Antifibrinolytic Agents: Agents that prevent fibrinolysis or lysis of a blood clot or thrombus. Several endogenous antiplasmins are known. The drugs are used to control massive hemorrhage and in other coagulation disorders.Aminocaproic Acid: An antifibrinolytic agent that acts by inhibiting plasminogen activators which have fibrinolytic properties.Tranexamic Acid: Antifibrinolytic hemostatic used in severe hemorrhage.Aminocaproates: Amino derivatives of caproic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the amino caproic acid structure.Aprotinin: A single-chain polypeptide derived from bovine tissues consisting of 58 amino-acid residues. It is an inhibitor of proteolytic enzymes including CHYMOTRYPSIN; KALLIKREIN; PLASMIN; and TRYPSIN. It is used in the treatment of HEMORRHAGE associated with raised plasma concentrations of plasmin. It is also used to reduce blood loss and transfusion requirements in patients at high risk of major blood loss during and following open heart surgery with EXTRACORPOREAL CIRCULATION. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1995)Blood Loss, Surgical: Loss of blood during a surgical procedure.Blood Transfusion: The introduction of whole blood or blood component directly into the blood stream. (Dorland, 27th ed)Carboxypeptidase U: A metallocarboxypeptidase that removes C-terminal lysine and arginine from biologically active peptides and proteins thereby regulating their activity. It is a zinc enzyme with no preference shown for lysine over arginine. Pro-carboxypeptidase U in human plasma is activated by thrombin or plasmin during clotting to form the unstable carboxypeptidase U.Fibrinolysis: The natural enzymatic dissolution of FIBRIN.Postoperative Hemorrhage: Hemorrhage following any surgical procedure. It may be immediate or delayed and is not restricted to the surgical wound.Carboxypeptidase B: A ZINC-dependent carboxypeptidase primary found in the DIGESTIVE SYSTEM. The enzyme catalyzes the preferential cleavage of a C-terminal peptidyl-L-lysine or arginine. It was formerly classified as EC 3.4.2.2 and EC 3.4.12.3.Hemostatics: Agents acting to arrest the flow of blood. Absorbable hemostatics arrest bleeding either by the formation of an artificial clot or by providing a mechanical matrix that facilitates clotting when applied directly to the bleeding surface. These agents function more at the capillary level and are not effective at stemming arterial or venous bleeding under any significant intravascular pressure.Thrombomodulin: A cell surface glycoprotein of endothelial cells that binds thrombin and serves as a cofactor in the activation of protein C and its regulation of blood coagulation.Blood Coagulation: The process of the interaction of BLOOD COAGULATION FACTORS that results in an insoluble FIBRIN clot.alpha-2-Antiplasmin: A member of the serpin superfamily found in plasma that inhibits the lysis of fibrin clots which are induced by plasminogen activator. It is a glycoprotein, molecular weight approximately 70,000 that migrates in the alpha 2 region in immunoelectrophoresis. It is the principal plasmin inactivator in blood, rapidly forming a very stable complex with plasmin.Hemostasis, Surgical: Control of bleeding during or after surgery.Carboxypeptidases: Enzymes that act at a free C-terminus of a polypeptide to liberate a single amino acid residue.Hemostasis: The process which spontaneously arrests the flow of BLOOD from vessels carrying blood under pressure. It is accomplished by contraction of the vessels, adhesion and aggregation of formed blood elements (eg. ERYTHROCYTE AGGREGATION), and the process of BLOOD COAGULATION.Cardiopulmonary Bypass: Diversion of the flow of blood from the entrance of the right atrium directly to the aorta (or femoral artery) via an oxygenator thus bypassing both the heart and lungs.Serine Proteinase Inhibitors: Exogenous or endogenous compounds which inhibit SERINE ENDOPEPTIDASES.