- Often electrodes different from the ones selected as optimal with spongy contact surface have been used. In these cases distortion of information which renders the patients' perception less comfortable, can determine a less effective treatment, and in the most critical cases prevents a successful stimulation fine tuning.
- It is specifically wrong to use “large” electrodes like the ones usually used for TENS. In this case, apart from the problems previously listed, the broad electrode surface, because of its poorly selective recruitment, can stimulate wrong areas. This could lead to a pain increase during or after the treatment.
- Electrodes are reused, impairing the ability of ST to transmit information and prompting skin irritation.
- Gel is not added in order to optimize conduction.
Main indicators of mistaken positioning and fine-tuning:
- The patient feels a single “sting” in one or more electrodes.
This is a sign of under-stimulation or that the electrode is positioned in an area still too close to pain. To eliminate the problem it is usually enough to slowly increase the stimulation level or slightly move the electrode if the sting increases.
- The patient perceives a burning under the electrodes.
It is usually a sensory deception that is overcome by increasing the stimulation level, or slightly moving the electrode if the feeling increases.
- The patient perceives a feeling of “unpleasant stimulation” that is not able to clearly describe.
To eliminate this feeling move the electrode outside the area of pain more.
Other causes that prevent the correct treatment are due to non spongy electrodes or lack of GEL. Non spongy electrodes on the skin should always be avoided.
Patient under high opiates dosage or other strong analgesic drugs can indicate wrong areas of pain and have hyperalgesia effects due to the drugs. In these cases it is always best to stay away more from the indicated area of pain to position the electrodes.
Overall, inability to zero pain (or almost zero) during the treatment always indicates inadequate electrode positioning or fine-tuning levels.
It is always wrong to position all electrodes around the pain area and regulate all stimulation levels without checking one by one the effects of each channel because:
- Useless electrodes reduce the treatment efficacy
- useful electrodes can conceal positioning mistakes that during or after the treatment can trigger pain
Pain increase during or after the treatment
This event normally occurs when during the treatment fibers still connected to pain have involuntarily been stimulated.
Anomaly: When a channel that is being stimulated produces analgesia but at the same time the patient feels a sensation of discomfort or pain in other areas increases.
Mistaken action: Cover induced pain by inadequate positioning with other electrodes
Correct action: zero the channel and modify electrode positioning until only analgesia is produced in the interested area.
Main indicators of mistaken positioning and fine-tuning.
Pain increase after a treatment
It might be due to movements that were before impossible because of original pain, thus new pain triggered by mechanical causes linked to increased mobility.
Anomaly: Very acute pain in different areas from the initial ones.
Mistaken action: Failure to inform the patient that the treatment does not modify organic injury.
Correct action: Inform the patient to control his movements even if after the treatment he feels no pain.
Pain increase after a treatment
During an ST treatment there should be no pain. This must be verified by asking the patient to assume positions that would normally produce pain and zero it completely if it emerges. Having done this, the patient must return to a position that does not evoke pain.
Anomaly: treatment progression is not satisfactory, there are “ups and downs”, it does not stabilize.
Mistaken action: failure to check the real pain extension before electrode positioning.
Correct action: in the positioning phase make sure that also pain connected to postures that evoke it are covered.
Difficulties in electrode positioning to achieve zero pain during the treatment
Anomaly: there are not enough areas free of pain to find an optimal electrode positioning.
Mistaken action: carry out an ineffective treatment.
Correct action: apply electrodes in order to reduce at least the intensity or extent of the pain area. If there is at least a partial analgesia in the treated area, increase stimulation level (without too much discomfort for the patient) to increase the number of receptors engaged thus broadening the analgesia area and depth. In the sessions that will follow improve electrode positioning.
In a new treatment, electrodes are repositioned in the same positions as in the previous treatment
Anomaly: the same analgesia effect of the previous treatment does not emerge.
Mistaken action: electrodes have been positioned without having checked their individual efficacy.
Correct action: Each application requires electrode positioning according to current pain status, always following its evolution. One must always be guided by the pain area and patient’s response, never by a fixed pattern, even if previously successful.
Analgesia response to the treatment is effective, but is difficult to stabilize. The treated pathology does not justify this outcome
Anomaly: at the beginning of each treatment the VAS curve does not progressively and linearly decrease.
Mistaken action: none if during the treatment pain is correctly brought to zero.
Correct action: if anticonvulsants are being used, start a gradual weaning off. This case calls for a longer treatment cycle. Verify other possible causes (non diagnosed pathologies or wrong diagnosis, emergence of unexpected complications etc.)
There is no analgesia response during the treatment even if electrode positioning seems correct.
Anomaly: unmodified pain intensity during treatment
Mistaken action: continue the treatment .
Correct action: Check if the patient is taking or has taken high dosage of ketamine, miorelaxants or anticonvulsants for analgesic purposes . Interrupt the treatment and reassess the patient after he/she stops taking these drugs. The timeframe between ketamine suspension and normal treatment response is still unknown. If the anomaly does not occur because of drug intake ask for the help of a specialist to check once more the correct electrode positioning and stimulation fine-tuning.