Term
| What is the name given to a series of reactions designed to stop bleeding? |
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Definition
|
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Term
| What are the 3 phases of hemostasis? |
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Definition
| 1) Vascular spasms (immediate response to injury) 2) Formation of platelet plug 3) Coagulation |
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Term
| What are fragments of megakaryocytes w/ a blue staining outer region and a purple granular center? |
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Definition
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Term
| Name substances contained within the granular center of platelets. |
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Definition
| 1) Von Willebrand factor 2) Factor IV 3) PDGF 4) ADP 5) Ca2+ 6) Histamine, serotonin, and epinephrine |
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Term
| What is the function of plts in the clotting mechanism? |
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Definition
| Forming a temporary plug in damaged blood vessels |
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Term
| What is the stem cell for platelets? |
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Definition
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Term
| How do platelets stick to blood vessel endothelium in response to injury? |
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Definition
| Injury of endothelium exposes collagen which platelets are able to adhere to w/ the aid of Von Willebrand factor |
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Term
| The release of what recruits more plts to help form the platelet plug? |
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Definition
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Term
| How is the platelet plug limited to the immediate area of injury? |
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Definition
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Term
| What is a set of reactions in which blood is transformed from a liquid to a gel? |
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Definition
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Term
| What is the end product of coagulation? |
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Definition
|
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Term
| what pathway does coagulation follow? |
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Definition
| Extrinsic and intrinsic leading to common pathway |
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Term
| Which pathway, also known as the tissue pathway, starts when blood is in contact w/ the factor III (tissue factor)? |
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Definition
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Term
| When does the intrinsic pathway start? |
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Definition
| Exposure of collagen as a result of endothelial damage (slow) |
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Term
| What are the final 3 steps of the common pathway? |
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Definition
| 1) Formation of prothrombin activator 2) Conversion of prothrombin II to IIa 3) Conversion of fribrinogen I into a fibrin mesh |
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Term
| What factors are involved in the extrinsic pathway? |
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Definition
| III (tissue factor) and VII |
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Term
| What factors are involved in the intrinsic pathway? |
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Definition
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Term
| What factors are involved in the common pathway? |
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Definition
| I (fribrinogen), II (prothrombin), V, X, and XIII |
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Term
| During phase 2 of coagulation, prothrombin activator catalyzes the transformation of ______ to the active enzyme ______. |
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Definition
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Term
| During coagulation phase I, once factor __ has been activated, it complexes with Ca2+, PF3, and factor V to form _______ _______. |
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Definition
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Term
| During coagulation phase 3, thrombin catalyzes the polymerization of ____ into _____. |
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Definition
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Term
| Fibrin in the presence of Ca2+ activates ____ to cross link fibrin, which stabilizes and strengthens the clot. |
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Definition
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Term
| What is the process of stabilization of the clot by sqeezing plasma from fibrin strands? |
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Definition
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Term
| What stimulates rebuilding of the blood vessel wall? what stimulates endothelial cells to multiply and restore the endothelial lining? |
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Definition
| Platelet-derived growth factor (PDGF). Vascular endothelial growth factor (VEGF) |
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Term
| What substances are released from endothelial cells after repair of a blood vessel to inhibit furhter coagulation? (2) |
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Definition
| 1) Heparin-like substances bind antithrombin III and inhibit thrombin activity. 2) Tissue plasminogen activators (t-PA) |
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Term
| Name 7 tests to evaluate the coagulation system. |
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Definition
| 1) Prothrombin time (PT-extrinsic pathway) 2) Partial thromboplastin time (PTT-intrinsic pathway) 3) Thrombin time (TT) 4) Specific factors 5) Fribrinogen 6) Fibrin-degradation products (FDP) 7) D-dimer |
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Term
| What is the general term for a condition of deficient # of circulating platelets (<50,000)? |
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Definition
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Term
| What is the most common cause of thrombocytopenia? |
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Definition
| Failure of production d/t suppresion (drugs - Heparin) |
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Term
| Other than drugs, what else can cause thrombocytopenia d/t failure of platelet production? |
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Definition
| Bone marrow failure, Etohism, aplastic anemia, autoimmune dz (RA, Lupus), viral infxns |
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Term
| What clinical manifestations may be present in thrombocytopenia? (3) |
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Definition
| 1) Hematomas (petechiae, purpura, ecchymosis) 2) Hemarthrosis 3) Bleeding gums |
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Term
| Name 3 sx of organ bleeding d/t thrombocytopenia? |
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Definition
| Hematuria, melena (black, tarry stools), hemoptysis |
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Term
| What lab findings in a pt w/ thrombocytopenia indicate the cause is d/t failure of production? |
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Definition
| Small size on smear, dec. megakaryocytes |
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Term
| What lab findings in a pt w/ thrombocytopenia indicate the cause is d/t ineffective production? |
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Definition
| Variable size in smear, normal or inc. megakaryocyte |
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Term
| What lab findings in a pt w/ thrombocytopenia indicate the cause is d/t increased destruction? |
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Definition
| large size on smear, inc. megakaryocytes |
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Term
| Name 3 tx for thrombocytopenia besides tx underlying cause and d/c any suspected drugs? |
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Definition
| 1) Corticosteroids (inc. prod. and dec. splenic sequestration) 2) Plt transfusion or plasmaphoresis 3) Splenectomy |
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Term
| What is the name of the condition of an immune-mediated thrombocytopenia in the absence of toxin or drug exposure, or a dz? |
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Definition
| Idiopathic Thrombocytopenia Purpura (ITP) |
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Term
|
Definition
| Following a viral infxn at any age in both sexes |
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Term
| Who is chronic ITP more common in? |
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Definition
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Term
| What conditions are sometimes associated with ITP? |
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Definition
| Immunosuppresive dz (HIV, lupus) |
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Term
| Name 4 clinical manifestations of ITP. |
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Definition
| 1) Petechia/purpura 2) Epitaxis 3) Gum bleeding 4) Menorrhagia |
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Term
| What would cause thrombocytopenia d/t abnormal sequestration of platelets? Dilutional loss? |
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Definition
| Splenic sequestration. Blood transfusion, IVF. |
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Term
| Name 3 causes of thrombocytopenia d/t inc. destruction. |
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Definition
| auto immune d/o, drugs, artificial heart valves |
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Term
| Would splenomegaly be an expected finding in a pt w/ ITP? |
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Definition
|
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Term
| Name 3 lab findings seen in a pt w/ ITP. |
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Definition
| 1) Plt <20,000 2) Lg. size on smear, inc. mega. 3) Normal coag studies |
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Term
| What is the initial tx consideration for ITP? |
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Definition
| Prednisone until plts are normal (>50,000) |
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Term
| If a pt has no response to the initial tx for ITP, what is considered the definitive tx? What procedure is not indicated to tx ITP? |
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Definition
| Splenectomy. Platelet transfusion. |
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Term
| If a pt has no response to the initial tx for ITP, what is considered the definitive tx? What procedure is not indicated to tx ITP? |
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Definition
| Splenectomy. Platelet transfusion. |
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Term
| What tx is indicated for bleeding emergenices in ITP? |
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Definition
| high-dose IV immunoglobulin |
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Term
| What is the type of thrombocytopenia w/ hemolytic anemia? |
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Definition
| Thrombocytic Thrombocytopenia Purpura (TTP) |
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Term
| The exact etiology of TTP is unknown, but what are 3 factors associated to its dev.? |
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Definition
| 1) Estrogen 2) Pregnancy 3) HIV |
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Term
| Who is TTP more common in? |
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Definition
|
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Term
| Which pt is expected to present febrile, ITP or TTP? |
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Definition
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Term
| Other than petechia and purpura, what additional clinical findings are expected in a pt w/ TTP? |
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Definition
| 1) Anemia 2) Fever 3) HA, confusion, ALOC |
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Term
| What is the hallmark finding of TTP on peripheral smear? |
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Definition
| Fragmented RBCs - schistocytes, helmet cells |
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|
Term
| what is the expected finding of platelet count in TTP? Coag studies? What additional lab value is elevated in TTP? |
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Definition
| Plt - dec, coag - normal, bili - inc. |
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Term
| Which thrombocytopenia is considered a medical emergency, ITP or TTP? What is the tx? |
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Definition
| TTP. Plasmophoresis or splenectomy if no response. |
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Term
| What is the name of aquired syndrome in which clotting and bleeding occur simultaneously? |
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Definition
| Disseminated Intravascular Coagulation (DIC) |
|
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Term
| What are the most common causes of acute DIC? |
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Definition
| 1) Pregnancy 2) Blood transfusion 3) Shock, burn, snake bite 4) Sepsis |
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|
Term
| What condition may cause chronic DIC? |
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Definition
|
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Term
| Other than petechia and ecchymosis, what clinical manifestations are seen in DIC? |
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Definition
| 1)Bleeding from orifices 2) Acrocyanosis 3) PE 4) RF |
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Term
| What lab results indicate DIC? (4) |
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Definition
| 1) Low plt 2) Abn bleeding time 3) Abn PT, PTT, and TT 4) Dec. fibrinogen |
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Term
| What blood products can be used to help replace depleted clotting factors in DIC? |
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Definition
| FFP, RBC, plts, or cryoprecipitate |
|
|
Term
| What is a controversial tx for DIC? |
|
Definition
| Heparin (stop thrombin formation) |
|
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Term
| What is the most common severe congenital clotting deficiency? |
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Definition
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|
Term
| Des. genetic inheritance of hemophilia A. |
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Definition
| X-linked recessive (t/f men are affected and women are carriers) |
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Term
| Hemophilia is a def. of what clotting factor? |
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Definition
|
|
Term
| What is the hallmark finding in hemophilia A? What is critical complication of hemophilia A? |
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Definition
| Hemarthrosis (knees, ankles, elbows). ICH. |
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|
Term
| What lab values are seen in hemophilia A? |
|
Definition
| prolonged PTT, normal bleeding time, PT, and fibrinogen, red. factor VIII |
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Term
| What lab values help to distinguish hemophilia A from Von willebrands dz? |
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Definition
| Hemo A - low factor VIII, normal bleeding time. VWD - low factor VIII + prolonged bleeding time |
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|
Term
| What is the standard tx for hemophilia A? |
|
Definition
| Factor VIII infusion (cryoprecipitate) |
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|
Term
| What tx is given to pts w/ mild hemophilia? What is a side effect of this med? |
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Definition
| Desmopressin - red. UOP (DDAVP). Hyponatremia. |
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|
Term
| What tx is given for hemarthrosis? |
|
Definition
| Infusion + immobilization of limb + application of ice |
|
|
Term
| What complication of hemophilia can result in life-threatening or limb-threatening hemorrhage? How can this be tx? |
|
Definition
| Dev. of neutralizing IgG Ab to factor VIII. Recombinant reactivated factor VII (rVIIa) |
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|
Term
| What condition is called "Christmas factor"? |
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Definition
|
|
Term
| What is the genetic transmission of hemophilia B? What factor is it a def. in? |
|
Definition
| X-linked recessive (males). Factor IX. |
|
|
Term
| What is the tx for hemophilia B? |
|
Definition
| Factor IX concentrate, FFP |
|
|
Term
| What is the most mild type of hemophilia that is typically provoked by surgery? |
|
Definition
|
|
Term
| How common in hemophilia C? Who does it typically affect? |
|
Definition
| Very rare. Jewish heritage. |
|
|
Term
| Des. the genetic transmission of hemophilia C. What factor is it a def. of? |
|
Definition
| Autosomal dominant (both sexes). Factor XI. |
|
|
Term
| When does hemophilia C req. tx? What is the tx? |
|
Definition
| Dental extractions or surgery. FFP, fector XI concentrate. |
|
|
Term
| What is the most common inherited abnormality of plt function? |
|
Definition
|
|
Term
| Des. the genetic transmission of vWD. What is it a def. of? |
|
Definition
| Autosomal dominant. Red. or abn fxn of von Willebrands factor (vWF) |
|
|
Term
| What are the 2 roles of vWF? |
|
Definition
| 1) Promote plt adhesion to damaged endothelium 2) Carrier molecule of factor VIII |
|
|
Term
| Name 3 expected clinical manifestations of vWD? Are spontaneous hemathroses expected findings? |
|
Definition
| Epitaxis, gum bleeding, menorrhagia. No - rare. |
|
|
Term
| What dec. bleeding manifestations in vWD? Increases? |
|
Definition
| Pregnancy and estrogen. Inc. w/ age. |
|
|
Term
| What are the expected lab findings in regards to plt counts, bleeding time, PT, factor VIII, and vWF? |
|
Definition
| Plt: normal, bleeding time: prolonged, PT: normal, Factor VIII and vWF: decreased. |
|
|
Term
| What is the routine tx for vWD? |
|
Definition
| No routine tx. Can give DDAVP if mild or vWF concentrate for very low levels. Can also give Factor VIII for rapid correction. |
|
|
Term
| What med. is rec. to be avoided in all d/o of the coagulation cascade? |
|
Definition
|
|
Term
| What lab test measures the extrinsic pathway of coagulation (Factors II, V, VII, X, and fibrinogen)? |
|
Definition
|
|
Term
|
Definition
| The ratio of a pt's PT to a normal value of PT |
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