Compression Flashcards
What is compression?
The inward directed mechanical force that increases pressure on the body or body part
What is the primary clinical application for compression?
To control/reduce peripheral edema associated with vascular or lymphatic dysfunction
What are some secondary applications for compression?
Prevent formation of DVT or to help with ulcers
what is compression used for?
To improve fluid balance and circulation (increases hydrostatic pressure in the interstitial space relative to vessels and lymph system
How can compression be administered?
Constant or intermittent
What is edema?
The presence of abnormal amounts of fluid in the extra cellular tissue spaces in the body
How is fluid equilibrium maintained through homeostasis?
Through a balance of osmotic pressure ad hydrostatic pressure
what is osmotic pressure determined by?
Concentration of proteins inside and outside the blood vessels
What is hydrostatic pressure determined by?
Blood pressure and gravity
What does a high hydrostatic pressure inside the vessel do?
Pushes fluid out of the vessels
What does a high osmotic pressure inside the vessel do?
Keeps fluid in the vessels
What generally happens in healthy tissue?
Hydrostatic pressure is slightly higher than osmotic pressure
-net loss of fluid to interstitial space
-lymphatics pick up interstitial fluid and return to venous system via subclavian veins
What are some causes of edema?
Venous or lymphatic obstruction/insufficiency
Increased plasma a volume from sodium and water retention
Trauma
Surgery
Burns
Infection
What are some diseases we wouldn’t want to compress?
Chronic heart failure, cirrhosis, kidney disease
How do healthy and normal veins prevent edema?
When muscles around a vein contract, they exert a pressure on the outside of veins to push blood proximally through the veins. Normally we get enough skeletal muscle activity to push venous blood proximally. Valves are key structures within venous and lymph vessels that prevent the back flow of fluid ensuring the fluid moves proximally toward the heart rather than pushed towards the extremities
What normal pressure do we get at the gastrocsoleus?
200 mmHg
What happens when there is a lack of physical activity or dysfunction of the valves?
Insufficiency and accumulation of fluid in the peripheral circulation system.
-space occupying lesion
-inflammation
What is the most common cause of venous insufficiency?
Plebitis which is inflammation of the veins
What are some other causes of venous insufficiency?
Varicose veins
Thickening of vessel wall with loss of elasticity- increase in hydrostatic pressure of venous system
Damage of valves- blood flows in both directions
What is lymphedema?
Concentration of proteins in lymph is generally high than interstitial space which causes fluid to flow into the lymph system
What are some major causes of lymphedema?
Low serum albumin- reduction in osmotic pressure
Lymphatic obstruction- resection d/t CA
Reduced activity
What are some consequences of edema?
Can limit ROM, limit function, and cause pain
What can chronic edema/ lymphedema cause?
Collagen to be laid down causing subcutaneous fibrosis and hardening of skin- joint contractures
What can edema increase the risk of?
Infection including cellulitis, ulceration, and limb amputation- worse if arterial obstruction
What will patients with chronic venous insufficiency complain of?
Itching secondary to status dermatitis-> itching -> cut -> infection -> poor healing -> ulcer -> poor healing -> amputation -> death
How does compression reduce edema?
Increases extra vascular hydrostatic pressure and increases circulation
If insufficient the hydrostatic pressure in the interstitial space becomes greater than the pressure in the veins and lymph vessels
Once the fluid is returned to the vessels it can be circulated back to the heart and vascular system
According to some studies what are some other indications for compression?
Prevent DVT
Flights > 8 hours especially after LE surgery
What is another indication for compression?
Residual limb shaping after amputation
Control of hypertrophic scarring
How does compression help with residual limb shaping after amputation?
-residual limb reduction and shaping are needed for the prosthetic device to fit after an amputation
- if device doesn’t fit excessive pressure can be placed on bony prominence and cause tissue breakdown
How can compression help the control of hypertrophic scarring?
-common complication of deep burns and other extensive soft tissue injuries
-hypertonic scars are raised and have a rigid appearance
-hypertonic scars limit ROM and function
-typically wear 23 hours a day with 20-30 mmHg
What are some contraindications of compression?
Patients with symptomatic heart failure and patients with DVT
If ABI is < 0.6 all forms contraindicated
If ABI > 0.8 then standard or full compression (30-400 mmHg) may be used
If ABI is between 0.6-0.8, compression should be reduced to 23-27 mmHg
What are some contraindications for intermittent or sequential pumps?
Heart failure or pulmonary edema
Recent to active DVT, thrombophlebitis, or PE
Obstructed lymphatic or venous return
Severe peripheral arterial disease
Skin infection
Hypoproteinemia
Actuar trauma or fracture
Arterial revascularization
What are some precautions for compression?
Impaired sensation or mentation
Uncontrolled hypertension
If they have lymphedema from cancer
Superficial peripheral nerves
What are some adverse effects of external compression?
Aggregate symptoms of pre-existing conditions
May cause soft tissue injury
What is the static application technique for compression?
Use of bandages/garments
Venous or lymphatic dysfunction or inflammation
Shaping of residual limbs
Burns
Venous static ulcers
What is the lymphedema management application technique for compression?
Focuses more on complete decongestive therapy
Manual lymphatic drainage (MLD)
Compression
Skin care
Exercise
What is the intermittent application technique for compression?
Electrical pneumatic pumps
Good for DVT in bedridden patients
How can compression bandages be applied?
Resting pressure, working pressure or a combination of both
How is resting pressure exerted?
from elastic material put on stretch
how is working pressure produced?
By active muscles pushing against the inelastic bandage
what are the types of bandages we can use for compression?
long stretch/high stretch
short stretch/low stretch
multi layered bandage
what is the long stretch/high stretch bandage?
can extend by 100-200%
provide the greatest resting pressure
can apply 60-70 mmHg pressure when stretched
little to no working pressure
(ace wrap)
what is the short stretch/low stretch bandage?
low elasticity
30-90% extension
low resting pressure but high working pressure
patient needs to be active
what is a multi layered bandage?
uses the combination of elastic and inelastic layers to apply moderate to high resting pressure
profore, unna boot
how should we apply compression bandages?
apply by wrapping in figure 8 pattern
start distally and move proximally
tension: distally > proximally (helps maintain the pressure gradient)
do not wrap in circumferential or spiral wraps because it can cause uneven pressure
T/F: wrapping a compression bandage alone will reduce edema?
false
what are compression garments?
recommended for treatment of lymphedema
made of spandex and nylon blend
how much pressure to antiembolism stockings provide and what are they used for?
16-18 mmHg used to prevent DVT. they don’t provide sufficient enough compression to prevent DVT or alter circulation when legs are in dependent position
should fit snugly and be worn 24 hours a day unless bathing
how much pressure from compression garments would we want for scar formation or upper extremity lymphedema?
20-30 mmHg
how much pressure from compression garments would we want to control LE edema in ambulatory patients?
30-40 mmHg
can compression garments reduce edema on their own?
they may not when applied alone
what is the intermittent pneumatic compression pump?
provides intermittent compression, should be done under medical supervision. once pump has reduced edema need to see if we can maintain it with garment or bandage between sessions. it is often used as part of complete decongestive therapy
what are the parameters for IPC for edema, venous stasis or DVT prevention?
IT (80-100s) DT (25-50s)
need to allow for venous refilling
use 3:1 ration for on:off
what are the parameters for IPC for residual limb reduction?
IT (40-60s) DT (10-15s)
use 4:1 ration for on:off
what is typically the pressure on IPCs?
between 30-120 mmHg on most units
why should you always check BP when using IPC?
it is recommended that the inflation pressure never exceed diastolic BP
