinolysis and thus guide the use of anti-fibrinolytic drugs and blood products such as cryoprecipitate and fibrinogen concentrate. It may also diagnose platelet dysfunction and hypercoagulability and potentially prevent inappropriate transfusions of hemostatic blood products to non-coagulopathic patients.
Thrombelastography has characteristics of an ideal coagulation test for use in early trauma resuscitation. It has limitations, but may prove useful as an additional test. Future studies should evaluate its potential to guide blood transfusion and the understanding of the mechanisms of trauma coagulopathy.
Scandinavian Journal of Trauma Resuscitation and Emergency Medicine 04/2013; 21(1):29. DOI:10.1186/1757-7241-21-29 · 2.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fibrin-based clot firmness is measured as maximum amplitude (MA) in the functional fibrinogen (FF) thrombelastographic assay and maximum clot firmness (MCF) in the FIBTEM thromboelastometric assay. Differences between the assays/devices may be clinically significant. Our objective was to compare clot firmness parameters through standard (FF on a thrombelastography device [TEG®]; FIBTEM on a thromboelastometry device [ROTEM®]) and crossover (FF on ROTEM®; FIBTEM on TEG®) analyses.
Whole-blood samples from healthy volunteers were subjected to thrombelastography and thromboelastometry analyses. Samples were investigated native and following stepwise dilution with sodium chloride solution (20%, 40%, and 60% dilution). Samples were also assessed after in vitro addition of medications (heparin, protamine, tranexamic acid) and 50% dilution with hydroxyethyl starch, gelatin, sodium chloride, and albumin.
FF produced higher values than FIBTEM, regardless of the device, and TEG® produced higher values than ROTEM®, regardless of the assay. With all added medications except heparin 400 U/kg bodyweight, FF MA remained significantly higher (P < 0.05) than FIBTEM MCF, which was largely unchanged. FF MA was significantly reduced (P = 0.04) by high-dose heparin and partially restored with protamine. Fifty percent dilution with hydroxyethyl starch, albumin, and gelatin decreased FIBTEM MCF and FF MA by >50%.
These results demonstrate differences when measuring fibrin-based clotting via the FF and FIBTEM assays on the TEG® and ROTEM® devices. Point-of-care targeted correction of fibrin-based clotting may be influenced by the assay and device used. For the FF assay, data are lacking.
Anesthesia and analgesia 02/2012; 114(4):721-30. DOI:10.1213/ANE.0b013e31824724c8 · 3.47 Impact Factor
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