Systematic evaluation of evidence on veterinary viscoelastic testing part 1: System comparability.

Objective: To systematically examine the evidence on system comparability between the thromboelastography and the rotational thromboelastometry viscoelastic point-of-care instruments and to identify knowledge gaps.

Design: Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence and quality, and development of consensus on conclusions for application of the concepts to clinical practice.

Setting: Academic and referral veterinary medical centers.

Results: Medline via PubMed, CAB abstracts, and Google Scholar were searched. A total of 8 relevant articles were chosen, none were in support of the question, 1 was neutral to the question (level of evidence [LOE] 6, Poor), and 7 were in opposition to the question (LOE 3 Good; LOE 6 Good; LOE 6 Fair; LOE 6 Poor).

Conclusions: Results from the 2 analyzers are not directly comparable and extrapolation of the results from one machine to the other should be avoided. Standardization of the preanalytical variables (eg, blood collection, holding time, and temperature during holding) is strongly recommended. It is recommended that each site create their own "site specific" reference values for each machine and that test samples be compared only to the standardized reference values established at that center. Start-up and consumable costs vary between countries and local comparisons should be performed. Decisions should be made based on the expected use of the machine and if multiple operators will be using it.