Thromboelastography results on citrated whole blood from clinically healthy cats depend on modes of activation

Abstract

BackgroundDuring the last decade, thromboelastography (TEG) has gained increasing acceptance as a diagnostic test in veterinary medicine for evaluation of haemostasis in dogs, however the use of TEG in cats has to date only been described in one previous study and a few abstracts. The objective of the present study was to evaluate and compare three different TEG assays in healthy cats, in order to establish which assay may be best suited for TEG analyses in cats.Methods90 TEG analyses were performed on citrated whole blood samples from 15 clinically healthy cats using assays without activator (native) or with human recombinant tissue factor (TF) or kaolin as activators. Results for reaction time (R), clotting time (K), angle (α), maximum amplitude (MA) and clot lysis (LY30; LY60) were recorded.ResultsCoefficients of variation (CVs) were highest in the native assay and comparable in TF and kaolin activated assays. Significant differences were observed between native and kaolin assays for all measured parameters, between kaolin and TF for all measured parameters except LY60 and between native and TF assays for R and K.ConclusionThe results indicate that TEG is a reproducible method for evaluation of haemostasis in clinically healthy cats. However, the three assays cannot be used interchangeably and the kaolin- and TF activated assays have the lowest analytical variation indicating that using an activator may be superior for performing TEG in cats.

Reference intervals for thromboelastometry with the ROTEM® delta in cats

“…The reference values established in the present study for feline citrated blood using the ROTEM ® delta analyser differ from those of previous studies, which evaluated reference values for viscoelastic measurements of feline blood using the TEG ® 5000 Hemostasis Analyser (Alwood et al, 2004(Alwood et al, , 2007Banerjee et al, 2011;Marschner et al, 2010;Montgomery et al, 2008). Even when focusing only on the non activated tests (to exclude reagent-dependent influences) large differences compared with previous studies cited earlier, but also between the cited studies became obvious.…”

“…In general, nonactivated tests showed the highest CVs in many of the parameters. This result was also reported in another study on viscoelastic measurements in cats using a different instrument (Marschner et al, 2010) and reflects the very delicate measurement if performed without using an activating reagent.…”

“…Precision analysis results for cats (Marschner et al, 2010) and dogs (Bauer et al, 2009;Wiinberg et al, 2005) are available for the instrument TEG ® 5000 Hemostasis Analyser, where tendentially higher intra-assay CVs were calculated when compared to our study. This discrepancy could indicate that the ROTEM ® analyser shows a higher precision than the TEG, which may be due to the fact that the ROTEM ® analyser is less prone to vibration as a consequence of a modified technology (the pin oscillates whereas the cup remains stationary).…”

“…In all these studies, the TEG ® 5000 Hemostasis Analyser was used. Reference values for TEG variables in cats have been established for this analyser (Alwood et al, 2004(Alwood et al, , 2007Banerjee et al, 2011;Hall et al, 2012;Marschner et al, 2010;Montgomery et al, 2008).…”

Comparing citrated native, kaolin-activated, and tissue factor–activated samples and determining intraindividual variability for feline thromboelastography

“…4,5 Additionally, activated samples produced lower analytical variability compared to unactivated samples in a group of healthy cats. 9 While TEG is extensively used to detect hemostatic abnormalities in dogs, 3,7,11,17 few studies have reported the use of TEG in cats. 1,9 The goals of the current study were to compare 3 TEG sample types in healthy cats and to determine 425595X XXXXX10.1177/1040638711425595Bane rjee, Blois, WoodDetermining intraindividual variability for feline thromboelastography From the Departments of Clinical Studies (Banerjee, Blois) and the intraindividual variability of TEG measured at 2 different time points in individual cats.…”