Galvanic current is a term for constant direct current, named after Luigi Galvani from Bologna in 1889, used in therapy since the end of the 19th century after the batteries for it were constructed successfully. Today we get galvanic current from the alternating current of 50 pulse per second frequency and 220 voltage. Devices for this transformation have several electronic tubes through which the alternating current flows through in a single direction (from cathode to anode). This gives us pulsating full-wave direct current which turns into constant after the filtering, used in therapy
Galvanic current is used via two electrodes, one positive (+, usually red), and the other negative (-, usually black).
It is an interrupted direct current also called long duration current having more than 1 ms up to 300 ms or 600 ms. But the commonly used duration is 100 ms duration requires a frequency of 30 pulses/ min. If the duration increases the frequency must be reduced. The interval between the impulses should never be of shorter duration than the impulses themselves.
HOW DO WE USE GALVANIC CURRENT?
In practical therapy, galvanic current is used in several ways:
Dry galvanization through moist electrodes
Special forms in certain body parts
1. DRY GALVANIZATION
Dry galvanization can be applied in several ways:
Transverse or transregional galvanization – set transversely on a certain body part. This way equal flow of tissue between the electrodes is achieved.
Longitudinal galvanization – electrodes are set on different extremity heights (on the endings) – e.g.one electrode on the shoulder, and the other on the palm of the hand. This way we achieve surface flow. Longitudinal galvanization can be descending (cathode is placed distally) or ascending (cathode is placed proximally).
Dotted galvanization – applied via two electrodes, one active (mobile, applied in painful spots), the other inactive and considerably bigger.
If the patient is experiencing trigeminal neuralgia, galvanization is applied through a special semi-mask (Bergoni) electrode. Mask-shaped cathodic electrode is fixated on the neuralgic side, while the inactive electrode is placed on the sternum or between the shoulder blades.
HOW TO PLACE ELECTRODES?
Electrodes are never placed directly on the skin – they need to have hydrophilic cloth folded over them. Most frequently we use sponges moisted with water. Prepared electrodes are usually fixated with elastic bandages or sandbags.
SCALING AND DURATION OF THE TREATMENT
When scaling the galvanic current we need to pay attention to two things. First is the patient’s subjective feeling – feelings of tingling have to be present, but not pain or burning. Galvanic current has to be gradually applied with constant assessment of the patient’s feeling.
The second parametre is current density on electrode surface ( mA/cm2 ). It needs to be within the limitations of the physiological sensitivity (0.1 to 0.5 mA/cm2). One application lasts between 10 and 20 minutes.
The intensity and duration of impulses in galvanic current is adequate so that it can cause a sluggish worm like contraction.
When current is applied it produces sensory stimulation resulting in the feeling stabbing or burning sensation.
It increases blood circulation causing erythema (redness) of the skin.
Stimulation of motor nerve with such current produces contraction of the muscle supplied by that nerve.
Galvanic current affects neural endings responsibole for transfer of pain so that the pain is diminished or removed completely.Cathodes enhance stimulativeness and conductiveness of the nerves, while anodes diminish them.
Vasodilataion (expansion of blood vessels) happens under the influence of the galvanic current , causing hyperaemia, excessive accumulation of blood in a part of the body. Skin under the electrode becomes warmer, redder, and moister, in a period of up to 30 minutes.
There has been confusion over the therapeutic use of electrical stimulation for denervated muscles for the last many years. The purpose of such current is to maintain the muscles in as healthy state as possible to prevent the complication by electrically artificial contraction. Skeletal muscles have greater power of regeneration. When the muscles are denervated the following changes will occur.
Loss of voluntary contraction and reflex activities
Atrophy: Resulting in fibrosis
Fibrillization: Spontaneous contraction
If some of the motor units (motor end plate + motor nerve + muscle fibers) are intact galvanic current is the choice of treatment.
Interrupted direct current is still recommended for the treatment of Axonotmesis and Neurotmesis nerve repair is to be taken
WHEN TO APPLY GALVANIC CURRENT ?
rheumatic diseases, except in their active or acute phase
paresis and paralyis – galvanic current is here used as the introduction for electrostimulation (galvanic current diminished skin resistance through hyperaemia, so we can achieve a strong muscle contraction with little stimulation
blood vessel dieases and circulation disorders
Cardiac pacemakers and Arrhythmias
Thrombosis and thrombophlebitis (inflammation of wall of vein)
Early tendon transfer and repair
Pregnancy: On pelvic, low back and abdomen
Child with mental disturbance
Infected wound and skin lesion