Iontophoresis, ultrasound, phonophoresis, and laser therapy Flashcards
Are iontophoresis and phono interchangeable?
No - no ionization takes place with ultrasound.
Describe Leduc’s classic experiment:
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.
Iontophoresis solutions indication and polarity: acetic acid
calcium deposits (-)
Iontophoresis solutions indication and polarity: dexamethasone sodium phosphate
inflammatory conditions (-)
Iontophoresis solutions indication and polarity: licocaine hydrochloride
skin anesthesia (+)
Iontophoresis solutions indication and polarity: potassium iodide
scar tissue (-)
Iontophoresis solutions indication and polarity: water
hyperhidrosis (alternate)
Iontophoresis solutions indication and polarity: Zinc oxide
ulcers, antiseptic (+)
Why are the effects of iontophoresis longer lasting than phonphoresis?
ions in superficial tissue with limited blood allows for time to be used, phono delivers it deeper where there is more vascularization.
Does increased drug concentration increase amount delivered?
No
Are there concerns with using direct current?
Yes, intact skin cannot tolerate current density >1 mA/cm2
Ion transfer depends on what factors?
1.) the concentration of ions in the solution 2. The current density of the active electrode 3. duration and current flow
List the polar effect on treated tissues produced by the anode (positive)
hyperpolarizes nerve fibers, repels bases, hardens tissues, stops hemorrhage, sedates/calms, reduces pain in acute situations
List the polar effect on treated tissues produced by the cathode (negative)
depolarizes nerve fibers, attracts bases (more damaging to skin), softens tissues, increases hemorrhage, stiumlates, reduces pain in chronic situations
Why do burns occur with ionto?
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
Where should iontophoretic electrodes be placed?
active electrode over treatment tissues, depressive electrode about 18 inches away to encourage a greater depth of penetration.