Electroanalgesia Flashcards
What does the Walla and Melzak Gate control theory state?
Wall and Melzak Gate Control theory - stimulation of large myelinated afferents with high frequency stimulation to “block” pain input
What does low frequency stimulation stimulated the release of? What type of “effect” does it have?
Stimulation of release of endogenous opiates ( endorphins and enkephalins) with low frequency stimulation; Acupuncture effect
What type of current is the TENS unit?
Pulsed current waveforms, often asymmetrical biphasic, unlike NMES which symmetrical biphasic
Name 4 indicationrs for using Electroanalgesia?
- acute and chronic pain syndromes - musculoskeletal , neurological pain
- post operative pain
- labor and delivery pain
- prior to painful procedures
Name 8 contraindications for using electroanalgesia
- demand type cardiac pacemakers or other implanted stimulating devices
- over eyes
- over the carotid sinus
- over the chest in the presence of cardiac dysfunction
- in the presence of seizure disorders, avoid the head and neck area
- with patients with cognitive impairment
- over open wounds or compromised skin including friable skin
- over areas in which movement is contraindicated if stimulating in a mode which creates visible muscle contractions
Name 1 precaution for electranalgesia
pregnancy - can use for labor pain
Name 2 types of modes for the TENS unit
1) Sensory-level mode
2) Motor-level mode
Which TENS mode is high rate, conventional?
Sensory-level mode
Which TENS mode is low rate, acupunture-like?
Motor-level mode
For TENS unit, what is the main goal for sensory-level mode?
Stimulate large A sensory afferents
What is the frequency used for sensory level mode? What is the most common?
50-200 pps, 100-150 is most common
TENS-Where do you stimulate over?
Usually stimulate directly over the site or over anatomically related sites such as dermatomes , spinal cord root levels
TENS-Electrodes can be placed over __ or “__” pain
Electrodes can be place over pain or “sandwiching” pain
TENS unit-What is the goal of the motor-level mode?
Stimulate small un-myelinated A delta and C fibers along with motor efferents to stimulate muscles rhythmically
TENS-What is the pulse duration and frequency fo the motor-level mode?
Pulse duration -> 100-200 microsec
Frequency -> very dependent on type of motor stimulation, but can be 2-10 pps with amplitude high enough to get a visible but not tetanic contraction
TENS-What is the pulse duration for sensory-level mode?
20-100 micro sec
TENS-Motor-level mode: What is burst (of pulse trains) mode (burst modulated pulsed currents)?
creates bursts of pulses at low repetitions (2 bursts per second)
What type of waveform does IFC (interferential current) use?
sinusoidal polyphasic AC waveforms
What are the 2 indications for IFC?
1) Electroanalgesia
2) Muscle stimulation (different parameters)
What are the two frequencies usually used for IFC? What is it known as?
4000-5000 Hz to create an interference freq., known as beat freq.
Example:
Channel 1 - 4100 Hz
Channel 2 - 4000 Hz
Beat frequency - 100 Hz (this is the working frequency or the beat frequency )
Name the 3 contraindications for IFC
1) Over metallic implants
2) Over excessive hair
3) Severe cardiopathies
What type of electrode technique is used in IFC?
Quadripolar electrode technique - 4 crossed electrodes (2 electrodes on each of 2 channels) - the interference current is generated in the body
In IFC, what does vector scan mean?
- amplitude of current is varied which increases the field
- can only be done with the quadripolar technique
- current is felt to move among and between the electrodes
In IFC, name the 2 different types of beat frequencies
- variable (sweep) - varies within a range (e.g. 1-15 bps, 80-150 bps)
- constant - set at one unchanging beat frequency
In IFC, the modes of application is similar to what? Name 3 how they are similar.
Modes of Application similar to TENS - conventional, acupuncture-like , or burst (sensory is most common)
