Pathophysiology of Congestion & Oedema Flashcards
what is congestion?
relative excess of blood in vessels of tissue
is congestion active or passive
passive
is congestion acute or chronic?
can be both
what are clinical pathology examples of congestion?
local acute congestion
local chronic congestion
generalised acute congestion
whats an example of local acute congestion?
deep vein thrombosis
whats an example of chronic congestion
hepatic cirrhosis
whats an example of generalised acute congestion?
congestive cardiac failure
what is the deep vain blocked by?
localised acute congestion
how does blood being backed up in veins/venules/capillaries effect blood, flow and pressure?
decreased outflow of blood
decreased pressure gradient
decreased flow across system
no oxygen therefore ischaemia and infarction
what does hepatic cirrhosis result from?
serious liver damage e.g. HBV and alcohol
where is the congestion in hepatic cirrhosis?
portal vein and branches
what happens to the heart with congestive heart failure?
unable to clear blood, right and left ventricle
what effects does congestive heart failure have on the body?
decreased cardiac output
decreased renal glomuler filtration rate
activation of RAAS
increase amount of fluid in the body
fluid overload in the veins
with what medication would treat fluid overload in the veins?
diuretics
what effects does congestive cardiac failure have on the lungs and in turn how does this effect anything else?
pulmonary oedema in the lungs, this results in -
left heart failure- blood dams back into lungs
crepitations in lungs, tachycardia
what effects does congestive cardiac failure have on the liver and in turn how does this effect anything else?
cetral venous congestion, this results in -
right heart failure- blood dams back into systemic circulation
increased JVP, hepatomegaly, peripheral oedema
what is the appearence of a hepatic central venous congested liver macroscopically?
“Nutmeg” liver red/brown & pale spotty appearance
why are pericentral hepatocytes red?
stasis of poorly oxygenated blood
why are periportal hepatocytes pale?
better oxygenated
why are periportal hepatocytes better oxygenated?
proximity of hepatic arterioles
what are the three components that affect net flux and filtration?
hydrostatic pressure
oncotic pressure
permeability characteristics and area of endotheliem
what is an oedema?
accumulation of abnormal amounts of fluid in the extravascular compartment
what is peripheral oedema?
iincreased interstitial fluid in tissues
what are effusions?
fluid collections in body cavities for eg pleural, pericardial
what is transudate?
fluid that has been pushed through the capillary wall due to high pressure
what is transudate composed of?
lots of H2O and electrolytes
not much protein or albumin
what is exudate?
part of inflammatory process due to increased vascular permeability
it leaks out the capillaries
what is exudate composed of?
higher protein/albumin and H2O and electrolytes
what is the pathophysiology of pulmonary oedema in left ventricular failure?
increased atrial pressure
increased pulmonary vascular pressure
increased pulmomary blood volume
increased pulmomary hydrostatic pressure
what is the pathophysiology of pulmonary oedema in lungs?
perivascular and interstitial transudate
progressive oedematous widening of alveolar septa
accumulation of oedema fluid in alveolar spaces
what is the pathophysiology of peripheral oedema in right heart failure?
right heart failure- cannot empty RV in systole
what is the pathophysiology of peripheral oedema in congestive cardiac failure?
right and left ventricles both fail
pulmonary oedea and peripheral oedema at the same time
all about the hydrostatic pressure
whats the pathophysiology of lymphatic obstruction?
hydrostatic pressure upset!
what does lymphatic system blocked lead to?
lymphoedema
what does the abnormal renal function result in?
salt and h2o retention
decreased renal function os the result of what? (4)
increased salt and h2o
increased intravascular fluid volume
secondary increased hydrostatic pressure
oedema
what is low protein oedema?
transudate
is oncotic pressure related to transudate?
yes
what does hypoalbuminaemia result in ?
decreased oncotic pressure which leads to increased filtration
in the arterial side,
which is bigger- capillary hydrostatic pressure or capillary oncotic pressure ?
capillary hydrostatic pressure
in the venous side,
which is bigger- capillary hydrostatic pressure or capillary oncotic pressure ?
capillary oncotic pressure
why does exudate contrain more protenis that transudate?
damage to endothelial lining produces large pores for proteins and larger molecules t leak out from not just water
upsetting the …… forces can lead to oedema?
starling
what is darcy’s law?
Q = blood flow P = pressure R = resistance
Q= change of P/R
how are nodules formed in hepatocytes?
liver tries to regenerate around the damage
what is the portal blood flow
Circulation of blood to the liver from the small intestine, the right half of the colon, and the spleen through the portal vein; sometimes specified as the hepatic portal circulation.
