Supplement Article Journal of Veterinary Emergency and Critical Care 24(1) 2014, pp 47–56 doi: 10.1111/vec.12145 Systematic evaluation of evidence on veterinary viscoelastic testing Part 4: Definitions and data reporting Rita M. Hanel, DVM, DACVIM, DACVECC; Daniel L. Chan ∗ , DVM, DACVECC, DACVN, MRCVS; Bobbi Conner ∗ , DVM, DACVECC; Vincent Gauthier ∗ , DVM, DVSc, DACVECC; Marie Holowaychuk ∗ , DVM, DACVECC; Stephanie Istvan ∗ , VMD, DACVECC; Julie M. Walker ∗ , DVM, DACVECC; Darren Wood ∗ , DVM, DVSc, DACVP; Robert Goggs, BVSc, DACVECC, MRCVS and Bo Wiinberg, DVM, PhD Abstract Objective – To systematically examine evidence surrounding definitions and reporting of data for viscoelastic testing in veterinary medicine. 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 – Databases searched included Medline, CAB abstracts, and Google Scholar. Conclusions – All 4 standard thromboelastography (TEG) and rotational thromboelastometry (ROTEM) vari- ables should be universally reported, and the reporting of shear elastic modulus in addition to maximum amplitude (MA) is encouraged. There is insufficient evidence to support universal usage of the coagulation index at this time. The K value and clot formation time are the most variable of the 4 parameters, with alpha angle, MA, and maximum clot firmness generally the least variable. Individual studies should report sufficient data on patients and institutional controls to enable definitions of hypo- and hypercoagulability to be evaluated post-hoc, and it is recommended that all studies specifically report how these conditions were defined. In re- porting data relating to fibrinolysis, the TEG variables LY30, LY60, CL30, CL60, and the ROTEM variables LI30, LI60, ML, LOT, and LT should be documented. Studies should report sufficient data on patients and controls to enable definitions of hyper- and hypofibrinolysis to be evaluated post-hoc, and we suggest that standard TEG/ROTEM assays may be unable to detect hypofibrinolysis in companion animals. We recommend that every center establish reference intervals, which are specific to either TEG or ROTEM. These reference intervals should be established using veterinary clinical pathology guidelines, standardized protocols, and a minimum of 40 healthy animals. There are currently insufficient data in companion animals to suggest a utility for Vcurve variables beyond that of standard TEG variables. (J Vet Emerg Crit Care 2014; 24(1): 47–56) doi: 10.1111/vec.12145 Keywords: cat, dog, thromboelastometry, thromboelastography From the Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607 (Hanel); Clinical Science and Services, The Royal Veterinary College, University to London, North Mymms, Hertfordshire, UK AL9 7TA (Chan); Department of Small Ani- mal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32608 (Conner); Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON N1L 1G6 (Gauthier, Holowaychuk); Emergency Animal Clinic, Phoenix, AZ 85021 (Istvan); De- partment of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI (Walker); Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1L 1G6 (Wood); Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (Goggs); and Novo Nordisk, Malov, Denmark (Wiinberg). ∗ These authors, listed alphabetically, contributed equally to this manuscript. Five of the authors (Hanel, Chan, Walker, Goggs, Wiinberg) are coauthors Introduction There are currently 2 main systems, thromboelas- tography (TEG) and rotational thromboelastometry (ROTEM), utilizing viscoelastic technology to evalu- ate hemostasis. Most current laboratory and clinical in one or more publications that met inclusion criteria for this domain. The authors declare no conflict of interests. Offprints will not be available from the authors. Address correspondence to Rita Hanel, DoCS, NCSU CVM, 1052 William Moore Drive, Raleigh, NC 27607. E-mail: Rita_Hanel@ncsu.edu Submitted November 13, 2013; Accepted November 15, 2013. C  Veterinary Emergency and Critical Care Society 2014 47