What is Coagulation Cascade?

Fibrinolysis and the control of blood coagulation

The hemostatic process begins when an injury occurs to blood vessels and involves (i) vasoconstriction, (ii) the formation of a platelet plug, and (iii) blood coagulation. Through a series of cascading events, fibrin-based blood clots are formed at the site of the injury. The clot must form rapidly to prevent hemorrhage from the wound, but after the wound has healed, the clot is dissolved and normal blood flow is restored. Clot dissolution is affected by the thrombolytic enzyme Plasmin, which degrades fibrin. Plasmin is itself activated by other enzymes including tissue Plasminogen Activator (tPA) that convert the inactive pro-enzyme Plasminogen into the active Plasmin. tPA is regulated by Plasminogen Activator Inhibitor (PAI). Thus, the timely and efficient dissolution of blood clots is dependent on the precise regulation of Plasmin production. Too little Plasmin and the blood clot will persist, potentially resulting in a thrombotic event; too much plasmin and the blood clot will degrade before the blood vessel can heal properly resulting in the risk of hemorrhage.

What is Hyperfibrinolytic Bleeding?

Hyperfibrinolytic bleeding occurs when fibrinolytic activity is in excess compared to fibrin formation at the site of a hemostatic clot, leading to excessive clot dissolution and new or increased bleeding. Bleeding due to hyperfibrinolysis is a distinct pathology from excessive bleeding due to the lack of clotting factors and platelets, requiring fundamentally different treatment modalities.

Why is the Accurate Diagnosis of Hyperfibrinolysis Critical?

The accurate diagnosis of hyperfibrinolysis is critical during surgery, trauma, and other situations because hyperfibrinolytic patients should be treated with antifibrinolytics such as tranexamic acid, followed by treatment with fibrinogen concentrate or cryoprecipitate. Blood, and blood product, transfusions should be reserved for patients who cannot form clots.

Events that Cause Hyperfibrinolytic Bleeding

Well known proceduresthat can cause hyperfibrinolytic bleeding includes cardiopulmonary bypass for open heart surgery and infusion of thrombolytic agents to lyse a thrombus for treating heart attack or stroke. Other causes of systemic hyperfibrinolytic bleeding include cirrhosis/liver transplantation, and hyperfibrinolysis associated with the acute coagulopathy of severe trauma. Localized hyperfibrinolytic bleeding occurs frequently during orthopedic surgery and during childbirth.

FibriLyzer™: Helping to Make Immediate Treatment Decisions

The intricate equilibrium between coagulation (clotting) and fibrinolysis (clot dissolution) has been termed "life in the balance". Because conditions can change significantly in just a few minutes, the FibriLyzer™ provides attending physicians with timely information regarding the fibrinolytic status of a patient to help physicians make timely and effective treatment decisions based on underlying cause of patient bleeding.