Supplement Article Journal of Veterinary Emergency and Critical Care 24(1) 2014, pp 30–36 doi: 10.1111/vec.12142 Systematic evaluation of evidence on veterinary viscoelastic testing Part 2: Sample acquisition and handling Bente Flatland, DVM, MS, DACVIM, DACVP; Amy M. Koenigshof, DVM, DACVECC; Elizabeth A. Rozanski, DVM, DACVIM, DACVECC; Robert Goggs, BVSc, DACVECC, MRCVS and Bo Wiinberg, DVM, PhD Abstract Objective – To examine systematically the evidence on sample acquisition and handling for the thrombo elastography (TEG) and rotational thromboelastometry (ROTEM) viscoelastic point of care instruments and to identify knowledge gaps. Design – Six questions were considered, addressing sampling site, collection system, anticoagulant, collection procedure, and sample storage. Standardized, systematic evaluation of the literature was performed. Relevant articles were categorized according to level of evidence (LOE). Consensus was developed regarding conclusions for application of concepts to clinical practice. Setting – Academic and referral veterinary medical centers. Results – PubMed and CAB abstracts were searched. Eighteen papers were initially chosen; 5 of these papers applied to > 1 domain question. Three papers were used to address 2 questions each, and 2 papers were used to address 3 questions each. Most papers were judged LOE 3 (Good or Fair). Two of 5 papers were judged to be the same LOE each time they were used; 2 papers were judged to be LOE 3, Fair for 1 question and 3, Good for a second question; 1 paper used to address 3 questions was judged LOE 3, Good twice and 3, Fair once. Fourteen additional papers were evaluated post hoc during manuscript preparation. Conclusions – Jugular venipuncture is recommended, but samples from IV catheters can be used. Consistent technique is important for serial sampling, and standardized sampling protocols are recommended for indi- vidual centers performing TEG/ROTEM. There is insufficient evidence to recommend use of a specific blood collection system, although use of evacuated blood tubes and 21-Ga or larger needles is suggested. Use of 3.2% buffered sodium citrate in a strict 1:9 ratio of citrate to blood is suggested. Suggested tube draw order is discard/serum, followed by citrate, EDTA, and then heparin. Samples should be held at room temperature for 30 minutes prior to analysis. (J Vet Emerg Crit Care 2014; 24(1): 30–36) doi: 10.1111/vec.12142 Keywords: cat, dog, thromboelastography, thromboelastometry Introduction Viscoelastic coagulationtesting was originally developed as a point-of-care test designed for use with fresh From the Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996 (Flat- land); Department of Small Animal Clinical Sciences, College of Vet- erinary Medicine, Michigan State University, East Lansing, MI 48824 (Koenigshof); the Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536 (Rozanski); Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (Goggs); and Novo Nordisk, Malov, Denmark (Wiinberg). The authors declare no conflicts of interests. Address correspondence and reprint requests to Dr. Bente Flatland, Department of Biomedical and Diagnostic Sciences A205, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, Knoxville, TN 37996. E-mail: bflatlan@utk.edu Submitted November 08, 2013; Accepted November 15, 2013. whole blood analyzed within minutes of collection. This approach is not practical if thromboelastography (TEG)/rotational thromboelastometry (ROTEM) testing is performed distant from patients, a limitation that led to use of citrate-anticoagulated whole blood. 1 Use of cit- rated whole blood for TEG/ROTEM requires recalcifica- tion, with calcium being added as a reagent at the be- ginning of the assay. 2 Generation of factor XIIa (contact activation) is not calcium-dependent and continues dur- ing storage of citrated whole blood; use of citrated blood samples for TEG/ROTEM means that thrombin gener- ation is affected by the degree of factor XIIa generation during storage (as a result of contact with surfaces) and prior to recalcification. 1 Accordingly, preanalytical fac- tors such as sample storage time and temperature have potential to impact TEG/ROTEM results. Additionally, 30 C  Veterinary Emergency and Critical Care Society 2014