Electric nerve stimulation (ENS): 70 clinical cases of bi-block aided by an electric bipolar signal.
BACKGROUND
The practice of local anaesthesia aided by ENS, among other things, is based on the use of available electric signals searching peripheral nerves. Most electric generators produce a square monopolar signal that is potentially dangerous because it exists a risk of hyperpolarization damage with neural lesions by galvanic effect.


OBJECTIVE
To inform about the use of a bipolar signal, different than the usual square monophasic signal. In theory a bipolar signal prevents the risk of hyperpolarization by lessening average intensity of current crossing the tissues.


METHODS
Our experience is based on 70 clinical cases of bi-block performed by searching the nerve by using an electric bipolar signal to locate a peripheral nerve.


RESULTS
Local anaesthesia can be successfully performed by using bipolar electric signals not currently employed. In 2/70 patients it was needed to perform surgery under general anesthesia. The rate of successful blocks was similar to the results of current literature.


CONCLUSIONS
Most authors search peripheral nerves by square monophasic signals. It arrives because it's widely believed that a square signal is advantageous because of high ratio di/dt (intensity/time). Today, it's not assessed in clinical practice that an electric signal is deeply modified in its parameters and its form by capacitive and resistive properties of the human body.
Di Massa
A
A
Dipartimento Scienze Odontostomatologiche, Università degli Studi, Siena.
Orlandini
N
N
Di Don Francesco
P
P
Simone
M E
ME
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000627:therapeutic use; D005260:Female; D005267:Femoral Nerve / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy / Q000628:therapy*; D004561:Transcutaneous Electric Nerve Stimulation / Q000009:adverse effects / Q000379:methods*
D000779:Anesthetics, Local