compression (week 10)

The Basics

Compression – A mechanical force that increases external pressure on the body or a body part

Hydrostatic pressure - Pressure exerted by a fluid

Improves Venous and Lymphatic Circulation

Compression applies pressure on the fluid in the interstitial space which becomes greater than it is in the vessel. This pressure limits or reverses the outflow of fluid from blood vessels and lymphatics. Forces the fluid back into the vessels causes it to circulate rather than accumulate in the interstitial space.

Intermittent compression may improve circulation more effectively than static compression because the varying amount of pressure “milks” the fluid from distal to proximal vessels.

Limits the Shape and Size of Tissue

Compression can be used to limit the shape and size of new tissue formation

Clinical uses for compression bandages or garments:

• Residual limb shaping after amputation

• Burn damaged skin

Increases Tissue Temperature

Increase in superficial tissue temperature because of insulation to the area

This increase in tissue temperature is thought to increase the activity of temperature-sensitive enzymes, which breaks down collagen.

Edema indications

is caused by imbalance between hydrostatic pressure (pushes fluid out of vessels) and osmotic pressure (pushes fluid into vessels)

• Injury

• Nutritional imbalance

• Venous insufficiency

• Lymphatic obstruction (not complete)

• Airline travel

• Pregnancy

• Physical activity or lack of physical activity (peripheral)**

Edema caused by the following conditions should NOT be treated with external compression:

Congestive heart failure

Cirrhosis

Acute renal disease

Diabetic glomerulonephritis

Malnutrition

Radiation

Prevention of Deep Vein Thrombosis

Most likely due to increasing venous blood flow and reducing opportunity for thrombus formation

Especially important for sedentary patients

Great for airline travel over 8 hours!

Venous Stasis Ulcers

Used to diminish risk for venous stasis ulcers and to facilitate healing of previously formed ulcers

Consist wearing schedule of stockings is important

Residual Limb Shaping After Amputation

Intermittent or static compression

Avoid excessive pressure on unprotected bony prominences

Limb shaping is especially important when preparing the patient for a prosthetic device

Control of Hypertrophic Scarring

Compression for at least 23 hours per days with 20-30 mm Hg for 12 months or longer

Contraindications of Intermittent or Sequential Compression Pumps

Heart failure or pulmonary edema

Recent or acute DVT, thrombophlebitis, or pulmonary edema

Totally obstructed lymphatic or venous return

Severe peripheral arterial disease or ulcers resulting from arterial insufficiency

Acute local skin infection

Significant hypoproteinemia

Acute trauma or fracture

Arterial revascularization

Precautions

Impaired sensation or mentation

Uncontrolled hypertension

Cancer

Stoke or significant cerebrovascular insufficiency

Superficial peripheral nerves

Compression Bandages

Come in a variety of degrees of extensibility and can be applied in single layers or multiple layers.

Resting pressure – Pressure is exerted by elastic when it is put on stretch

Work pressure – Pressure produced by active measures pushing against an inelastic bandage

Compression Garments pressures

16-18 mmHg- Used to prevent DVTs

20-30 mmHg – Used for scar tissue control

30-40 mm Hg – Used for edema control

Velcro Closure Devices

Removable and adjustable compression devices that fasten with Velcro straps

Low cost option that can be applied with the patient

Intermittent Pneumatic Compression Pump

First application should always begin with clinical supervision

For treatment of edema, venous stasis ulcers or DVT prevention

• Typically: Inflation 80-100 seconds, Deflation 25-50 seconds

For residual limb reduction

• Typically: Inflation 40-60 seconds, 10-15 seconds in a 3:1 ration

Inflation Pressure for Intermittent Compression

Must be below diastolic pressure. 30-80 mm Hg

Upper extremities – 30-60 mmHg (Cameron)/ 20-50 mmHg (Behrens)

Lower Extremities – 40-80 mmHg (Cameron)/ 40-60 mmHg (Behrens)

Adverse Effects of External Compression

Aggravation of physiological problem causing edema (heart, kidney, liver failure)

Impaired arterial compression (if compression acts like a tourniquet)

Increased edema

Increased blood pressure