Theombosis And Embolism

Question 1

is air likely to embolise via the venous system?

Answer 1

no, Air enters the venous system but then passes through an interatrial or interventricular defect in the heart to the arterial system (paradoxical embolism)

Question 2

if u have a thrombus in the carotid artery and embolism occurs it can go to _____

Answer 2

BRAIN

Question 3

what r outcomes of thrombus? (5)

Answer 3

1) LYSIS (Most likely if thrombus is small)
2) PROPAGATION thrombus grows
3) ORGANISATION undergoes fibrous repair & forms fibrous scar on vessel wall
4) RECANALISATION bloodflow re- established but usually incompletely
5) EMBOLISM part of it breaks off and travels in BS.

Question 4

**recurrent minor PE can lead to pulmonary hypertension.

Answer 4

bc u get generalised increase pressure in lungs

Question 5

What an embolism?

Answer 5

When a thrombis breaks, and blocks a vessel.

Blockage of a vessel by solid, liquid, or gas away from its origin

**over 90% are THROMBO-EmBOLI

Question 6

What is a saddle embolus?

Answer 6

a large pulmonary embolism that straddles the bifurcation of the pulmonary trunk, extending into the left and right pulmonary arteries.

Question 7

Why does thrombois occur? (3)

explain virchows triad and how each one may leasd o formation if thrombus!

Answer 7

• VESSEL WALL ABNORMAILTY -atheroma >> mostly in artery -direct i jury -inflammation
• BLOOD FLOW ABNORMAL -stagnation ex (DVT) -turbulence
• BLOOD COMPONENT GONE WRONG ( hypercoagubility)
• ppl who smoke >> stivky blood
• Post partum>> area of placenta
• Post operation>> ur lying down too much (u can get stagnation

Question 8

define 3 stages of pulmonary embolism?

Answer 8

-massive -major -minor > asymptomatic

Question 9

how can nitrogen embolism form?

Answer 9

happens in divers when they come up to the surface too quickly and the dissolved nitrogen become GASEOUS nitrogen.

Question 10

What is a paradoxical embolus?

Answer 10

emboli can pass through an inter-atrial or inter-ventricular defect and gain access to the SYSTEMIC circulation (ex those with ASD or PFO)

OR

emboli in the peripheral vein bypass the lungs and enter systemic circulation

Question 11

what can thrombosis do to u ? (in arteries and veins)

Answer 11

ARTERIES -Cause ischemia>>infarct (depends if theres collateral circulation or not)

VENOUS -congestion ( bc pressure in vein increases) -edema (hydrostatic p. increases, forces fluid out of veins into interstitial fluid -ischemia -infarction

Question 12

thromboembolic from systemic veins go to the ______

Answer 12

LUNGs

Question 13

what does stagnation mean?

Answer 13

the state of not flowing or moving

Question 14

what r predisposing factors/Risks of DVT?

Answer 14

• immobility/ bed rest
• Post-operative
• pregnancy, Post-partum (after birth)
• oral contraceptives (shmul)
• severe burns
• Cardiac failure

Question 15

prevention and treatment of thromboembolic disease?

Answer 15

reduce risk by (prevent):

1) give stockings>they compress veins to prevent stagnation 2) flowtron boots> they inflate, activating muscle calf pump!

TREATMENT: (both r anticoagulents)

1) give IV heparin (doesn’t really dissolve thrombus, but prevents it from getting bigger)
2) oral Warfarin **starts with heparin (bc it starts quickly)

Question 16

what is the main prophylaxis for deep vein thrombosis

Answer 16

Heparin

Question 17

Subcutaneous __________is the main prophylaxis for DVT

Answer 17

Heparin

Question 18

What is thrombosis?

Answer 18

Solid mass formation made from the constituents of the blood with the circulatory system, during LIFE (mu nafs clotting) Can occur in veins, arteries, THROMBIS AND CLOT R DIFFERENT THINGS

Question 19

what r some types of embolism?

Answer 19

• air ( u need 150ml to cause air embolism)
• amniotic fluid (was a problem during abortion)
• nitrogen (when nitrogen GAS form in blood)
• medical equipment ( -tumour cells

Question 20

How does thrombi look like? how would that differ in arterial and veins?

Answer 20

ARETERIAL

• granular
• lines of zahn
• pale
• less cell content (causing the paleness)

VENOUS -

• soft
• gelatinous
• Deep red (bc has a high cell content)

Question 21

if u get a thrombus in ur abdominal aorta (infra renal portion) what consequence it this cause

Answer 21

it can go to leg DVT causing ischemia>> gangrene

Question 22

how can u get fat embolism (ex in brain)

Answer 22

via long bone fracture. -fracture leads to release of marrow into bloodstream, and may get into the brain

Question 23

what is venous Congestion?

Answer 23

venostatis>> slow BF in veins

Question 24

term to describe> “painful superficial thrombi which have associated inflammation in the wall of the vein.”

Answer 24

thrombophlebetis

Question 25

when do ‘occlusive’ thrombi usually occur?

Answer 25

when an atheroscelrotic plaque ruptures, a thrombi tend to form on top of it becoming occlusive.

(such thrombi in coronory arteries can be no bigger than a matche head>but can be fatal)

Question 26

what is vegetation?

Answer 26

a thrombus on a cardiac valve. (most commonly left side)

can easily embolise.

can be infected too> mostly in IV drug abusers.

(looks like caulifloers florets 2-3cm long))

lol.

Question 27

what r dangerous sources (locations) of thromboemboli? (3)

Answer 27

thrombi that form in the large veins of the Lower limbs

-femoral, ilial, popliteal veins

Question 28

what r the clinical effects of thrombosis? (4)

Answer 28

• MI
• pulmonary embolism
• congestion and edema in venous bed
• repeated miscarrigaes du to thrombus of uteroplacental vasculature

Question 29

80% of pulmonary emboli arise from thrombi in the deep veins of the _____&______

Answer 29

thigh and popliteal vein

Question 30

what type of thrombus is this? describe its characteristics

Answer 30

Arterial thrombus> is a laminated structure

• lines of Zahn
• Pale in colour due to lower cell content
• Granular

Question 31

in paradoxical emboli, thrombus manages to bypass the lungs and gain acess to the systemic circualtion.

exaplin 2 ways in which this can occur (hint: whether its a large emboli or small emboli)

Answer 31

Small emboli > manage to bypass the lungs by going through the Arterio-venous anastomoses in the pulmonary circulation (also fat droplets can ambolise this way too!)

Large Emboli> via PFO o r atrio-ventrciular septal defect (during coughing or lifting)

Question 32

how can fat droplets embolise to the lungs in fat embolism?

Answer 32

they pass through the atrio-venous anastomoses in the pulmonary circulation.

Question 33

Patients with Stroke r 4x likely to have a PFO when compared with general population…

Answer 33

therefore, paradoxical embolis should be considered in these young patients that present w/ ischemic stroke!

Question 35

when can u get fat or marrow emboli?

what r the symptoms that may arise?

Answer 35

after trauma or liposuction.

when a bone is fractures, bone marrow fat cells that r injured break up and realease oil droplets. these oil droplets sticktogether & sucked into the ruptured veins.

(Respiratory & neurological symptoms)

mostly seen in those with pelvic or long bone fracture!

Question 36

Describe how amniotic fluid embolism occurs and the symptoms it can cause.

how can it cause DIC?

Answer 36

During delivery, ceserian section, a tear in the amniotic membrane can occur and amniotic fluid can get into the maternal circulation.

ARDS, hypotension, seizures, loss of conciousness, DIC

(bc amnionic fluid has prothrombotic substances)

Question 37

what the f**is a talc emboli?

Answer 37

no idea wt thos shit is

Question 38

prevention and treatment of Thromboembolic disease

Answer 38

• Prophylaxis
• Aspirin
• Warafarin
• fliters

Question 39

why is DVT asymptomatic in many people?

Answer 39

We can develop alternative channels in our veins so thats why swelling sometimes doesn’t appear. (More collatrels in the veins).

Question 40

How does a thrombus form?

Answer 40

Platelets r the most formed elements in the blood, & they r more concentrated along the endothelium, (like a waterstream and pebbles.

theyre most likely to be caught by a valve.

1) form an aggregate (if blood flow is slow) more aggregate
2) Fibrinogen will bind platelets together
3) fibrin gorws out of the layer & traps RBC
4) White layer of platelets r covered by a red layer fibrin + RBC’s
5) the surf. of the red layer is thrombogenic and again platelets stick to exposed fibrin
6) a second white layer forms & process goes on

theyre making a layered sandwhich of white and red layer.

Question 41

Give two reasons why a woman in late pregnancy is
predisposed to DVT?

Answer 41

In pregnancy the blood is hypercoagulable (1 mark) and the presence of a pelvic ‘tumour’ can compress venous outflow from the legs resulting in venous stasis