Ch. 12 Disorders of Hemostasis Flashcards
Hemostatis
the stoppage of blood
normal state
blood is fluid. prevention of blood loss is done by sealing of torn vessels
abnormal state
inappropriate clotting (thrombus formation) insufficient clotting (clots not being made)
what are the components of hemostasis?
- platelets
- coagulation system
- anticoagulants
- endothelial lining of blood vessels
platelets in relation to hemostasis
thrombocytes - made in bone marrow, stored in spleen (in the ULQ)
coagulation system in relation to hemostasis
-plasma clotting factors (synthesized in the liver) that are designated by roman numerals
anticoagulants in relation to hemostasis
anticoagulants dissolve clots and prevent clots from forming unnecessarily
PLASMIN
endothelial lining of blood vessels in relation to hemostasis
promotes blood flow
what is the cascade event?
multistep event that makes the clot and prevents clots from being made. very predictable
What are normal steps that occur during injury to vessels?
- vessel spasm
- vasoconstriction
- release of platelets
- platelet plug
- von Willebrand factor
- platelet aggregation
- Fibrin Clot Formation
- blood coagulation
- intrinsic pathway
- extrinsic pathway
- coagulation cascade
- Repaired Vessel
- clot retraction
- clot dissolution
von Willebrand factor
(2nd step) released from the endothelium and causes adhesion of components/platelets to the opening of the vessel wall
platelet aggregation
(2nd step) platelets come in contact with the damaged wall and adhere to the wall and get sticky so they can stick to each other
intrinsic pathway
(3rd step) activation of specific factors. slow process. Factor XII (12) activation
extrinsic pathway
(3rd step) occurs when there is more injury. much faster. Factor X (10).
Factor X changes prothrombin to thrombin (fibrous threads)
coagulation cascade
(3rd step) step wise process of fibrinogen into fibrin
clot retraction
(4th step) shrinkage of clot over a couple of days. as it shrinks it pulls edges together of the blood vessel at the point of injury. Fibrin strands contract and squeeze out plasm
clot dissolution
(4th step)fibrinolysis. strands of the clot are dissolved
hypercoagulability
over coagulation. too many platelets.
- thrombocytosis : elevated (abnormal) platelet count
- caused by: reactive disorders like anemia, cancer and rheumatoid arthritis or endothelial injury, vascular wall damage like atherosclerosis
atherosclerosis
hardening of arteries caused by hypertension( constant hard pressure on vessels so they stiffen up and become stiff). caused by smoking and high cholesterol
what causes increased clotting activity?
Primary: inherited disorders like genetic Factor V deficiency (deep veins prone to thrombosis).
Or
Secondary:Acquired disorders like… bed rest, immobility, hyper viscosity syndrome (polycythemia, Sickle Cell), oral contraceptives, pregnancy
what should nurses do to help people who have increased clotting activity?
keep patients hydrated, compression hoes, give anticoagulants
Bleeding Disorders
- either not enough or not activating appropriately
- problem in one cascade even (leads to incomplete cascade event)
- problem in vessels
ITP (thrombotic thrombocytopenic purpura)
bleeding disorder. autoimmune disorder where there is excessive destruction of platelets with bruising, noise bleeds, blood in stools, spleen enlargement (site where platelet destruction occurs), spontaneous adhesion of platelets these patients do have in small vessels (see a lot of bruising in fingers)
Thrombocytopenia
bleeding disorder. decrease number of platelets
what are some medications that interfere with platelet formation?
Nsaids (Motrin and Tylenols), Aspirin
what are some common places to bleed spontaneously?
skin, mucus membranes in mouth, nose, uterine cavity, GI tract
deep vein thrombosis is often seen in who?
patients on bed rest. clots form in the deep veins of their legs
people with what sort of disorders should avoid sports?
coagulation… but really shouldn’t they all???
Hemophilia
inherited coagulation disorder.
- deficient Factor VIII (8)
- x-linked recessive deficient factor VII
- mainly seen in males
- diagnosed as children because children get a lot of injuries
- could be either no factor 8 or insufficient factor 8
von Willebrand disease
inherited coagulation disorder.
- autosomal dominate disorder
- disturbs platelet function and coagulation pathways
Manifestations: mucus membranes bleed excessively and for prolonged periods
Acquired Coagulation Disorders
- Liver Disease (Hepatitis or drinking)
- Vitamin K : needed to make clotting factor, made in the liver
- DIC (disseminated intravascular coagulation)
DIC
massive activation of coagulation. a process of clothing in some areas (no blood flow) along with hemorrhaging in other areas because there are no platelets flowing in the blood because they are used elsewhere.
with DIC you worry about organ failure or hemorrhaging to death.
DIC is seen in patients with sepsis, massive injury, TSS (toxic shock syndrome: pulls out magnesium?bigger sizes make it worse)
