ELECTROANALGESIA APPARATUS

Typical Number in Hospital: 5

Cost Bands: 2

References: 4

Electrical stimulation of tissue has been shown to be effective in the reduction of pain in some disorders. The most common clinical use of this is transcutaneous electrical neural stimulation (TENS) in which pulsed stimulation is provided for long periods using large area electrodes over the site of the pain. The stimulation causes a tingling sensation and also reduces the level of the perceived pain. About one third of patients with chronic pain benefit from this treatment which may be applied in the case of herniated discs, injury, arthritis, strain, and postoperative pain. Typical stimulation parameters are 100-150 pulses/s, pulse width of 250-400 [u]s, and output levels of 20-35 mA. Such devices may be used by the patient at home, with parameters and treatment periods set according to the daily needs of the patient. Treatment periods may extend for several hours at a time, and the relief from pain may persist for an equivalent period.

Electroanalgesia may also be applied by direct stimulation to the nerves or spinal cord. Although this may be less applicable to a large population suffering from chronic pain it may be used in selected patients employing needle electrodes or implanted electrodes and receivers, the power source being external to the body with an inductive loop operating at a frequency of 100-500 kHz.