This document discusses T.E.N.S. (Transcutaneous Electrical Nerve Stimulation), a non-invasive pain management technique. It stimulates nerves under the skin to reduce pain signals according to the gate control theory. T.E.N.S. has efficacy rates of 50-80% for controlling chronic and acute pain, such as post-surgical or injury pain. Different T.E.N.S. techniques like high frequency, low frequency, and brief intense stimulation are described along with their parameters and applications. Placement of electrodes and contraindications are also covered.
2. General Concepts:
An Approach to pain control
Trancutaneous Electrical Nerve Stimulation:
Any stimulation in which a current is applied across the
skin to stimulate nerves
1965 Gate Control Theory created a great popularity of
TENS
TENS has 50-80% efficacy rate
TENS stimulates afferent sensory fibers to elicit
production of neurohumneral substances such as
endorphins, enkephalins and serotonin (i.e. gate theory)
3. TENS
Indications
Control Chronic Pain
Management post-
surgical pain
Reduction of post-
traumatic & acute pain
Precautions
Can mask underlying pain
Burns or skin irritation
prolonged use may result in
muscle spasm/soreness
caffeine intake may reduce
effectiveness
Narcotics decrease
effectiveness
4. Biophysical Effects
Primary use is to control pain through Gate Control Theory
May produce muscle contractions
Various methods
High TENS (Activate A-delta fibers)
Low TENS (release of -endorphins from pituitary)
Brief-Intense TENS (noxious stimulation to active C fibers)
5. Techniques of TENS
application:
Conventional or High Frequency
Acupuncture or Low Frequency
Brief Intense
Burst Mode
Modulated
6. Various Methods of TENS
Parameter High TENS Low TENS Brief-Intense
TENS
Intensity Sensory Motor Noxious
Pulse Fq 60-100 pps 2-4 pps Variable
Pulse
Duration
60-100 sec 150-250 sec 300-1000sec
Mode Modulated Modulated
Burst
Modluated
Tx Duration As needed 30 min 15-30 min
Onset of
Relief
< 10 min 20-40 min <15 min
7. Conventional Tens/High
Frequency TENS
Paresthesia is created without motor response
A Beta filers are stimulated to SG enkephlin interneuron (pure
gate theory)
Creates the fastest relief of all techniques
Applied 30 minutes to 24 hours
relief is short lives (45 sec 1/2 life)
May stop the pain-spasms cycle
8. Application of High TENS
Pulse rate: high 75-100 Hz (generally 80), constant
Pulse width: narrow, less than 300 mSec generally 60
microSec
Intensity: comfortable to tolerance
9. Set up:
2 to 4 electrodes, often will be placed on post-op. Readjust
parameters after response has been established. Turn on the
intensity to a strong stimulation. Increase the pulse width and
ask if the stimulation is getting wider (if deeper=good, if
stronger...use shorter width)
10. Low Frequency/Acupuncture-
like TENS:
Level III pain relief, A delta fibers get Beta endorphins
Longer lasting pain relief but slower to start
Application
pulse rate low 1-5ppx (below 10)
Pulse width: 200-300 microSec
Intensity: strong you want rhythmical contractions within the
patient’s tolerance
11. Burst Mode TENS
Carrier frequency is at a certain rate with a built in duty
cycle
Similar to low frequency TENS
Carrier frequency of 70-100 Hz packaged in bursts of
about 7 bursts per second
Pulses within burst can vary
Burst frequency is 1-5 bursts per second
Strong contraction at lower frequencies
Combines efficacy of low rate TENS with the comfort of
conventional TENS
13. Brief, Intense TENS: hyper-
stimulation analgesia
Stimulates C fibers for level II pain control (PAG etc.)
Similar to high frequency TENS
Highest rate (100 Hz), 200 mSec pulse width intensity to a
very strong but tolerable level
Treatment time is only 15 minutes, if no relief then treat
again after 2-3 minutes
Mono or biphasic current give a “bee sting” sensation
Utilize motor, trigger or acupuncture points.
14. Brief Intense TENS -
Application
Pulse width: as high as possible
Pulse rate: depends on the type of stimulator
Intensity: as high as tolerated
Duration: 15 minutes with conventional TENS unit. Locus
stimulator is advocated for this treatment type, treatment time
is 30 seconds per point.
15. Modulated Stimulation:
Keeps tissues reactive so no accommodation occurs
Simultaneous modulation of amplitude and pulse width
As amplitude is decreased, pulse width is automatically
increased to deliver more consistent energy per pulse
Rate can also be modulated
16. Electrode Placement:
May be over the painful sites, dermatomes, myotomes, trigger
points, acupuncture points or spinal nerve roots.
May be crossed or uncrossed (horizontal or vertical)
17. Contraindications:
Demand pacemakers
over carotid sinuses
Pregnancy
Cerebral vascular disorders (stroke patients)
Over the chest if patient has any cardiac condition
18. THANK YOU
Prof. Dr. M. RAJESH, PT,M.P.T(cardio),B.C.R.C
TRINITY MISSIOIN AND MEDICAL FOUNDATION
MADURAI.
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www.skpfc.wordpress.com