NURS601 Week 1
Concept 1: Oedema
What is an Oedema?
A shift of plasma to interstitial fluid
An oedema is an accumulation of fluid in the interstitial space
Occurs if venous hydrostatic pressure rises, plasma oncotic pressure decreases or interstitial oncotic pressure rises
May also develop if an obstruction of lymphatic outflow causes decreased removal of interstitial fluid
Oedema caused by heart failure
Extracellular fluid volume excess caused by addition or retention of saline (saline overload)
Leaky cap bed
Obstruction to lymph flow
Plasma oncotic pressure decreases
Interstitial oncotic pressure rises
Increase in intravascular hydrostatic pressure/if venous hydrostatic pressure
Associated with cardiac, hepatic, or renal failure & venous insufficiency
Where is the oedema? Localised or Generalised?
Related to trauma or inflammation.
Other examples of localised oedema: Cerebral, pulmonary, pleural effusion, pericardial effusion, and ascites
More uniform distrubution of fluid in interstitial spaces
How long has the patient had oedema?
Longer than 3 months
What could be the cause?
How does this affect the patient?
Fluid shifts in heart failure
All fluids in the body are where they should be. There is normal distribution of fluid in the ICF and ECF
Abnormal accumulation of fluid in interstitial spaces, such as oedema. This abnormal accumulation can still be easily moved back to ICF/ECF, where it should be
Abnormal accumulation of fluid trapped in spaces where it is difficult or impossible to return to where it should be, such as ascites or burn related injuries. This requires medical intervention to reverse.
Dependent oedema: Pitting and non-pitting
Slight pitting/2mm, disappears rapidly
Deeper pit/4mm, disappears in 10-15s
Deep pit/6mm, may last >1m, extremity swollen
Very deep pit/8mm. lasts 2-5m, extremely grossly distorted
Ensure underlying cause is being managed appropriately, attempting to reverse
Position patient to reduce positional fluid collection
Recording measurements of pitting oedema
Administering diuretics if prescribed
Protecting affected tissue from further injury
What is the pathophysiological rationale?
Effects of oedema: determined by location
Fluid leaves bloodstream and accumulates in interstitial spaces
Circulating blood volume and blood pressure decline
Tissue more susceptible to injury
Poor supply of nutrients and oxygen to support healthy tissue
Up to 50% of patients suffering from oedema experience leg ulceration, with 31% of these people having the ulcer for more than 5 years