Iontophoresis, ultrasound, phonophoresis, and laser therapy

Question 1

Are iontophoresis and phono interchangeable?

Answer 1

No - no ionization takes place with ultrasound.

Question 2

Describe Leduc’s classic experiment:

Answer 2

To show that ionic medication could penetrate intact skin and produce local and systemic effects in animals he used two rabbits connected in the same current. One rabbit by a positive electrode soaked in a positive ion posion, the other connected to a negative electrode soaked in negative ion poison. Both rabbits died. When reversed neither rabbit was harmed.

Question 3

Iontophoresis solutions indication and polarity: acetic acid

Answer 3

calcium deposits (-)

Question 4

Iontophoresis solutions indication and polarity: dexamethasone sodium phosphate

Answer 4

inflammatory conditions (-)

Question 5

Iontophoresis solutions indication and polarity: licocaine hydrochloride

Answer 5

skin anesthesia (+)

Question 6

Iontophoresis solutions indication and polarity: potassium iodide

Answer 6

scar tissue (-)

Question 7

Iontophoresis solutions indication and polarity: water

Answer 7

hyperhidrosis (alternate)

Question 8

Iontophoresis solutions indication and polarity: Zinc oxide

Answer 8

ulcers, antiseptic (+)

Question 9

Why are the effects of iontophoresis longer lasting than phonphoresis?

Answer 9

ions in superficial tissue with limited blood allows for time to be used, phono delivers it deeper where there is more vascularization.

Question 10

Does increased drug concentration increase amount delivered?

Answer 10

No

Question 11

Are there concerns with using direct current?

Answer 11

Yes, intact skin cannot tolerate current density >1 mA/cm2

Question 12

Ion transfer depends on what factors?

Answer 12

1.) the concentration of ions in the solution 2. The current density of the active electrode 3. duration and current flow

Question 13

List the polar effect on treated tissues produced by the anode (positive)

Answer 13

hyperpolarizes nerve fibers, repels bases, hardens tissues, stops hemorrhage, sedates/calms, reduces pain in acute situations

Question 14

List the polar effect on treated tissues produced by the cathode (negative)

Answer 14

depolarizes nerve fibers, attracts bases (more damaging to skin), softens tissues, increases hemorrhage, stiumlates, reduces pain in chronic situations

Question 15

Why do burns occur with ionto?

Answer 15

poor technique: poor skin-electrode interfaces, intensity too high, velcro straps too tight, electrodes too small/dry/size differential between anode and cathode, wrong polarity, DC current used

Question 16

Where should iontophoretic electrodes be placed?

Answer 16

active electrode over treatment tissues, depressive electrode about 18 inches away to encourage a greater depth of penetration.

Question 17

What are the advantages of ionto vs injection?

Answer 17

No carrier fluids, reduced risk of infections to noninvasive application, relatively painless, local delivery without GI side effects

Question 18

Disadvantages of ionto?

Answer 18

numerous tx’s may be required, limited depth penetration, costly electrodes, there are risks of polar effects and skin damage, setup and application are time consuming

Question 19

How many serial iontophoretic treatments are safe?

Answer 19

one - six of dexamethasone

Question 20

Does the magnitude current determine the depth of penetration?

Answer 20

No, diffusion vs magnitude of current determines depth penetration. Low magnitude ma be more effective than those at 10-30 mins.

Question 21

Do buffered electrodes stabilize skin pH under the cathode?

Answer 21

Normal treatment conditions between 20-40 mA/min do not require it, but it is effective at 80 mA/min

Question 22

What is the piezoelectric effect?

Answer 22

The crystal in the sound head will mechanically respond or deform when subjeced to AC by expanding and contracting at the same frequency at which the current changes polarity. material in front of the crystal compresses the material in front of it, when the crystal contracts it rarefies the material in front of it.

Question 23

What is the beam nonuniformity ration (BNR)?

Answer 23

Variability of US wave produced by the machine. A low ratio means more uniform treatment. A higher ratio ie 8 W, means a 1W setting could vary from 1-8W during tx.

Question 24

What is the effective radiating area (ERA) of a transducer?

Answer 24

About the size of ultrasound head, and treatment area should only be 2-3 x this size

Question 25

What are the nonthermal and thermal ranges for US?

Answer 25

nonthermal .1-.3 W/cm2, thermal is anything greater than .3 W/cm2

Question 26

Reported nonthermal effects of US?

Answer 26

increases cell permability, increases vascular permeability, increases blood flow in chronically ischemic tissue, stimulates collagen synthesis, stimulates phagocytosis, promotes tissue regeneration, breakes down scar tissue in acute injuries, kills bacteria and viruses in chronic situations

Question 27

What are reported thermal effects of US?

Answer 27

heats collagen-rich tissues, increases tissue elasticity of collagen-rich tissue, increases blood flow, increases pain threshold, decreases muscle spasm, decreases pain and joint stiffness, causes a mild inflammatory response

Question 28

How does ultrasound frequency relate to depth of penetration?

Answer 28

Increasing frequency will decrease depth; 1 MHz 2-5 cm depth, 3MHz 1-2 cm depth

Question 29

Will tissue temp increases in human muscle vary between pulsed and continuous US application?

Answer 29

The same heating effect occurs between pulsed and constant

Question 30

Is a metal implant an absolute contraindication for the use of ultrasound?

Answer 30

No, however caution should be exercised becuase ultrasound is contraindicated over plastic implants and joint cement, which are often components of a total joint replacement.

Question 31

Is US effective in treating calcific tendonitis of the shoulder?

Answer 31

Yes, it has been suggested that US tx helps resolve calcifications and is associated with short-term improvements in pain and quality of life. In a study by Ebenbichler pts received 24 15 min sessions at 25% pulsed at 2.5 W/cm2 over 6 wks. After 6 wks calcifications resoved in 19% of patients and decreased in 50% in 28 % of patients (0-10% in sham). 9 month F/U 42% resolved and improved in 23% vs 8% and 12% in sham.

Question 32

Is there sufficient support for the use of US in PT?

Answer 32

From the most current reviews it would seem that there lacks quality research to support the use of US, but further research is needed to answer this question.

Question 33

How does phonophoresis work?

Answer 33

Two theories: pressure by the ultrasound vs. changes in the permeability (US before treatment of a drug to the skin increases penetration and supports the second option)

Question 34

Preferred dosage for phonophoresis?

Answer 34

high intensity and short time, or low intensity long time produce best results.

Question 35

What concentrations of hydrocortisone are most effective?

Answer 35

10% for relieving pain associated with tendonitis or bursitis(vs 1%)

Question 36

How many serial phonophoretic treatments are safe?

Answer 36

It is recommended that a second administration of phono should not be performed without consent of a physician to ensure that therapeutic levels are not exceeded.

Question 37

What drugs can be administered by phono?

Answer 37

dexamethasone, hydrocortisone, iodine, lidocaine, magnesium sulfate, salicylates, sodium salicylate, zinc oxide

Question 38

Provide an example of a topical NSAID that may be administered by phono?

Answer 38

Fastum gel (ketoprofen) - more effective with US vs topical only

Question 39

Most efficiently transmitted topical antiinflammatory media used in phono?

Answer 39

Fluocinonide and methyl salicylate

Question 40

Is phonophoresis effective in treating lateral epicondylitis

Answer 40

Baskurt et al suggests that phono of naproxen may be equally effective as ionto of naproxen in reducing pain and improving grip strength

Question 41

Is laser tx effective for relieving symptoms of arthritis?

Answer 41

May be somewhat effective with RA, but inconsistent with OA. RA other treatments that may be helpfu - E-stim, thermotherapy, and US

Question 42

Is low level laser therapy effective for carpal tunnel syndrome?

Answer 42

Irvine et al showed no difference from sham to real tx with laser.