Abnormal Hemostasis Flashcards Preview

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Flashcards in Abnormal Hemostasis Deck (49):
1

What is APTT?

Activated partial thromboplastin time (APTT) is a medical test that characterizes blood coagulation. It is an indicator of the Intrinsic Pathway.

2

What is PT/INR?

Prothrombin time (PT) and international normalized ratio (INR) are assays that evaluate the Extrinsic Pathway.

3

Thrombocytosis

Increased platelet count

4

Thrombocytopenia

Decreased platelet count

5

Primary fibrinolysis

In primary fibrinolysis, fibrinogen is converted into fibrinogen degradation products.

6

Secondary fibrinolysis

In secondary fibrinolysis both fibrin and fibrinogen are digested by plasmin.

7

What are the categories of quantitative platelet disorders?

Thrombocytopenia
Thrombocytosis

8

What are some of the common causes of thrombocytopenia?

- Bone marrow hypoplasia
- Hereditary thrombocytopenia
- Drug induced thrombocytopenia

9

Immune thrombocytopenic purpura (ITP)

Presentation with purpura on the skin and increased bleeding due to IgG mediated autoimmunity resulting in low platelets

10

Thrombotic thrombocytopenic purpura (TTP)

Cause formation of microscopic thrombi that can damage organs due to the inhibition of ADAMTS13 which results in multimers of vWF to increase in the blood and increase the amount of platelets in adhesion.

11

How does aspirin alter platelets?

It blocks the formation of thromboxane A2 as it is a COX inhibitor which leads to the inhibition of platelet aggregation

12

Glanzmann's Thrombasthenia

Defect in GP IIb and IIIa that interferes with platelet aggregation and increases the bleeding time

13

Bernard-Soulier Disease

Defect in GP Ib prevents platelet adhesion which will increase the bleeding time

14

Storage Pool Disease

Decrease in the number of dense granules so aggregation is interfered with and bleeding is prolonged.

15

What are some causes of thrombocytosis?

- Splenectomy
- Reaction to cancer/drugs/infection
- Autonomous increase in platelets (thrombocythemia)

16

What are qualitative platelet disorders?

Platelet numbers are usually normal, however, platelet function is impaired.

17

What are some causes of qualitative platelet disorders?

- Disease induced platelet defects
- Drug induced platelet defects
- Diet induced platelet defects

18

What is the cause and manifestation of Gray Platelet Syndrome?

Lack of alpha granules. Present with purpura of unknown origin.

19

How does Omega-3 affect platelet function?

Blocks generation of thromboxane A2

20

Polycythemia Vera

Cancer of the red cell and there is a high production in the amount of RBCs

21

What are the 3 categories of vascular disorders that lead to bleeding?

- Subendothelial
- Endothelial
- Mechanical

22

What is an example of a congenital sub endothelial disorder?

Ehler Danlos Syndrome

23

What are some symptoms of Ehler Danlos Syndrome?

Hypermobile joints. Hyperflexible skin, osteogenesis imperfecta, drugs, infections, amyloidosis.

24

Telangiectasias

Small dilated blood vessels near surface of skin

25

What are examples of congenital endothelial disorders?

Telangiectasia (HHT)
Arteriovenous malformation
Giant hemangioma (Kasaback- Merritt syndrome)

26

What is a nutritional disorder that can affect bleeding?

Scurvy

27

What are examples of bleeding disorders due to coagulation factor abnormalities?

Hemophilias
von Willebrand's Disease

28

Hemophilia A

VIII coagulation factor deficiency

29

Hemophilia B

IX coagulation factor deficiency

30

What pathway does Hemophilia A and B affect?

Intrinsic

31

What is the effect of hemophilia on APTT?

It is elevated

32

What is the effect of hemophilia on platelet function?

Normal Platelet Function

33

What is the effect of hemophilia on bleeding time?

Normal bleeding time

34

von Willebrand's Disease with Types 1, 2 and 3

1. Type-1 and Type-3 von Willebrand’s diseases are characterized by a decrease in the circulating level of the factor.
2. Type-2 von Willebrand’s disease is characterized by a qualitative defect in the protein.

35

What is the effect of vW's disease on APTT?

Slightly elevated

36

What is the effect of vW's disease on platelet function?

Impaired platelet adhesion

37

What is the effect of vW's disease on bleeding time?

Increased bleeding time

38

What can excessive activation of the fibrinolytic system cause?

Bleeding

39

What is the D-dimer test used for?

It tests for fibrin degradation products and is used to assess DIC/DVT states.

40

What can lead to Disseminated Intravascular Coagulation (DIC)?

Sepsis
Tissue Destruction
Endothelial Injury

41

What is DIC?

Disseminated Intravascular Coagulation. Occurs when both fibrinogen and fibrin are degraded by plasmin which consumes clotting factors and platelets leading to bleeding.

42

What can α2-antiplasmin deficiency cause?

Increased fibrinolysis and bleeding

43

Heparin Induced Thrombocytopenia

Platelet Factor 4 complexes with heparin and causes and antibody response which leads to HIT as platelets are targeted by antibodies

44

What is bleeding in HIV mainly associated with?

Thrombocytopenia

45

Which of the blood clotting tests is commonly used for the diagnosis of Hemophilias?
A. Activated partial thromboplastin time
B. Prothrombintime/INR
C. Thrombin time
D. Bleeding time
E. Fibrinogenlevels

A. Activated partial thromboplastin time

46

A patient was admitted to the hospital with an urinary tract infection. Two days later he developed fever and his coagulation parameters and platelet count became abnormal. Additional test showed D-dimer positive and positive blood cultures for E. Coli. What is the likely diagnosis of this patient?
A. DIC
B. Hemophilia B
C. Hypercoagulable state
D. APC Resistance
E. Von Willebrand disease

A. DIC

47

Factor V Leiden

Abnormal V is cleaved to Va and it is resistant to Protein C cleavage which leads to thrombophilia leading to increased clotting

48

Prothrombin 20210A

Elevated plasma prothrombin levels leads to an increase in venous thrombosis.

49

Hyperhomocysteinemia

Methylene tetrahydrofolate reductase mutation (mtHfr C677t) results in a moderate increase in serum homocysteine, which is associated
with both arterial and venous thrombosis.

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