Bleeding Disorders - Ch. 14 Flashcards

1
Q

Petechiae and purpura, normal PT and PTT, normal platelet count

A

Bleeding due to abnormalities in vessel walls

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2
Q

Major infection that can cause vasculitis, DIC, and abnormal bleeding

A

Meningococcemia (N. meningitidis)

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3
Q

Ehlers-Danlos syndrome

A

Collagen defect –> microvascular bleeding

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4
Q

Vitamin C deficiency, bleeding

A

Scurvy –> collagen defect, microvascular bleeding

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5
Q

Cushing syndrome, bleeding

A

Excessive corticosteroid production –> protein wasting –> loss of perivascular support tissue –> microvascular bleeding

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6
Q

***Hereditary hemorrhagic telangiectasia (W-O-R syndrome)

A

AD, mutations cause TGF-beta signaling abnormalities, causing dilated tortuous blood vessels that bleed easily (nose, tongue, mouth, eyes, GI tract)

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7
Q

Henoch-Schonlein purpura

A

Systemic immune IgA nephropathy/vasculitis disorder – immune complex deposition –> rash/palpable purpura, colicky abdominal pain, polyarthralgia, acute glomerulonephritis

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8
Q

4 general causes of thrombocytopenia

A
  • Decreased production
  • Decreased survival
  • Sequestration
  • Dilution
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9
Q

Things that may selectively affect/inhibit megakaryotyes, causing thrombocytopenia

A

Cytotoxic drugs, thiazide drugs, alcohol, measles, HIV

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10
Q

Things that may decrease platelet production due to BM failure

A

B12 or folate deficiency, aplastic anemia, myelodysplastic syndrome, metastatic cancer, granulomatous disease, leukemia

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11
Q

A woman is pregnant, but the fetus has very few platelets. Cause?

A

Alloantibodies - the baby’s platelets are destroyed by antibodies in the mother

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12
Q

A person with a mechanical heart valve has anemia and thrombocytopenia. Why?

A

Heart valve can cause damage to both RBCs and platelets

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13
Q

A patient receives a blood transfusion and develops thrombocytopenia. Why?

A

Platelets die over time in stored blood, so the patient’s platelet concentration is diluted with transfusion

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14
Q

Large spleen + thrombocytopenia

A

Spleen can sequester platelets, causing thrombocytopenia

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15
Q

Autoantibody destruction of platelets, bleeding

A

Immune thrombocytopenic purpura

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16
Q

3 causes of secondary chronic ITP

A
  • SLE
  • HIV
  • B cell neoplasms (CLL)
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17
Q

Antibodies against platelet glycoproteins 2b-3a or 1b-IX

What antibody type?

A

Immune thrombocytopenic purpura

IgG

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18
Q

Adult woman under 40, petechiae in skin and mouth, history of easy bruising, nose bleeds, and hemorrhaging after minor trauma. Menorrhagia and melena. Spleen appears normal, no LAD is noted.

A

Idiopathic chronic ITP

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19
Q

Adult woman under 40, petechiae in skin and mouth, history of easy bruising, nose bleeds, and hemorrhaging after minor trauma. Menorrhagia and melena. Splenomegaly and lymphadenopathy are notable.

A

Secondary chronic ITP - B-cell neoplasm

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20
Q

Thrombocytopenia, increased megakaryocytes in the marrow, large platelets in the blood, normal PT and PTT

A

Accelerated platelet destruction, causing increased thrombopoiesis

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21
Q

Child, recently had an upper respiratory viral illness, now presents with thrombocytopenia, petechiae, and purpura. PT and PTT are normal. Increased megakaryocytes in the marrow.

A

Acute ITP

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22
Q

Drugs that cause thrombocytopenia via antibody recognition

A

Quinine, quinidine, vancomycin, heparin

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23
Q

A patient is being treated for an acute MI with IV heparin in the hospital. About a week after treatment, signs of bleeding begin. She barely survives a pulmonary embolism. Blood work shows antibodies against platelet factor 4

A

Heparin-induced thrombocytopenia (HIT) - Type 2

24
Q

CD4, CXCR4

A

Receptor and co-receptor for HIV infection, found on megakaryocytes

25
Q

An HIV+ patient develops thrombocytopenia of no other known cause. Why? (2)

A
  • HIV infects megakaryocytes via CD4/CXCR4 and causes apoptosis
  • HIV infects plasma cells and causes autoantibody formation against platelet 2b-3 complexes, leading to phagocytosis
26
Q

Adult female, petechiae/purpura, fever, pallor, weakness, fatigue, transient neurologic deficits. Labs show thrombocytopenia, normal PT and PTT. PB smear shows schistocytes or helmet cells. BM biopsy shows increased megakaryocytes.

Cause?

A

Thrombotic thrombocytopenic purpura (TTP)

Anti-ADAMTS13 autoantibodies (acquired form) or mutation (inherited)

27
Q

Child started having bloody diarrhea, fever, and abdominal pain 3 days ago. Now presents to the ER w/ petechiae/purpura, oliguria, and hematuria. Labs show throbocytopenia, normal PT and PTT. PB shows schistocytes or helmet cells. BM biopsy shows increased megakaryocytes.

Cause?

A

Hemolytic-uremic syndrome (HUS)

EHEC (or other) infection/toxin, causing endothelial damage, platelet activation, micro-thrombi, and inflammation

28
Q

Defect in complement factor H, CD46, or factor I

A

Atypical HUS

29
Q

Petechiae/purpura, mild thrombocytopenia, enlarged platelets in blood, GP1b-IX deficiency/mutation

Inherent problem?

A

Bernard-Soulier syndrome

Defective platelet adhesion (vWF receptor deficit)

30
Q

Petechiae/purpura/bleeding, normal platelet amount, IIb-IIIa deficiency/mutation

Inherent problem?

A

Glanzmann thrombasthenia

Impaired platelet aggregation (cannot form bridges via fibrinogen)

31
Q

Effect of uremia on platelets

A

Disrupts adhesion AND aggregation

32
Q

Storage pool disorders

A

Defective release of thromboxane and ADP from activated platelets

33
Q

Effect of aspirin on platelets

A

Inhibits production of TxA2 and PGs, which are needed for proper platelet function

34
Q

Post-traumatic ecchymoses, prolonged bleeding after surgeries, bleeding into GI tract, GU tract, and weight-bearing joints

A

Coagulation factor deficiencies

35
Q

Patient has obvious bleeding issue. Labs show normal platelet amount, prolonged PTT, decreased factor VIII level. Ristocetin activity is reduced.

A

Von Willebrand Disease

36
Q

Why is factor VIII decreased in vWD types 1 and 3?

A

vWF stabilizes factor VIII, thus deficient vWF causes decreased factor VIII

37
Q

What is Ristocetin?

A

Causes platelet aggregation via vWF binding to GP1b. Reduced if vWF is deficient.

38
Q

Male, history of easy bruising and progressive joint pain, presents to the ER due to massive hemorrhage after falling from a tree. Normal platelet amount, prolonged PTT, decreased factor VIII level or activity.

A

Hemophilia A (factor VIII deficiency)

39
Q

How to distinguish Hemophilia A from Hemophilia B?

A

ONLY from factor VIII and IX assays

40
Q

A chronic alcoholic presents with excessive bleeding following minor trauma. Labs show normal platelet amount. PT and PTT are prolonged.

A

Liver disease –> deficient coagulation factors and epoxide reductase (vitamin K activation)

41
Q

Triggers of DIC

A
  • Amniotic fluid tTP (pregnancy complication)
  • Septic endotoxins (E. coli, meningococcemia)
  • Mucinous adenocarcinoma
  • APL primary granules
  • Ag-Ab complexes (SLE)
  • Heat stroke or burns
42
Q

Bilateral renal cortical necrosis

A

DIC

43
Q

Kasabach-Merritt syndrome

A

DIC thrombi w/in giant hemangiomas due to stasis and fragile BV trauma

44
Q

Waterhouse-Friderichsen syndrome

A

DIC thrombi via meningococcemia causing massive adrenal hemorrhage and failure

45
Q

Read more about DIC

A

a

46
Q

Bleeding or thrombosis, thrombocytopenia, increased PT and PTT, decreased fibrinogen, D-dimer increase

A

DIC

47
Q

Acute DIC is most often due to _____ and presents with _____

A

Obstetric complications; bleeding

48
Q

Chronic DIC is most often due to _____ and presents with _____

A

Cancers (adenocarcinomas, APL); thrombosis

49
Q

A patient is in the hospital and receives a transfusion of packed RBCs and/or platelets. Soon after, she develops a fever, chills, and dyspnea. She responds well to acetaminophen.

Cause?

A

Febrile nonhemolytic reaction (transfusion complication)

Donor leukocytes secreting inflammatory mediators due to the foreign environment

50
Q

A patient receives a blood transfusion and develops a severe anaphylactic reaction. Explain

A

IgA deficiency –> IgG antibodies develop against the IgA in the donor blood –> allergic reaction

51
Q

A patient receives a blood transfusion and develops hives all over his body. Explain

A

Allergen in the donor blood –> IgE reaction in the patient

52
Q

A patient receives a blood transfusion and develops fever, shaking chills, and flank pain. Hemoglobinuria. A direct Coombs test is positive. May progress to severe symptoms. Explain

A

IgM reaction to inappropriate ABO blood type, causing complement-mediated hemolysis and inflammation

53
Q

Blood transfusion, low haptoglobin, high LDH, positive direct Coombs test, anti-Rh, anti-Kell, anti-Kid antibodies

Antibody type? To what?

A

Delayed hemolytic transfusion reaction

IgG - to foreign protein RBC antigens

54
Q

Patient w/ COPD, blood transfusion, sudden SOB, respiratory failure, b/l pulmonary infiltrates, fever, hypotension

Due to what?

The donor was most likely what?

A

Transfusion-related acute lung injury (TRALI)

Lung neutrophil activation via antibodies from the transfused blood against MHC antigens

A mother of multiple children

55
Q

Blood transfusion, fever, hypotension, chills. Must be cautious of what?

Should do what?

A

Infectious spread via transfusion

Start on prophylactic antibiotics while awaiting lab results