Prospective evaluation of platelet function and fibrinolysis in 20 dogs with trauma

Objectives

To determine platelet function and assess fibrinolysis in dogs following trauma using multiple electrical impedance aggregometry and a modified thromboelastographic (TEG) technique. To determine if the severity of trauma, as assessed by the Animal Trauma Triage (ATT) score and clinicopathological markers of shock, is associated with a greater degree of platelet dysfunction and fibrinolysis.

Setting

University teaching hospital.

Animals

Twenty client-owned dogs with trauma (occurring <24 h prior to admission and blood sampling) and ATT score of >4 were prospectively recruited. A control group of 10 healthy dogs was included.

Interventions

None.

Measurements and Main Results

Platelet function was measured using multiple electrode platelet aggregometry (MEPA) utilizing arachidonic acid, ADP, and collagen agonists. Fibrinolysis was assessed in citrated whole blood with the addition of tissue plasminogen activator (tPA; 50 U/mL) using kaolin-activated TEG. Conventional statistical analysis was performed to compare coagulation parameters between the groups and assess linear correlations. Median (interquartile range) ATT score was 5 (5–7), and 65% (n = 13) of dogs suffered polytrauma. Mean (± SD) time from trauma to blood sampling was 9 hours (± 6). Median (interquartile range) shock index and plasma lactate concentration were 1.1 (0.7–2.0, n = 16) and 2.9 mmol/L (0.9–16.0, n = 18), respectively. Four dogs did not survive to discharge (20%). There were no differences between the trauma and control group coagulation variables. A moderate negative correlation between ATT score and area under the curve for ADP was found (P = 0.043, r² = −0.496).

Conclusions

Preliminary evaluation of platelet function measured by MEPA, and fibrinolysis measured by tPA-modified TEG, is not significantly different in this population of dogs with traumatic injury compared to healthy dogs.