Effects of storage time and temperature on thromboelastographic analysis in dogs and horses

Abstract

Thromboelastography (TEG) is an assay that (to date) provides the most extensive analysis of haemostasis. Accessibility of TEG to general practitioners is limited by short sample storage times (30 minutes) and storage temperature (20_ 23_C). This limited accessibility is evident in human and veterinary medicine, but especially affects veterinary general practitioners in the field. This study evaluated the stability of canine and equine citrated blood samples when stored for extended periods of time, both at room temperature (RT) (20_23_C) and refrigeration temperature (FT) (2_7.5_C). Citrated whole blood samples from healthy dogs and horses (n=10 for each) were stored for 30 minutes at RT before TEG analysis. Baseline values for TEG variables R, K, _, MA, LY30 and LY60 were compared to those from samples stored for 2 hours, 8 hours, and 22.5 hours, both at RT and FT. Results were compared using ANOVA (p < 0.05) and reference intervals. In dogs, statistically significant differences included shorter R, longer K, decreased MA, and increased LY60 at various time points and storage temperatures from 2 hours. R, _, _ and MA values were stable at 8 hours FT. No clinically relevant differences in R, _, or MA values were found at 2 hours RT or FT. In horses, statistically significant difference included shorter R and K, and decreased _, LY30 and LY60 at various time points and storage temperatures from 2 hours. R, _, _ and MA values were stable at 2 hours and 8 hours FT. No clinically relevant differences in R, _, or MA values were found at 2 hours RT. This study suggests that canine samples can be stored for up to 2 hours at RT or FT and equine samples can be stored for up to 2 hours at RT without affecting TEG results.