Electrical Stimulation for Wound Healing & Edema PDF

Electrical Stimulation for Wound Healing & Edema Electrotherapy INTEGUMENTARY SYSTEM Skin Hair Oil and sweat glands Nails Sensory receptors FUNCTIONS 1. Regulates body temperature 2. Stores blood 3. Protects body from external environment 4. Detects cutaneous sensations 5. Ex...

Electrical Stimulation for Wound Healing & Edema Electrotherapy INTEGUMENTARY SYSTEM Skin Hair Oil and sweat glands Nails Sensory receptors FUNCTIONS 1. Regulates body temperature 2. Stores blood 3. Protects body from external environment 4. Detects cutaneous sensations 5. Excretes and absorbs substances 6. Synthesizes vitamin D SKIN Largest organ of the body ~15% of total body weight Two layers – Epidermis – Dermis Subcutaneous tissue – Hypodermis Epidermis Keratinized stratified squamous epithelium Superficial thin layer; (-) blood vessels Dermis Corium or “true skin” Contains blood vessels, lymphatics, nerves, collagen, and elastic fibers Encloses the epidermal appendages 20 to 30 times thicker than the epidermis Comprised primarily of interwoven collagen and elastic fibers, which provide the skin with its tensile strength and elasticity to resist deformation Subcutaneous Tissue Hypodermis Fibroblasts, adipocytes, & macrophages Used to estimate the total body fat by pinching the skin at selected locations and measuring the thickness of the skin fold and underlying subcutaneous tissue Phase 1: INFLAMMATION The normal immune system reaction to injury The central activity in wound healing Temporary repair initiated by – Coagulation (clotting factors, platelets) – Short-term decreased blood flow Necrosis occurs after cells have been injured or destroyed Phase 1: Inflammation The spread of pathogens is slowed: debris and bacteria are attacked by a host of cells – Infiltration of leukocytes and macrophage cells – If the wound is acute, some periwound edema, erythema, and drainage can be expected – Pus – fluid that accumulates at the injury site Oxygen is delivered via increased blood flow to keep the phagocytic cells alive and functioning Phase 1: Inflammation Permanent repair is facilitated by creating a clean wound, setting the stage for the next phase of healing; signals are generated that re-epithelialization can begin Time frame: day of injury to ~day 10 Phase 2: PROLIFERATION New tissue fills in the wound as fibroblasts secrete collagen Skin integrity is restored by re-epithelialization and/or contraction Angiogenesis occurs – New blood vessel growth from endothelial cells, fragile capillary buds grow into the wound bed; new reddish, slightly bumpy tissue is formed (granulation tissue) Phase 2: Proliferation Epithelial cells differentiate into type I collagen – Collagen synthesis occurs but the resulting new scar tissue is fragile and must be protected; trauma during this phase may return the wound to the inflammatory process Time frame: day 3 of injury to ~day 20 Phase 3: MATURATION Maturation or remodeling of new tissue begins while granulation tissue is forming during the proliferative phase Epithelial cells continue to differentiate into Type I collagen New skin has tensile strength that is 15% of normal – Scar tissue is rebuilding but at best reaches 80% of original tensile strength Phase 3: Maturation Underlying granulation tissue is replaced by less vascular tissue In deep wounds, dermal appendages are rarely repaired (hair follicles, sebaceous and sweat glands, nerves) but instead are replaced by fibrous tissue Over time the scar tissue matures, changing from red to pink to white and from raised and rigid to flat and flexible Phase 3: Maturation Time frame: ~day 9 of injury up to 2 years Newly formed skin breaks down with little provocation Scar tissue may build up within the outline of the original wound (hypertrophic) or beyond the margins of the original wound (keloid) The presence and contraction of the scar can lead to both functional and cosmetic deformities Phase 3: Maturation Hypertrophic scar –A red and raised scar with rigid texture; it stays within the boundary of the original wound Phase 3: Maturation Keloid –A large, firm scar that overflows the boundaries of the original wound –More common in darkly pigmented individuals Factors Affecting Wound Healing ✓Age ✓Blood flow ✓Size of wound ✓Medications ✓Co-morbidities ✓Stress ✓Continued trauma ✓Infection ✓Nutrition ELECTRICAL STIMULATION Has been shown to have beneficial effects on the different phases of cutaneous wound healing in both chronic and acute wounds – Pressure ulcers, venous ulcers, arterial ulcers and diabetic foot wounds Can reduce infection, improve cellular immunity, increase perfusion, and accelerate cutaneous wound healing Electrical Stimulation CONTRAINDICATIONS Demand cardiac pacemaker Over carotid sinus Areas where venous or arterial thrombosis or thrombophlebitis is present Cancer Osteomyelitis under the wound Over pregnant uterus Electrical Stimulation PRECAUTIONS Cardiac disease Impaired mentation Areas with impaired sensation Areas of skin irritation Infection control Infection Control If electrodes are placed in wounds, a new electrode should be used each time Self-adhesive electrodes should be single-patient use only Chronic open wounds should be kept clean Protective covers for ES devices and leads are available to minimize the transmission of communicable diseases such as methicillin resistant Staphylococcus aureus (MRSA); after these covers are used, they should be left in the patient’s room Electrical Stimulation Undamaged human skin has an endogenous electrical potential and a transcutaneous current potential of 10–60 mV – This is generated by the movement of sodium ions through Na+/K+ ATPase pumps in the epidermis Following an injury to the skin, a flow of current through the wound pathway generates a lateral electrical field and this is termed the “current of injury” or “skin battery” effect Pulsed Current Unidirectional or bidirectional flow of electrons or ions Has two waveforms – monophasic or biphasic Delivered to the wound tissues by conductive coupling with a hydrogel or moist gauze filling the defect and the electrodes of appropriate polarity placed on top Low Voltage PC (LVPC) WoundEL® – ES wound management system that has been especially developed to kick-start and accelerate healing processes and reduce wound-related pain – Hard-to-heal chronic wounds – Activate and maintain healing with a monophasic pulsed direct current and low frequency generated by an electrical console High Voltage PC (HVPC) Employs a monophasic pulsed current where the pulses are delivered in doubles – Each pulse is of short duration (less that 200 micro seconds) and it has a high peak voltage (150–500 V) Typically delivered by a device with both negative and positive electrodes either placed on the wound site or proximally on the skin Used in wound healing, pain relief and edema resolution Direct Current Able to mimic the physiological endogenous current Low-intensity direct current – 20–1000 microamps – Used to avoid damaging healthy tissue – Promotes chronic wound healing by two mechanisms – Galvanotaxis (stimulating the migration of fibroblasts and keratinocytes along an electrical gradient) Antimicrobial effect TENS(AC) Aside from its analgesic effects can also alter skin temperature and increase blood flow FREMS Frequency rhythmic electrical modulation system A form of transcutaneous electrotherapy using ES that automatically varies the pulse, frequency, duration, and voltage Biofeedback ES Fenzian system Degenerate waves Used successfully in the treatment of symptoms in keloid and hypertrophic scarring and in accelerating the process of acute wound healing in the skin A transcutaneous low intensity device, which detects changes in skin impedance This device forms part of an electrobiofeedback link with the individual’s normal physiological repair Bioelectric Dressings Procellera® A woven metallic bandage with embedded microbatteries, which is used as a dressing for partial or full thickness wounds Delivers ES to the wound site Produces a low voltage of 2–10 mV by microbatteries of Ag and Zn metals which are inside a woven material and are activated by the moisture in the wound Delivers 0.6–0.7 V at 10 microamps ES for Wound Healing Variations in the type of current, duration, and dosing –HVPC –Unidirectional ES with the electrodes placed in or around the wound site –60 – 120 minutes, applied for 7 days a week for 5 weeks demonstrated optimal healing ES for Wound Healing Its use show significant improvement in wound area reduction or wound healing Safe and easy to use, as no device-related complications or adverse effects have been reported to date Relatively cost effective compared to other comparative treatments ES TO CONTROL EDEMA Edema is a normal response after tissue trauma –Associated with increased pain, decreased function, and prolonged recovery Abnormal accumulation of fluid that produces swelling Potential causes are inflammation, lack of motion, & systemic disorders Edema due to inflammation Directly after an acute injury as part of the inflammatory response HVPC administered using negative polarity Pulse frequency of 120 pulses/s Intensity of 90% of visible motor contraction Four 30-minute sessions 4 hours apart or for one continuous 180-minute session Edema due to lack of motion ES is applied to produce muscle contractions in order to reduce edema caused by poor peripheral circulation due to lack of motion – Muscles fail to pump fluid proximally through the veins and lymphatics Improves blood flow that can accelerate tissue healing and help reduce the risk of DVT formation Edema due to lack of motion Motor-level electrical stimulation –Limb elevation + compression garments References Bellew, J. W., Michlovitz, S. L., Nolan, T. P. (2016). Modalities for therapeutic intervention (6th ed.). Philadelphia, PA: F.A. Davis Company. Cameron, M. (2018). Physical agents in rehabilitation: An evidence-based approach to practice (5th ed.). St. Louis, MO: Elsevier, Inc. Prentice, W. E. (2002). Therapeutic modalities for physical therapists (2nd ed.). USA: McGraw-Hill Companies, Inc. References O’Sullivan, S. B., Schmitz, T. J., & Fulk, G. D. (2019). Physical rehabilitation (7th ed.). Philadelphia, PA: F.A. Davis Company. Seeley, R., Cinnamon, V., Regan, J., & Russo, A. (2014). Seeley’s anatomy & physiology (10th ed.). NY, USA: McGraw-Hill Companies, Inc. Ud-Din, S. & Bayat, A. (2014). Electrical stimulation and cutaneous wound healing: A review of clinical evidence. Healthcare (Basel, Switzerland), 2(4), 445–467. https://doi.org/10.3390/healthcare2040445