Evaluation of hemostatic activity of canine frozen plasma for transfusion by thromboelastography.

Background: In humans, fresh frozen plasma (FFP) loses factor V and VIII activities after 1 year. It then becomes frozen plasma (FP), and theoretically is unsuitable for use in patients with coagulopathies. These findings have not been reported for dogs.

Hypothesis: Canine FP is hemostatically active after 5 years of storage.

Animals: Fresh plasma (Group FsP; n = 15) and 5-year-old FP (Group FzP; n = 10) from blood bank donors.

Methods: Group FsP and Group FzP samples were evaluated by thromboelastography (TEG), one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), fibrinogen, and antithrombin. Fresh plasma (n = 6) and a subset of Group FzP (n = 8) were evaluated for clotting factor activities (V, VIII, IX, X). A 2nd experiment using short-term storage of thawed FP under suboptimal conditions (refrigerated [4°C] or refrozen [-20°C]) by TEG was performed to simulate general practice storage capabilities.

Results: Group FzP had shorter reaction time (P = .0007) and larger angle (P = .0004) compared with Group FsP by TEG, suggesting hypercoaguability. Factor VIII and X activities were lower in Group FzP (P = .02 and .005, respectively). Fibrinogen, OSPT, and APTT were significantly lower or longer for Group FzP than Group FsP (P < .05), but most values remained within reference intervals for dogs.

Conclusions And Clinical Importance: Five-year-old canine FP stored at -30°C is hemostatically active and should be clinically evaluated in patients with coagulopathies. If active, the monetary savings of using older plasma will be substantial.