Thrombosis & Shock Flashcards
what is the most common cause of death in the US?
arterial thrombi
what are the most common sites of arterial thrombi?
coronary a
cerebral a
femoral a
arterial thrombi result in ischemic _____
infarction
arterial thrombi can cause death due to infarction of what 3 areas?
- myocardial infarction
- cerebral infarction
- renal infarction
what are 2 other names for a thrombosis in the venous?
phlebothrombosis
red thrombi (cause colour change)
what is the most common site for a thrombosis of the venous system?
in the superficial leg veins (varicose vv)
what is the most common clinical manifestation of a thrombosis in the venous system?
deep leg vein thrombosis
what are 4 morphological attributes of thrombi?
- lines of Zahn
- mural thrombi
- vegetations (infective endocarditis)
- verrucous (libman sacks) endocarditis
what are lines of Zahn?
lines that show up due to the stop-start growth pattern of a clot
what are mural thrombi?
a thrombi that attaches itself to a blood vessel or a heart chamber
what kind of endocarditis are vegetations?
infective endocarditis
what usually causes infective endocarditis?
strep and staph
what does infective endocarditis present as and where?
tiny blood clots at the cusp of valve ( key word: Tip of valve)
most commonly found = mitral valve
what kind of endocarditis is Verrucous endocarditis?
autoimmune
what is an example of verrucous endocarditis?
lupus
what is the typical location of the blood clots for verrucous endocarditis?
on top of the valve usually
what are the 4 CLINICAL manifestations of DEEP VEIN THROMBOSIS?
- edema of foot and ankle
- pain of foot and ankle
- local ischemia (bacterial skin infections)
- PULMONARY EMBOLIZATION
what are the potential fates of a thrombus from least to most severe?
- dissolution
- propagation
- Organization
- Recanalization
- Embolization
what is a detached intravascular mass that is carried by the blood to a site distant from its point of origin?
embolism
what are the subtypes of embolisms?
Thromboembolism
Fat
Air
Amniotic
what is the most common subtype of embolism?
thromboembolism
a thromboembolism results in a partial or complete occlusion of vessel ____
lumina
a thromboembolism may lodge in ____ or ____ circulation
pulmonary or systemic
what usually causes a fat embolism?
from a long bone fracture usually (seen as red acid-fast staining)
name 3 examples of how an air embolus could form
- The Bends (diving): gases become more soluble and form bubbles in vv
- intubation during surgery - too much air
- laproscopic surgery errors - inject air while compressing abdomen (distended) to make room
what are possible causes of amniotic embolism?
placental tear/abruption -> epithelial cells (shed from fetus) expressed in the mother’s blood
what is the most common preventable death in hospitalized patients that arise from deep leg vein thrombi?
pulmonary emboli
what type of embolus may form in the bifurcation of the pulmonary trunk?
saddle embolus
is a systemic emboli venous or arterial in origin?
arterial in origin (left ventricle, atherosclerotic plaques)
what are the most common sites of lodgment of a systemic emboli?
lower extremities (75%)
brain (10%)
viscera (10%)
what is an area of ischemic necrosis within a tissue or organ called?
infarction
what is an infarction most often caused by?
most often caused by thrombotic or embolic occlusion
what sign on imaging signals an infarct?
Morphology = triangle/wedge shape
what is a white infarct due to?
ischemic infarct (tissue turns pale/white)
(classic wedge shape)
what is a red infarct due to?
hemorrhage (tissue turns red)
name 3 determining factors of infarction
- nature of vascular supply = rate of blood loss
- rate of development of occlusion (instant/necrosis vs chronic/atrophy) = vol of blood loss
- vulnerability of tissue to hypoxia = site or location
what are the margins of an infarct lined by?
rim of hyperemia/inflammation
what is the surface of an infarct covered by?
fibrinous exudate
what pattern of necrosis does an infarct most commonly cause?
coagulative necrosis (eg. heart attack)
what is hypoperfusion of tissues?
shock (hemodynamic; can’t supply blood to tissues)
what are the major subtypes of shock
- cardiogenic shock
- hypovolemic shock
- septic shock
- anaphylactic
- neurogenic
what is cardiogenic shock?
heart fails as a pump
name 3 potential causes of cardiogenic shock
- myocardial infarction
- cardiac tamponade
- cor pulmonale
what is cardiac tamponade?
myocardial rupture -> bleed into the pericardial sac -> causes atrial collapse -> drop in cardiac output **causes shock*
what is cor pulmonale?
right ventricular dilation (R side fills up w/blood that can’t leave) & hypertrophy
what is the path that usually causes acute cor pulmonale?
DVT-> Embolus -> saddles at bifurcation of pulmonary trunk
Clenbuterol is a horse anti-asthmatic drug that can cause ____ in humans
cor pulmonale
what is hypovolemic shock?
not enough blood due to blood loss
name 3 potential causes of hypovolemic shock
- hemorrhage
- severe trauma
- extensive burns
how do extensive burns cause hypovolemic shock?
2nd degree burn = Edema fluid filled blisters (derived from blood plasma, over 40% of your body you will lose blood volume quicker than you can make it
3rd degree= bleeding from skin —> quick decrease of blood volume
what is septic shock and what causes it?
due to blood born infection
(the body is incapable of maintaining BP because of all of the blood vessels are dilated for moving the mediators)
PATHOPHYSIOLOGY OF SEPTIC SHOCK
- ____ release from gram -/ve bacteria
- endotoxins stimulate the release of ____
- cytokines trigger the release of what 6 molecules?
endotoxins
cytokines
PAF, NO, bradykinin, complement, prostaglandins, leukotrienes
what are some examples of cytokines that are stimulated by endotoxins?
- IL-1, 6, and 8
- TNF
what are the 3 stages of shock?
- non progressive stage
- progressive stage
- irreversible stage
what happens in the non progressive stage of shock?
compensatory mechanisms to maintain blood pressure
what are some examples of compensatory mechanisms to maintain blood pressure?
- Sympathetic nervous system
- RAA axis
- autoregulation
what is the progressive stage of shock?
tissue hypoxia and metabolic acidosis (tissues not dying yet)
what is the irreversible stage of shock?
enzyme leakage, organ shutdown
(point of no return, short time course)
how can you tell that you are in the irreversible stage of shock?
- increase in troponin, amylase, and lipase in blood
- increase B.U.N, creatinine (decrease in GFR) = kidney failure
