Respiratory - Pulmonary oedema Flashcards
What is pulmonary oedema?
Abnormal accumulation of extravascular fluid in the lung parenchyma
What 3 factors determine how fluid moves between the capillaries and the interstitium?
Hydrostatic pressure
Oncotic pressure
Capillary permeability
What is hydrostatic pressure?
pressure exerted by blood on the wall of the capillary
What is Oncotic pressure?
levels of protein (mainly albumin), cause osmosis of water
What is capillary permeability?
The condition of the capillary wall that enables substances to pass through
What can low oncotic pressure cause?
Edema
What are the cardiogenic cause of pulmonary oedema?
Heart disease
What are 3 the non cardiogenic causes of pulmonary oedema?
Chest trauma
low oncotic pressure
inhalation of toxic substance
How does heart failure cause oedema?
The heart is insufficient, so kidneys become less effective at removing fluid. Causes low oncotic pressure - The fluid cannot diffuse as efficiently so builds up
What are the two main symptoms of right side heart failure?
System oedema
hepatomegaly
What is the main symptom of left side heart failure?
Pulmonary oedema
How do cardiogenic causes lead to pulmonary oedema?
Increased hydrostatic pressure, forces fluid through the interstitial fluid into the alveoli
How do non-cardiogenic causes lead to pulmonary oedema?
A weakening of the capillary walls, causes fluids to leak through
What are signs of pulmonary oedema?
- Productive cough possibly with blood
- dyspnoea when laying down, feels like drowning
- swelling in lower extremities
What is the aim of treatment for non cardiogenic pulmonary oedema?
- Manage inflammation
- Lower oncotic pressure (diuretics flush out fluids - furosemide)
- nitrates (increase capacity via dilation - GTN)
