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Exam 1
Chapter 32: Disorders of Secondary Hemostasis
131
Science
Graduate
02/25/2013

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Term
Deficiency
Definition
can refer to decreased amount which is the typical definition or in the case of disorders of secondary hemostasis it can refer to functional deficiencies in that proteins are present in the blood, but they are not functioning correctly
Term
Expected results of laboratory screening tests the detect abnormalities of the proteins of secondary hemostasis
Definition
Screening tests based on length of time it takes a clot to form in plasma will be prolonged because they depend on adequate amount of clot forming proteins and functional ability of those proteins to work. These tests do not differentiate between the two (qualitative and quantitative)
Term
vWD Type 1 Laboratory Results
Definition
Plasma levels of VIII, vWF, and vWF: Ag are decreased or normal, bleeding time may be prolonged or normal
Term
vWD Type 1 Pathophysiology
Definition
Autosomal mutation which causes partial quantitative deficiency in which all multimers of vWF are present in plasma in same relative proportion as in normal plasma but they are all reduced in numbers.
Term
vWD Type 1 clinical symptoms
Definition
mild bleeding symptoms characterized by hemorrhage from delicate mucocutaneous tissues, bleeding into joints is NOT present
Term
Hemostatic proteins that are deficient in hemophilias A
Definition
Factor VIII deficiency (anti-hemophilic factor)
Term
Hemostatic proteins that are deficient in hemophilias B
Definition
Factor IX deficiency (Christmas factor)
Term
Factor VIII and IX deficiency inheritance pattern
Definition
X- linked recessive, affects sons who inherit from heterozygous carrier usually their mother
Term
Factor VIII and IX deficiency clinical symptoms
Definition
depending on severity can range from mild to severe bleeding problems characterized by unusual bleeding symptoms early in life (earlier depending on severity). Severe manifestations (factors < 1 units/dL) are frequent spontaneous hemarthrosis with crippling and frequent and severe spontaneous hemorrhaging. Moderate symptoms (factors = 1-5 units/dL) are bleeding at circumcision, infrequent spontaneous joint and tissue blood, excessive bleeding after surgery, trauma or minor injury. Mild symptoms (factors = 6-30 units/dL) are rare spontaneous bleeds and excessive bleeding after surgery
Term
Factor VIII and IX deficiency laboratory findings
Definition
mixing studies with F-VIII and F-IX return sample to 100% activity in aPTT, prolonged aPTT when low VII (>30%) and IX (>20%). Factor VIII deficiency yields prolonged aPTT and decreased factor VIII assay. Factor IX deficiency yields prolonged aPTT and decreased factor IX assay.
Term
vWD versus Factor VIII and IX deficiencies based on laboratory results
Definition
vWD type 1 patients will show a decreased vWF: Ag assay, while factor deficiency patients will not. The factor deficiencies are characterized by a prolonged aPTT and a decreased factor assay.
Term
vWD versus Factor VIII and IX deficiencies based on clinical symptoms
Definition
Factor deficiency symptoms are characterized by hemarthrosis (bleeding into the joint), vWD symptoms are usually mild, if they are present at all and it usually hemorrhage in mucosal and cutaneous tissue (not joints).
Term
Clinical conditions associated with acquired disorders of hemostatic proteins
Definition
DIC, Primary fibrinolysis, Liver disease, vitamin-K deficiency, and pathologic inhibitors
Term
Expected results in laboratory screening tests for acquired disorders of hemostatic proteins
Definition
prolonged aPTT, PT and Thrombin time (except for specific factor inhibitors)
Term
Etiology of DIC
Definition
group of system secondary to a primary condition which can trigger the DIC. The most common trigger is severe infections because of the inflammatory cytokines which activate epithelial collagen to expressed tissue factor in turn activating the clotting cascade (extrinsic).
Term
Pathophysiology of DIC
Definition
the initiating event is generalized formation of thrombin and activation of coagulation. Thrombin acts on its substrates which allows for unregulated over expression of thrombin and consumption of all its substrates (fibrinogen, V, VIII, and XIII) there is a depletion of Prothrombin, activation and aggregation of platelets. Thrombin activated release of t-PA activating plasmin triggering secondary fibrinolysis, the normal inhibitory pathways which prevent system events of thrombin fail. Coagulation factors are overwhelmed and bleeding ensues. Fibrin strands in small vessels cause MAHA (schistocytes) can also obstruct blood flow and cause organ failure.
Term
Laboratory testing of DIC
Definition
prolonged PT, aPTT, and fibrinogen, decreased AT, plasminogen and anti-plasmin, positive for FDPs and D-Dimer, decreased platelet count and abnormal platelet function tests, schistocytes on the PBS.
Term
Physiologic variations in the reference ranges for hemostatic screening tests in newborns
Definition
reference ranges for coagulation factors (produced in the liver) are low because liver synthesis is not optimal at birth. Laboratory tests are prolonged which can be interpreted as normal
Term
Clinical consequences of abnormality in proteins of secondary hemostasis
Definition
excessive bleeding
Term
Clinical symptoms of deficiencies of fibrin forming proteins
Definition
The symptoms of both primary and secondary hemostasis disorders overlap but petechiae is unique to primary hemostasis disorders while delayed bleeding, deep muscular bleeding and spontaneous joint bleeding is characteristic of disorders of secondary hemostasis.
Term
Laboratory tests for disorders of primary hemostasis
Definition
can be normal (vascular disorders, except bleeding time), Platelet tests (quantitative and qualitative) are usually abnormal in platelet disorders.
Term
Laboratory tests for disorders of secondary hemostasis
Definition
screening tests and specific factor assays establish diagnosis, platelet studies are usually normal (except in DIC).
Term
Genetic mutations
Definition
specific molecular defects in genes and corresponding protein due to mutations during DNA replication.
Term
Autosomal dominant diseases
Definition
vWD or dysfibrinogenemia
Term
X-linked recessive diseases
Definition
hemophilia
Term
autosomal recessive diseases
Definition
factor I, Factor II, factor V, Factor VII, Factor X, Factor XI, Factor XIII, combined (V and VIII), and vitamin-K dependent factors
Term
vWD subtypes inheritance pattern
Definition
Autosomal dominant inheritance, inherited
Term
vWD subtypes pathophysiology: Type 1
Definition
partial quantitative deficiency in vWF in which all multimers of vWF are present but in lower concentrations than normal
Term
vWD subtypes pathophysiology: Type 2
Definition
qualitative abnormality in vWF which has normal levels of vWF but the proteins are dysfunctional
Term
vWD subtypes pathophysiology: Type 2A
Definition
qualitative variant in which there is defective platelet-vWF interactions associated with the absence of HMW multimers in plasma, either the vWF multimers are abnormal or they are more prone to proteolysis
Term
vWD subtypes pathophysiology: Type 2B
Definition
- qualitative abnormality vWF in which there is an increased affinity of vWF to platelet receptor, middle and low MW multimers are present in plasma, HMW is absent in plasma.
Term
vWD subtypes clinical symptoms
Definition
hemorrhagic tendency, mild bleeding from delicate mucocutaneous tissues
Term
vWD subtypes laboratory findings: Type 1
Definition
all tests are abnormal (bleeding time, vWF: Ag, RIPA and vWF: RCo),
Term
vWD subtypes laboratory findings: Type 2A
Definition
decreased platelet agglutination in response to ristocetin
Term
vWD subtypes laboratory findings: Type 2B
Definition
enhanced agglutination in response to reduced concentrations of ristocetin
Term
Deficiencies of factors of fibrin formation inheritance
Definition
deficiencies of factors VIII and IX are X-linked recessive (inherited) and deficiencies of factors II, VII, X, XI, and XIII are autosomal recessive (inherited).
Term
Deficiencies of factors of fibrin formation pathophysiology
Definition
deficiencies of factors VIII and IX are deficiencies of the intrinsic pathway. There is insufficient generation of thrombin by the IX/VIII complex through the intrinsic pathway, bleeding is complicated by excessive fibrinolysis because of decreased generation of thrombin and decreased inhibition of fibrinolysis by TAFI.
Term
Pathophysiology Factor II deficiency (Prothrombin)
Definition
is the rarest inherited bleeding disorder and is due to a qualitative defect in Prothrombin. Prothrombin is a precursor to thrombin which converts fibrinogen to fibrin. Complete lack of Prothrombin is incompatible with life
Term
Pathophysiology Factor VII deficiency
Definition
- the VIIa/TF complex is a key initiator of extrinsic coagulation in vivo, deficiencies can result in significant clinical manifestations
Term
Pathophysiology Factor X deficiency
Definition
important in the initiation of the common pathway and stabilization of the platelet plug.
Term
Pathophysiology Factor XI deficiency
Definition
occurs most often in Ashkenazi Jews, deficiency in the intrinsic pathway
Term
Pathophysiology Factor XIII deficiency
Definition
mutations which affect A or B chain of XIII, patients lack both plasma and platelet factor XIII. XIII actors after formation of fibrin, in vitro clot formation is abnormal.
Term
Deficiencies of factors of fibrin formation clinical symptoms
Definition
deficiencies of factors VIII and IX are indistinguishable in clinical presentation; they are readily diagnosed in patients with positive family histories. The diagnosis is based on unusual bleeding early in life, physical exam, laboratory evaluation and family history.
Term
Factor II (Prothrombin)clinical symptoms
Definition
severe bruising, bleeding from the nose and mouth, menorrhagia, as well as muscle bleeds, head bleeds and bleeding after trauma
Term
Factor VII clinical symptoms
Definition
serious bleeding
Term
Factor X clinical symptoms
Definition
bleeding into joints, muscle bleeding, mucus membrane bleeding, nosebleeds
Term
Factor XI clinical symptoms
Definition
major deficiency (homozygote) presents with excessive bleeding
Term
Factor XIII clinical symptoms
Definition
umbilical stump bleeding in neonatal period, intracranial hemorrhage with little to no trauma, recurrent soft tissue hemorrhage, and recurrent spontaneous abortion, delayed bleeding
Term
Deficiencies of factors of fibrin formation laboratory findings
Definition
deficiencies of factors VIII and IX shows prolonged aPTT, mixing study will be normal
Term
Factor II (Prothrombin)laboratory findings
Definition
aPTT and PT are prolonged, TT and BT are normal, diagnosis by specific assay for functional Prothrombin and immunologic tests for antigen levels
Term
Factor VII deficiency laboratory findings
Definition
prolonged PT, normal aPTT, fibrinogen and BT, specific factor assay for VII for diagnosis, naturally low at birth
Term
Factor X deficiency laboratory findings
Definition
PT and aPTT screening tests are prolonged, Russell’s viper venom test (activates X) is prolonged, X assay functional and immunologic for diagnosis
Term
Factor XI deficiency laboratory findings
Definition
prolonged aPTT, normal PT, fibrinogen and BT
Term
Factor XIII deficiency laboratory findings
Definition
normal PT, aPTT, fibrinogen, BT, solubility of fibrin clots in 5 M urea or 1% monochloroacetic acid
Term
Laboratory tests and results for vWD subtypes
Definition
platelet count, aPTT, PT, BT, and PFA-100 (platelet aggregation studies).
Term
Laboratory tests and results vWD Type 1
Definition
normal platelet count, normal or increased aPTT, normal PT, normal or increased BT, and normal aggregation with ADP, collagen, and epinephrine but decreased or absent aggregation with ristocetin.
Term
Laboratory tests and results vWD Type 2A
Definition
normal platelet count, increased BT
Term
Laboratory tests and results vWD Type 2B
Definition
decreased platelet count, increased BT
Term
Clinical symptoms for vWD subtypes
Definition
hemorrhagic tendency depends on type; both types are characterized by hemorrhage from delicate mucocutaneous tissues
Term
Laboratory tests and results for deficiencies of factors VII and IX
Definition
platelet count, PFA-100, PT, aPTT, BT and factor specific assays. All normal laboratory results except for prolonged aPTT, factor VIII deficiency a decreased factor VIII assay, and in factor IX deficiency a decreased factor IX assay.
Term
Clinical symptoms for deficiencies of factors VII and IX
Definition
unusual bleeding symptoms early in life, family history, physical exam and laboratory evaluation, bleeding into joints
Term
Laboratory tests and results for Bernard-Soulier disease
Definition
platelet count is normal or decreased, increased BT, abnormal platelet aggregation with ristocetin, giant platelets seen in PBS
Term
Clinical symptoms for Bernard-Soulier disease
Definition
bleeding symptoms similar to thrombocytopenia (excess, abnormal bleeding), giant platelets
Term
Laboratory tests and results for Glanzmann’s Thrombasthenia
Definition
normal platelet count, increased BT, and abnormal platelet aggregation studies with ADP, collagen and epinephrine
Term
Clinical symptoms for Glanzmann’s Thrombasthenia
Definition
bleeding symptoms in infancy and involved superficial areas of the body characteristic of platelet abnormalities, can cause death
Term
Conditions that result in acquired abnormalities of the hemostatic system
Definition
DIC, Liver disease, Vitamin K deficiency, acquired pathological inhibitors
Term
DIC pathophysiology
Definition
secondary to a condition that serves as a trigger, the initiating even is a generalized or systemic formation of thrombin and activation of coagulation, thrombin circulates and acts on its substrates causing a consumption of coagulation factors, the problem is that there is a failure in the mechanisms that limit blood clotting and thrombin generation and bleeding ensues. Fibrin strands within vessels damage the RBCs as they flow through causing MAHA (schistocytes). Fibrin also obstructs the vasculature and can result in hypoxia and organ failure.
Term
Confirmatory laboratory procedures for DIC
Definition
PT, aPTT, and fibrinogen are prolonged, decreased AT, plasminogen and anti-plasmin levels, positive for FDP and D-Dimer, decreased platelet count and platelet function tests are abnormal, schistocytes and thrombocytopenia on the PBS
Term
Liver Disease pathophysiology
Definition
disease and inhibition of liver activity inhibits all hemostatic functions because the liver synthesizes most procoagulant factors, fibrinolytic proteins and naturally occurring hemostatic inhibitors.
Term
Confirmatory laboratory procedures for Liver Disease
Definition
all screening coagulation tests are prolonged, platelet count can be decreased, positive for hyper-splenism and decreased TPO, increased FDPs and a lack of hepatic clearance of FDPs and plasminogen activators
Term
Vitamin K deficiency pathophysiology
Definition
malabsorptive syndromes, biliary tract obstruction, and prolonged antibodies can cause the precursor proteins to vitamin K to lack the calcium binding sites (nonfunctional) which induces functional deficiencies in all of the vitamin K dependent proteins.
Term
Confirmatory laboratory procedures for Vitamin-K deficiency
Definition
PT and/or aPTT prolonged for newborns
Term
Acquired pathological inhibitors pathophysiology
Definition
usually associated with diseases and drugs, inhibitor deficiencies can interfere with or neutralize clotting factor activity
Term
Confirmatory laboratory procedures for acquired pathological inhibitors
Definition
prolonged screening test is not corrected with 1:1 mixture with normal plasma (mixing study)
Term
Laboratory screening methods for deficiencies
Definition
mixing studies correct abnormal coagulation tests
Term
Laboratory screening methods for inhibitors
Definition
mixing studies do not correct abnormal coagulation tests
Term
A patient who has a deficiency of a clotting factor could have
Definition
inherited an abnormal gene from a parent, aquired the deficiency because of another disease present, or decreased amount of the particular factor in the blood
Term
Why do patients who have deficiencies of clottin factors usually have abnormal bleeding?
Definition
Fibrin formation is slower and less effective
Term
What clotting factor is deficient in a patient with hemophilia?
Definition
F-VIII
Term
The most probable cause of bleeding when platelet aggregation with risotcetin is abnormal, aPTT is prolonged and F-VIII assay is abnormal
Definition
von willebrand disease
Term
what laboratory test that is abnormal in vWD is different from that of a patient with hemophilia A
Definition
platelet aggregation studies
Term
What result of a platelet count would you expect in a patient with hemophilia A?
Definition
normal
Term
Which are characteristics of a patient with DIC?
Definition
prolonged PT, aPTT, and decreased platelet count
Term
What result would be expected in a newborn infant?
Definition
longer aPTT test than in an adult
Term
The results indicating abnormal aggregation with ristocetin indicate that the patient has a defect in what
Definition
platelet adhesion
Term
WHat is the usual inhereitence pattern of vWD
Definition
autosomal dominant
Term
What is characteristic of Type 1 vWD?
Definition
decreased amounts of all VWF multimers
Term
what laboratory procedure analyzes vWF qualitatively for abnormalities of the molecular structure?
Definition
SDS-page gel electrophoresis
Term
What is the cause of von Willebrand disease?
Definition
genetic mutations in the vWF gene
Term
What would the presence of delayed bleeding and deep muscular hematomas be most likely in?
Definition
a patient with F-VIII deficiency
Term
What disease would most likley find an abnormal PT?
Definition
DIC
Term
What is true concerning aquired circulating pathologic to single coagulation factors?
Definition
They cause the same symptoms in the patient as an inhereited deficency of the same factor
Term
What is true in the condition known as DIC?
Definition
Fibrinogen and platelets becomes depleated
Term
What laboratory test is helpful in differentiating primary and secondary fibrin(ogeno)lysis?
Definition
D-Dimer test
Term
Why do patients with type 1 VWD have 25-50% of VWF in their plasma?
Definition
autosomal dominant, abnormalities in one gene, other gene is functional
Term
Why do type 1 VWD patients have corresponding decrease in F-VIII in their plasma?
Definition
F-VIII requires VWF
Term
What causes a true quantitative decrease in F-VIII
Definition
tests for function and immunologic activity are both decreased
Term
Equal decrease in F-VIII assay, VWF:RCo and VWF: Ag assay
Definition
VWD type 1
Term
Antigenic properties of VWF
Definition
VWF:Ag
Term
functional activity of F-VIII
Definition
F-VIII:C
Term
complex of F-VIII and VWF?
Definition
F-VIII/VWF Complex
Term
Why are platelet functions abnormal in VWD?
Definition
VWF is necessary for platelets to adhere to collagen, ristocetin replaces collagen in the test. Without VWF platelets do not adhere and do not aggregate
Term
Why is TT abnormal in afibrinogemia
Definition
no fibrinogen to convert to fibrin, TT depends on the adequte conversion of soluble fibrinogen to fibrin
Term
Why is TT abnormal in dysfibrinogenemia
Definition
fibrinogen with abnormal ability to conver to fibrin
Term
Why is PT but not aPTT prolonged in F-VII deficiency
Definition
Reagent in PT is tissue thromboplastin which is activated by F-VII, fibrin formation is delayed because deficient F-VII. No thromboplastin in the aPTT, fibrin is formed by activating contact factor system and F-VII is bypassed
Term
Why are tests normal in patients with F-XIII deficiency?
Definition
all tests depend on fibrin formation regardless of cross-linking. F-XIII functions after fibrin is formed
Term
Why is thrombocytopenia present with DIC?
Definition
platelets are consumed, activated by thrombin and incorporated into the fibrin clots within circulation
Term
Decreased F-V?
Definition
prolonged PT and aPTT
Term
Decreased F-VIII
Definition
prolonged aPTT
Term
decreased fibrinogen
Definition
prolonged PT and aPTT
Term
decreased antithrombin
Definition
neither PT or aPTT prolonged
Term
Which lab test distinguishs DIC from Hemophilia A?
Definition
aPTT is prolonged and F-VIII assay is decreased in hemophilia A, everything else is normal. All factor assays are abnormal, platelet count is abnormal in DIC
Term
The traumatic injury to the head and the wound infection are common causes of
Definition
DIC
Term
The reason for the abnormal prothrombin time and APTT in DIC is
Definition
acquired deficiency of several clotting factors because the patient has abnormal clotting within the blood vessels
Term
Platelet adhesion to collagen requires the presence of adequate functional:
Definition
von Willebrand factor and glycoprotein Ib
Term
Patients with blood group O have:
Definition
lower levels of von Willebrand factor than patients with other blood groups
Term
Which of the following laboratory results is typical of a patient with a disorder of one of the clotting proteins?
Definition
prolonged prothrombin time and/or APTT
Term
A clotting factor deficiency that is inherited in an X-linked manner is:
Definition
factor IX deficiency
Term
Patients with clotting factor deficiencies may have abnormal bleeding because:
Definition
Fibrin is formed more slowly and is inadequate to stop bleeding.
Term
The laboratory test that is necessary to differentiate a factor VIII deficiency from a factor IX deficiency is:
Definition
factor assay
Term
Which hemostasis screening test(s) will be abnormal in patients with hemophilia A or B?
Definition
APTT only
Term
What should you do next is there is a prolonged aPTT?
Definition
Mix patient's plasma with normal plasma and repeat the APTT.
Term
If the repeated APTT result was 120.3 sec. the results of the repeated APTT indicate:
Definition
The original APTT test was not corrected.
Term
What is the most likely interpretation of the uncorrected aPTT?
Definition
lupus anticoagulant
Term
Which of the following procedures should be performed next to diagnose Lupus anticoagulant?
Definition
a dilute Russell's viper venom test or a kaolin clotting time test
Term
The lupus anticoagulant is:
Definition
an antibody that reacts with phospholipids in the reagents for hemostasis tests, causing prolongation of the tests
Term
The structure of the von Willebrand factor molecule is:
Definition
a large multimer composed of several identical dimeric subunits oriented by their N terminal ends
Term
The subtype of von Willebrand disease in which patients would have abnormal functional tests but normal immunologic tests for von Willebrand factor is:
Definition
type 2
Term
Which of the following is a functional test for von Willebrand factor?
Definition
ristocetin cofactor assay
Term
Vitamin K deficiency will cause:
Definition
deficiencies of functional forms of coagulation factors II, VII, IX, and X
Term
Patients with dysfibrinogenemia will usually demonstrate:
Definition
abnormal thrombin time as the only abnormal test for hemostasis
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