Galvanization

Galvanization– the use for therapeutic and prophylactic purposes of a constant continuous electric current of low voltage and low strength, called galvanic. The method and type of current were named after the Italian physiologist Luigi Galvani.

Electric current is the directed (ordered) movement of charged particles. Based on the ability of substances to conduct electric current, they are divided into conductors and dielectrics. This division is arbitrary, since most substances are semiconductors: some do not conduct electric current well enough to be classified as conductors, others are not so bad as to be called dielectrics.
Conductors of electric current are divided into two groups: metals, whose conductivity is due to the movement of free electrons, and electrolytes, where charge carriers are ions.
Living tissues are electrolytes-conductors and dielectrics. Blood plasma and cerebrospinal fluid have the highest electrical conductivity. Somewhat smaller – whole blood, muscles, parenchymal organs. Great resistance to electric current is created by bones, adipose tissue, fascia, tendons and other connective tissue formations. Dry skin, hair, and nails come close to dielectrics.
Mechanism of physiological action
When galvanization is carried out in the underlying tissues, regional blood circulation improves and the content of biologically active substances increases, the synthesis of macroergs in cells is enhanced and metabolic and trophic processes are stimulated. Galvanization is accompanied by strengthening of the regulatory and trophic functions of the nervous system, improvement of blood supply and metabolism in the brain, which, in turn, leads to normalization of the activity of internal organs.
Deep into the tissues, the electric current is directed mainly through the blood and lymphatic vessels, “looping” through the tissues.
When the electrical circuit is turned on, the directional movement of ions immediately begins in accordance with their polarity, their accumulation at the electrodes – the process of polarization.
Negatively charged ions (anions) are concentrated at the positive electrode (anode), positively charged ions (cations) – at the negative electrode (cathode). When in contact with the electrodes, cations receive the missing electrons, and anions give up extra electrons. As a result, a process of substance release occurs on the electrodes – electrolysis. In this case, such a significant amount of alkali and acid is released on the electrodes that to eliminate their cauterizing effect, cloth pads with a thickness of at least 1 cm are used.
On the path of ions when moving to the electrodes inside tissues, there are cell membranes that have significant resistance to electric current. Ions accumulate near membranes, forming polarization zones and fields inside tissues. The polarization potential, measured by an electronic voltmeter, reaches its maximum value (200 – 500 mV) after 25 – 30 minutes from the start of exposure.  When the electric current is turned off, it decreases in hyperbole, getting lost in the physiological fluctuations of tissue potential after 3 – 5 hours.
Device:  
– AGN (wall-mounted galvanizing apparatus):
– AGP (portable galvanizing apparatus);
– AGS (dental galvanization apparatus);
– GR (oral cavity galvanizer);
Therapeutic effect
Galvanization has an analgesic effect and anti-inflammatory effect. sedative (at the anode), vasodilator, muscle relaxant and secretory (at the cathode) effects.
The concentration of these ions and their ratio are of great importance for excitation processes. The change in tissue excitability under the influence of electric current is called electrotone. At the moment of closing the electrical circuit under the cathode, the excitability of the tissue increases, the permeability of the membranes increases and their electrical resistance decreases. This change in excitability under the cathode is called catelectroton. Under the anode, tissue excitability decreases, cell membranes become denser, and their electrical resistance increases. These changes are called anelectroton.   After some time, in the process of continued exposure to direct electric current, excitability under both poles returns to its original values.  When using direct electric current therapeutically, the peculiarities of changes in excitability under and under the cathode are taken into account. If the purpose of the treatment is to reduce tissue excitability, this area is affected by the anode. To increase tissue excitability, the cathode is applied.
A direct electric current is applied to the tissues using electrodes placed on the skin.   The significant amount of skin resistance results in almost all of the voltage applied to the electrodes being applied to the skin. In this area of ​​the skin, a crawling sensation and a slight burning sensation appear, which is associated with irritation of sensitive nerve endings. Skin hyperemia and swelling with swelling of all its layers appear under the electrodes. These changes are in no way related to thermal effects. The galvanization method uses an electric current of such low strength that no practically significant amount of heat is released in the interelectrode space. The mechanism of hyperemia formation is neuro-reflex. Irritation of sensitive nerve endings causes reflex reactions that have a local segmental nature. Their consequence is the dilation of blood vessels. The severity of the response depends on the saturation of a given area of ​​skin with receptors. From the corresponding skin zones, it is possible to influence internal organs through autonomic nerve fibers and spinal centers, causing in them by reflex the same changes as in the skin: increased membrane permeability, intensified diffusion and osmosis. The intensity of metabolic processes in the affected area increases.
Direct electric current can also affect the central nervous system. In the brain and spinal cord there is a functional polarity of the descending direction: the overlying centers are positively charged, the underlying ones are negatively charged. This condition, called physiological anelectroton, ensures the normal functioning of the central nervous system. It can be enhanced by direct electrical current by positioning the electrodes accordingly. For example, a positive electrode in the forehead area, a negative electrode in the interscapular space. This effect helps improve the coordinating and regulatory functions of the brain, which can be useful for cortico-visceral diseases.
The duration of the procedure can vary from 10-15 (for general and segmental-reflex effects) to 30-40 minutes (for local procedures). A course of treatment usually involves 10-12 to 20 procedures, which can be performed daily or every other day.
Indications:
  • injuries and diseases of the peripheral nervous system (plexitis, neuralgia, mono- and polyneuropathy, etc.);
  • injuries and diseases of the central nervous system (traumatic brain injury, cerebrovascular accidents, migraine, functional disorders);
  • Diseases of the digestive organs that occur with impaired motor and secretory functions (chronic colitis, chronic gastritis, cholecystitis, biliary dyskinesia, peptic ulcer of the stomach and duodenum);  
  • cardiovascular diseases (arterial hypertension, angina, atherosclerosis);
  • chronic inflammatory processes in various organs and tissues;
  • bone fractures;
  • some dental diseases (periodontal disease, glossalgia, stomatitis, etc.).
Contraindications:
  • new growths or suspicions of them,
  • acute inflammatory and purulent processes,
  • systemic skin diseases, extensive damage and violations of the integrity of the skin, disorders of skin sensitivity in the areas where electrodes are applied,
  • severe cardiovascular diseases,
  • fever
  • pregnancy
  • severe cachexia
  • individual intolerance to galvanic current.

Dosage:

1) by electric current density (0.01 – 0.1 mA per 1 sq. cm, laying area);
2) according to the patient’s sensations (slight tingling, burning);
3) by duration of the procedure (from 15 to 30 minutes)

       Today, galvanization in its pure form is used relatively rarely; galvanic current is used much more widely in methods of medicinal electrophoresis (see Electrophoresis of medicinal substances).