[Iontophoresis - local anesthesia at the ear canal and tympanic membrane (author's transl)].

Operations to the external ear canal and tympanic membrane necessitate sufficient local anesthesia. General sedation followed by infiltration anestesia, is rather time-consumming, can be painful due to the injection, and is not particularly satisfactory for the treatment of outpatients. The iontophorese-technique, however, of local anesthesia, is applicable particularly for the treatment of outpatients. Principally, the local anesthetic is transported in ionisised form to the nerve membrane, by means of calvanic currents through the healthy surface epithelial tissue of the external ear canal or the eardrum. The technique described for the first time in 1911 no longer shows toxic sides-effects since the introduction of improved electrodes and more modern local anesthetic. The anatomic, pharmacological, chemical and physical basics of the technique will be described. The lecture will be based on personal experience of the method, taken from large groups of patients over a period of more than two years, using equipment specially designed for this purpose.