physiotherapy electrotherapy topic for students

1. Iontophoresis
Prepared by –Dr Pankaj R jayswal
[M.P.T ORTHO]

2. introduction
• Ion transfer or iontophoresis is the introduction
of topically applied ,physiologically active &
therapeutic useful ions in to epidermis & mucus
membrane of body by use of low voltage
continuous direct current
• Discovered by lue due 1903

3.  Electrically charged electrode will repel similarly charged
ion
 So place the ion under an electrode with same charge
 Negative ion under the cathode. constant D.C applied &
ion is electrically propelled in to skin
 It has been successfully used for many condition like
oedema, hyperhidrosis, wound healing ,muscular pains
,arthritic ,fungal infection,bursitis & tendinits

4. • Depth of penetration is 6 -20 mm below the
skin

5. • Iontophoresis of appropriate drugs May be used
for
• Local anesthetic action
• Antibacterial ,
• Anti -inflammatory action
• Relief of Neurogenic pain

6. • Hyperhydrosis
• Oedema reduction
• Chronic wound healing
• Increase extensibility of scar
• Fungal infection of skin

7. Theoretical basis of iontophoresis
• Distilled water is not good conductor of
electricity
• But when ionziable substance is dissolved in
water ,get dissolved ,
• Known as “Ionization ”

8. • The solution is called “electrolyte ”
• Electrolyte is able to conduct the electric current
• When continuous D.C. is applied via 2 electrodes
in electrolyte solution
• +ve ions towards –ve pole ,,,-ve ions towards + ve
pole

9. Mechanism of iontophoresis
• If voltage applied in electrolyte cause ionic movement
• Atoms & molecules in electrolyte constantly gaining &
loosing electrons to become ions & reversing to their
non ionized form .. “Brownian motion ”
• If Drug is in ionic form ,can be made to travel in either
direction depending on polarity applied

11. • The passage of current(ions) occurs mainly via
sweat glands ,lesser via hair follicles & sebaceous
gland
• No of Ions entering the tissue from any given
area depends on both current density & time of
application
• Cube root of product of current density & time

12. • Current density for practical purpose 0.1-
0.5mA/cm²
• Concentration of ions in solution have effect
on availablilty of ions
• 1-2 % concentration of ions satisfactory

13. • Zinc or silver ion ,may insoluble & limit
penetration
• Applied current should be enough to
overcome skin electrode resistance ,along
with enough energy to drive the ions through
skin portals

14. Physics of Iontophoresis
• Applied with modality provide continuous
galvanic current
• Use low voltage generators ,as well as battery
opearted units
• Treatment is not current but ions introduced

15. • Selection of specific substance depends upon
the target reaction /condition
• Non invasive ,low concentration of ion
required

16. The amount of substance introduced
• Amount of substance introduced in grams
=I*T*ECE
• I= INTENSITY of current in ampere
• T=time in hours
• ECE= electrochemical equivalence of the
substance

17. • Ionic polarity
• Low level amperage
• Enlarged negative electrode

19. Physiological effect
• Can describe in terms of ions selected for Rx
• Specialize ions are utilized for pain ,spasm
,inflammation

20. Ion penetration
Acid /alkaline reaction
Hyperaemia
Dissociation

21. Ion penetration
• Penetration is less than 1 mm but subsequent
absorption to deeper tissue via capillary
circulation & trans membrane transport
• Depth of penetration is uncertain , 3 to 20 mm
• Bulk of ions are deposited under the active
electrode ,as a soluble or insoluble compound
,depleted by blood ,or used locally for further
re combination

22. Acid /alkaline Reaction
Anode
• acid reaction [weak
hydrochloric acid ]
• Sclerotic effect ,tend to
harden the tissue
• Analgesic effect due to
local release of O2
Cathode
• strong alkaline reaction
[sodium hydroxide ]
• Sclerolytic effect ,softening
agent
• Softening agent ,hydrogen
release
• Used in management of
scars ,burns ,keloids

23. Hyperemia
• Anode & cathode both cause hyperemia due to
vasodilation that occurs due to heat production
according to joule’s law
• Disappear with in one hour
• Cathodal hyperemia little pronounced & longer
compare to anodal

24. Dissociation
• Ionizable substance release ions & radicles
,free to move opposite pole when applied
direct current
• That ions combine with the ions in tissue fluid
,forming compound got therapeutic effect
• Additional current enhanced flow of electron,
improve normal migration ,improve ion
transfer

25. Therapeutic effects
• Local anesthesia
• Relief of idiopathic hyperhydrosis
• Application of antibiotics
• Application of anti inflammatory drugs
• Neurogenic pain

26. • Oedema relief
• Ischemic ulcer
• Scar mobilization
• Fungal infection
• Allergic rhinitis

27. Local anaesthesia
By suitable agent like lignocaine or procaine
Condition like herpes zoster & trigeminal
neuralgia
Valuable technique for patient sensitive for
needle

28. Hyperhydrosis
 Most successful use of iontophoresis
 Condition affecting palms ,soles sometime
axillae
 Need to do symapathectomy for hand & feet
,removal of skin for axillary hyperhydrosis

29. • Use of Glycopyroneum [Ant cholinergic agent
]
• Sweat gland in palms & soles are controlled by
sympathetic system ,stimulated by
acetylcholine
• Implication of ant cholinergic agent cause
relief ,cause anhydrosis
•

30. The effect last for variable length of time ,17 -
62 days palms & soles average 38 days ,axilla 7
-10 days
Other drugs like poldine methylsulphate

31. Application of antibiotics
Use for avascular area
Metallic silver for chronic infected wound
For chronic non healing ulcer use xanthinol
nicotinate [capillary dilator ]& histamine
diphosphate

32. • For ear chondritis following burns ,chronic
infected ulcer

33. Application of anti inflammatory
drugs
For tendinitis & bursitis,tennis elbow
Advantage is over conventional Rx ,painless &
sterility of Rx
Disadvantage is less efficacy ,expensive

34. • The drug reaches the deeply placed structure
is doubtful
• Various steroidal & non steroidal drugs are
used in musculoskeletal pain
• Sodium salicylate & sodium diclofenac

35. Neurogenic pain
• Vincia alkaloids are used for Neurogenic pain
• That drugs are used as they are cytotoxic &
microtubular inhibitors
• That drugs act on nerve endings ,affect
axoplasmic transport ,decrese neurogenic pain
• Post herpetic neuralgia ,trigeminal neuralgia
,carcinoma pain

36. Oedema relief
• Hyaluronidase used
• Stability & usefulness is doubtful
• Anode as a active electrode

37. • Iodine & chlorine ions increase extensibility of
scar tissue along with passive stretching
• Cu ions for tinea pedis ,fungal skin infection
,athletes fee

38. Principle of application
• The principle of application of D.C is same
same whether used for current or
iontophoresis
• The aim is produce uniform current density
through out the skin applied

39. Before Rx therapist should know
Knowledge of pathology
Particular Ions for underlying pathology
Identify Polarity of ions
Find out the source of ions

40. • Select the particular E.S generator for current
• Allergic patient
• Checkout the area of Rx for sensation ,abrasion
,cuts
• Clean the skin

41. • Fully explain the procedure to pt as well as the
mild prickling sensation followed by gentle
warmth
• Tell the patient about to warn any increase in
sensation or painful sensation

42. • Having selected proper ion & electrode ,the
solution cream containing the ions is applied
to bare skin of the Rx area & massaged into
superficial tissue

43. • One site of therapist interest is active
electrode ,other electrode will complete the
circuit
• Can be applied the current through container
of water or solution or by using suitable
material to hold the water or solution
• It can be lint ,gauze ,sponge ,towel,1cm thick
when gently pressed

44. Current can be applied to the pad by some form
of malleable carbon rubber electrode ,aluminum
foil or other metal sheet
 extremities can be treated by immersing the part
in container of water
current is fed by electrode deep to side of
container ,away from the immersed part

45. • Pt is instructed not to remove the limb from
bath, brake the circuit ,marked sensory shock
• Rx duration 10 -30 min ,depending of area of
Rx
• Checked after 5 min

46. Dose

47. Dangers
• Burns
• Shock
• Skin irritation
• Systemic effect

48. Burns
• Chemical burns –due to excessive current
density
• Skin appear grey spot surrounded by red area
• Due to
• low skin resistance
• Less even pressure or thickness of pad
• Bare piece of metal ,electrode

49. • Excessive formation of NAOH at cathode
,sclerolysis effect
• Its take long time to heal

50. • Heat burns
• Execssive heat produce at the high skin
resistance ,sclerotic skin area
• Electrode are not moist properely
• Wrinkles area
• Excessive pressure area ,ischmeic effect
• Rx by sterile dressing

51. Shock
• Lead breakdown during Rx
• Suddenly pt remove the body part

52. Skin irritation
• Hypersensitivity to chemicals

53. Systemic effect
• In anticholinergic drugs [abdominal pain
,headache ,dryness of mouth ]
• Avoid vigorous exs after Rx
• Histamine iontophoresis[ cardivascular
response like heart rate ,bp along with ski
reactions ]

54. Indications
• Acute & chronic inflammation
• Local anesthetic effect
• Arthritis
• Myofascial pain syndrome
• Myositis ossification
• Oedema
• Hyperhydrosis
• Bursitis

55. • Tendinitis
• Ischemic skin ulcer

56. Contraindication
• Impaired skin sensation
• Allergy or sensetivity

57. Prepared by –Dr Pankaj R jayswal
[M.P.T ORTHO]