Thrombosis and Embolism

Question 1

T/F: a thrombus may occur in an artery or vein

Answer 1

true

Question 2

Where do DVTs normally occur?

Answer 2

below the knee

Question 3

DVTs are characterized by lines of (blank) and attachment to the vessel wall

Answer 3

lines of Zahn

Question 4

what are the three risk factors for thrombus that makeup Virchow’s triangle?

Answer 4

1. disruption in blood flow
2. endothelial cell damage
3. hypercoagulable state

Question 5

T/F: turbulent non-laminar blood flow can cause clot formation

Answer 5

true

Question 6

Immobilization, cardiac wall dysfunction, and anuerysm are all things that cause a (blank) in blood flow

Answer 6

disruption

Question 7

Endothelial cells prevent thrombosis by protecting expsoure to subendothelial (blank) and underlying tissue factor

Answer 7

SEC

Question 8

What two molecules do the endothelial cells produce that prevent thrombosis?

Answer 8

PGI2 and NO; PGI2 is opposite of TXA2 and NO causes vasodilation

Question 9

Endothelial cells secrete heparin-like molecules that augment (blank) which inactivates thrombin and coag factors

Answer 9

ATIII

Question 10

What are the three actions of tPA?

Answer 10

1. converts plasminogen to plasmin
2. cleaves fibrin and serum fibrinogen and destroys coag factors
3. blocks PLT aggregation

Question 11

Atherosclerosis, vasculitis, and high levels of (blank) can cause endothelial damage

Answer 11

homocysteine

Question 12

What two vitamin defs can lead to high homocysteine?

Answer 12

Vit. B12 and folate def

Question 13

What enzyme deficiency can lead to homocysteine buildup?

Answer 13

Chystathionine beta synthase (CBS)

Question 14

Vessel thrombosis, mental retardation, lens dislocation, long slender fingers, and high levels of homocysteine are indicative of what congential enzyme def?

Answer 14

CBS

Question 15

Hypercoagulable states are due to excess (blank) or deficiencies of (blank)

Answer 15

excess procoagulants or def. anticoags

Question 16

DVTs normally ocurr below the knee or in what two arteries?

Answer 16

hepatic and cerebral

Question 17

Protein C or S def decreases (neg/pos) feedback on the coag cascade

Answer 17

negative, they are ANTICOAGS

Question 18

What factor do proteins C and S inactivate?

Answer 18

FVIII

Question 19

Protein C and S def has an increased risk of what drug reaction?

Answer 19

warfarin skin necrosis

Question 20

Warfarin works by decreasing Vit. K dependent factors. Why does a protein C or S deficiency cause concern at the beginning of warfarin Tx?

Answer 20

The half life of C and S is shorter than that of the 2 7 9 10; therefore the anticoags disappear faster than the coags and the pt is at risk of a microvessel thrombus

Question 21

What is Factor V Leidin?

Answer 21

FV that lacks the cleavage site for C and S

Question 22

What is the most common cause of hypercoagulable state?

Answer 22

Factor V Leidin

Question 23

An inherited point mutation that increases prothrombin expression is caused by (blank)

Answer 23

Prothrombin 20210A;

Question 24

ATIII def decreases the effect of what class of molecules released by the endothelium?

Answer 24

heparin like molecules

Question 25

What is unique about the PT/PTT in ATIII def when treating with heparin?

Answer 25

PTT does not rise with standard heparin dosing ATIII def; since aTIII is bound by HEPARIN-like molecules, the action of heparin is going to be limited!!

Question 26

Once high doses of heparin are given to acheive an anticoag'd state in ATIII def pts, what is given to maintain their blood viscosity?

Answer 26

coumadin

Question 27

The pill increases a hypercoagulable state via what mechanism?

Answer 27

estrogen increases the production of coagulation factors.

Question 28

What is the most common type of embolus?

Answer 28

thromboembolus

Question 29

What histo finding is characteristic of an atherosclerotic embolus?

Answer 29

cholesterol clefts in the embolus

Question 30

a (blank) embolus is common after traumatic bone fractures (long bones) and soft tissue trauma

Answer 30

soft tissue trauma

Question 31

in relation to the trauma, when does a fat embolus form?

Answer 31

while trauma is still present or during repair

Question 32

What clinical findings are associated with a fat emoblus/

Answer 32

SOB, and skin petechiae on the CHEST

Question 33

(blank) emobolus is seen in decompression sickness

Answer 33

gas embolus

Question 34

What is the chronic form of gas embolus that causes multifocal ischemic necrosis of bone/

Answer 34

Caisson disease

Question 35

Gas embolus may also form during what type surgery?

Answer 35

laparoscopic

Question 36

Amniotic fluid is rich in what coagulation precursor?

Answer 36

TT

Question 37

Amniotic fluid emboli present with what symptoms as they travel the lung, brain, and systemically?

Answer 37

SOB, neurologic symptoms, DIC

Question 38

Squamous cells and keratin debris in the embolus is characteristic of what?

Answer 38

amniotic fluid embolus

Question 39

PE normally arises from a DVT in the lower extremity involving what three veins?

Answer 39

1. femoral 2. iliac 3. popliteal

Question 40

T/F: PE is normally clinically silent

Answer 40

true, b/c the lung has dual blood supply

Question 41

What percent of PEs result in infarction?

Answer 41

10%; need pre-existing compromise!

Question 42

what symptoms do pts with PE have?

Answer 42

SOB, hemoptysis, pleuritic chest pain, pleural effusion

Question 43

``` Describe the labs for PE: V/Q spiral CT Lower extremity US D-dimer ```

Answer 43

V/Q mismatch; perfusion is abnormal CT shows vascular filling defect US shows a DVT elevated D-dimer because they are trying to lyse the PE AND the DVT!!

Question 44

What type of embolus in PE causes sudden death?

Answer 44

saddle embolus; death by electromechanical dissociation

Question 45

WHat happens with chronic pulmonary emboli?

Answer 45

plumonary HTN

Question 46

Where do most systemic emoboli come from?

Answer 46

left heart, normally go to lower extremities