Direct current
Continuous unidirectional flow of charged particles
1. Denervated muscle contractions
2. Wound care
DC is used for: (2)
contractions
Continuous DC applied for a number of seconds can produce ________ in denervated muscle
Current amplitude
_________ (intensity) is increased gradually to full amplitude over a number of seconds
10
Current must last more than _____ms
1. Muscle fibers become smaller
2. Fibrous tissue forms between the muscle fibers
DC
Since denervated muscle cannot contract physiologically, muscles atrophy and fibrose (2). Use of ____ to muscles helps to retard or reverse this
Direct current (DC)
Used to treat Bell's Palsy
Iontophoresis
Is the use of low amplitude DC to facilitate transdermal drug delivery
1. Like charges REPEL each other
2. Opposite charges LIKE each other
Iontophoresis is based on: (2)
the same
Using ______ charges pushes the medication through the skin
increases
Using the same charges _______ skin permeability of the stratum corneum
3-20 mm
Iontophoresis: How deep?
transdermal drug
For electrical current to facilitate ___________penetration, current must be sufficient to overcome the combined resistance of skin and electrode
1. Milliamp minutes (mA-min)
2. Current amplitude (mA) and time
3. Recommended 40 mA-min for each treatment
Amount of electricity used measured as: (3)
4
Most clinical devices only allow max of ____ mA
electrodes
DC can produce undesirable changes under ______.
Alkaline reaction
Sodium hydroxide can form under (-) electrode and cause discomfort, skin irritation or chemical burns
current
negative
Risk can be reduced by decreasing ______ density
Make ______ electrode larger or reducing intensity
Acidic reaction
Hydrochloric acid can form under (+) electrode
Slightly less uncomfortable
24 hour Ionto patch
Machines have low voltage output to minimize skin irritation, optimize comfort, and provide prolonged drug delivery
24 hour Ionto patch
Applied at extremely low current for longer time
0.1 and 0.3
Deliver between ___ and ____ mA for 1-24 hours
40-80
Total dose of ___-___ mA-min (24 hr Ionto patch)
24 hour Ionto patch
Battery activated by drug applied to electrode (patch)
Requires no other machine or external battery
Hybrid patch
More comfortable
Low voltage
Has small wireless, rechargeable dose controller that attaches to patch with drug to be delivered
NEEDS MORE STUDIES!!!
3
3 min of ___ mA is applied by clinician using controller at beginning of treatment (to decrease skin resistance) followed by wearing of patch for 1-2 hours
Hybrid patch
Turns off automatically after preset dose achieved
1. Need to be ionized and in stable solution
2. Need to be unaffected by addition of electricity
3. Ions that are small to moderate in size
4. Different drugs used for different pathologies
Iontophoresis drug facts: (4)
Iontophoresis
Recommended to only use Lidocaine or dexamethasone for this TX:
dexamethasone
Corticosteroid with anti-inflammatory action
Used for tendonitis or bursitis
0.4% solution
Negative polarity
Lidocaine
Anesthetic
Was used with dexamethasone to make ionto more comfortable to patient
Can be used for local anesthesia in children
1. Drug delivery electrode placed over area of "itis"
2. Dispersive placed a few inches away over site of convenience and large muscle belly
3. Electrode should be large enough that current density not > 0.5 mA/cm2 (cathode) not > 1.0 mA/cm2 (anode)
Electrode placement and size: (3)
polarity
Drug delivery electrode needs to be SAME _____ as drug delivered
Current amplitude
Patient comfort
Not > 4.0 mA
Treatment time
Adjusted to produce total of 40 mA/min
Check patient's skin during treatment due to increased risk of burning
NOT
Recommended ionto (TO/NOT) be applied after another physical agent that may alter skin permeability
physical agents
Heat, ice or US
vasodilation
Heat causes ________ and increased blood flow that can accelerate dispersion of drug from treatment area