Coagulation Modifiers Flashcards
What is an anticoagulant?
- drug that interferes with the normal coagulation process by interfering with the clotting cascade and thrombin formation
- a drug that slows the body’s normal blood-clotting processes to prevent harmful blood clots from forming. This type of drug is often called a “blood thinner”; however, it cannot dissolve any clots that have already formed and does not make your blood thin.
What are antiplatelet agents and what do they do?
drugs that decrease the formation of the platelet plug by decreasing the responsiveness of the platelets to stimuli that would cause them to stick and aggregate on a vessel wall.
What are clotting factors and what processes do they perform in the body?
substances formed in the liver—many requiring vitamin K—that react in a cascading sequence to cause the formation of thrombin from prothrombin; thrombin then breaks down fibrin threads from fibrinogen to form a clot.
What process does coagulation perform in the body?
the process of blood changing from a fluid state to a solid state to plug injuries to the vascular system
What is the extrinsic pathway?
the cascade of clotting factors in blood that has escaped the vascular system to form a clot on the outside of the injured vessel
What is the Hageman factor and what role does it play in coagulation?
first factor activated when a blood vessel or cell is injured; starts the cascading reaction of the clotting factors, activates the conversion of plasminogen to plasmin to dissolve clots, and activates the kinin system responsible for activation of the inflammatory response
What are hemorrhagic disorders?
disorders characterized by a lack of clot-forming substances, leading to states of excessive bleeding
What are hemostatic agents and how do they work?
drugs that stop blood loss, usually by blocking the plasminogen mechanism and preventing clot dissolution
What is the intrinsic pathway?
cascade of clotting factors leading to the formation of a clot within an injured vessel
What is plasminogen and what role does it play in the formation or breakdown of clots?
natural clot-dissolving system, converted to plasmin (also called fibrinolysin) by many substances to dissolve clots that have formed and to maintain the patency of injured vessels
What is platelet aggregation and what role does it play in platelet function?
property of platelets to adhere to an injured surface and then attract other platelets, which clump together or aggregate at the area, plugging up an injury to the vascular system
What are thromboembolic disorders and their characteristics?
disorders characterized by the formation of clots or thrombi on injured blood vessels with potential breaking of the clot to form emboli that can travel to smaller vessels, where they become lodged and occlude the vessel
How do thrombolytic agents work?
drugs that lyse, or break down, a clot that has formed; these drugs activate the plasminogen mechanism to dissolve fibrin threads.
What happens when a vessel is injured?
- Local vasoconstriction seals off the small injury b/c decreased surface area makes it easier to heal
- Platelet aggregation forms a platelet plug
- Hageman factor (factor XIII) is activated
- The intrinsic pathway converts prothrombin to thrombin to seal the system
- The extrinsic pathway clots the blood that has leaked out of the vascular system
How should you educate children and their parents about the use of coagulation agents?
Teach about injury prevention and safety precautions such as no contact sports and no rough-housing.
Teach what do it if the child begins to bleed: Apply firm pressure for awhile and if it doesn’t stop, call the doctor.
