Pathophys - DVT

Question 1

define thrombosis

Answer 1

formation of thrombus (clot) in the vascular lumen

aggregate of coagulated blood, platelets, fibrin, and cells

Question 2

briefly explain how a thrombus (clot) forms

Answer 2

injury exposes basement membrane

platelets adhere to the exposed collagen - forming “plug” over the area

this causes the release and aggregation of addtional platelets, and von wildebrand factor which adheres to Gp1b on the platelet membrane and to fibrinogen

activated platelets release ADP and TxA2 which recruit even more platelets

thrombus is stabilized when platelet protein GpIIB-IIa adheres to fibrinogen – forming bridge between platelets

Question 3

according to virchow’s triad, name the 3 mechanisms of venous thrombosis (clot in vein)

Answer 3

stasis
damage to the endothelium
hypercoagulability

Question 4

name some causes of stasis/slowing of blood flow

Answer 4

not moving, heart failure, varicose veins

Question 5

as mentioned “damage to the endothelium” is part of the triad for clot formation in the veins

name 4 specific

Answer 5

surgery
trauma
toxic substances
hypoxia

Question 6

name some ways hypercoaguability can happen

Answer 6

dehydration
chronic hypoxia
cancer
oral contraceptives
pregnancy

Question 7

how does hypoxia increase the coaguability of blood?

Answer 7

hypoxia leads to increases RBC which increases blood viscosity

polycythema vera is a cancer of hematopoietic stem cells

Question 8

name some possible outcomes of a thrombus

Answer 8

• it can increase in size

-can become a plaque and seal the vessel

-may be lysed

-may contract and allow blood to flow around it

-may break off and cause embolism!

Question 9

define an embolus

Answer 9

thrombus that breaks free

Question 10

explain where an embolus travels

Answer 10

floats free in the venous system – will get to the heart, but is usually not caught there because the valves are large

however, if it gets to the pulmonary circulation, the vessels are very small and it will most likely cause a pulmonary embolism

Question 11

the seriousness of a pulmonary embolism depends on what?

Answer 11

where it occurs in the lungs

Question 12

true or false

large pulmonary emboli are often fatal

Answer 12

true

Question 13

smaller emboli (pulmonary) are usually not lethal, but may be lethal if….

Answer 13

-caught in the left or right pulmonary artery
-or caught in multiple primary and secondary branches

Question 14

pulmonary infarction is usually seen in what condition

Answer 14

CHF

Question 15

symptoms of pulmonary infarction

Answer 15

cough, stabbing pain, SOB, pleural effusions, scar

Question 16

if a patient survives from a pulmonary embolism, what is the fate of it

Answer 16

a larger one may leave behind strings of fibrous tissue attached to the wall

Question 17

what is the most common site for embolism formation in the ARTERIAL system

Answer 17

the heart

will lead to heart attack

Question 18

what happens if there is an arterial embolism in the brain?

Answer 18

stroke

Question 19

3 other forms of emboli (not blood)

Answer 19

air
fat
tumor