Department
of Podiatry - Vascular Assessment
Oedema
Oedema
(oidema, swelling) is the abnormal accumulation of excess fluid
in the interstitial spaces (Mosby, 1997). Oedema may have a multitude
of causes, and it is important for the clinician to determine this cause.
The simplest way to do this is ask yourself “is the oedema bilateral?”
and “on palpation, is it soft (pitted) or indurated (non-pitted)?”
(Nelson, 1992).
If the condition is bilateral, then it is most likely of a systemic origin,
which is causing venous hypertension. The most common cause of this is
congestive heart failure, usually simply due to ageing. Other systemic
causes include renal and thyroid conditions. Bilateral oedema is usually
pitted and involves the entire lower leg and foot to the level of the
digits.
If the condition is unilateral, oedema is most likely due a localised
abnormality. The most common cause is DVT, but may include lymphangiactasis,
lymphatic obstruction, varicose vein, previous trauma with venous obstruction,
or failure of the muscle pump due to AFO’s or neuromuscular conditions
that cause apropulsive gait (Nelson, 1992).
Most unilateral oedema is also pitted, however lymphatic-originated oedema
will be seen as indurated.
Oedema
basically prevents “ideal” tissue perfusion. Depending on the
cause, in the early stages this may have no impact on the patient’s
life, as there is adequate perfusion for tissue sustainance. However,
long-term oedema can manifest into a number of conditions, due to the
pressure being directly exerted onto blood vessels and surrounding tissues.
These include: haemosiderin, telangiactasia,
cellulitis, varicosities,
and venous ulceration (LTU PM331 manual).
As mentioned above, the calf “muscle-pump” that is activated
during normal gait helps greatly assists in return blood to the heart
against gravity, so it is worth being aware that patient’s with an
apropulsive gait or wheel chair bound patients may develop oedema and
require calf exercises.
So the podiatrist must be aware of oedema as it can be a good indicator
of venous insufficiency and lymphatic problems; and may also elicit other
manifestations.
Foot, ankle
and lower limb oedema.
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