02a: Hemostasis/clotting

Question 1

Tissue factor and Factor (X) act on/activate which clotting factors?

Answer 1

X = VIIa

IX and X

Question 2

Which clotting factors have been identified in clinically relevant disorders of deficiency?

Answer 2

VIII (hemophilia A/severe vWF disease), IX (hemophilia B), XI

Question 3

Which clotting factors have been identified in clinically IRRELEVANT disorders of deficiency?

Answer 3

XII and kallikrein

Question 4

List common antibody inhibitors to clotting factors

Answer 4

1. anti-VIII (acquired hemophilia A)

2. Lupus anticoagulant

Question 5

Menhorragia and oozing ulcers makes you think of (platelet/clotting factor) issues.

Answer 5

Platelet

Question 6

Stroke makes you think of (platelet/clotting factor) issues.

Answer 6

Clotting factor

Question 7

Subarachnoid hemorrhages make you think of (platelet/clotting factor) issues.

Answer 7

Platelet

Question 8

DIC: platelet count is (high/low/normal), PT is (long/short/normal) and PTT is (long/short/normal).

Answer 8

Low; long; long

Question 9

T/F: In platelet function abnormalities, platelet count, PT, and PTT are all normal.

Answer 9

True

Question 10

Factor XIII functions to (X) and deficiency in this clotting factor causes (Y).

Answer 10

X = crosslink fibrin
Y = decrease in fibrin clot stability

Question 11

List some chronic medical illnesses that serve as persistent risk factors for VTE.

Answer 11

1. Cancer
2. PNH
3. IBD
4. Nephrotic syndrome

Question 12

Recurrent thrombosis with no identifiable risk factor may be sign of thrombophilia, esp if in patient under age of:

Answer 12

50

Question 13

Protein C/S deficiency causes increased risk (bleeding/clot).

Answer 13

Clot (VENOUS, not arterial)

Question 14

Hep-induced thrombocytopenia (HIT) causes increased risk (bleeding/clot).

Answer 14

Clot (venous OR arterial)

Question 15

Antithrombin deficiency causes increased risk (venous/arterial) clot.

Answer 15

VENOUS

Question 16

Anti-Phospholipid Antibody Syndrome causes increased risk (bleeding/clot).

Answer 16

Clot (venous OR arterial)

Question 17

Patient with arterial clot may have (PNH/Factor V Leiden).

Answer 17

PNH (Factor V Leiden ONLY venous clot)

Question 18

T/F: DIC can cause either venous or arterial clot.

Answer 18

True

Question 19

Which clinical sign would make you run genetic test for Prothrombin G20210A mutation?

Answer 19

Venous clot

Question 20

Your 46 y.o patient being treated for breast cancer presents with VTE. After treatment, should you test her for hereditary thrombophilia?

Answer 20

No

Question 21

T/F: Patients with retinal vein thrombosis should be tested for hereditary thrombophilia.

Answer 21

False

Question 22

T/F: Patients with portal/mesenteric vein thrombosis should be tested for hereditary thrombophilia.

Answer 22

True

Question 23

Your 24 y.o. patient wants to be put on oral contraceptives for the first time. Should she be tested for hereditary thrombophilia?

Answer 23

No (esp if no fam hx)

Question 24

What’s the clinical (Sapporro) criteria for Antiphospholipid Antibody Syndrome (APS)?

Answer 24

1. Venous/arterial thrombosis

2. Recurrent fetal loss

Question 25

What's the lab (Sapporro) criteria for Antiphospholipid Antibody Syndrome (APS)?

Answer 25

1. Lupus anticoagulant 2. Anticardiolipin Ab (IgG/IgM) 3. Beta-glycoprotein I Ab (IgG/IgM)

Question 26

T/F: 50% of patients with VTE have cancer

Answer 26

False - 20%

Question 27

VTE in cancer patients should be treated with:

Answer 27

LMWH

Question 28

Pt with idiopathic thrombosis will have (X)% reduction in risk of recurrent VTE if placed on warfarin.

Answer 28

X = 95

Question 29

Heparin's specificity for Factor (X) over Factor (Y) is determined by which characteristic?

Answer 29

``` X = Xa Y = IIa (thrombin) ``` Length of polypeptide chain (which wraps around thrombin)

Question 30

T/F: Intensity and duration of | unfractionated heparin's effect increase proportionately with increasing dose.

Answer 30

False - plateau at v high doses

Question 31

T/F: Unfractionated heparin usually administered by boluses and monitored every hour.

Answer 31

False - continuous infusion, monitored every 4-6h

Question 32

Greatest risk of hemorrhage from heparin seen in which patients?

Answer 32

Elderly and low weight

Question 33

Heparin toxicity can be reversed with (oral/parenteral) administration of (X).

Answer 33

Parenteral | X = protamine sulfate

Question 34

The clotting of blood is prevented by the presence of (X) chelators.

Answer 34

X = Ca

Question 35

You'd expect patient with polycythemia vera to be at (increased/decreased) risk for thrombosis. Why?

Answer 35

Increased; increased viscosity/stasis of blood

Question 36

T/F: Of the three components of Virchow's triad, hypercoagulability/thrombophilia is the least common cause of thrombosis.

Answer 36

True

Question 37

Of the inherited causes of hypercoagulability, (X) mutations in the (Y) gene(s) are the most common.

Answer 37

``` X = point Y = Factor V and prothrombin ```

Question 38

Factor V Leiden mutation causes factor V to be:

Answer 38

resistant to cleavage by Protein C

Question 39

Patients homozygous for Factor V Leiden have (X)-fold increased risk for (bleeding/thrombosis).

Answer 39

X = 50 | Venous Thrombosis

Question 40

(X) is a fairly common mutation in prothrombin that is responsible for (hyper/hypo)-coagulability.

Answer 40

X= G20210A Hypercoag

Question 41

(High/low) levels of homocysteine in blood may be caused by an inherited deficiency, leading to increased risk of (bleeding/thrombosis).

Answer 41

High; thrombosis

Question 42

T/F: Heparin-induced thrombocytopenia (HIT) syndrome is the fault of antibodies.

Answer 42

True - recognize complexes of heparin and platelet factor 4 on platelets

Question 43

Repeated miscarriages should make you think of which clotting disorder?

Answer 43

Antiphospholipid antibody syndrome

Question 44

Repetitive false-positive tests for syphilis may be seen in which clotting disorder?

Answer 44

Antiphospholipid antibody syndrome

Question 45

List the four major categories of thrombocytopenia

Answer 45

1. Decreased production 2. Decreased survival 3. Sequestration (splenomeg) 4. Dilution (transfusion)

Question 46

Chronic Immune Thrombocytopenic Purpura (ITP): what's the basic issue in this disease?

Answer 46

Auto-antibodies (IgG) to platelet (usually IIb-IIIa glycoproteins)

Question 47

T/F: Chronic Immune Thrombocytopenic Purpura (ITP) is usually markedly improved by splenectomy.

Answer 47

True - common treatment for chronic ITP

Question 48

Splenomegaly and lymphadenopathy point more toward (primary/secondary) chronic ITP.

Answer 48

Secondary - uncommon in primary disease

Question 49

T/F: Chronic ITP is typically diagnosed by measuring anti-platelet Ab.

Answer 49

False - these tests not widely available; diagnosis is one of exclusion (after other causes of thrombocytopenia have been ruled out)

Question 50

T/F: Both chronic and acute ITP are seen more often in females.

Answer 50

False - acute ITP seen equally in both sexes

Question 51

Pentad of TTP:

Answer 51

1. Fever 2. Thombocytopenia 3. Microangiopathic hemolytic anemia 4. Transient neuro deficits 5. Renal failure

Question 52

(X) disease is associated with deficiency in ADAMTS13, which normally has which function?

Answer 52

X = TTP Cleaves vWF multimers

Question 53

Bivalirudin is what type of agent? List some other agents in this category of drugs.

Answer 53

Direct thrombin inhibitor Dabigatran and Argatroban

Question 54

Only oral direct thrombin inhibitor

Answer 54

Dabigatran

Question 55

T/F: Dabigatran does not require monitoring.

Answer 55

True

Question 56

Why does warfarin have (short/long) onset of action?

Answer 56

Long t(1/2) of clotting factors; remember, it interferes with gamma-carboxylation of FUTURE clotting factors

Question 57

Warfarin reversal options:

Answer 57

1. Vit K 2. FFP (Fresh Frozen Plasma) 3. PCC

Question 58

Alteplase: binds to (X) via (Y) binding sites does what?

Answer 58

``` X = fibrin Y = lysine ``` Activates bound plasminogen

Question 59

Clopidogrel (reversibly/irreversibly) binds (X), inhibiting (Y)-mediated activation of (Z).

Answer 59

Irreversibly; X = P2Y12 receptor Y = ADP Z = Gp IIb-IIIa receptor