Pathophysiology of Cardiac failure and oedema Flashcards
What is Darcy`s law?
Blood flow = pressure gradient over resistance
What is congestion?
Relative excess of blood in vessels of tissue or organ
What are the three clinical pathologies of congestion?
- Local acute congestion
- Local chronic congestion
- Generalised acute congestion
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 causes hepatic cirrhosis?
HBV alcohol
What happens to the structure of the liver in hepatic cirrhosis?
Regenerating liver forms nodules of hepatocytes with intervening fibrosis
What does the altered structure of the liver cause?
- altered hepatic blood flow
- Congestion in portal vein and branches
- collateral circulation
What are two consequnces of portal-systemic shunts?
- Oesophageal varices
- Caput Medusae
What is congestive cardiac failure?
-Heart unable to clear blood, right and left ventricles
What causes heart congestion?
Ischaemia
valve disease
What are the pathophysiology steps of congestive cardiac failure?
-Decreased CO
-Renal Glomerular filtration rate
(activation of renin-angiotensin-aldosterone system)
-Na And H2O retention
-Increase in fluid in body
Whats the treatment for cardiac failure?
Diuretics
Right heart failure causes?
Blood dams back to systemic
Increase JVP
hepatomegaly
peripheral oedema
Left heart failure causes?
Blood dams into lungs
Pulmonary Oedmea
What appearances of the liver can be seen when hepatic central venous congestion?
-Nutmeg
What is Oedema?
Accumulation of abnormal amounts of fluid in the extravascular compartment
What is an effusion?
Fluid collection in body cavities
What is ascites?
Fluid in abdominal cavity
What are the features of transudate?
Not much protein/albumin
Lots of H20 & electrolytes
What part of starlings law does pulmonary oedema affect?
Capillary hydrostatic
what part of starlings law does peripheral oedema affect?
Capillary hydrostatic
What can breast cancer radiotherapy to the axilla cause?
-Fibrosis=decreased outflow=oedema of the upper lip
How does hypoalbuminaemia cause oedema?
Decreases oncotic capillary pressure meaning water is not dragged back into capillary so filtration in creases
What is starlings equation?
look that shit up
What can cause hypoproteinaemia (which can lead to oedema)?
Nephrotic syndrome (leaky basement membrane)
Hepatic cirrhosis
Malnutrition
What happens in permeability oedema?
- Damage to endothelial lining
- proteins and larger molecules can leak out.. NO oncotic cap pressure to bring water back in.
