1. T.E.N.S. Trancutaneous Electrical Nerve Stimulation

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 Precautions 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. TENS may be: high voltage interferential acuscope
low voltage AC stimulator
classical portable TENS unit

5. 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)

6. Techniques of TENS application:
Conventional or High Frequency
Acupuncture or Low Frequency
Brief Intense
Burst Mode
Modulated

7. Protocol for Various Methods of TENS

8. 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

9. Application of High TENS
Pulse rate: high Hz (generally 80), constant
Pulse width: narrow, less than 300 mSec generally 60 microSec
Intensity: comfortable to tolerance

10. 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)

11. 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: microSec
Intensity: strong you want rhythmical contractions within the patient’s tolerance

12. Burst Mode TENS
Carrier frequency is at a certain rate with a built in duty cycle
Similar to low frequency TENS
Carrier frequency of 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. Burst Mode TENS - Application
Pulse width: high microSec
Pulse rate: pps modulated to 1-5 burst/sec
Intensity: strong but comfortable
treatment length: minutes

14. 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.

15. 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.

16. Locus point stimulator
Locus (point) stimulators treatment occurs once per day generally 8 points per session
Auricular points are often utilized
Treat distal to proximal
Allow three treatment trails before efficacy is determined
Use first then try other modalities

17. 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

18. 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

19. Contraindications: Demand pacemakers over carotid sinuses Pregnancy
Cerebral vascular disorders (stroke patients)
Over the chest if patient has any cardiac condition