Influence of needle gauge and venepuncture difficulty on thromboelastography in healthy cats.

Objectives: The aim of this study was to evaluate the effect of two differently sized butterfly catheter needles and the effect of venepuncture difficulty on thromboelastography (TEG) results in healthy cats.
Methods: Twenty-four healthy cats were included. Blood samples were collected from the jugular vein by syringe aspiration via direct venepuncture with 21 G and 22 G butterfly needles. The venepuncture difficulty score was classified into four categories. The first 1.5 ml blood drawn from each subject was discarded before collecting a sample for TEG analysis. TEG analyses were performed on citrated whole blood samples from 17 clinically healthy cats, using assays with kaolin as activators. Among the TEG parameters, reaction time (R), clot formation time (κ), alpha angle (α), maximum amplitude (MA) and global clot strength (G) were recorded from each tracing.
Results: Seven cats were excluded from the study; results were obtained for the remaining 17 cats. There were no statistically significant differences between the use of two different needles for R ( P = 0.72), κ ( P = 0.74), α ( P = 0.99), MA ( P = 0.08) and G ( P = 0.09). Samples with difficulty scores ⩾1 were not significantly different from samples with difficulty scores of 0 for R ( P = 0.24), κ ( P = 0.65), α ( P = 0.65), MA ( P = 0.72) and G ( P = 0.77).
Conclusions and Relevance: The results of TEG in clinically healthy cats do not differ significantly when using two different gauge needles. There was no significant difference in the TEG results according to venepuncture difficulty scoring.