4.8 TENS

Question 1

Describe the set-up of TENS

Answer 1

1. Delivery of Pulsed Electrical Currents
2. across intact skin surface
   stimulate underlying A-B fibres
3. Portable battery operated generator
   Deliver pulsed currents
   via connecting leads
   to self adhering electrode conducting pads
4. Self operated
   home or hosp

Preferably after supervised trial
trained nurses

strength frequency self controlled

Question 2

Settings

Answer 2

Pulse durations 50-200usec
1-200 pulses/sec

biphasic pulsed pattern

Maybe be used at

Low
1-2Hz or

High
45-150Hz

Frequencies according to need

Question 3

Proposed MOA

Answer 3

1. Stimulation of A-B inhibit
2. Stimulation of smaller diameter
3. Neurotransmitter release

Question 4

1. Stimulation of A-B inhibit

Answer 4

second order nociceptor neuron

in dorsal horn of S.Cord
Melzacks and Walls gate theory

Question 5

2. Stimulation of smaller diameter

Answer 5

ad fibres
inhibit descending nociceptive pain pathways

activate descending inhibitory pathways
From PAG And ventromedial medulla

block peripheral nociceptive impulse

Question 6

3. Neurotransmitter release

Answer 6

Opioids 5HT3 ach Gaba aspartate glutamate

May be modulated by use of high or low freq tens

Question 7

Benefits

Answer 7

1. Labour analgesia
   Placed back @ level corresponding pain
   during 1st and second stages
2. Post op pain / N+V
   some evidence >placebo
3. Varying forms chronic pain
   neuropathic
4. Other pain
   Fractured ribs
   LBP
   Angina

Question 8

Contraindications

Answer 8

1. Lack Knowledge or understanding device
2. Placement infected/ inflamed / broken / anaesthetic skin
3. Placement over anterior portion neck
   may stimulate laryngospasm / vagal response
4. Epileptics head or neck
   - may induce seizures
5. Directly eyes = Increase IOP

Question 9

C/I

Answer 9

6. Patient w/ pacemakers
   cardio r.v w/ trial tens directly under obs
7. AP placement thorax
   may inhibition ventilation
   excess intercostal stim
8. Anterior abdomen during preg
   may stim labour
   affect fetal dev
9. Ischaemic necrotic / thrombosed tissue
   emboli
10. Recent Haemorrhage areas
    further haemorrhage