IONTOPHORESIS Reading: Cameron pgs 272-276

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IONTOPHORESISReading Cameron pgs 272-276

• Use of Direct Current to facilitate delivery of
  ions into the skin for therapeutic purposes.
• Mechanism of delivery
• LIKE CHARGES REPEL

Positive Electrode (anode) delivers () ions
Negative Electrode (cathode) delivers - ions
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Historical Highlights

• Concept first developed researched over a
  century ago.
• Therapeutic use for more than 70 years.
• Popularity usage was declining until Joseph
  Kahn PhD,PT had 9 publications from 1973 to 1983.
  
• Most case studies clinical commentariesKahn,
  J. Case Report Lithium lontophoresis for Gouty
  Arthritis. J Orthop Sports Phys Ther
  19824(2)113-114.

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Contemporary Use

• In PT primarily for treating localized
  inflammatory conditions in superficial tissues
• Use corticosteroids, (usually dexamethasone)
• Multiple uses of other non-steroidal ions both
  within outside PT
• Ex Dentistry, Dermatology, Emergency Dept,
  Ophthalmology

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Ionto Advantages over injection

• non-invasive less risk of infection
• less pain anxiety
• less drug into systemic circulation decreased
  side effects
• Less risk of local collagen catabolism
• assuming use of corticosteroid

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Ionto Advantages over drug PO

• avoids first-pass elimination by liver.
• less drug into systemic circulation decreased
  side effects.
• potentially greater concentration of drug in the
  target area
• supervised maximizes compliance.

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Ionto Disadvantages

• risk skin irritation or burn
• depth of penetration known to vary b/c of
  variation of current density, skin impedence,
  skin/fat thickness, and ionization/pH
• greater risk of local collagen catabolism than
  oral administration
• Action of drug localized immunosuppression
• assuming use of corticosteroid

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Treatment Parameters(when using a DC stimulator
eg. dose controller)

• Current DC high current, short duration
• Amplitude 0.5 to 4.0 mA is the range
• depends on pt. tolerance, polarity, electrode
  size
• Dosage 40 to 80 mA-min
• Dosage Formula amplitude X time mA min
• Time calculated by the unit, you set the dosage
• The dispersive pad should be put about 6 inches
  away from the active pad on the same side of the
  body. 

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Parameters cont. . .

• Polarity use the same polarity as the drug ion
• Rx frequency every other day at the most
• steroid effects can be delayed last several
  days
• allows time for skin to recover
• minimize risk of side effects
• cost effective
• Rx number 4 - 7 max
• More than 7 treatments in a short period of time
  can produce detrimental effects such as skin and
  connective tissue break-down.

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Parameters cont. . .

• Due to continuous stim using DC, no need for
  dealing with
• Waveform
• Ramp-surge
• Frequency
• Width
• Amplitude, Time, Polarity abide

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Treatment Guidelines (Skin Safety)

• Amplitude the patient feels a slight tingling,
  itching or mild stinging.  Check the skin under
  both electrodes after 5 minutes. 
• Mildly red skin under the electrodes is a normal
  reaction due to vasodilation heat buildup. 
• DC can cause mast cells to release histamine
  small bumps/vesicles and maybe petechiae. These
  reactions are normal and resolve within hours.
• If the skin is bright red or if many small
  vesicles are forming, should decrease the
  amplitude and check skin again after a few
  minutes.  In some cases, may terminate

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Many factors affect skin reaction

• The patient's skin type sensitivity to DC
  current
• Current density not gt 0.5 mA/cm2
• Heat build-up Chemical build-up
• Skin pigmentation skin response harder to judge.

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Skin safety cont..

• Caution you about increasing the amplitude after
  accommodation occurs.
• Counterbalance with repeated skin checks
• Some clinicians end the treatment by application
  of a skin lotion containing lanolin or aloe vera.
  

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Contraindications Precautions

• E-stim standard contraindications precautions
  apply
• Pt. allergic to ions/drugs
• Impaired skin sensation is a precaution
• No thermal modalities immediately before or
  after. Why??
• No conductive gel before Ionto. Why??
• Diabetes is a precaution due to decreased
  peripheral sensation and secondary to localized
  immunosuppression caused by corticosteroid.

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Most Common Ion in PT

• Dexamethasone Sodium Phosphate
• 0.4 aqueous solution
• 0.4 0.004 g/ml 4 mg/ml
• corticosteroid for anti-inflammatory
• effects polarity is (-)

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Additional Ions(know name, polarity, usage)

• Acetic Acid (-) dissolve Ca deposits
• Calcium Chloride () ms. relaxant
• Hyaluronidase () disperse edema not acute
• Iodine (-) softens adhesions scar tissue
• Magnesium Sulfate () ms. relaxant
• Sodium Salicylate (-) ms. joint pain
• Lidocaine () local anesthetic
• Example pharmacy services

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Equipment Supplies

• Drug ion dissolved in aqueous solution or
  suspended in ointment
• Absorbent buffered electrode
• Iontophoresis devices
• Dupel DC stimulator by EMPI is what we will use
• Numerous other brands of DC stimulators exist
• Patch products Iontopatch, ActionPatch
• Newest Hybresis by EMPI

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Dupel by EMPI
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Phoresor II and look-a-likes
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Patch (Integrated) Systems

• Current DC, low current, long duration
• Amplitude 0.2 mA and less (if constant
  voltage)
• Dosage 40 to 80 mA-min
• more convenient for clinicians and perhaps
  patients because in-clinic wear time is greatly
  decreased. Efficacy??

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Iontopatch by Birch Medical
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Action Patch by EMPI
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HYBRESIS by EMPI
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Effectiveness Factors

• Dosage mA-min
• Little evidence exists that different
  combinations of amplitude duration provide
  equivalent amounts of ion transfer some
  evidence that 4mA X 10 min is best. 40 mAmin is
  a commonly accepted standard.
• Preparation of skin
• must be clean no competing ions.
• Depth of target tissue
• skin thickness, fat layer, overlying tissues
• Electrode Contact

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Depth of ion penetration

• Believed to occur primarily thru pores (sweat
  oil) hair follicles
• Passsive diffusion and local circulation are
  required to shuttle the drug deeper, to the cells
  of the target tissue
• Research effect is often inferred based on
  clinical effectiveness (pain, ROM, MMT, function)
• max depth of ion penetration is largely unknown
  in humans (8-10mm in mammals)