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Effect of Experimental Endotoxemia on Thrombelastography Parameters, Secondary and Tertiary Hemostasis in Dogs

Authors


Corresponding author: Dr Natali Bauer, Department of Veterinary Clinical Sciences, Clinical Pathology and Clinical Pathophysiology, Justus-Liebig University Giessen, Frankfurterstr. 126, 35392 Giessen, Germany; e-mail: Natali.Bauer@vetmed.uni-giessen.de.

Abstract

Background: Thrombelastography (TEG) and indicators of secondary and tertiary hemostasis might be altered in dogs with endotoxemia.

Hypothesis: Endotoxemia influences measures of coagulation in dogs.

Animals: Ten healthy cross-bred dogs.

Material and Methods: Prospective laboratory study between controls (n = 5) receiving 0.9% saline IV and the study group (n = 5) treated with low-dose lipopolysaccharide (0.02 mg/kg IV). Physical examination and sampling for measurement of leukocytes, platelets, and coagulation variables were performed at time points 0, 1, 4, and 24 hours. Coagulation variables included kaolin-activated TEG, 1-stage prothrombin time (OSPT), activated partial thromboplastin time (aPTT), fibrinogen, factor VIII, antithrombin, protein C, protein S, activated protein C (APC)-ratio calculated from aPTT with and without presence of APC), and D-Dimers.

Results: Endotoxemia-induced clinical signs included lethargy (n = 5/5), diarrhea (n = 4/5), emesis (n = 4/5), and abdominal pain (2/5). After 1 hour there was severe leukopenia (2.5 ± 0.7 × 109/L; mean ± SD, P < .0001) and a 2.2-fold increase in D-Dimers (0.81 ± 0.64 mg/L, P < .0001). After 4 hours there was hyperthermia (40.3 ± 0.4°C, P < .0001) and increases in OSPT (10.5 ± 2.7 seconds, P < .0001), aPTT (16.7±5.2 seconds, P= 0.002). A significant decrease in fibrinogen (1.5±1.0 g/L, P= 0.001), protein C (31 ± 33%, P <.0001), protein S (63 ± 47%, P < .0001), TEG α (58 ± 19, P= .007), and TEG maximal amplitude (50 ± 19 mm, P= .003) was seen compared with the controls. APC-ratio rose significantly (2.5 ± 0.2, P < .0001) without exceeding the reference interval (n = 4/5).

Conclusion and Clinical Importance: D-Dimers are the earliest indicator for endotoxemia-associated coagulation abnormalities followed by decreased protein C concentration. APC-ratio and TEG were not good screening variables.

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