Compression Flashcards
What is Compression?
The application of a mechanical force that increases the external pressure on the body or body part
Compression is generally used to do what?
- Control peripheral edema caused by vascular or lymphatic dysfunction
- Improve fluid balance and circulation
- Prevent formation of DVTs
- Facilitate residual limb shaping after amputation
- Modify scar formation
How does compression improved fluid balance?
It increases hydrostatic pressure in the interstitial space, which means the fluid in the vessels is circulated rather than pooled
2 Edema classsifications
- Lymphatic edema
- Venous edema
Lymphatic edema vs. Venous edema
Lymphatic edema occurs when plasma proteins in the tissues stagnate owing to mechanical insufficiency of lymphatic drainage
Venous edema results from increased capillary pressure and venous obstruction
How is normal fluid equilibrium in the tissues maintained?
By the balance between hydrostatic and osmotic pressures inside and outside of the blood vessels
Higher hydrostatic pressure inside the vessels acts to push fluid ___ of the vessels
OUT
Higher protein concentration and osmotic pressure inside the vessels act to keep fluid _____ the vessels
INSIDE
Which is higher, hydrostatic or osmotic pressure? What does this result in?
Hydrostatic pressure which results in a slight loss of fluid into the interstitial space
The interstitial fluid is taken up and returned to the venous system via what?
the lymphatic system
3 effects of external compression
- Improve venous and lymphatic circulation
- Limits the shape and size of tissue
- Increases tissue temperature
How does compression improve venous and lymphatic circulation?
- By increasing the hydrostatic pressure in the interstitial space
- By limiting the outflow of fluid from vessels into the interstitial space
- By milking” the fluids from the tissues
8 major causes of edema
- Venous or lymphatic obstruction or insufficiency
- Increased capillary permeability
- Increased plasma volume due to sodium/water retention
- After trauma, surgery or burns
- With infections
- After exercise
- Airplane travel
- Pregnancy
6 other causes of edema
- Congestive heart failure
- Liver failure
- Acute renal disease
- Diabetic glomerulonephritis
- Malnutrition
- Radiation injury
What is the primary factor propelling lymphatic and venous flow?
Muscle contractions
What 3 things cause venous insufficiency?
- Lack of physical activity
- Degenerated valves
- Mechanical obstruction of the veins by a tumor or inflammation
What is phlebitis?
Inflammation of the veins
How does phlebitis increase hydrostatic pressure?
By the thickening and loss of elasticity of vessel walls
What 2 things does phlebitis result in?
- Decreased circulation of deoxygenated blood out of the veins and increased venous pressure
- Dependent position further increases hydrostatic pressure
3 unique characteristics of venous edema
- Generally it is a soft pitting edema
- It has a tendency to pool in the distal extremities
- The skin has a glossy, shiny appearance
What is lymphedema?
It is a condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system
What is the most common cause of venous or lymphatic edema?
Infection
What is the result as plasma proteins are laid down in the tissues over time?
subcutaneous tissue fibrosis and hard induration of the skin
Most effective therapeutic treatment of edema
Low pulse rate electrical stimulation accompanied by elevation
Mechanical compression devices should be pumped up to __ - __ mm Hg for the UE and __ - __ mm Hg for the LE
30-60 mmHg
40-80 mmHg
Treatment on-off time ratios for compression devices should be either _:1 or _:1 with at least __ second off time recommended
5:1 or 2:1
10 second
Total treatment time for compression varies from __ - __ minutes
10-60
can also be as long as 3 hours long
4 uses of compression
- Prevention of DVT
- Venous stasis ulcers
- Residual limb shaping
- Control of hypertrophic scarring
10 risk factors of DVT
- Age
- Surgery or trauma
- Confinement to bed
- Cancer
- Central vein catheterization
- Prior superficial vein thrombosis
- Varicose veins
- Paralysis
- Oral contraceptives
- Pregnancy
- Hormone therapy
5 treatment approaches to prevent DVTs
- Compression stockings
- Intermittent pneumatic compression
- Gastroc/soleus exercises
- Calf muscle E-stim
- Anticoagulant medications
How does compression reduce DVT formation?
It improves venous flow which reduces venous stasis and thrombus formation
What are venous stasis ulcers?
Areas of tissue breakdown and necrosis that occur in areas of impaired venous circulation
What causes venous stasis ulcers?
As venous pressure increases venous circulation is impaired which leads to endovascular and inflammatory changes which provide a setting for ulcer formation
How does compression affect the formation of venous stasis ulcers?
- Improves venous circulation
- Reduces the adverse effects of poor venous flow
- Diminishes the risk of vascular ulcer formation
- Facilitates healing of previously formed ulcers
Should intermittent or static compression be used in residual limb shaping?
Intermittent compression has been shown to reduce the residual limb in half the time required by other techniques
Describe hypertrophic scars
They are not pliable and are raised and ridged in appearance
The risk of hypertrophic scarring increases with what 6 things?
- Delayed healing
- Deep wounds
- Repeated trauma
- Infection
- Presence of a foreign body
- Genetic predisposition
8 Contraindications to Compression
- Heart failure or pulmonary edema
- Recent or acute DVT, thrombophlebitis, or PE
- Obstructed lymphatic or venous return
- Severe peripheral arterial disease and/or ulcers due to arterial insufficiency
- Acute local skin infection
- Significant Hypoproteinemia (protein levels <2 gm/dL)
- Acute trauma or fracture
- Arterial revascularization
5 Precautions for Compression
- Impaired sensation or mentation
- Uncontrolled hypertension
- Cancer
- Stroke or significant cerebrovascular insufficiency
- Superficial peripheral nerves
Compression bandages work in what 2 ways?
They apply working or resting pressure
- Resting pressure is exerted by elastic when it is put on stretch - Working pressure is produced by active muscles pushing against an inelastic bandage
A long-stretch bandage applies how much pressure?
60 - 70 mmHg
Examples of long-stretch bandages
Ace wraps and Tubigrip
When should short-stretch bandages be used?
Most useful during exercise, however they do not control edema effectively
Example of a short-stretch bandage
Comprilan
What is a Unna boot?
a special gauze bandage, which can be used for the treatment of venous stasis ulcers
How much pressure should antiembolism stockings produce?
16-18 mmHg
How much pressure should stockings for scar tissue control produce?
20-30 mmHg
How much pressure should stockings for edema control produce?
30-40 mmHg
Intermittent compression devices help mostly with what?
edema reduction
Static compression devices help mostly with what?
the maintenance of edema reversal
Are intermittent compression devices used for control of scar formation?
NO
Should a patient with venous insufficiency use intermittent compression?
only after the patient has tried compression stockings for 6 months, with unsuccessful results
What should the inflation/deflation time be for edema, DVT prevention, and venous stasis ulcers?
80-100/25-35 seconds
at a 3:1 ratio
What should the inflation/deflation time be for residual limb reduction?
40-60/10-15 seconds
at a 4:1 ratio
