Evaluation of the Effect of Storage Time on ROTEM S® Parameters in Healthy and Ill Dogs

Abstract

Viscoelastic testing as a bedside test to assess global haemostasis has gained popularity in the past decade, with rotational thromboelastometry (ROTEM) and thromboelastography (TEG) being the two commonly used devices. TEG studies suggest analysis 30 min after blood sampling. However, the reproducibility of results over time for ROTEM analysis using lyophilized samples in dogs has not been established. In this study, we investigated the influence of time on viscoelastic testing, using 33 healthy staff-/client-owned dogs for blood sampling and repeated measurements of ROTEM tracings at three different time points after blood collection. Additionally, a group of 21 hospitalized patients with suspected coagulation disorders were included to investigate whether stability over time was comparable between healthy and ill dogs. We demonstrated a significant difference of ROTEM tracings over time, with a tendency towards hypocoagulability over time. These changes do have a clinical relevance as they exceed reference intervals and could therefore lead to erroneous conclusions about a patient’s coagulation status. Therefore, time-specific reference intervals are proposed and presented in this publication.

Comparison of Jugular vs. Saphenous Blood Samples, Intrarater and In-Between Device Reliability of Clinically Used ROTEM S Parameters in Dogs

“…Healthy, adult, staff-owned dogs were recruited for the purposes of this and another study [ 20 ]. The study was approved by the ethics committee on animal research of the Canton of Zurich (ZH 057/19) and signed owner consent was available.…”

Evaluation of the Effect of Induced Endotoxemia on ROTEM S® and Platelet Parameters in Beagle Dogs Anaesthetized with Sevoflurane

“…For the observed changes in ROTEM platelet variables, the different resting times were therefore not deemed important. In a pilot study in seven healthy dogs, lithium-heparin sample ARA-tem and ADP-tem AUC values had a tendency to increase slightly between 10 and 60 min resting time [16], which is in contrast to ROTEM delta variables that became more hypocoaguable over time in a recent study [31].…”

“…Leucocyte count (reference interval 4700-11,300/µL) decreased (p < 0.01) from 5940 (5230-8490)/µL) to median values of <2000/µL during all other timepoints (p < 0.01) (Figure 2a). The hematocrit (reference interval in awake animals: 36-54%) increased (p < 0.01) from a baseline value of 29 (28)(29)(30)(31)(32)(33) % to maximal values of 49 (39-55) % at timepoint 85_1 (Figure 2b).…”

“…The resting time of the ROTEM delta samples had a tendency to increase (Table A1) during the study due to the one-hour duration of measurements in the ROTEM delta device compared to shorter times between blood collections. In a study comparing reference intervals for different resting times, a tendency to become hypocoaguable was found in ROTEM delta samples resting 40 or 70 compared to 10 min [31]. We cannot exclude that some of the observed changes in ROTEM delta were caused by increasing the resting time of the samples at later time points (BL2 and 85_2, Table A1).…”