Congestion Flashcards
What are three main types of congestion?
local acute
local chronic
generalised acute
name an example of local acute congestion
DVT
name an example of local chronic congestion
Hepatic cirrhosis
name an example of generalised acute congestion
congestive heart failure
Describe the pathophysiology of a DVT
- A thrombosis forms in the deep venous system
- This decreases the diameter of the lumen
- Less pressure gradient as the arterial pressure remains the same but the venous pressure increases
therefore flow must decrease (flow=pressure/resistance) - Less oxygen is being supplied
- Can result in ischaemia and infarction
- A sign of a DVT can be varicose veins
Describe the pathophysiology of hepatic cirrhosis
- This occurs when the liver becomes damaged
- Liver cells regenerate to repair the damage but they dint grow back normally
- Fibrosis occurs as a result of altered blood flow ad abnormal architecture
- The portal veins (gut to the liver) have an increased pressure and cause an increased pressure downstream (in the gut)
- Therefore there is congestion in the liver, gut and spleen.
- Collaterals become dilated which can be a haemorrhage risk and can be visible sometimes.
Name two ways the liver can become damaged
high alcohol intake
HBV
When does congestive heart failure occur?
when the left and right ventricles cannot ump blood out effectively
Describe the pathophysiology of generalised acute congestion.
there is a decreased cardiac output
BP is decreased
RAAS is activated in the loop of Henle to try increase the BP
this increases the permeability of the kidneys so more water is reabsorbed
this increases the plasma volume and can result in fluid over load and oedema because even with the increase of plasma volume, the heart can still not pump properly
What does right heart failure cause
liver enlargement
less pre load, increase congestion in the liver
What does left heart failure cause
pulmonary oedema, tachycardia
less blood leaving the heart, increased blood volume in the pulmonary circulation
the body increases the sympathetic tone to the heart to increase the contractibility of the heart to increase the cardiac output to normal as a rest of the baroreceptors having less stretch
What is the macroscopic appearance of the liver if the patient has hepatic central venous congestion ?
spotty nutmeg: red/brown and pale
What cells are red/brown and which cells are pale?
red/brown = pericentral pale = periportal
What accumulates in the liver cells during congestion?
fat
What appearance does the fat give to the liver cells?
yellow appearance
