iontophoresis-130823105315-phpapp02.pptx

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1. Iontophoresis Sreeraj S R

2. Iontophoresis Sreeraj S R The term iontophoresis is simply defined as ion transfer (ionto = ion; phoresis = transfer). Introduction of ions into the body using direct electrical current

3. Iontophoresis Sreeraj S R It is a specialized technique of electrical stimulation that uses electrical polarity of continuous direct current to ionize medicines placed beneath surface electrodes and transfers them into the body through the skin

4. Iontophoresis vs Phonophoresis Sreeraj S R Iontophoresis uses electrical current to transport ions into tissues Phonophoresis uses acoustic energy (ultrasound) to drive molecules into tissues

5. How does it work? Sreeraj S R

6. Basic Principles Sreeraj S R Current Required Ionic Polarity Low- level Amplitude Electrode Size

7. Current Required Sreeraj S R In order to 'drive' the ions into the tissues, a DIRECT (Galvanic) CURRENT needs to be employed A monophasic pulsed application can also be used Constant current is preferable to constant voltage - thus, the magnitude of the applied current will not exceed the preset level in terms of skin resistance.

8. Ionic polarity Sreeraj S R The basis of successful ion transfer lies in physics principle “like poles repel and unlike poles attract’ Ions with a polarity which is the same as that of the stimulating electrode are repelled into the skin the electrode under which the ionic solution is placed is called the ACTIVE electrode The other electrode, which is used to complete the circuit is most commonly called the DISPERSIVE, INDIFFERENT, INACTIVE or RETURN ectrode.

9. Low- level Amplitude Sreeraj S R l ow- level amplitude is more effective The treatment is usually applied with currents up to 5mA with low ionic concentrations – up to 5%, Treatment times are typically in the 10 - 30 minute range

10. Electrode Size Sreeraj S R the negative electrode should be made larger than the positive electrode (usually twice) enlarging the negative electrode size lowers the current density on the negative pad, leading to reduction of irritation.

11. Physiological changes Sreeraj S R Ion penetration Acid / alkaline reactions Hyperemia Dissociation

12. Ionic Penetration Sreeraj S R penetration does not exceed 1 mm, subsequent deeper absorption through the capillary circulation. The bulk of deposited ions at the active electrode are stored, to be depleted by the sweep of circulating blood.

13. Acid / alkaline reactions Sreeraj S R Will get ACID accumulation under the POSITIVE (anode) electrode (weak HCl) This is because the negatively charged chloride ions (Cl- from NaCl) is attracted towards the anode. This is considered sclerotic, which tends to harden tissues, serving as an analgesic agent due to local release of oxygen .

14. Acid / alkaline reactions Sreeraj S R Will get ALKALINE accumulation under the NEGATIVE (cathode) electrode because the positively charged sodium ions (Na+ from NaCl) will move towards the cathode. The Na+ ions react with water to form sodium hydroxide (NaOH). considered sclerolytic, which is a softening agent due to the hydrogen release, serving in the management of scars and burns.

15. Hyperemia Sreeraj S R Both the positive and negative electrodes produce hyperemia and heat due to the resulting vasodilatation. The cathodal hyperemia is generally more pronounced and takes more time to disappear than that of the anode. Generally, hyperemia under both electrodes does not lasts more than one hour.

16. Dissociation Sreeraj S R ionizable substances dissociate in solution releasing ions, with the passage of direct current into the solution migrate toward the other pole. Gets absorbed through the capillary circulation. This is the concept of ion transfer.

17. Complications Sreeraj S R Chemical burns Heat burns Sensitivities and allergic reactions to ions

18. Chemical burns Sreeraj S R This is due to excessive formation of the strong sodium hydroxide at the cathode . The skin becomes pinkish initially, to be grayish and oozing wound few hours later. These burns take a long time to heel Should be treated with antibiotics and sterile dressings. Burns under the anode are rare, Appears as a hardened red area similar to a scab.

19. Heat burns Sreeraj S R occurs due to excessive heat buildup in areas with high resistance Most of these burns occurs when the electrodes are not moist enough, they are not fitting well or not in good contact with the skin. Should be treated with antibiotics and sterile dressings.

20. Allergic reactions to ions Sreeraj S R If the patient is allergic to seafood, “iodine” should not be used. Patients with an active peptic ulcer or gastritis, react poorly to “hydrocortisone” . Patients, who have problems with aspirin, react poorly to “salicylates” . Patients sensitive to metals may react to “copper, zinc or magnesium” .

21. Indications Sreeraj S R Local anesthesia. Inflammatory conditions. Relief of pain. Skin conditions. Tension headache. Inhibition of spasticity.

22. Selecting the Appropriate Ion Sreeraj S R Dexamethasone (- ) Hydrocortisone (- ) Salicylate (- ) Inflammation • Edema • Spasm Calcium (+) Magnesium (+) Analgesia Lidocaine (+) Magnesium (+) Open Skin Lesions Zinc (+) Hyaluronidase(+) Salicylate (- ) Mecholyl (+) Scar Tissue Chlorine (- ) Iodine (- ) Salicylate (- ) Hyperhydrosis Tap Water (+) Glycopyrronium Bromide (+)

23. Contraindications Sreeraj S R Open wounds or burns. Patients with cardiac pacemakers. Allergy to medication. Loss of sensation. Greasy or dirty skin. Sole of foot (hard for the ions to pass inside).

24. Precautions Sreeraj S R Don’t use two chemicals under the same electrode, even if they are of the same polarity. Don’t administer ions with opposite polarities during the same treatment session.

25. Current Density Sreeraj S R the current density is measured in mA/cm 2 If the current density reaches too high a level, tissue damage, especially skin burn, may ensue. It is suggested that a Maximum Safe Current Density of; 0.5mA/cm 2 is applicable at the negative(cathode) and 1.0mA/cm 2 at the positive(anodal) electrode . (Belanger, 2010)

26. Current Intensity Sreeraj S R Calculated as Maximum Current (mA) = Maximum Safe Current Density (mA/cm 2 ) X Electrode area (cm 2 ) Recommended current intensity is 3 to 5 mA

27. Treatment Time Sreeraj S R Treatment Time: ranges between 10 - 20 min. Patient should be comfortable with no reported or visible signs of pain or burning Check skin every 3-5 minutes for signs of skin irritation

28. Formula for iontophoresis Sreeraj S R I x T x ECE = grams of substance introduced, Where: I : (Intensity) measured in amperes. T : (Time) measured in hours. ECE : (Electro- Chemical Equivalent) represents standardized figures for ionic transfer with known currents and time factors. As the determination of the ECE for many complex substances is very difficult, fewer milligrams of these complex substances will penetrate the skin.

29. Electrodes Sreeraj S R Traditional Electrodes Commercial Electrodes

30. Traditional Electrodes Sreeraj S R Older electrodes made of tin, copper, lead, aluminum, or platinum backed by rubber Completely covered by sponge, towel, or gauze which contacts skin Absorbent material is soaked with ionized solution (medication) If medicated ointment is used, it should be rubbed into the skin and covered by some absorbent material

31. Commercial Electrodes Sold with most iontophoresis systems Electrodes have a small chamber covered by a semipermeable membrane into which ionized solution may be injected The electrode self adheres to the skin Sreeraj S R

32. Electrode Preparation Attach self- adhering active electrode to skin Inject ionized solution into the chamber Attach self- adhering inactive electrode to the skin and attach lead wires from the generator Sreeraj S R

33. Application Sreeraj S R The skin should be abrasion / cut free and the area carefully washed (soap & water is fine). Dry electrodes are inappropriate and should not be used. If pregelled electrodes are being used, ensure that a good even contact is achieved. Adequate fixation of the electrode and pad to the skin needs to be carefully maintained. Uneven current distribution can easily lead to skin burns and/or irritation Explain to the patient what is expected and ensure that they know to report immediately if any untoward or painful sensations are felt. Turn the current up slowly to the required amount At the end of the treatment time, ensure that the current is turned down slowly.

34. References Sreeraj S R http://www.electrotherapy.org/modality/iontophoresis?highlight=iontophore sis , Tim Watson (2012) Iontophoresis from internet, n.p. Jennifer Doherty- Restrepo, Iontophoresis. PET 4995: Therapeutic Modalities. Ppt presentation Low J, Reed A. Electrotherapy explained, 4 th edition, Elsevier, 2006; pp 193 – 195 Foster A, Palastanga N. Clayton’s electrotherapy,9 th edition, AITBS Publishers, pp 85 – 86 Mitra PK. Handbook of practical electrotherapy,1 edition, Jaypee publications. 2006; pp 61 – 64 Singh Jagmohan. Textbook of Electrotherapy, 2 edition, 2012;pp 128 – 129