The effect of heparin and fresh frozen plasma on plasma antithrombin III activity, prothrombin time and activated partial thromboplastin time in critically III dogs

摘要

Objective: To evaluate the effect of therapy with heparin and/or fresh frozen plasma on plasma antithrombin activity, prothrombin time and activated partial thromboplastin time. Design: Prospective clinical trial. Setting: Veterinary Teaching Hospital Intensive Care Unit. Patients: Twenty-four dogs with naturally-occurring critical illnesses. Intervention: Dogs were divided into three groups. Dogs received heparin (n=6; 200 IU/kg sc q 6 hr); heparin and fresh frozen plasma (n=9; 200 IU/kg heparin sc q 6 hr and 10-15 ml/kg plasma q 12 hr); or fresh frozen plasma (n=9; 10-15 ml/kg plasma q 12 hr). Measurements and Main Results: The mean baseline plasma antithrombin activity was 69 percent. At 24 hours after initiation of the study, there was a significant decrease in plasma antithrombin activity in dogs receiving heparin and plasma, whereas transfusion with plasma did not significantly increase antithrombin activity. Heparin therapy alone prolonged activated partial thromboplastin time in 5 of 6 dogs, whereas plasma therapy alone significantly shortened activated partial thromboplastin time and prothrombin time. Sixty-three percent of dogs survived to hospital discharge. All dogs with an increase in antithrombin activity survived. Conclusions: Transfusion of fresh frozen plasma was capable of maintaining, but ineffective in raising antithrombin activity. Fresh frozen plasma combined with exogenous heparin resulted in significantly diminished antithrombin activity. Heparin therapy alone may resultin substantial prolongation of activated partial thromboplastin time in sick dogs, while fresh frozen plasma transfusion alone may correct a pre-existing hypocoagulable state. Fresh frozen plasma and heparin therapy should be administered on an individual basis to critically ill animals with close monitoring of coagulation parameters.