Shock & Atheroma Flashcards
what is shock
complex syndrome with a variety of aetiologies
what does show causes result in
acute circ fail wth hypotension and inadequate tissue perfusion
what are some major types of shock
hypovolaemic septic cariogenic anaphylactic neurogenic
what is chemical shock
acute pancreatitis
acute peritonitis from perforated gastric ulcer
what is hypovolaemic shock
reached blood volume
- haemorrhage
- burns
- comit
what are the effects of hypovolaemic shock
inadequate circ vol
susceptible influence of age and prior health
elderly and hypertensive pt
what is max loss no symptoms blood loss
10% asymptomatic
rapid loss of half blood volume lead to coma and death
what is septic shock
severe infection
gm -ve bacilli = endotoxins
LPS - bind and activates macrophages and ends cells
set off TNF enzyme cascade
wha are the effects of septic shock
peripheral vasodilation tissues under perfused injury end cells leak fluid oedema activated coagulation disseminated intravascular coagulation
what do endotoxins do
activate macrophages and ends cells and trigger roads pathways
what is acrdiogenic shock
due tos every acute reduction in CO duet pump fail
decreased CO leads to
dec tissue perfusion
hypoxic injury
circ effects
metab effects - meat acidosis, hypoxia, distress syndrome
what happens in hypoxia cellular level
increase in anaerobic glycolysis lead to acidosis dec energy supply dec activity of mem incorrect Na K levels in cells cells swell
what is anaphylactic shock
type 1 hypersensitivity
massive asa cell degranulation causes release vasodilators and perm factors
what is example of neurogenic shock
acute brain or spinal cord injury
lack tissue perfusion
what are th compensatory mechs
early stages mech which maintain good flow to vital organs - CNS - heart -kidneys reused perfusion in other tissues
what is example of compensation mech
increased simp activity - fight/flight
rennin angiotensin-aldosterone system
CNS, heart and kidney auto regulate their own perfusion
if tissue perfusion not restored
ischaemia cases multiorgna fail and ultimate death
- fluid into pt to maintain adequate tissue perfusion
result shock in lung
diffuse (widespread) alveolar injury
- ARDS
result shock in heart
ischaemia - inefficient blood to pump
failure
result of shock input
ischaemia - segmented areas
endotoxaemia - release endotoxins
result of shocking adrenal organs
initially stimulated (simp activity) then failing
result of shock in bain and kidneys
initially auto regulate blood supply
later loss of consciousness and acute renal fail
shocked pt shows
restless
confused
pale - blood diverted away
cold
sweaty
rapid pulse - CV system increase to get blood around
weak pulse - not enough blood lack perfusion
low BP
increased rate and depth - try to compensate
drowsy - comatose
organs effected by shock
key vital organs - heart - kidney brian 0 gut
normal artery
edno
lamina
muscularis
adventitia
what si the aorta
multiple layers of elastic tissue to absorb impulse of cardiac systole and maintain blood flow in diastole
what to medium sized arteries regale
hist blood to various rogans
restriction
constriction
dilation so process thick media wall less elastic tissue
what is arteriosclerosis
hardening of artery
affecting arteries and arterioles
how does arteriosclerosis occur
due to gradual replace vasc smooth muscle by collagen and depo plasma proteins in smooth muscle
what i arteriosclerosis accelerated by
age
hypotension and diabetess
what is the most imp disease of arteries
atherosclerosis
what does atherosclerosis cause
ischaemic heart disease
stroke
peripheral vasc disease
hat does atherosclerosis arise for
as an inflam respone of vessel to chronic multifactorial injury
incidence fo ischaemic heart disease
indicator of extent of terosclerosis in community
rik actors of atheroma
family history male age cigarette smoke hypertension diabetes hyperlipidaemis exercise leve
what are the two types of risks
modifiable
non modiafiables
what reaches the risk of atehrom
family history pre menopausal female non smoker BP control DM control diet exercise low/mod alcohol
what is atherosclerosis
focal accumulation of lipid in intimate of arteries with inflammation and fibrosis - plaque
what does atherosclerosis affects
medium to large arteries - aorta, coronary,carotid ,cerebral
what does atherosclerosis cause
narrowing lumen with ischaemia in brain, heart, lower limbs
what does plaque rupture
- thrombosis causes acute ischaemia and infarct
what is the pathogenesis of atherosclerosis
fatty street
early atherosclerosis plaque
advanced plaque
complicated plaque
what are lipoproteins
fat and protein
- enable fat in bloodstream
what is LDL
- LDL - from plasma move free in and out
what does an oxidised LDL act as
inflam stimulus and invokes
- adhesion mol expression by end cells
- monocyte migration
cytokine production
what is oxidised LDL taken up by
macrophages
foam cell die = release lipid
what does monocytes sticking to end cells in intimate involves
endo dysfunction
influx lipid macrophages and t lymphocytes, inflam, smooth muscle prolif, depo collagen and elastic tissue
what is the fatty streak
easiest lesion seen - foam cells
intact endo
start of plaque
what happens to intimal lesions
develop and acquire EC lipid, intracellular lipid in foamy macrophages, collagen and other CT matrix prod by smooth muscle
what does atherosclerotic place contain
collagen cap
core lipid
calcium depo
vascularisation fro vasa vasorum
where is early plaque confined to
intima
where does advanced plaque erode
media
what are changes in plaque
suface ulceration
intraplaque haemorrhage
rupture
thrombosis - imp
what are some complications of atheroma
ichaemic heart disease cerebrovascular disease peirpehrla vasc disease mesenteric vasc disease renovasc disease aneurysms
what does ischaemic heart disease do
sudden death
MI
heart fail
what does cerebrovasc disease do
Transient Ischaemic As - tiny stroke
cerebral infarction
what does periephal vasc disease do
intermittent claudication
gangrene
what does mesenteric vasc disease
mesenteric claudication
intestinal infarction
what does renovasc disease do
hypertension
renal fail
what do aneurysms do
atlas 50% locl increase in luminal diameter of an artery
rupture
whats atheroma
disease process of elastic artery walls
response to injury mechanism
complicate common and serious
degree of prventbailiy
