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Coagulation Disorders: Secondary Hemostasis

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Fibrin formation ineffective and slowed so patient presents with abnormal bleeding ... Factor IX Deficiency Hemophilia B, Christmas Disease 20% of all hemophiliacs ... – PowerPoint PPT presentation

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Title: Coagulation Disorders: Secondary Hemostasis


1
MLAB 1227 CoagulationKeri Brophy-Martinez
  • Coagulation Disorders Secondary Hemostasis

2
Disorders of the Proteins of Fibrin Formation
  • Inheritance of a defective gene
  • Failure of synthesis of a hemostatic protein
  • Malfunction or impaired molecule
  • Acquisition of a deficiency secondary to another
    condition
  • Fibrin formation ineffective and slowed so
    patient presents with abnormal bleeding

3
Terms
  • Quantitative absence of a coagulation protein
  • Qualitative Present in plasma but functionally
    defective

4
Lab Diagnosis General
  • PT prolonged
  • aPTT prolonged
  • Platelets normal

5
Patient Presentation
  • Coagulation Factor Disorders
  • Platelet Disorders
  • Bleed from ruptured arterioles
  • Deep muscular joint bleeding
  • Delayed bleeding
  • Ecchymoses
  • Hematuria
  • No petechiae
  • Bleed from capillaries
  • Superficial bleeding
  • Acute bleeding
  • Ecchymoses
  • Hematuria
  • Petechiae

6
Factor VIII Deficiency
  • Hemophilia A classical hemophilia
  • Sex-linked recessive (carried by female,
    manifested in the male) causing a marked decrease
    in VIIIC (VIIIvWf is normal)
  • Deficiency of factor VIII portion of VIII/vWf
    complex
  • Patient has normal circulating vWf
  • Accounts for 80 of all hemophiliacs
  • Less than 5 Factor VIII activity
  • Results in symptoms of
  • Bleeding occurs with NO trauma or trivial injury
  • Spontaneous bleeding into joints, causes extreme
    pain and destroys cartilage of knees, elbows,
    ankles
  • Deep tissue hemorrhage internally
  • Hematuria
  • CNS bleeding
  • PTT is greatly prolonged ( normal platelet
    function tests)

7
Factor VIII Deficiency
  • Von Willebrand's Disease lack of or defective
    VIIIvWF
  • Autosomal dominant seen in both males and
    females
  • Most common inherited blood disorder
  • Mild to moderately low Factor VIIIvWF (5-15).
    Factor VIII function is affected more than the
    quantity.
  • Platelet abnormalities adhesiveness and
    aggregation, bleeding times

8
Von Willebrand's Disease
  • Clinical Features
  • Lab Diagnosis
  • Mild bleeding in mucosal cutaneous tissues
  • Easy bruising
  • Hallmark is variability of symptoms
  • PTT prolonged
  • PT normal
  • Platelet count normal
  • BT abnormal

9
Factor IX Deficiency Hemophilia B, Christmas
Disease
  • lt20 of all hemophiliacs
  • Sex-linked recessive
  • No Factor IX function
  • Clinically indistinguishable from hemophilia A
    must do special coag tests to distinguish
  • Can be acquired in coumadin therapy and liver
    disease

10
Factor XI Deficiency Rosenthal's Disease or
Hemophilia C
  • lt5 of all hemophiliacs
  • Autosomal recessive
  • Highest incidence in Jewish persons of Russian
    decent
  • Mucosal bleeding
  • Requires therapy only following childbirth or
    surgery

11
Congenital Disorders of the Other Factors
  • The following factors are rarely deficient or
    defective to the extent that coagulation is
    slowed I, II, V, VII, X, XII, XIII
  • Very rarely seen
  • Severity of bleeding dependent upon concentration
    of factor present
  • PK and HMWK disorders do exist but patients do
    not have bleeding tendencies.
  • Defective activation of the fibrinolytic system
    are seentherefore an increased chance of
    thrombosis
  • PTT results are often markedly prolonged in
    these asymptomatic patients.

12
Acquired Coagulation Disorders
  • Two or more factors generally affected
  • Bleeding from multiple sites
  • Usually result from underlying disease
    acquired
  • Produced by a variety of conditions
  • Liver Disease
  • Impaired or abnormal synthesis of I, II, V, VII,
    IX and X, XI, XII, XIII, PK, HMWK (also AT III,
    the antiplasmins, plasminogen)
  • Enhanced destruction (primary fibrinolysis) of
    these factors
  • Vitamin K Deficiency II, VII, IX and X (also
    Protein C and S)
  • Absence of vitamin K renders calcium binding
    sites nonfunctional
  • Sources are diet and intestinal bacterial flora
  • At birth, deficiency exists due to decreased
    production of factors since the liver is immature
    and absence of normal intestinal flora
  • DIC see next slides
  • Pathologic Inhibitors see next slides

13
DIC Disseminated Intravascular Coagulation
  • Consumption Coagulopathy
  • Coagulation Disorder
  • Thrombo-hemorrhagic disorder
  • Life threatening
  • Bleeding is the most apparent characteristic
  • Initiating events are thrombotic, where material
    enters circulation
  • Occurs due to lack of the negative feedback
    mechanism

14
DIC Disseminated Intravascular Coagulation
  • Pathological syndrome
  • Uncontrolled formation of fibrin clots in
    circulating blood
  • Small and large vessel thrombosis with impairment
    of blood flow and possible organ damage
    (systemic)
  • Activation of fibrinolytic system to break down
    the excessive clots. Large amounts of FDP formed
    due to large number of clots being broken down
  • Consumption of factors and platelets resulting in
    hemorrhage
  • Secondary complication of conditions which cause
    hyperactivation of the intrinsic or extrinsic
    coagulation systems

15
DIC
  • Causes
  • Extrinsic activation
  • Obstetric usually due to major tissue damage
    such as retained dead fetus, abruptio placentae,
    or placenta previa
  • Acute leukemias Promyelocytic increase number
    of granules released into circulation as cells
    break down
  • Intravascular hemolysis ex transfusion
    reaction
  • Massive trauma (especially crushing injuries),
    burns, surgical procedures
  • Heat stroke
  • Snake venoms

16
DIC Causes cont
  • Causes
  • Intrinsic activation
  • Septicemias and infections viral, bacterial,
    rickettsial, fungal, protozoan (especially gram
    negative that release endotoxins)
  • Tumors foreign tissues and cells
  • Prosthetic devices heart valves, aortic
    balloon, peritoneal shunting
  • Vascular disease damaged endothelial lining
  • Snake venoms

17
DIC How Does It Occur?
  • Step 1 Out of control clotting
  • Causes widespread fibrin deposits in vessels of
    tissues and organs
  • Subsequent event Hemorrhage
  • Clotting proteins consumed at a high rate
  • Causes multiple factor deficiencies, especially
    fibrinogen group
  • Platelets caught in thrombi and removed

18
DIC How Does It Occur?
  • Step 2 Triggers Fibrinolytic system to remove
    fibrin
  • Results in
  • Circulating degradation products that interfere
    with platelet function normal clot formation
  • Degradation of Factor V VIII

19
DIC How Does It Occur?
  • Step 3 Uncontrolled plasmin and thrombin enter
    circulation
  • Why?
  • Inhibitors such as ATIII have been depleted

20
DIC How Does It Occur?
  • Step 4 Appearance of Symptoms
  • Bleeding from multiple sites
  • Petechiae
  • Purpura
  • Occlusions in organs
  • Oozing from arterial lines, venipuncture sites

21
DIC
  • No one specific test for DIC, but FDP is the most
    helpful
  • Lab values
  • platelet count decreased
  • PT increased
  • PTT increased
  • Fibrinogen decreased
  • FDP /D-dimer positive
  • RBC fragments present
  • ATIII decreased

22
DIC
  • Treatment
  • Goal is to treat the underlying condition
  • Remove the triggering process treat with
    antibiotics, antineoplasms, remove dead tissue,
    treat the diseases or conditions
  • Heparin to prevent or limit further coagulation
  • Replace factors, platelets give FFP

23
Acquired Coagulation Disorders Pathologic
Inhibitors
  • Develop in patients with certain disease states
    and others with no underlying conditions
  • Circulating anticoagulants which may develop
    against any clotting factor
  • Classed as immunoglobulins
  • Either IgG or IgM
  • Can be alloantibodies or autoantibodies
  • Not normally synthesized by the body, bind with
    the factors making them unavailable for use in
    the cascade

24
Types of Inhibitors
  • Directed against a single coagulation factor
  • Seen in patients with inherited factor
    deficiencies that have had replacement therapy
    for bleeding complications
  • Less commonly seen in healthy people and those
    taking certain drugs
  • Rare, except Factor VIII IX
  • How do we find them?
  • Interfere with clotting factor activity
  • PTT prolonged, other tests normal
  • Mixing study test will still be prolonged

25
Types of Inhibitors
  • Lupus Inhibitor/Anticoagulant
  • Seen in patients with autoimmune diseases, drug
    reactions, but also in normal patients
  • Antibodies do not bind coag factors, but
    interfere with phospholipid-dependent reagents
    used in coag lab tests
  • Patients have no in vivo bleeding problems
    (though some have an increase risk of thrombosis)
  • In vitro, any coag test using a phospholipid
    reagent will be falsely prolonged (PT, PTT)
  • Coag studies must be performed using reagents
    that do not contain phospholipids
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