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2013-05-02 23:37:11
Thrombotic Hemorrhagic Disorders

Thrombotic and Hemorrhagic Disorders, Sample Collection and Handling, Tests
Show Answers:

  1. What disorder:
    Genetic deficiency
    Associated with DVT and pulmonary embolism
    Serine proteases not inhibited
    Negative feedback to cascade impaired
    Lab test used: Antithrombin activity assay
    Antithrombin (AT) deficiency
  2. What disorder:
    Vitamin K-dependent regulatory proteins that inactivate factors V and VIII
    Can cause superficial and deep vein thrombosis (DVT) and/or pulmonary embolism
    Protein C or Protein S deficiencies
  3. What disorder:
    Associated with thrombosis
    Prolonged PTT
    Factor XII assay confirms
    Faxtor XII (Hageman or Contact factor) deficiency
  4. What disorder:
    Associated with thrombosis
    Prolong PTT
    PTT shortens in patient plasma incubated with kaolin
    Prekallikrein (Fletcher factor) deficiency
  5. What disorder:
    Associated with thrombosis
    Slightly prolonged PTT
    HMWK (Fitzgerald factor) deficiency
  6. What disorder:
    Associated with thrombosis
    Inability to generate plasmin
    Plasminogen deficiency
  7. What disorder:
    Cause of thrombosis because of an amino acid substitution
    Causes thrombin generation and subsequent fibrin clot formation
    Lab test used: PCR-based molecular assay to single point mutation in the gene for factor V
    Most common hereditary cause of thrombosis
    Factor V Leiden (Activated Protein C Resistance - APCR)
  8. What disorder:
    Cause of thrombosis because of an amino acid substitution
    May have slightly elevated prothrombin level
    Lab test used: PCR-based molecular assay
    2nd most common hereditary cause of thrombosis
    Prothrombin gene mutation 20210
  9. What disorder:
    Abnormal structure of fibrinogen
    Caused by gene mutations
    Associated with either bleeding or thrombosis
    Dependent on the specific gene mutation
  10. What is the most common hereditary bleeding disorder?
    von Willebrand disease
  11. What disorder:
    Abnormalities in both primary and secondary hemostasis
    Caused by a defect that is needed for platelet adhesion to collagen in primary hemostasis
    The defect is also a carrier protein for factor VIII:C in secondary hemostasis
    Mild-Moderate bleeding
    Decreased vWF:RCo, vWF:Ag, and VIII:C
    Abnormal platelet aggregation with ristocetin
    Variable PTT
    Prolonged bleeding time
    von Willebrand disease
  12. How is von Willebrand treated?
    • Factor VIII concentrates
    • DDAVP (deamino-D-arginine-vasopressin) - used to raise plasma levels of vWF and VIII:C
    • Cryoprecipitate
  13. What disorder:
    Sex linked disorder transmitted on the X chromosome by carrier women to their sons
    Bleeding symptoms are proportional to the degree of the factor deficiency
    Spontaneous bleeding occurs often and is especially bad in joint regions
    Prolonged PTT
    Factor VIII:C assay to confirm
    • Factor VIII:C deficiency
    • (hemophilia A or classic hemophilia)
  14. How is Factor VIII:C deficiency (hemophilia A, classic hemophilia) treated?
    • Cryoprecipitate and factor VIII concentrates are used
    • In mild cases, DDAVP can be used to stimulate the release of VIII:C and vWF from stored reserves
  15. What disorder:
    Sex linked recessive
    Bleeding symptoms are proportional to degree of deficiency
    Prolonged PTT
    Factor IX assay to confirm
    • Factor IX (Christmas factor) deficiency
    • (hemophilia B or Christmas disease)
  16. How is Factor IX (hemophilia B, Christmas disease) treated?
    FFP or Factor IX concentrates
  17. What disorder:
    Mainly seen in the Ashkenazi Jewish population
    Characterized by clinical bleeding that is asymptomatic until surgery or trauma
    Prolonged PTT
    Factor XI assay to confirm
    • Factor XI deficiency
    • (hemophilia C)
  18. What disorder:
    Spontaneous bleeding of mucosa, intestines, and intracranial sites
    Prolonged bleeding time
    Decreased fibrinogen concentration
    Prolonged PT, PTT, and thrombin time
    • Factor I deficiency
    • (fibrinogen)
  19. What disorder:
    Spontaneous bleeding
    Delayed wound healing
    Unusualy scar formation
    Increased incidence of spontaneous abortion
    Abnormal 5.0 M Urea test
    Enzymatic and immunologic studies can be done
    • Factor XIII deficiency
    • (fibrin/clot-stabilizing factor)
  20. What disorder:
    Results in decreased synthesis of coag or regulatory proteins
    Causes impaired clearance of activated hemostatic components
    Prolonged PT, PTT, bleeding time
    Decreased plt counts
    Hepatic disease
  21. Where is Vitamin K synthesized?
    Produced by normal intestinal flora
  22. What is Vitamin K needed for?
    Liver synthesis of functional factors II, VII, IX, and X
  23. How can vitamin K deficiency occur?
    • Oral antibiotics
    • Warfarin/coumadin
    • Decreased absorption resulting from obstructive jaundice
    • Breast fed babies because breast milk is sterile
  24. What disorder:
    Predisposing condition triggers systemic clotting
    Leads to systemic fibrinolysis and bleeding
    Prolonged PT, PTT, thrombin time
    Decreased Plt count, antithrombin, fibrinogen
    Fibrin and FDPs are present
    Systemic thrombotic event causes multiple organ failure and systemic lysis ultimately leads to severe hemorrhage
    DIC with secondary fibrinolysis
  25. What disorder:
    Plamsminogen is inappropriately activated to plasmin in the absence of clot formation
    Plasmin circulates free in plasma and destroys factors I, V, VIII
    Prolonged PT, PTT, thrombin time
    Decreased fibrinogen
    Fibrinogen degradation products are present BUT fibrin degradation products are absent  b/c no clot formation
    Hemorrhagic symptoms may resemble DIC
    Primary fibrinogenolysis
  26. What would happen if you collect coag tests in a glass tube?
    Plain glass tubes will activate the intrinsic pathway, including the activation of the contact factors (prekallikrein, XI, XII)
  27. What is the ratio of blood to anticoagulant in sodium citrate tubes?
  28. What is the specimen processing time limit for PT and PTT?
    • PT: 24 hours room temp
    • PTT: 4 hours room temp
  29. What is the best temperature to test for coagulation tests?
    37 degrees celcius
  30. What factors does the PTT test screen for?
    • XII (Hageman Factor or Contact Factor)
    • XI
    • Prekallikrein
    • HMWK
    • IX (Christmas Factor)
    • VIII (Anti-hemophilic Factor)
    • X (Stewart Prower)
    • V (Labile Factor)
    • II (Prothrombin)
    • I (Fibrinogen)
    • (Intrinsic and common pathways)
  31. What test screens for:
    XII (Hageman or Contact Factor)
    IX (Christmas Factor)
    VIII (Anti-hemophiliac Factor)
    X (Stewart Prower Factor)
    V (Labile Factor)
    II (Prothrombin)
    I (Fibrinogen)
  32. What 2 reagents are needed to test for PTT?
    • Platelet phopholipid substitute with an activator (kaolin, celite, silica, or ellagic acid)
    • Calcium chloride
  33. What is the normal reference range for PTT?
    23-35 seconds
  34. What clinical conditions are associated with a prolonged PTT?
    • Factor deficiencies in the intrinsic/common pathways
    • Acquired circulating inhibitor (heparin, lupus, or antibody to a specific factor)
  35. What factors does the PT test screen for?
    • VII (Stabile Factor)
    • X (Stewart Prower Factor)
    • V (Labile Factor)
    • II (Prothrombin)
    • I (Fibrinogen)
    • (extrinsic and common pathway)
  36. What test screens for:
    VII (Stabile Factor)
    X (Stewart Prower Factor)
    V (Labile Factor)
    II (Prothrombin)
    I (Fibrinogen)
  37. What reagents are used to test for PT?
    • Thromboplastin source (tissue factor)
    • Calcium chloride
  38. What is the normal reference range of PT?
    10-14 seconds
  39. What is used as a means of standardizing PT reporting worldwide - it is not dependent upon thromboplastin reagent or instruments?
  40. What is the calculation for INR?
    • ISI: is the international sensitivity index for the thromboplastin reagent, which is provided by the manufacturer (lot number and instrument specific) 
  41. What can a prolonged PT indicate?
    Factor deficiencies in the extrinsic/common pathways
  42. What test will differentiate a factor deficiency from a circulatory inhibitor?
    Mixing study
  43. What does a shortening of the time in a mixing study indicate?
    • Factor deficiency
    • (hereditary, acquired, or liver disease)
  44. What does a partial or no correction with a mixing study indicate?
    • Circulating inhibitor
    • (heparin, lupus inhibitor, VIII inhibitor, IX inhibitor)
  45. What test is used for fibrinogen?
    • Fibrinogen level
    • Thrombin time
  46. What test is used to confirm a suspected factor deficiency?
    Factor assays
  47. What test differentiates an unstable clot that forms in factor XIII deficiency and a factor XIIIa stabilized clot and what are the results?
    • 5.0 M urea clot solubility test
    • XIII: dissolves in 5.0 M urea
    • XIIIa: remains intact in 5.0 M urea
  48. What test is used to see if the lupus inhibitor is present or not and what is the result?
    • Dilute Russell viper venom
    • If lupus inhibitor is present, the venom is neutralized, and the test is prolonged
  49. What test:
    Usually a point of care test performed at a clinic, cardiac cath lab, or surgical suite
    Most often used to monitor high dose heparin therapy during coronary artery bypass surgery
    Activated clotting time (ACT)
  50. What test is used to see if either fibrin degradation products or fibrinogen degradation products are present?
    • FDPs
    • (fibrin degradation products)
  51. What test is highly specific for fibrin degradation products only?
    D-Dimer Assay
  52. How does Heparin therapy work and what must be monitored?
    • Antithrombin/heparin complex inhibits serine proteases (XIIa, XIa, IXa, Xa, IIa, and kallikrein) - which is immediate
    • Monitor PTT (supposed to be 1.5-2 times a patient's baseline PTT) and platelet counts (for heparin induced thrombocytopenia)
  53. Can heparin therapy be reversed?
    • Yes
    • Protamine sulfate
  54. How does Warfarin (Coumadin) therapy work?
    • Vitamin K antagonist
    • Inhibits liver synthesis of functional prothrombin group factors II, VII, IX, X
  55. Can Warfarin (Coumadin) be reversed?
    • Yes
    • Vitamin K can be administered
  56. What needs to be monitored when giving Warfarin (Coumadin) therapy?
    • PT
    • INR
    • (INR therapeutic range for most conditions is 2-3)
  57. What medication is used in hemostasis:
    Lower risk of heparin induced thrombocytopenia
    Mainly an anti-Xa inhibitor, anti-IIa response is reduced
    Low-molecular weight heparin
  58. What medication is used in hemostasis:
    Inactivates thrombin only
    Does not require antithrombin to work
    Used in place of unfractionated or low molecular weight heparin when HIT is suspected
    Prolongs PT, PTT, and thrombin time
    Direct thrombin inhibitor
  59. What medication is used in hemostasis:
    Can be used to lyse existing clots 
    Reestablish vascular perfusion
    Convert plasminogen to plasmin - which destroys the fibrin clot, factors I, V, VIII
    Affected tests: PT, PTT, thrombin time, fibrinogen, FDP, and D-Dimer
    Fibrinolytic therapy
  60. What medication is used in conjunction with other anticoagulant therapies to prevent recurrence of thrombotic events?
    • Antiplatelet medications
    • (aspirin, Plavix, ticlopidine, and nonsteroidal anti-inflammatory drugs/NSAIDS)