The Pathophysiology of Congestion and Oedema Flashcards
What is Darcy’s law?
Blood flow = Total pressure/ Resistance
What is congestion?
Relative excess of blood in vessels of tissue or organ
What type of process is congestion?
Passive process, secondary phenomenon
Give an example of local acute congestion
Deep vein thrombosis
Give an example of local chronic congestion
Hepatic cirrhosis
Give an example of generalised acute congestion
Congestive cardiac failure
What does congestion cause?
Ischaemia and infarction
What is hepatic cirrhosis a result of?
Serious liver damage
What is the long term effect of hepatic cirrhosis on the liver?
Regenerated liver forms nodes of hepatocytes with intervening fibrosis so changes hepatic blood flow and can cause blockage of portal blood flow. This causes local chronic congestion with a haemorrhage risk
What is the final consequence of hepatic cirrhosis?
Portal-systemic shunts
What is a portal-systemic shunt?
A bypass of the liver by the body’s circulatory system
What is congestive cardiac failure?
When the heart is unable to clear blood from the right and left ventricles, it reduces CO, which reduces renal glomerular filtration rate which increases the amount of fluid in the body so there is fluid overload in the veins
What is the treatment of congestive cardiac failure?
Diuretics
What is the effect of congestive cardiac failure on the lungs?
Pulmonary oedema
How does pulmonary oedema happen?
There is left heart failure so blood dams back into the lungs
What is the effect of congestive cardiac failure on the liver?
Central venous congestion
How does central venous congestion happen?
There is right heart failure so blood dams back to the systemic circulation. This increases the JVP which causes hepatomegaly and peripheral oedema
What does the liver look like in central venous congestion?
“Nutmeg” liver has red/brown and pale spots