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Compression
Therapy with Bandages and Elastic Compression Garments
Without the beneficial
support provided by both forms of compression (garments
and bandages), lymphedema physical therapy treatment would not be possible.
It is helpful to understand precisely how these forms
achieve the desired affect (limb reduction) and how
they complement each other in the successful lymphedema training and treatment.
The Effects
of Lymphedema Compression Therapy
Bandaging/Garments
Reduce the Ultrafiltration Rate
Lymph originates as a clear, protein-rich fluid in
tissue spaces throughout the body. This fluid (1-2
liters/day) is usually carried by lymph vessels, passes
through regional lymph nodes, and joins the venous
blood shortly before this blood enters the heart. The
circulation of lymph is important in maintaining normal
tissue homeostasis throughout the body. The balance
between the fluid leaving the arterial side of the
capillaries (ultrafiltration) on the one hand and the
re-absorption that occurs in the venous capillaries
plus the drainage via the lymphatics on the other,
is known as Starling's Equilibrium. Because of the
disturbed lymph drainage in lymphedema, this equilibrium
collapses, protein-rich fluid accumulates in the tissue
spaces, the colloid-osmotic pressure rises, and all
of these events favor ultrafiltration. By raising the
tissue (interstitial) pressure by means of an external
force (the compression bandage), the effective ultrafiltration
pressure is reduced, less fluid accumulates, and less
fluid has to be removed from the tissue spaces, thereby
improving the lymphedema.
Bandaging/Garments
Improve the Efficiency of the Muscle and Joint Pumps
Lymph is propelled through the various lymph vessels
by muscular activity, by contraction of the lymph vessels
themselves, by the movements of the diaphragm (breathing),
and by negative pressures within the chest during the
breathing cycle. In the extremities, the activity of
the skeletal muscles is an important factor in lymph
transport. During contraction of an arm or a leg muscle,
the venous and lymphatic systems propel the fluids
they contain toward the heart. This results in a more
rapid flow and a decompression of both systems. In
order to preserve this process, normal tissue (skin
and muscle) and joints are essential. In lymphedema
these elements are damaged. The skin is overstretched
and, following decongestion of the lymphedema via CDT,
skin and tissue pressure is further diminished. The
use of external compression bandages compensates for
this diminished tissue pressure and thus improves the
efficiency of the muscle and joint pumps.
Bandaging/Garments
Prevent the Re-Accumulation of Evacuated Lymph Fluid
Manual Lymph Drainage (MLD) involves specific manual
motions that follow lymphatic pathways, emptying and
decompressing obstructed lymph vessels in the swollen
body part. Each MLD treatment decongests the limb and
helps return it to a more normal size. The reduction
of edema volume and the elastic insufficiency of the
skin make refilling of the limb with edema fluid quite
easy. Because compression bandages make up for the
diminished tissue pressure of the skin, they prevent
the re-accumulation of evacuated, stagnating lymph
fluid and thereby maintain the result of the MLD treatment.
MLD and Bandaging
Break Up Deposits of Accumulated Scar and Connective
Tissue
First stage lymphedema is caused by an accumulation
of protein-rich edema fluid. Lymphedema in a later
stage is associated with thickening of the skin and
hardening of the limb. This hardening is due to the
proliferation of connective and scar tissue. In order
to soften this connective tissue buildup, special techniques
during the MLD treatment are needed. Additional softening
and breakdown of this fibrotic tissue is obtained by
including foam rubber padding materials within a moderately-tight
bandage. This achieves a localized pressure increase
in the affected area. Muscular activity further acts
upon these fibrotic areas, loosening and breaking up
accumulated deposits of scar and connective tissue.
In addition to the listed beneficial effects of compression
bandages in lymphedema, they are also valuable in venous
disorders.
The Two Forms
of Compression: Garments and Bandages
The nature of compression varies greatly when a comparison
is made between short stretch bandages and elastic
compression garments. Both are necessary complements
to a program of Complete Decongestive Therapy but must
only be utilized by competent and well-trained therapists.
The distinction lies in the working and resting forces
generated by these two forms of compression.
Qualities of Compression:
Working and Resting Pressure
When a short stretch compression bandage is applied
to the lymphedematous limb it supports the tissues
without "squeezing" because its fabric does
not contain elastic materials. This means that the
bandage is not capable of shortening around the limb
after application and is therefore not exerting ever-increasing
pressure during inactivity. This dynamic is called
resting pressure and is considered safe and comfortable
for long-term treatment. Conversely, the stability
of the bandage creates a very high resistance to stretch
when pressure is applied through internal muscle contraction
and joint movement. This force is called working pressure.
The multi-layering of these bandages creates a soft "cast-like" environment
which fully resists these forces and further prevents
refilling of evacuated lymph fluid. Additionally, the
exercise regimen prescribed for each patient is maximized
by this working pressure as these forces promote further
lymph removal.
Garments are considered
a necessary complement to effective lymphedema management
for various reasons. The compression garment liberates
the patient from continual wearing of bandages which,
due to the multi-layering and integrated padding components,
become quite bulky and cumbersome. The single layer
support of compression garments is a welcome addition
to daily homecare. Typically patients remove bandages
upon awakening in the morning and apply either a compression
sleeve (arm patients) or stocking (leg patients). The
compression garment allows for a non-bulky and natural
limb contour while maintaining limb size in a nearly
edema-free state. Another important benefit to compression
garments is the integrated medically-correct "compression
gradient." This implies that the support is graduated
from distal to proximal along the limb allowing for
an overall decrease in compression at the trunk and
more compression at the ends of the extremity. A gradient
is of paramount importance for effective lymphedema
management because lymph fluid must be allowed to flow
toward the trunk efficiently, thus allowing for drainage
and limb reduction. Whereas bandages generate high
working pressures, compression garments generate low
working pressures due to the elastic materials utilized
in their construction. Garments generate very high
resting pressures while bandages generate low resting
pressure. For these reasons the comfort of a garment
is not as high at night as is therefore discouraged
for nighttime use. Also, due to their low working pressures,
garments will permit some fluid to return to the limb.
It is for these reasons that a well-rounded approach
to compression therapy involves a daily rotation between
both bandages and garments. Daily accumulations of
lymph are removed during bandaging sessions and limb
cosmesis is maintained through daily garment application.
Compression Gradient
and Mobility
After the compression bandage is applied, care should
be taken to insure that the proper pressure gradient
exists. To maintain normal blood and lymph circulation
within a rigid bandage sheath on an arm or a leg, the
bandaged pressure is moderately strong in the distal
areas of the extremity (hand/foot) and less in the
proximal areas (upper arm/thigh). In a medically-correct
compression garment the gradient is automatically integrated
into the construction materials through sophisticated
manufacturing and testing methods. The compressive
strength of the garment can then be prescribed according
to the desired support indicated for each patient's
unique requirements. |
