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

Abstract

Abstract. Thromboelastography (TEG) is a point-of-care whole blood test of hemostasis. While TEG is becoming more widely used in veterinary medicine, few studies describe the use of TEG in cats. The objectives of the current study were to: 1) document the range of TEG variables produced in healthy cats using 3 sample types (citrated native, kaolin-activated, and tissue factor-activated), and 2) determine if there was a significant difference between 2 separate samples obtained from individual healthy cats on the same day. Jugular venipuncture was performed in 20 cats, and citrated blood collected for TEG. TEG analysis was performed on citrated native, kaolin-activated, and tissue factor-activated blood for each sample. Two hours later, the procedure was repeated from the opposite jugular vein, yielding a total of 120 analyses. Reaction time (R), alpha angle (α), kappa value (κ), and maximum amplitude (MA) were recorded from each tracing. No significant differences were found between TEG tracings from the first and second venipuncture samples. Significant differences were found between sample types for R, α, κ, and MA. Means for citrated native/kaolin-activated/tissue factor-activated methods were R = 4.1/3.7/0.6 min; κ = 2.5/1.8/2.2 min; α = 59.9/65.1/70.4 degrees; MA = 47.4/49.9/44.7 mm. A limitation of this study was the small number of cats used. Thromboelastography analysis may be a suitable method of evaluating hemostasis in cats.

Thrombelastography indicates limitations of animal models of trauma-induced coagulopathy

“…Interestingly, the R-time in swine and rats is similar to previously published values of native TEGs for cats [8]. Reported data for both pigs and rats have shown similar prothombin time (PT) and activated thromboplastin time (APTT) compared to humans [5, 9] (Table 1).…”

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.…”

“…For example, in most cases the present study investigated shorter CT and CFT values and greater MCF and α values. Only Alwood et al (2004) and Banerjee et al (2011) published shorter reaction times (R; corresponding to CT) and Alwood et al (2004) also found shorter K values (corresponding to CFT). The fact that ROTEM ® delta showed shorter CT and CFT and greater MCF and α-values for feline blood than the TEG ® 5000 Hemostasis Analyser is well in accordance with a previous human study which directly compared both instruments (Nielsen, 2007).…”

“…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).…”

Evaluation of thromboelastography in two factor XII-deficient cats

“…The addition of activators decreases TEG variability in some species, although this has been an inconsistent finding in studies of healthy cats. 6,7 Kaolin activates in vitro coagulation primarily via the intrinsic or contact-activated pathway, while TF activates in vitro coagulation via the extrinsic or FVII:TF pathway. 8 This explains the difference between the TEG tracings in the cats with FXII deficiency described herein.…”