Coag U4 - Thrombotic Disorders

Question 1

thrombosis

Answer 1

inappropriate formation of a PLT or fibrin clot that obstructs a blood vessel

Question 2

ischemia

Answer 2

loss of blood supply

Question 3

necrosis

Answer 3

tissue death

Question 4

thrombophilia

Answer 4

AKA hypercoagulability, predisposition to
thrombosis secondary to a condition

Question 5

emboli

Answer 5

fragments of thrombi that move through the circulatory system and lodge in vasculature

Question 6

pulmonary emboli (PE)

Answer 6

emboli that move through the heart and lodge in the arterial pulmonary vasculature

Question 7

venous thromboembolism

Answer 7

prevalent in African Americans and women of childbearing age
symptoms of localized pain, sensation of heat, redness, edema

Question 8

what are some examples of venous thrombosis?

Answer 8

PE and DVT

Question 9

arterial thrombosis

Answer 9

activated PLTs, monocytes, and macrophages
embed fatty plaque within endothelial lining, suppress normal release of antithrombotic molecules (ex. NO, tissue factor) →
atherosclerotic plaque →
plaques rupture →
occlude arteries and trigger thrombotic events

Question 10

what are some examples of arterial thrombosis?

Answer 10

MI and stroke

Question 11

risk factors for thrombosis

Answer 11

age, immobilization, diet, pregnancy, smoking, inflammation, oral contraceptive use, hip/knee/prostate surgery

Question 12

lupus anticoagulant

Answer 12

antiphospholipid antibody, the patient would clot which prolongs the result of PTT and therefore is more at risk for thrombosis

Question 13

LAC testing

Answer 13

PTT – prolonged
mixing study – shortens prolonged PTT
DRVVT – ratio > 1.2
silica-based PTT – ratio < 1.2, difference of 8 seconds >

Question 14

what are the 3 antiphospholipid antibodies?

Answer 14

LACs
ACL antibodies
anti-B2-GPI antibodies

Question 15

APC resistance

Answer 15

factor V Leiden (R506Q) mutation gain of function renders factor V resistant to APC

Question 16

prothrombin G20210A

Answer 16

mutation in prothrombin gene untranslated 3′ promoter region

moderate prothrombin activity elevation

Question 17

factor V leiden (FVL)

Answer 17

a mutation in the factor V gene

substitutes glutamine for arginine at position 506 of the factor V molecule (FV R506Q)

Question 18

what happens in FVL?

Answer 18

arginine substitution slows or resists APC hydrolysis

resistant factor Va remains active and raises production of thrombin, leading to thrombosis

Question 19

AT deficiency

Answer 19

enhanced by heparin, inhibits serine proteases IIa, IXa, Xa, and XIa

Question 20

PC deficiency

Answer 20

a serine protease that hydrolyzes factors Va and
VIIIa, requires protein S as a stabilizing cofactor

Question 21

PS deficiency

Answer 21

a stabilizing cofactor for activated protein C, 40% free, 60% circulates bound to C4bBP

Question 22

lipoprotein (a)

Answer 22

low-density lipoprotein that may predict
arterial thrombosis, contributes to thrombosis with antifibrinolytic property

Question 23

CRP

Answer 23

calcium-dependent pentameric ligand-binding member of pentraxin family
made in the liver

chronic CRP concentrations of 1.5 mg/L or greater =
atherosclerosis, low-grade inflammation → increased risk of MI or stroke

Question 24

FBG

Answer 24

increased fibrinogen = increased thrombosis

Question 25

homocysteine

Answer 25

amino acid intermediate in metabolism of dietary methionine

risk factor for arterial thrombosis

Question 26

disseminated intravascular coagulation (DIC)

Answer 26

consumption of coagulopathy, where generalized and uncontrolled hemostasis activation; bleeding and clotting at the same time

Question 27

DIC testings

Answer 27

PT and PTT – prolonged
FBG – decreased
PLT count and peripheral smear exam – confirms thrombocytopenia and schistocytes
D-dimer – increased

Question 28

acute DIC

Answer 28

associated with obstetric emergencies, intravascular hemolysis, septicemia, viremia, burns, acute inflammation, etc

Question 29

chronic DIC

Answer 29

associated with tissue necrosis

Question 30

Trousseau syndrome

Answer 30

tumor-induced chronic DIC that generates DVT and migrating thromboses causing ecchymoses and purpura fulminans

Question 31

heparin-induced thrombocytopenia (HIT)

Answer 31

an antiplatelet factor IV, consequence of an immune response to UFH and LMWH that is reflected in a reduced PLT count

Question 32

how does HIT affect hemostasis?

Answer 32

increases hemostasis