Exam 2: Coagulation and Hemostasis Flashcards
What is Primary Hemostasis
immediate vasoconstriction, platelet plug
What is Secondary Hemostasis
The coagulation cascade, formation of fibrin clot
What are clinical manifestations of bleeding?
Petechiae, purpura, telangiectasia, ecchymosis
What is Petechiae?
pinpoint round spots
What is Purpura?
purple colored spots of patches
What is Telangiectasia?
fiery, stare-shaped mark, widened blood vessels
What is Ecchymosis?
bruising
What is Hematochezia?
blood passed from rectum
What is Melena?
black stools from GI bleeding
What is Hematuria?
pinkish or red colored urine from presence of RBC, blood in urine
What is Hemoptysis?
coughing up blood from lungs
What is Menorrhagia?
abnormally heavy or prolonged bleeding during period
What is Epistaxis?
nosebleed
What laboratory tests are done to evaluate bleeding?
PT/INR (Extrinsic pathway), aPTT (intrinsic pathway), bleeding time (platelet function)
What causes decreased production of Platelet?
chemotherapy/ radiation, cancer of the bone marrow, B12/Folate Deficiency
What causes decreased survival of platelets?
ITP, HIT, DIC, Medications (thiazides/ digoxin/ heparin)
What causes platelet splenic sequestration (too many blood cells stuck in the spleen?
splenomegaly, hypothermia
What causes dilution leading to decreased platelets?
large blood transfusions
What is Thrombocytopenia?
Low platelet count, symptoms appear when it falls below 100,000, symptoms: easy bruising, mucosal hemorrhage, petechiae, purpura, “deep” bleeding
What is Idiopathic Thrombocytopenic Purpura (ITP)?
abnormal decrease in the number of platelets in the blood, immune system attacking platelets
What is Hemophilia A
factor VIII deficiency, coagulation disorder, ability to clot decreases, most common hemophilia
What is Hemophilia B
Factor IX deficiency, coagulation disorder, ability to clot decreases, “Christmas disease”
What are the clinical manifestations of hemophilia?
spontaneous bleeding, prolonged bleeding after minor procedures, A and B are clinically indistinguishable
What is Disseminated Intravascular Coagulation (DIC)
proteins that control clotting become overactive causing small clots to form and block small blood vessels. This then consumes clotting factors and platelets leading to excessive bleeding
What is hepatic disease?
Chronic liver disease (liver is the protein factory)
What clotting factors are Vitamin K Dependent?
II, VII, IX, X
What does Vitamin K Deficiency in Infancy look like?
babies need vitamin K supplements, it is associated with breast feeding, rare in developed world
What does acquired Vitamin K deficiency look like?
malnutrition, malabsorption, may be from antibiotic treatment or anticoagulation therapy?
What does Heparin do?
anticoagulant, it stimulates the activity of ATIII which inhibits Thrombin
What does Coumadin do?
anticoagulant, blocks the production of vitamin K dependent clotting factors
Intrinsic pathway in hemostasis
This pathway is the longer pathway of secondary hemostasis. It begins with the activation of Factor XII, which becomes Factor XIIA after exposure to endothelial collagen
Extrinsic pathway of hemostasis
The extrinsic pathway is the shorter pathway of secondary hemostasis. Once the damage to the vessel is done, the endothelial cells release tissue factor which goes on to activate factor VII to factor VIIa. Factor VIIa goes on to activate factor X into factor Xa
