Thromboelastographic evaluation of hemostatic function in dogs treated for crotalid snake envenomation

Abstract

AbstractObjectiveTo characterize the overall hemostatic changes in dogs envenomated by crotaline snakes via kaolin‐activated thromboelastography (TEG), and to determine any prognostic/monitoring value from a TEG tracing on presentation, as well as during treatment with antivenom therapy.DesignProspective observational, cohort study.SettingUniversity teaching hospital and primary emergency hospital.AnimalsThirty‐eight dogs envenomated by crotaline snakes.InterventionsTEG tracings were evaluated on presentation to the hospital (pre) as well as immediately following (post) and 12 hours (12 h post) after antivenom treatment, if administered.Measurements and Main ResultsAt presentation, data were available for 38 dogs envenomated by crotaline snakes. Twenty dogs were in Group 1 (Antivenin [Crotalidae] Polyvalent antivenom), 12 dogs were in Group 2 (Antivipmyn antivenom), and 6 dogs in Group 3 that were not treated with antivenom. The average number of vials administered to group 1 and 2 were equal at 2.2. On presentation, based on a G value < TEG reference range, 15/38 (39%) of the dogs had hypocoagulable TEG tracings. There was a significant increase in G and MA value from the pre and 12 hour post measurement (P = 0.0001 and 0.0003, respectively), as well as from the post to 12 hour post measurement (P = 0.003 and, 0.014, respectively). During the study, 5 of 38 dogs died (13%) and of the dogs that died, 4/5 (80%) had angle and MA equal to zero on presentation. A decreased G and MA were significantly associated with mortality (P = 0.02 and 0.04, respectively).ConclusionsA hypocoagulable TEG tracing, particularly a decreased G value and MA, is associated with an increased mortality in crotaline snake envenomation. G and MA also demonstrate a significant increase over treatment time.