Hi-Volt or High-Volt Galvanic Flashcards
What is Direct Current (DC)?
the continuous, unidirectional flow of charged particles that lasts longer than one second. The result is a net flow of electrons
What are the parameters for very low intensity direct current?
Amplitude: 200-800 miliamps
Tx time: 1-2 hours
Tx per day: 1-3
Freq/wk: 5-7x/wk
Direct current can be used in high volt and low volt for what dx?
wound healing
What is the wave form of high volt pulsed current (HVPC)?
paired monophasic with instantaneous rise and exponential fall of current; twin-peak monophasic pulse
What is the phase duration of HVPC?
25 micro seconds, sometimes adjustable; this is a comfortable but weak current, net DC, does not usually exceed 1hr
What is the modulation options of HVPC?
continuous, surged, or interrupted
What is Hi-Volt usually used for?
edema control & wound healing
What are the goals and indications for Hi-Volt?
edema
inflammation phase: free from necrosis and exudates, promote granulation
proliferation phase: reduce wound size including, depth, diameter, and tunneling.
epitheliazation phase: stimulate epidermal proliferation and capillary growth
What are the contraindications for Hi-Volt?
- osteomyelitis
- malignancies/neoplasms
- carotid sinus/laryngeal m.
- through the thorax
- demand-type pacemakers
- over topical agents containing metal ions (iodine, mercury, zinc, silver; e.g. betadine mercurochrome, silvadene)
- others as previously learned; except for open tissue
- decreased sensation
Is the goal for NMES stimulation of the peripheral nerve or some other tissue?
PN stim is the goal; best for mild to moderate contractions and areas not covered with excess adipose
Is the goal for TENS for stimulation of the peripheral nerve or some of other tissue?
PN stim is the goal
Is the goal for wound healing for stimulation of the peripheral nerve or some other tissue?
CHRONIC, slow healing wounds; PN still happens
Is the goal for acute edema formation for stimulation of the peripheral nerve or some other tissue?
based in animal research; PN still happens
Is the goal for iontophoresis for stimulation of the peripheral nerve or some other tissue?
not widely supported; PN still happens
When Hi-Volt is used for muscle stimulation what is the basic set-up?
- slowly increase intensity until a m. response is observed
- 10-25 m. contractions may be sufficient to obtain tx. goal
What is the duty cycle for Hi-Volt used for m. stimulation (on/off ratio)?
- interrupted/ramped modulation of currents allows the m. to recovery between stimulation periods
- it has been shown that stimulation on:off ratios of 1:3 minimizes the fatigue effects of ES
What are the factors using HVPC for NMES or TENS?
- amplitude (based on desired excitatory response)
- pulse rate (related to pain control theory or motor response needed)
- mode: continuous, ramp-surge, alternate
- placement of electrodes: as with Russian or FES
What are the 6 effects of electrical stimulation said to enhance the rate of healing in chronic wounds?
- Galvanotaxis: the attraction of body cells to an electrical conductor of the opposite polarity (+ or -)
- Augmentation of collagen synthesis and proliferation of fibroblasts
- Angiogenesis stimulation of wound microperfusion
- Bactericide killing or impeding the growth of bacteria in the wound
- epithelization electrical stimulation may enhance the rate of epithelium growth
- electrical stimulation may enhance flood flow to the wound area
What are the 4 concepts of healing?
- intact skin surface negative with respect to deeper epidermal layers
- injury to skin develops positive potentials initially and negative potentials during healing process
- absent or insufficient positive potentials retard tissue regeneration.
- addition of positive potentials, initially through anode, may promote or accelerate healing
What are the charges of skin, deeper tissues, neuraxis (unpaired part of CNS: cord & brain stem), periphery, & wound tissue?
skin (-), deeper tissues (+), neuraxis (+), periphery (-), wound tissue (+)