Compression

COMPRESSION

WHAT IS IT?

• Compression is defined as an inward-directed mechanical force that increases external pressure on the body or a body part.

• Compression can be classified into two types:

  • Static Compression: Constant pressure applied.

  • Intermittent Compression: Pressure that fluctuates periodically.

WHY DO WE USE IT?

• Compression is generally employed for various therapeutic purposes:

  • Improve Fluid Balance and Circulation: Helps maintain homeostasis within body tissues and fluids.

  • Modify Scar Tissue Formation: Aids in controlling or directing tissue growth post-injury or surgery.

  • Control Peripheral Edema: Reduces swelling in extremities due to fluid retention.

  • Prevent Deep Vein Thrombosis (DVT): Reduces the risks of clot formation in veins, typically during immobility.

  • Facilitate Residual Limb Shaping: Assists in the shaping of limbs post-amputation for enhanced prosthetic fittings.

  • Aid Healing of Venous Ulcers: Promotes wound healing in cases of vascular insufficiency.

EFFECTS OF COMPRESSION

• Improving Venous and Lymphatic Circulation:

  • Both static and intermittent compression devices increase circulation by boosting hydrostatic pressure in the interstitial space outside blood and lymphatic vessels.

• Limit Shape and Size of Tissue:

  • Static compression garments or bandaging can restrict the shape and size of new tissue growth, particularly effective over:

  • Residual limbs after amputations.

  • Edematous limbs.

  • Skin areas affected by burns.

• Increase Tissue Temperature:

  • Compression is thought to elevate tissue temperature, thereby increasing the activity of temperature-sensitive enzymes like collagenase, which contributes to collagen breakdown. This process is linked to the control of scar formation.

CLINICAL INDICATIONS FOR COMPRESSION - EDEMA

• Definition of Edema:

  • Edema arises from fluid accumulation in the interstitial spaces, driven by various pressures:

  • Hydrostatic Pressure: Pushes fluid out of blood vessels, influenced by blood pressure and gravity.

  • Osmotic Pressure: Maintains fluid within vessels, which is determined by protein concentrations inside and outside vessels.

  • In a healthy state, there is a balance where slightly higher hydrostatic pressure facilitates lymph fluid movement into the interstitial space, with lymph capillaries clearing this fluid, which contains proteins, water, and macrophages.

CAUSES OF EDEMA

• Edema can be attributed to several conditions:

  • Venous or Lymphatic Obstruction or Insufficiency: Impaired drainage of edematous fluid.

  • Increased Capillary Permeability: Loss of selective barrier at capillary walls.

  • Increased Plasma Volume: Resulting from sodium and water retention.

  • Other Factors: Exercise, trauma, surgery, burns, infections, prolonged airline travel, pregnancy, and a range of medical conditions.

TYPES OF EDEMA

• Acute Edema: Sudden onset, typically due to injury or trauma.

• Chronic Edema: Long-term fluid retention issues.

• Venous Edema: Associated specifically with venous problems.

• Lymphatic Edema: Due to lymphatic system failure.

• Systemic Edema: Affecting the body as a whole.

• Toxic Edema: Related to inflammatory responses or systemic diseases.

TREATMENT OPTIONS FOR EDEMA

• Elevation: Reduces hydrostatic pressure in the lower limbs.

• Cryotherapy: Reduces local inflammation and swelling.

• Weight Bearing Activities: Encourages venous return through muscle contraction.

• Compression: To control and reduce edema effectively.

EDEMA CAUSED BY VENOUS INSUFFICIENCY

• The development of peripheral edema is often due to:

  • Lack of Physical Activity: Reduces natural venous return mechanisms.

  • Venous or Lymphatic Valve Dysfunction: Leads to stasis and fluid retention.

  • Venous Obstruction: Impedes blood drainage, exacerbating edema.

  • The most common etiology for venous insufficiency is phlebitis, an inflammation of veins.

LYMPHATIC SYSTEM

• Hydrostatic pressure that exceeds osmotic pressure in veins leads to lymph production. The lymphatic system serves as an auxiliary channel, facilitating the return of lymph fluid to general circulation, thus preventing lymphatic congestion.

LYMPHEDEMA

• Causes of lymphedema include:

  • Low Serum Albumin: Can alter oncotic pressure.

  • Lymphatic Obstruction: Impairs normal lymphatic flow.

  • Abnormal Lymphatic Vessel Distribution: Variants in anatomy can predispose individuals.

  • Reduced Physical Activity: Contributes to poor lymphatic drainage.

  • Lymphedema can be classified as primary (genetic) or secondary (due to disease or dysfunction), with secondary lymphedema being the most prevalent caused by various factors affecting the lymphatic system.

ADVERSE CONSEQUENCES OF EDEMA

• Potential negative outcomes include:

  • Interruption of Repair Mechanisms: Impairs nutrient diffusion to cells.

  • Increased Pain: Due to pressure on sensory nerves.

  • Impeded Blood Flow: Could lead to further circulatory issues.

  • Disuse Osteoporosis: Bone density loss due to inactivity.

  • Cellulitis: Skin infections resulting from compromised barriers.

  • Thrombosis: Risk of clot formation due to stasis.

  • Reduced Range of Motion (ROM) and Function: Limits physical capabilities.

  • Pain and Itching: Common symptoms associated with excess fluid.

  • Brown Skin Pigmentation: Due to hemosiderin deposits from extravasated red blood cells.

  • Ulceration: Chronically swollen areas may break down.

HOW DOES COMPRESSION HELP EDEMA?

• Compression aids in the management of edema through:

  • Increasing Extravascular Hydrostatic Pressure: This helps promote circulation.

  • Controlling Fluid Movement: Creates pressure in the interstitial space that exceeds that in vessels, which limits or reverses outflow from blood and lymphatic vessels.

  • Facilitating Fluid Return to Circulation: Increases extravascular pressure encouraging fluid movement back into the vascular system.

• Intermittent/Sequential Compression: Often more effective than static compression due to its ability to mimic natural muscle action and venous pump mechanisms.

COMPRESSION – LIMIT SHAPE & SIZE - SCAR MODIFICATION

• Static Compression Effects:

  • Can decrease oxygen levels to the area where applied.

  • Collagen synthesis requires oxygen, whereas collagen lysis does not.

  • It is proposed that by increasing tissue temperature, metabolism, and the activity of collagenase, compression can modify scar formation following tissue injury.

  • Important in the shaping of residual limbs post-amputation and management of hypertrophic scars.

COMPRESSION - CONTRAINDICATIONS

• Compression therapy may be contraindicated in the following situations:

  • Cardiac Failure (CHF) or Pulmonary Edema: Risk of further fluid overload.

  • Recent or Acute DVT, Thrombophlebitis, or PE: Risk of dislodging clots.

  • Complete Obstruction of Lymphatic or Venous Return: Risk of exacerbating edema.

  • Severe Peripheral Arterial Disease (PAD) and/or ulcers resulting from arterial insufficiency.

  • Acute Local Skin Infections: Increased risk of infection.

  • Arterial Revascularization: Safety concern regarding blood flow.

  • Significant Hypoproteinemia: Serum levels of less than 2 g/dL.

  • Acute Trauma or Fracture: Considerations for stabilization first.

  • Static Compression: Safe to apply immediately in some circumstances, while intermittent compression may only be appropriate after the acute inflammatory phase and once mechanically stable.

COMPRESSION - PRECAUTIONS

• Precautions to consider before applying compression:

  • Impaired Sensation or Mentation: Patient may not perceive harmful levels of compression.

  • Uncontrolled Hypertension: Risk of exacerbation of cardiovascular issues.

  • Cancer: Potential for increased risk of metastasis in lymphatic confirmed cases.

  • Stroke or Significant Cerebrovascular Insufficiency: High risk for further complications.

  • Superficial Peripheral Nerves: Compression may damage nerves or circulation.

COMPRESSION SCREENING QUESTIONS

• Essential questions to ask prior to compression application:

  • Do you have heart or lung problems?

  • Do you have difficulty breathing?

  • Are you taking medications for heart or blood pressure?

  • Is there swelling in both legs?

  • Are you experiencing pain in your calves?

  • Assess Homan’s Sign: Clinical test for DVT by dorsiflexing the ankle.

  • Positive Homan Sign: Pain behind the knee indicating potential DVT.

  • Do you experience decreased mobility?

  • Are you experiencing pain in your calves when walking?

  • Do you have any ulcers?

  • Arterial Ulcer Characteristics: Typically small, round, with defined borders and painful; often found between the toes or lateral malleolus.

  • Ask for or check Ankle-Brachial Index (ABI): No compression if ABI is less than 0.8, indicating blood pressure at the ankle is lower than 80% compared to the upper extremities.

SCREENING QUESTIONS CONTINUED

• Additional considerations:

  • History of artery problems or surgery.

  • Signs of skin infections?

  • Notable recent weight loss or diet changes?

  • Check for low protein levels through lab values.

  • Any significant diseases?

  • Time-frame of injury occurrence?

  • Cancer history?

  • History of stroke?

ADVERSE EFFECTS OF COMPRESSION

• Potential adverse effects include:

  • Aggravating a Condition: That is causing the edema.

  • Impairing Circulation: If excessive pressure is employed.

  • Indicators of Excessive Pressure:

  • Cold extremity: Insufficient blood supply.

  • Blue discoloration: Cyanosis from lack of oxygen.

  • Distal pain and numbness: Signs of restricted blood flow to tissues.