Influence of blood collection technique on platelet function and coagulation variables in dogs

To investigate the influence of diameter of the catheter and blood collection technique on platelet function and variables reflecting secondary hemostasis, physiologic anticoagulation, and fibrinolysis in dogs.

6 healthy Beagles.

Blood samples were collected with 20- and 18-gauge venous catheters immediately after catheters were inserted in a peripheral vein, through a 14-gauge central venous catheter that had been placed via the Seldinger technique in a jugular vein < 30 minutes before sample collection, and through a 13-gauge central venous catheter placed via a catheter-through-the-needle technique < 30 minutes before sample collection (techniques 1 to 4, respectively). Platelet function was assessed in hirudin-anticoagulated whole blood via an impedance-based aggregometer with collagen (0.8, 0.4, 0.2, 0.1, and 0.05 μg/mL) as an inductor. Kaolin-activated thromboelastography variables were determined in citrated whole blood. Prothrombin time, activated partial thromboplastin time, fibrinogen and fibrin D-dimer concentrations, and activity of factor VIII, antithrombin, protein C, and protein S were assessed automatically in citrated plasma.

At 0.05 μg of collagen/mL, the highest median rate of aggregation was observed for collection techniques 2 and 3 with 4.3 (range, 2.5 to 6.5) and 3.7 (range, 2.8 to 8.3) aggregation units/min; however, these values were not significantly different from values for the other collection techniques. Generally, sample collection technique did not have a significant impact on results of coagulation variables investigated.

Various blood collection techniques can be used to obtain samples for coagulation testing.