Pulmonary Oedema Flashcards
what does the interstitial fluid do
act as the go between blood and body cells
what do terminal arterioles regulate
regional blood flow to capillary beds (in most) tissues
what does fluid follow
a pressure gradient
how is transcapillary fluid flow driven
by pressure gradients across the capillary wall
how is the net filtration pressure calculated
forces favouring filtration - forces opposing filtration
what are the factors favouring filtration
PC - capillary hydrostatic pressure
πI - interstitial fluid osmotic pressure
what are the factors opposing filtration
πC - capillary osmotic pressure
Pi - interstitial fluid hydrostatic pressure
what is the NFP equation
NFP = (PC + πi) - (πC + Pi)
what is oedema
accumulation of fluid in interstitial space
what happens in pulmonary oedema
Diffusion distance increases - gas exchange compromised
what are the causes of oedema
1 - raised capillary pressure
2 - reduced plasma osmotic pressure
3 - lymphatic insufficiency
4 - changes in capillary permeability
what are causes of raised capillary pressure
- arteriolar dilatation
- raised venous pressure
what are causes of raised venous pressure
Left ventricular failure - pulmonary oedema
Right ventricular failure - peripheral oedema (ankle, sacral)
what are heard at the base of the lung when pulmonary oedema is present
crepitations
