Iontophoresis/Phonophoresis Flashcards
1
Q
Iontophoresis
A
- Driving ions (medication) into the body by use of direct current
~ Can penetrate up to 2 cm - Takes advantage of the fact that direct current has constant positive and negative poles
~ The negative pole repels negative ions
and positive pole repels positive ions
~ Driving force for medications that
have a negative or positive charge - Like charges repel = good
- Opposite charges attract = bad
2
Q
Advantages of Iontophoresis
A
- No painful needles
- Low risk infection
- No systematic effects from taking a pill
- Delivered specifically to the treatment area
3
Q
Delivery of Ions To the Tissue: Quantity
A
- Quantity of transferred ions depends on:
~ Intensity of the current (important
because it can be manipulated)
> The higher the current, the higher
the transfer
~ Duration of the current flow
(important because it can be
manipulated)
> The longer the duration, the
higher the transfer
~ Concentration of ions in solution
> The higher the concentration, the
higher the transfer
~ Impedance of tissues
> The lower the impedance, the
higher the transfer
4
Q
Delivery of Ions To the Tissue: Impedance
A
- Different tissues have different impedance
~ Dependent on Water/Electrolyte
Content
~ Good Conductors: 70-75% water
> Muscle
> Nerve
> Blood
~ Poor Conductors: 20-30% water
> Bone
> Tendons
> Fascia
> Adipose
> Skin
• Can still treat these but
getting through skin is hard
5
Q
Delivery of Ions To the Tissue: Skin
A
- Overcoming Skin Barrier
~ Skin has high impedance, but sweat
glands and hair follicles have low
impedance
> Sweat glands and hair follicles
are the main path of ion delivery
> As ions move into the skin, blood
flow increases which reduces the
impedance of the skin
6
Q
Movement of Ions Through the Tissues/Undesired
A
- In addition to the movement of ions (medication) into the tissues free ions move within the tissues.
~ Current causes migration of the
charged ions within tissues towards
the pole of opposite polarity.
> Negative ions to the positive
and positive to the negative.
• Concentration of the
negative ions causes an
Acidic reaction
• Concentration of the
positive ions causes an
Alkaline reaction
7
Q
Movement of Ions Through the Tissues/Undesired: Chemical Burns
A
- Both acidic and alkaline reactions are potentially damaging to tissues
~ Acidic reaction drops skin pH and
alkaline reaction raises ph
~ Changes in pH cause chemical burns - Pt. should be informed that only a slight tingle should be felt
~ Feeling nothing is ok, but a tingle
suggests unit is working
~ Burning sensation or pain indicates
possible chemical burn
> Produces pink, raised lesion
that changes to gray oozing
wound
8
Q
Iontophoresis Dosage
A
- Based on the relationship between the intensity of the electrical current and the treatment duration.
~ Measured in milliamps per minute
(mA/min) - Different medications have different accepted dosages.
~ Between 1 and 80 mA/min
~ Typical Dosage = 40 mA/min
9
Q
Iontophoresis Dosage: Intensity and Tx Time
A
- Dosage determines the intensity and treatment time.
~ Modern generators allow dosage to
be entered and generator calculates
intensity and time.
~ Ex. Enter 40 mA/min & generator
delivers treatment at 4 mA for 10
minutes - Intensity or time can be adjusted and generator will adjust the other parameter to deliver the correct dosage.
~ Ex. (40 mA dosage) Decreasing the
preset intensity to 3 mA would cause
the generator to adjust the time to
13.33 minutes
10
Q
Why would you decrease the intensity?
A
Pt. is feeling pain instead of a tingle
11
Q
Iontophoresis: Common Medications Used
A
- Acetic Acid: Negatively charged, used for treatment of calcium deposits (myositis ossificans).
- Dexamethasone: Negatively charged, used for inflammation.
- Sodium Salicylate (Aspirin): Negatively charged, used for inflammation
- Lidocaine: Positively charged, used for pain
12
Q
Electrodes: Sponge
A
- Can use any standard reusable electrical stimulation electrode.
~ Use sponge, gauze or towel soak in
the medication.
~ Can be found in many different sizes.
~ Do not conform to irregularly shaped
areas.
~ Low Cost
13
Q
Electrodes: Commercial
A
- Usually available from the same companies that make the generators.
- Self Adhesive
- Contain absorbent area or chamber that the medication can be injected into.
- Much easier to use
- Come in fixed sizes
- Active/Delivery electrode placed directly over the treatment site.
- Dispersive/Return electrode placed proximal or distal to active electrode.
14
Q
Why are electrodes placed 6-18 inches apart?
A
In order to not mix polarity of the electrodes
15
Q
Iontophoresis Indications
A
- Inflammation
- Pain
- Myositis Ossificans
