BLEEDING AND THROMBOTIC DISORDERS Flashcards Preview

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Flashcards in BLEEDING AND THROMBOTIC DISORDERS Deck (35):
1

dyspnea, acute renal failure

BT-prolonged

Platelet count- Low

PT- Prolonged

PTT-Prolonged

Fibrinogen- decreased1. 

1.Diagnosis?

2. Most sensitive screen?

 

Q image thumb

1. DIC

2. Elevated D-Dimers

2

Why is PT/INR used to monitor patients on warfarin?

Among all Vit K dependent coag factors Factor VII has the shortest half life. 

So if you give a patient Coumadin, the first factor to show a decrease in activity will be factor VII (the others will drop off too, but not until later on). 

it’s best to monitor therapy by taking a look at the extrinsic pathway (using the PT/INR), since that’s the pathway that will be affected first. 

3

Defect assoc with Glanzmann thrombasthenia

deficiency or dysfunction of glycoprotein IIb-IIIa

4

Young female 

malar rash, renal failure

PS- Thrombocytopenia

PTT – Prolonged

Mixing study – does not correct the PTT

Kidney biopsy- Glomeruli show multiple capillary and arterial thromboses

Diagnosis?

ANTIPHOSPHOLIPID ANTIBODY SYNDROME

5

2 to 5-mm mm, red or purple macules (spots); in the distal lower extremities ,conjunctiva and palate

Q image thumb

Petechiae

6

1. Diagnosis?

Neurologic symptoms
Fever
Kidney Failure

BT-Prolonged

Platelet count- Low

PT- Normal

PTT- Normal

2. Etiology?

Q image thumb

1. Thrombotic Thrombocytopenic Purpura (TTP)

2. Deficiency of ADAMTS13

7

2 properties of antiphospholipid antibodies

 

a. Bind to phospholipid surface

b. bind to the phospholipid part of the PTT reagent

8

cause of hemorrhage in DIC

depletion of factors required for hemostasis and the activation of fibrinolytic mechanisms

9

1. Does heparin prolong PT or PTT ?

2. How?

1. Prolongation of PT and PTT 

Gotcha ;)

2. Heparin activates ATIII- this in turn inhibits both sides of the coagulation cascade – VIIa, IXa, Xa, XIa and thrombin

 

10

Individual with known parenchymal liver disease

ecchymoses, easy bruisability

BT- Normal

Platelet count- Normal

PT- Prolonged

PTT- Prolonged

Fibrinogen - Normal

1. Diagnosis?

2. Name the special poikilocyte seen on the peripheral smear. What history given above explains its appearance on the smear?

Q image thumb

1. Vitamin K deficiency

2. Acanthocyte- if due to severe liver disease

11

Why do women with APLA have recurrent miscarriages?

Due to antibody-mediated inhibition of t-PA activity necessary for trophoblastic invasion of the uterus

12

Consequence of microthrombi formation in DIC

tissue hypoxia and infarction

13

superficial bleeding localized to skin and mucous membranes

Purpura

14

Bernard Soulier/ vW disease?

BT- Prolonged

Platelet count-Low

PT- Normal

PTT- Normal

reduced ristocetin cofactor activity which does not normalize after the addition of normal plasma

Bernard-Soulier syndrome

15

1. One test that you will perform to distinguish decreased production from increased destruction of a coagulation factor

2. Explain the steps and interpretation of mixing studies.

1. Mixing studies

2. 

Procedure: Normal plasma mixed with patient plasma

Interpretation:

a. Correction of the PT and/or PTT indicates decreased production of coagulation factors.

b. No correction of the PT and/or the PTT indicates immune destruction of coagulation factors is present. Antibody is also destroying the coagulation factor in the normal plasma that is added to the test tube.

16

1. Inherited thrombotic disorder caused by replacement of arginine by glutamine at position 506.

2. Which coagulation factor levels are increased in this disorder as a result of the single base change?

1. Factor V Leiden

 

2. Factor Va

17

What's your diagnosis?

Child

Abrupt onset of petechiae/ecchymoses around 1-2 weeks after  viral illness

BT-Prolonged

Platelet count- low

PT- normal

PTT- normal

 The bone marrow aspirate shows an increase in immature megakaryocytes

 

Q image thumb

Acute immune thrombocytopenic purpura (ITP)

18

Primary versus secondary antiphospholipid syndrome

Primary antiphospholipid syndrome : 

  • manifestations of a hypercoagulable state
  • No evidence of other autoimmune disorders;
  • happens in association with certain drugs or infections.

Secondary antiphospholipid syndrome : seen in individuals with a well-defined autoimmune disease, such as systemic lupus erythematosus

19

How does heparin cause life threatening thrombosis?

1. large complexes of IgG, PF4, and heparin detach from platelets, , attach to endothelial cells, and damage the endothelial cells, causing activation of the coagulation system

2. Enhances AT III's affinity for thrombin, IXa,Xa, XIa and XIIa

20

Give one word that describes this :

Circulating antibodies that destroy specific coagulation factors

Inhibitors

21

glomerular capillaries occluded by  microthrombi

renal failure

Schistocytes on a peripheral smear

BT- Prolonged

Platelet count- Low

PT- Normal

PTT- Normal

history of bloody diarrhea after eating an undercooked hamburger at a restaurant

 

HUS

22

A 56 year old female with atrial fibrillation is started on a drug. 2 days later , she develops a lesion on her left lower limb as seen below. PT is prolonged.

1. What is the reason for the development of the lesion?

2. If this woman had an inherited Protein C deficiency, would she have a greater risk of developing this lesion?

 

Q image thumb

1. Warfarin induced skin necrosis

2. Protein C together with Factor VII has the shortest half life (6 and 14 hours respectively).  In normal individuals, the fall in protein C activity following the start of warfarin is generally not of clinical significance, but in heterozygotes with levels of protein C that are about half of normal, a further drop in protein C activity during the first day of therapy can trigger thrombosis in the skin.

 

23

Vitamin K dependent coagulation factors

II, VII, IX and X

24

List the causes for DIC

STOP Making Thrombi

Sepsis (gram negative)

Trauma

Obstetric complications

Pancreatitis

Malignancy

Transfusion

25

easy bruising

recurrent joint bleeds

BT- Normal

Platelet count- Normal

PT- Normal

PTT- Prolonged

What are the chances of a female heterozygous carrier with a normal male partner, conceiving an affected son?

 

50%

The diseases is Hemophilia A , X-linked recessive

26

List some antiphospholipid antibodies

anticardiolipin antibodies

anti-β2-glycoprotein antibodies

 lupus anticoagulants

27

Mechanism of heparin induced thrombocytopenia

Drug + PF 4 = antigenic complex which reacts with antibodies--> immune complex--> bind to platelet Fc receptor -->platelet activation

 

28

Why do individuals with antiphospholipid antibodies exhibit prolonged PTT?

 

The autoantibodies also just happen to bind to the phospholipid part of the PTT reagent . Then there’s not enough usable reagent in the test tube, and the patient’s specimen doesn’t clot! The coagulation tests are therefore falsely prolonged.

29

1. What's your diagnosis?

Young adult, female

Insidious onset of petechiae, ecchymoses

BT- Prolonged

Platelet count- Low

PT - Normal

PTT- Normal

The bone marrow aspirate shows an increase in immature megakaryocytes

2. What are the antibodies detected? 

 

 

Q image thumb

1. Chronic Immune Thrombocytopenic Purpura (ITP)

2. autoantibodies directed against platelet membrane glycoproteins IIb-IIIa or Ib-IX

30

Defect assoc with Bernard Soulier?

 

inherited deficiency of the platelet membrane glyco­protein complex Ib-IX.

31

Can you recall 2 examples of "inhibitors" 

Factor VIII antibodies (most common)

antiphospholipid antibodies 

32

Bernard Soulier/ vW disease?

BT- Prolonged

Platelet count-Normal

PT- Normal

PTT- Prolonged

reduced ristocetin cofactor activity which normalizes after the addition of normal plasma

vW disease

33

Very large, purpuric lesions

Q image thumb

Ecchymoses

34

3 examples of malignancy associated with thromboses

Trousseau Syndrome i.e migratory superficial thrombophlebitis

Thrombosis with chronic DIC

Nonbacterial thrombotic (marantic) endocarditis

35

Consequence of a single base substitution in the 3′ untranslated region of the prothrombin gene

30% higher plasma levels of structurally normal prothrombin