E-stim for tissue healing Flashcards
Wound healing: inflammatory stage
- hemostasis: blood clotting due to platelets binding and adhering to periphery of wound
- phagocytosis- driven by macrophages, monocytes, inactive neutraphils; breakdown and elimination of bacteria/foreign substances and -Autolysis=breakdown of other foreign debris
- Fibroblast migration
Wound healing: hemostasis
- blood clotting occurs platelets bind and adhere to collagen of periphery of injured tissue
- platelets attract other cells> kemotatic influence
- some cells attracted= macrophages, monocytes, and inactive neutraphils
Wound healing: proliferation stage
- collagen synthesis
- angiogenesis= new BVs; critical for nutrients for healing
- epithelialization
- wound contraction
Wound healing: maturation stage
- collagen lysis
- collagen replacement
Factors that impede wound healing
- some systemic medications
- corticosteriods, aspirin, indomethacin?
- some topical medications
- *iodine- can kill cells that help with healing
- malnutrition
- prolonged pressure or stretch-
- interrupt development of capillaries (angiogenesis) disrupting blood supply
- infection
- immunodificency
- impairment to inflammatory response
- smoking
- dryness or necrotic tissue
Assessment of chronic wounds:
Size - Surface area: **tape measure width and length of wound @ greatest pt **most commonly measured -depth -volume ** look at total volume of wound ** create (-) mold of wound, volume measured by displacement of model description of wound base assessment of periwound tissue Drainage of wound - clear or pinkage drainage w/out odor= inflammatory stage - yellow/cloudy drainage= infection
Types of chronic wounds
- Pressure sores
- arterial insufficiency ulcers
- venous insufficiency ulcers
- Diabetic ulcers
Pressure sore
- Area of local tissue loss due to prolonged tissue compression between boney prominences and external surfaces
- Common locations
- sacrum, heels, ischial tuberosity, greater trochanter, malleoli
- etiology:
- compression of tissue reduces blood perfusion in tissues and produces necrosis
Stages of pressure sores
- Stage 1: non-blanchable erythema of intact skin
- Stage II: partial thickness skin loss to epidermis, dermis, or both
- Stage III: full thickness skin loss including damage to subcutaneous tissue
- Stage IV: full thickness skin loss with destruction or damage to muscle, bone, or support structures
Arterial insufficiency ulcers
- area of local tissue loss due to arterial blood supply deficiency
- common locations:
- on foot, over malleoli, toe joints, lateral foot border
- Etiology:
- arteriosclerosis, arterial occlusion (ex thrombosis), arterial disruption
Venous insufficiency ulcers
- area of local blood loss due to deficiency in venous drainage
- common locations:
- above the ankle, medial lower leg
- etiology:
- *sustained venous hypertension, venous valvular dysfunction
Diabetic ulcers
- area of local tissue loss due to sensory neuropathy and arterial blood supply deficiency
- common locations:
- *plantar surface of foot, over heel, lateral border of foot, plantar surface of metatarsal heads
- etiology:
- tissue trauma in insensate tissue, PVD
biological effect of electricity: electrochemical
Formation of new chemical compounds
- negative electrode
- 2 Na + 2 H20 > 2 NaOH + H2 (alkaline)
- positive electrode
- 2 Cl2 + 2H20 > 4 HCL + O2 (acid)
biological effect of electricity: electrophysical
- electrokinetic effect- ion movement
- negative electrode = attraction of + ions, drive (-) electrodes away
- ex. depolarization of excitable membrane
biological effect of electricity: electrothermal
- Microvibration of charged particles produces heat
- H= 0.24 x I^2 x R x t
- H=heat produced
- I= RMS amp current
- R= impedance of tissue
- t= time
- High RMS, high skin impedance and prolonged treatment time increase thermal effect
Physiological effects of E-Stim that benefit wound healing
- Galvanotaxis= ability to attract ions
- collagen synthesis
- proliferation of fibroblasts
- angiogenesis and wound microperfusion
- bacteriacidial
- enhanced rate of epithelialization
- enhanced blood flow to wound
Galvanotaxis of cells during the phases of healing: inflammatory
- macrophages- negative > phagocytosis
- inactive neutrophils- negative > autolysis
Galvanotaxis of cells during the phases of healing: proliferation
-Fibroblasts- positive > collagen fomation
Galvanotaxis of cells during the phases of healing: maturation
- myofibroblasts- positive > wound contraction
- keratinocytes- positive > epithelialization
- epidermal - negative > epithelialization
Collagen Synthesis and Proliferation of Fibroblasts study
- Stimulation of human fibroblast cell culture
- cathode > protein synthesis in fibroblasts increased 160% over control
- parameters: 50-75 V and 150 pps
Stimulation of Angiogenesis and Wound Microperfusion study
- Cathode 7-14 treatments followed by anode 3-10 days followed by cathode
- 44% increase in capillary density
- 82% increase in transcutaneous oxygen partial pressure
Enhancing the Rate of Epithelialization study
- Partial thickness wounds in pigs
- Anode x 7 days or cathode day 1 and anode x 6 days wound closure in 6 days
- Cathode 62% closure in 6 days
Enhanced Blood Flow to Wound study
- Rectangular, balanced, biphasic pulsed current
- 250μs pulse duration, 30 pps x 5 minutes
- 50% greater ave blood flow measured with laser doppler
Types of current used in wound healing: low intensity direct current (DC)
- Amplitude: 200-800 mA
- tx duration: 1-2 hours
- tx per day: 1-3 per day
- Tx days per week: 5-7 days per week
Types of current used in wound healing: high volt pulsed current (HVPC)
- Pulse amp: 100-150 V peak
- pulse duration: 100 usec
- pulse frequency: 30-130 pps
- mode: continuous
- tx duration: 30-60 mins
- tx per day: 1-2
- tx day per week: 5-7 days
HVPC
Twin peaked monophasic pulse
- pair of monophasic spike like waveforms
- almost instantaneous rise followed by exponential decline
- pulse duration: short
- 100-200 usec
Types of current used in wound healing: rectangular monophasic pulsed current (RMPC)
- Pulse amp: 30-35 mA peak
- pulse duration: 150 usec
- pulse frequency: 64-128 pps
- mode: continuous
- tx duration: 30 mins
- tx per day: 2
- tx days per week: 7 days
Types of current used in wound healing: biphasic pulsed current (rectangular asymmetric)
- pulse amp: strong sensory; just less than motor level
- pulse duration: 100 usec
- pulse frequency: 50 pps
- mode: continuous
- tx duration: 30 mins
- tx per day: 3
- tx days per week: 5-7 days
The human battery
- outside of skin has negative chare
- inside of skin has positive charge
- with injury, polarity shifts
- outside> positive
- inside> negative
Polarity used in wound healing: protocol 1
- Protocol 1
* * cathode over wound days 1-5
Polarity used in wound healing: protocol 2
- Protocol 2
- cathode over wound if infected with E. coli, P aeruginosa
- anode over wound if infected with S. aureas
Polarity used in wound healing: protocol 3
Based upon type of healing clinician wants to induce
- anode: attract macrophages, and neutrophils to stimulate phageocytosis and autolysis
- cathode: attract fibroblasts to increase granulation tissue; stimulate myofibroblast to increase wound contraction; stimulate keratinocytes to increase rate of re-epithelialization
Polarity Used in Wound Healing: protocol 4
Based upon electrochemical response in tissues being stimulated
- Cathode – solubilize, liquefy, soften tissue
-Anode – stimulate epithelialization
Cathode – NegativeTherapeutic Effects
- Increased blood flow
- Galvanotaxic for
- *activated neutrophils, fibroblasts, lymphocytes, platelets, mast cells, keratinocytes
- Enhances growth of granulation tissue
- Induces epidermal cell migration
- Antimicrobial
Anode – Positive Therapeutic Effects
- Galvanotaxic for:
- *macrophages, epidermal cells, inactive neutrophils,
- Promoted growth and reorganization of epithelial cells
- Decreases mast cells in healing wounds
- Vasoconstriction
- Decreases blood flow
- Antimicrobial
Physiological and Therapuetic Effects
Reduce edema formed with acute injury and inflammation
- -Negative pole (Theories)
- *Repel negatively charged serum proteins
- *Reduce microvessel diameter
- *Reduce pore size
Edema Reduction Parameters
- Waveform: HVPC
- Pulse Duration: 40 – 100 μsec.
- Polarity: Negative
- Frequency: 100 – 200 pps
- On/off time: continuous
- Current amplitude: comfortable sensory
- Treatment time: 20 – 30 minutes
