Transcutaneous electrical nerve stimulation (TENS) for pain management in sickle cell disease

As defined by the American Physical Therapy Association, TENS is the application of electrical stimulation to the skin for pain control. It is non-invasive, inexpensive, safe, and easy to use; a small battery-powered device applies an electric current via two or more non-invasive skin electrodes to stimulate underlying nerves and thus reduce pain perception. It can be applied with different frequencies, varying from low (< 10 Hz) to high (> 50 Hz). Intensity can also vary with low-intensity stimulation producing a sensation alone, while high-intensity stimulation triggers muscle contraction, and hence movement. Low-frequency TENS is usually given at high-intensity (producing motor contraction and sensation), while high-frequency TENS is given at lower intensities (producing both sensation and muscle contraction) (DeSantana 2008). Conventional TENS has a high-stimulation frequency (40 Hz to 150 Hz) and low intensity between 10 mA to 30 mA. The pulse duration is short (up to 50 microseconds). The onset of analgesia with this setup is virtually immediate. Pain relief lasts while the stimulus is turned on, but it usually abates when the stimulation stops. In acupuncture like settings, the TENS unit delivers low frequency stimulus trains at 1 Hz to 10 Hz, at a high stimulus intensity, close to the tolerance limit of the individual. This method is uncomfortable and is often considered for those who do not respond to conventional TENS. Pulsed (burst) TENS uses low-intensity stimuli firing in high-frequency bursts, but does not have any added advantage over the conventional method. Abstract source