title: Assessment of hemostatic changes in a model of acute hemorrhage in dogs.
abstract: OBJECTIVE
  To evaluate hemostatic changes following experimental acute hemorrhage in dogs using traditional coagulation tests (eg, platelet count, prothrombin time [PT], and activated partial thromboplastin time [aPTT]), kaolin-activated thromboelastography (TEG), and whole blood multiple electrode impedance platelet aggregometry.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  Five Beagles.
  
  
  METHODS
  Dogs were anesthetized prior to obtaining blood samples for baseline PCV, total plasma protein (TPP), arterial blood-gas, platelet count, PT, aPTT, TEG, fibrinogen, and aggregometry. Blood was obtained at 4 additional time points, following 20% blood volume loss, 40% blood volume loss, 60 minutes of sustained hypotension, and after autologous blood transfusion. In addition, heart rate and direct arterial blood pressure were measured at each time point.
  
  
  RESULTS
  Significant decreases were noted for PCV (P = 0.048), TPP (P < 0.0001), and arterial blood pressures (P < 0.0001) over time. Platelet count did not change significantly (P = 0.879), but platelet function was decreased following hemorrhage when arachidonic acid (P = 0.004) and ADP (P = 0.008) were used as agonists. The TEG variables R (P = 0.030), MA (P = 0.043), and G (P = 0.037) were significantly, albeit mildly, changed following hemorrhage. Significant prolongations in PT (P < 0.0001) and aPTT (P = 0.041), and decreases in fibrinogen concentration (P = 0.002) were also seen.
  
  
  CONCLUSIONS
  Platelet dysfunction occurred following hemorrhage in this model, despite a stable platelet count. Additionally, significant changes associated with hemorrhage were documented in aPTT, fibrinogen, and MA. Platelet function testing in dogs with naturally occurring hemorrhage warrants further investigation.
authors.affiliation: Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA.
authors.forename: Alex M
authors.initials: AM
authors.lastname: Lynch
authors.affiliation: Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA.
authors.forename: Armelle M
authors.initials: AM
authors.lastname: deLaforcade
authors.affiliation: Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA.
authors.forename: Dawn
authors.initials: D
authors.lastname: Meola
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FL.
authors.forename: Andre
authors.initials: A
authors.lastname: Shih
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, FL.
authors.forename: Carsten
authors.initials: C
authors.lastname: Bandt
authors.affiliation: Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA.
authors.forename: Natalia Henao
authors.initials: NH
authors.lastname: Guerrero
authors.affiliation: Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA.
authors.forename: Carolina
authors.initials: C
authors.lastname: Riccó
mesh_terms: D000818:Animals; D001780:Blood Coagulation Tests / Q000662:veterinary; D004195:Disease Models, Animal; D004283:Dog Diseases / Q000175:diagnosis* / Q000503:physiopathology; D004285:Dogs; D005260:Female; D006470:Hemorrhage / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary*; D006487:Hemostasis; D008297:Male; D010314:Partial Thromboplastin Time / Q000662:veterinary; D010976:Platelet Count / Q000662:veterinary; D010979:Platelet Function Tests / Q000662:veterinary; D011446:Prospective Studies; D011517:Prothrombin Time / Q000662:veterinary; D013916:Thrombelastography / Q000662:veterinary*
keywords: acute coagulopathy of trauma and shock; platelet function; platelet function testing; viscoelastic monitoring