Comparison of citrated native and kaolin-activated samples for thrombelastographic analysis in healthy dogs
Article first published online: 2 MAY 2012
© 2012 American Society for Veterinary Clinical Pathology
Veterinary Clinical Pathology
Volume 41, Issue 2, pages 249–255, June 2012
How to Cite
Flint, S. K., Wood, R. D., Abrams-Ogg, A. C.G., Kruth, S. A. and Bersenas, A. (2012), Comparison of citrated native and kaolin-activated samples for thrombelastographic analysis in healthy dogs. Veterinary Clinical Pathology, 41: 249–255. doi: 10.1111/j.1939-165X.2012.00431.x
- Issue published online: 1 JUN 2012
- Article first published online: 2 MAY 2012
- reference limit;
- tissue factor
Thrombelastographic (TEG) analysis is a test of global hemostasis in veterinary medicine; however, there have been limited comparisons of analysis of citrated native and kaolin-activated samples.
The purpose of this study was to determine the variation in TEG variables between citrated native and kaolin-activated whole blood samples and to establish reference intervals for both sample types.
Citrated whole blood samples were obtained from 40 healthy dogs. Thirty minutes after collection, TEG analysis was performed simultaneously on samples with and without kaolin-activation. Reaction time (R), clotting time (K), angle (α), maximum amplitude (MA), global clot strength (G), and clot lysis at 30 minutes (LY30) were recorded, and the concordance correlation coefficient (ρc) was calculated for each sample type.
Significant differences between results obtained for kaolin-activated and native samples were obtained for R (mean difference −1.3 minute, P = .0009), K (−0.7 minute, P = .0003), α (+5.1º, P = .002), MA (+2.4 mm, P = .002), and G (+568 dyn/cm2, P = .0009). LY30 was not different between methods. There was substantial agreement between methods for G (ρc = .69) and MA (ρc = .65), moderate agreement for R (ρc = .45) and α (ρc = .44), fair agreement for K (ρc = .29), and slight agreement for LY30 (ρc = .04).
The TEG variables were significantly altered by kaolin activation; however, some agreement between sample types suggests a consistent bias. In citrated whole blood activated with kaolin, clot formation time is shortened and the amplitude of the tracing is increased, resulting in a TEG tracing that appears to indicate relative hypercoagulability compared with that obtained using native citrated whole blood samples.