AJVR, Vol 75, No. 5, May 2014 425 Evaluation of thromboelastography for prediction of clinical bleeding in thrombocytopenic dogs after total body irradiation and hematopoietic cell transplantation Melissa C. Bucknoff, DVM; Rita M. Hanel, DVM; Steven L. Marks, BVSc, MS; Alison A. Motsinger-Reif, PhD; Steven E. Suter, VMD, PhD Objective—To determine whether thromboelastography is more accurate than convention- al methods of evaluating hemostasis for the prediction of clinical bleeding in thrombocyto- penic dogs following total body irradiation (TBI) and bone marrow transplantation (BMT). Animals—10 client-owned thrombocytopenic dogs with multicentric lymphoma. Procedures—Results of a kaolin-activated thromboelastography assay, platelet count, and buccal mucosal bleeding time were evaluated for correlation to clinical bleeding. Results—Maximum amplitude, derived via thromboelastography, was the only hemostatic variable with significant correlation to clinical bleeding. Buccal mucosal bleeding time had a high sensitivity but poor specificity for identifying dogs with clinical bleeding. Conclusions and Clinical Relevance—Compared with buccal mucosal bleeding time and platelet count, thromboelastography was more reliable at identifying thrombocytopenic dogs with a low risk of bleeding and could be considered to help guide the use of transfu- sion products in dogs undergoing TBI and BMT. (Am J Vet Res 2014;75:425–432) Received April 5, 2013. Accepted November 8, 2013. From the Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536 (Bucknoff); the Department of Clinical Sciences, College of Vet- erinary Medicine, North Carolina State University, Raleigh, NC 27607 (Hanel, Marks, Suter); and the Bioinformatics Research Center, Department of Statistics, College of Physical and Math- ematical Sciences, College of Agricultural and Life Sciences, North Carolina State University, Raleigh, NC 27695 (Motsinger- Reif). Presented as an oral presentation at the American College of Veteri- nary Internal Medicine, 31st Annual Scientific Forum, New Or- leans, June 2012. The authors thank Matthew Heft for technical assistance. Address correspondence to Dr. Hanel (rita_hanel@ncsu.edu). T hrombocytopenia is a common abnormality in vet- erinary patients and an important cause of mucosal bleeding. The ability to correlate results of hemostat- ic assays to clinical phenotypes in such patients is an emerging topic of exploration. 1 Conventional methods of predicting the risk of bleeding in thrombocytopenic veterinary patients consist of an absolute platelet count and tests of primary hemostasis, such as determina- tion of BMBT. 2 Thromboelastography and rotational thromboelastometry are diagnostic tools that use the viscoelastic properties of clot formation to provide an assessment of global coagulation, thereby identifying both hyper- and hypocoagulable states. 3,4 In human medicine, thromboelastography and rotational throm- boelastometry are used to monitor and guide transfu- sion therapy in patients with trauma-associated co- agulopathy 5 and those undergoing cardiac bypass or liver transplantation. 6–9 Thromboelastography has also been used to monitor therapeutic efficacy of platelet transfusions in patients with chemotherapy-induced thrombocytopenia. 10 In veterinary medicine, several studies have used thromboelastography as a means of assessing global hemostatic function in both healthy dogs 11,12 and those with a multitude of diseases causing hypo- and hypercoagulable states, including parvovirus enteritis, 13 protein-losing nephropathy, 14 neoplasia, 15 immune-mediated hemolytic anemia, 16,17 and dissemi- nated intravascular coagulation. 18 However, the authors are aware of only 1 study 1 evaluating the correlation of thromboelastography to clinical bleeding in dogs and are not aware of any studies evaluating the correlation of thromboelastography variables to clinical bleeding in dogs with thrombocytopenia as the primary contribu- tor to abnormal hemostasis. Immune-mediated thrombocytopenia is the most common disease in small animal veterinary medicine requiring blood transfusions as a result of thrombocy- topenia. 19 However, causation, onset, and progression ABBREVIATIONS aPTT Activated partial thromboplastin time BMBT Buccal mucosal bleeding time BMT Bone marrow transplant IMTP Immune-mediated thrombocytopenia MA Maximum amplitude PT Prothrombin time ROC Receiver operating characteristic TBI Total body irradiation Unauthenticated | Downloaded 09/23/22 05:29 PM UTC