Transcript Electrical Stimulation - Therapeutic Modalities

Electrical
Stimulation
Clinical Application
© 2005 – FA Davis
High Volt Pulsed
Stimulation
© 2005 – FA Davis
Parameters
Current: Monophasic
Amplitude:
0 to 500 mA
Voltage:
0 to 500V
Pulse Frequency:
1 to 120 pps
Pulse Duration:
13 to 100 µsec
Phase Duration:
20 to 45 µsec
Adjustable Parameters
 Duty cycle
 Electrode alternating rate
 Electrode balance
 Intensity
 Polarity
 Probe electrode
 Surge/Ramp
Theory
 Short-duration, high amplitude (voltage) pulses
can produce comfortable, moderate
contractions.
 Short phase duration targets sensory nerves and
motor nerves
 Wave form is modified to decrease total current to
improve comfort
 Each electrode has a known polarity
 May cause galvanic (ion) changes
 Short phase duration and long interpulse interval
probably negates any effect
Uses
 Reeducation of
peripheral nerves
 Delay denervation and
disuse atrophy by
stimulating muscle
contractions
 Reduction of posttraumatic edema
 Increase in local blood
circulation
(unsubstantiated)
 Restoring range of
motion:
 Reduction of muscle
spasm
 Inhibition of spasticity
 Reeducation of partially
denervated muscle
 Facilitation of voluntary
motor function
Effects
 Neuromuscular Stimulation
 Moderate to strong muscle contractions
 Less torque production than NMES
 Pain Control
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Sensory-level (short-term)
Motor-level
Acute pain: Positive electrode over painful site
Chronic pain: Negative electrode over site
Effects
 Edema Control
 Negative electrode may prevent the
formation of edema
 Causes the gaps between endothelial cells
to close, preventing leakage
 Edema Reduction
 Motor-level stimulation “milks” the venous
and lymphatic vessels.
Effects
 Blood Flow
 Associated with frequency and intensity of
muscle contraction
 Wound Healing
 Electrode polarity kills or repels different
microbes
 Assists healing and inhibits bacteria growth
 Direct current techniques are more effective
than HVPS
Notes and Precautions
 Motor-level stimulation can cause unwanted
tension on the muscle fibers, the tendons, or
the bony insertion.
 Muscle fatigue can occur if the duty cycle is too
high.
 Intense or prolonged stimulation may result in
muscle spasm and/or muscle soreness.
 Improper use can cause electrode burns or
irritation.
Transcutaneous
Electrical Nerve
Stimulation
© 2005 – FA Davis
Parameters
Current: Biphasic
Total current flow
0 to 100 mA
Pulse frequency
1 to 150 pps
Pulse duration
10 to 500 µsec
Phase duration
5 to 250 µsec
Adjustable Parameters
 Intensity
 Mode (output
modulation)
 Pulse duration
 Pulse frequency
Theory
 Adjustable phase durations specifically
target sensory, motor, and pain fibers
 Phase duration is matched with pulse
frequency to produce specific effects
 Biphasic form prevents net residual
charge
Uses
 Control of acute or chronic pain
 Management of postsurgical pain
 Reduction of post-traumatic acute pain
Effects
 High – Frequency TENS (Sensory Level)
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Short phase duration (< 100 µsec)
High pulse frequency (60 to 100+ pps)
Sensory-level output
Activates spinal gate
Long-term treatment
 Output must be modulated to reduce
accommodation
Effects
 Low – Frequency TENS (Motor level)
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Long phase duration (150 to 250 µsec)
Low pulse frequency (2 to 4 pps)
Motor-level output
Pituitary gland releases:
 ACTH
 β-lipotropin
 Causes the release of β-endorphin
 Binds to the A-beta and C fiber receptor sites
 Blocks the transmission of pain
Effects
 Brief – Intense TENS (Noxious level)
 Long phase duration (300 to 1,000 µsec)
 High pulse frequency (> 100 pps)
 Noxious-level output
 Very short treatment duration
 Creates a negative feedback loop in the CNS
 Theoretically “short circuits” the pain carrying loop
 Opiates inhibit the release of Substance P
 Blocks or reduces pain transmission
Notes and Precautions
 Do not use to treat pain of unknown origin
 TENS is a symptomatic treatment
 Improper use can result in electrode burns or
skin irritation.
 Intense or prolonged stimulation may result in
muscle spasm and/or muscle soreness.
 Intake of 200 mg or more of caffeine may
reduce the effectiveness of TENS
 Narcotics decrease the effectiveness of TENS
Interferrential
Stimulation
© 2005 – FA Davis
Parameters
Current: Alternating
Two alternating currents form a single
interference current. Premodulated output is
based on a single alternating current.
Current:
1 to 100 mA
Current flow (RMS)
0 to 50 mA
Voltage:
0 to 200 V
Carrier Frequency:
Fixed at 2500 to 5000 Hz
Beat Frequency:
0 to 299 Hz
Sweep Frequency:
10 to 500 µsec
Adjustable Parameters
 Intensity
 Beat frequency – Analogous to the
number of cycles or pulses per
second
 Burst duty cycle – Bursts separated
by periods of no stimulation
(interburst interval)
 Interburst interval – Duration of time
between bursts
 Premodulation (e.g., Russian
Stimulation)
 Ramp
 Sweep – Variation in the beat
frequency; Set with a low value and a
high value
 Vector/Scan – Variation in current
intensity
Theory
Carrier Wave
Interference Wave
=
Variable Wave
 High-frequency waves easily overcome
skin resistance
 The two waves are slightly out of
frequency
 They cancel each other out and produce
a frequency of 1 to 299 Hz in the tissues
 Results in a comfortable stimulation
capable of depolarizing sensory and
motor nerves
Uses
 Acute pain
 Chronic pain
 Muscle spasm
Effects
 Pain Control
 Similar to TENS
 Most frequently used for motor-level pain
control
 Muscle Contractions
 Neuromuscular re-education
 Edema reduction
Notes and Precautions
 Do not use in the presence of unknown
pain or pain of central origin
 Can cause electrode burns, skin irritation
 Motor-level use can cause muscle spasm
or muscle soreness
Neuromuscular
Electrical Stimulation
© 2005 – FA Davis
Parameters
Current: Biphasic, Premodulated
Total current:
0 to 200 mA
Pulse frequency:
1 to 200 pps
Phase duration:
20 to 300 µsec
Intrapulse interval:
Appx. 100 µsec
Adjustable Parameters
 Intensity
 Pulses per second
 Duty cycle
 Reciprocal rate
 Ramp
Theory
 Current type varies by manufacturer
 Tends to have long phase duration
 Biphasic and alternating current
decreases possibility of electrode
irritation
Uses
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Maintaining range of motion
Muscle reeducation
Prevention of joint contractures
Prevention of disuse atrophy
Increasing local blood flow
Decreasing muscle spasm
Effects
 Can produce substantial muscular
tension
 Capable of increasing strength
 Used when limb is immobilized
 Also slows the onset of atrophy
 Duty cycle is required to prevent fatigue
Notes and Precautions
 Improper use may result in electrode burns or
skin irritation
 Intense or prolonged stimulation may result in
muscle spasm and/or muscle soreness.
 An electrically induced contraction can
generate too much tension within the muscle
 Use caution:
 Musculotendinous lesions, the tension from the
contraction may injure the muscle or tendon fibers
 Cases where the muscle’s bony attachment is not
secure
Iontophoresis
© 2005 – FA Davis
Parameters
Current: Direct
Total current:
Up to 5 mA
Voltage:
80 V
Dosage:
0 to 80 mA/min
Adjustable Parameters:
 Dosage:
 Amperage
 Duration
 Polarity
Theory
 The charges associated with a DC can “drive”
medications into the tissue
 Medication must have an electrical charge
 Negative charges driven from the cathode
Attracted towards the anode
 And vice-versa
 Requires specialized electrodes to hold the
medication
Dose-Oriented Treatments
 Medications are
delivered in mA/Min
 Milliamp Minutes
 Function of the amount
of current times the
duration of the
treatment:
 5 mA applied for 20
minutes
 5mA * 20 min = 100
mA/Min
 4 mA applied for 25
minutes
 4mA * 25 minutes = 100
mA/Min
Dose-oriented treatments
provide the basis for the
Ionotopatch™ which delivers
the medication using a low
current applied for an
extended time.
Uses
 Delivers medication to the tissues
to treat:
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Acute inflammation
Chronic inflammation
Arthritis
Myositis ossificans
Myofascial pain syndromes
Delivering local anesthetics before
injection or other minor invasive
procedures
 Hyperhidrosis
Sample Medications
Medication
Pathology
Acetic acid
Myositis ossificans 2%
80 mA/Min Negative
Dexamethason
and lidocaine
Inflammation
Pain control
4mg Decadron
4% Xylocaine
41 mA/Min Negative
40 mA/Min Positive
Lidocaine and
epinephrine
Pain control
4% Lidocaine
30 mA/Min Positive
0.01 mL/1:50,000 30 mA/Min Positive
Dexamethasone Inflammation
Concentration
2cc 4mg/mL
Dosage
Polarity
41 mA/Min Negative
Refer to the prescription for the exact treatment parameters.
Each electrode size has a maximum treatment amperage. Consult the packaging
information included with the electrodes.
Notes and Precautions
 Controlled medications require a physician’s
prescription:
 Each patient requires his/her own prescription
 Follow any notes or instructions provided by the pharmacist.
 State practice acts may further regulate the delivery of
iontophoresis.
 The exact medication dosage delivered is unknown.
 Erythema under the electrodes is common
 Too intense of a treatment dose can result in electrode
burns
 Do not reuse electrodes
 Medications remain, contaminating the electrode
Microcurrent
© 2005 – FA Davis
Parameters
Current: Monophasic.
(Polarity reverses)
Total current flow:
1 to 999 µA (Peak current)
25 to 600 µA (RMS)
Pulse frequency:
0.1 to 1000 Hz
Pulse duration:
0.5 to 5000 µsec
Phase duration:
0.5 to 5000 µsec
Adjustable Parameters:
 Intensity
 Polarity/alternating
polarity
 Ramp
 Threshold – Ohm Meter
Theory
 Small, subsensory pulses can affect the
function of healing tissues
 Injured tissues have a reversal of their normal
electrical charges (“injury potential”)
 MET attempts to normalize the electrical
potential
 Activation of ATP and increased ATP levels
 The efficacy of MET has not been
substantiated.
Uses*
 Acute and chronic
pain
 Acute and chronic
inflammation
 Reduction of edema
 Sprains
 Strains
 Contusions
* Efficacy has not been established
 Temporomandibular
joint dysfunction
 Carpal tunnel
syndrome
 Superficial wound
healing
 Scar tissue
 Neuropathies
Notes and Precautions
 If the patient is dehydrated, nausea,
dizziness, and/or headaches may result.
 Electrical “shocks” may be reported by
the patient when MET is applied to scar
tissue.
 Caused by decreased electrical resistance.