TENS Flashcards
(24 cards)
TENS defintion
use of electrical current for pain relief/modulated
activates
Which parameter affects rate of firing?
frequency
Which parameter affects depth of penetration
amplitude/intensity
Tens& Pain
Tens does not change pain
TENS changes perception of pain vis stimulation of specific nerve fibers using electrical current
Sensory Level Fibers
Sensation: pins and needles or tapping
A beta fibers in superficial dermis
Motor Level Fibers
Sensation: fasiculations, twitches, contractions
Alpha motor neurons
Noxious Level Fibers
Sensation: pain
A delta and C fibers
Gate System
gate closes by preferential depolarization of A beta fibers- sensation of pain blocked via high rate TENS
80- 130 Hz
Opiate System
gate opens by preferential depolarization of a delta and C fibers, activates the opiate system, causing the body to release endorphins
Low rate TENS
2-10 pps
Analgesic Mechanism of Low Frequency
less than 10 Hz
CNS- activates opiod receptors in RVM and spinal cord descending pathway
Spinal Cord- activates serotonin and muscarinic receptors cause inc in serotonin
Peripheral NS- opiod receptors involved activates alpha adrenergic receptors
Analgesic Mechanism of High Frequency TENS
increase concentrations of beta endorphins in the blood stream and CSF
CNS- Spinal Cord- activates delta opiod receptors; enhances release of NT GABA
Peripheral NS- reduce substance P
activate alpha adrenergic receptors
Conventional TENS Parameters
Short Pulse Duration <150 usec High Frequency >80Hz current amplitude- sensory stimulate- a beta fibers sensation- tingling Analgesia- rapid onset, brief duration
Acupuncture TENS
Long pulse duration >150 usec
Low frequency <10 Hz
Current Amplitude- sensory and motor
Fibers- A beta and motor
Sensation- tingling & visible muscle contraction
Pain modulation- opiate system
Analgesia- slow onset, sustained, relatively long duration
Carry over relief after stimulation is removed
30 min max
Brief Intense TENS
Long pulse duration >150 usec
High frequency >80 Hz
Current amplitude- sensory, motor, noxious
fibers- a beta, a delta, c fibers
sensation- mixed sensation, strong muscle contraction with max tolerable pain
Analgesia= rapid onset,, sustained for long time
Burst TENS
Bursts of pulses instead of individual pulses
Low frequency <10 Hz
current amplitude- sensory motor
fibers- a beta, motor
mixed sensation with moderate motor contraction
Analgesia- slow onset, sustained for relatively long period of time
Modulation TENS
variable; random parameters to stimulate the same time to decrease habituation
Contraindications
Over pelvis, abdomen, trunk and low back area during pregnancy
Over carotid sinus
Demand pacemaker or unstable arrythmia
Venous/ arterial thrombosis
Additional Contra
Epileptic pt Over metal implants Over eyes Mucosal membranes Undiagnosed pain Implanted defib Thoracic and cranial
Precautions
Cardiac disease/ mocardial infarction impaired mentation/ sensation skin irritation or open wounds TENS units at least 10 ft from SWD active epiphyseal regions no children
Opioids and TENS
Opioid drug users are non responders to low frequency tens
Caffeine and TENS
Caffeine can affect TENS effectiveness
Electrode Placements
on or around painful area
over specific dermatomes, myotomes, or sclerotomes that correspond to painful area
over sites where peripheral nerves that innervate the painful area becomes superficial and can be easily stimulated
Close Electrode Proximity
Close Placement
superficial current flow
Low number of parallel paths
at least 1 inch apart
Distant Placement
current reaches deeper and higher number of parallel paths
