Oedema Flashcards
What is oedema and what are the 2 categories of oedema?
Swelling
Local and systemic
List some causes of local oedema?
DVT
Injuries
Cellulitis
Ruptured Baker’s cyst
What is a Baker’s cyst?
How can it be mistaken for a DVT?
What is different about a ruptured Baker’s cyst and a DVT?
When excess joint fluid is pushed into one of the small sacs of tissue behind the knee. Seen in osteoarthritis.
If it ruptures the fluid goes down into the calf causing oedema and inflammation there.
Ruptured Baker’s cyst would not usually be painful whereas a DVT would.
List some systemic causes of oedema?
Heart failure Liver failure Renal failure Nephrotic syndrome Iatrogenic
How does heart failure cause oedema?
The heart fails to pump enough blood around the body, so in the capillaries there is more blood that has backed up. More blood in the capillary = higher hydrostatic pressure, so more fluid is forced out of the capillary into the tissues & body space.
How does liver failure cause oedema?
Liver failure = reduced production of proteins like albumin. Less albumin = less oncotic pressure in the capillaries. If there’s less oncotic pressure, less fluid is drawn from the tissues into the vessels, so fluid builds up in the tissues & body space
What is oncotic pressure and hydrostatic pressure?
Oncotic pressure: the pressure within a capillary that draws fluid from surrounding tissue into the capillary
Hydrostatic pressure: pressure within a capillary that forces fluid out into the surrounding tissue
How does renal failure cause oedema?
Kidneys are impaired so can’t process the fluid in the bloodstream quickly enough. There is too much, so fluid is forced out into the tissues and body spaces.
What’s the main iatrogenic cause of oedema?
Giving too much IV fluid, the kidneys can’t process the fluid in the bloodstream quickly enough. There is too much, so fluid is forced out into the tissues and body spaces.
Often when patients are unwell the fluid is required (for example in sepsis blood vessels are dilated so fluid is needed to keep blood pressure up) but when they start getting better oedema occurs.
What is nephrotic syndrome?
Large proteinuria
Hypoalbuminaemia
Hyperlipidaemia
Oedema: generalised, facial
Describe pulmonary oedema?
Fluid in the alveolar space and surrounding parenchyma.
What’s worse pulmonary oedema or pleural effusion?
PO = worse because fluid in alveolar space means no transfer of oxygen into blood.
What is SVC obstruction? What are the symptoms and cause?
Superior vena cava obstruction, means blood is trapped and can’t get back down to heart as quickly so BP in veins increases and fluid is forced out into tissues
Caused by head and neck tumours that press on SVC
They get a swollen head and neck, struggle to breathe because of pressure on larynx.
What is IVC obstruction? What are the symptoms and cause?
Inferior vena cava obstruction, means blood is trapped and can’t get back up to heart as quickly so BP in veins increases and fluid is forced out into tissues
Caused by bowel, gynae tumours
Oedema of legs, tachycardia
Management of oedema caused by decreased oncotic pressure?
- Loop diuretics: furosemide
2. Colloids, only albumin is good
