MONITORING PLATELET FUNCTION DURING ANTI-PLATELET THERAPY

摘要

Normal blood hemostasis is a complicated process that involves the vascular endothelium, numerous coagulation factors, and several interacting cells. When exposed to injured or damaged endothelium, either due to normal cell turnover or vessel trauma,platelets undergo several functional responses, including platelet adhesion and aggregation, release of pro-coagulant substances, and surface expression of procoagulant receptors.1 The formation of a platelet plug during primary hemostasis is the first step in coagulation, and plays a major role in preventing blood loss. Inadequate platelet number and function will increase the risk of hemorrhage; while continual platelet activation, especially in hypercoagulable states, may lead to inappropriate thrombus formation. The risk of thromboembolism has been identified as a significant complication in many commonly encountered diseases, and can be a devastating complication of otherwise treatable conditions. In veterinary medicine, the diseases/conditions that are associated with an increased risk of thromboembolic complications include immune-mediated hemolytic anemia (IMHA), protein-losing nephropathies, hyperadrenocorticism, sepsis, disseminated intravascular coagulation, and systemic inflammatory response syndrome.2'3 Because of the devastating complications associated with a thromboembolic event, preventative therapy is an essential component of the treatment of hypercoagulable patients. Unfortunately, many of the medications used in veterinary medicine that inhibit coagulation factors, such as heparins, can only be given by injection or are cost prohibitive for long term administration, making anti-platelet therapy the most commonly administered preventative therapy.