NCLEX-RNBasic Care and ComfortMedium
A client with chronic osteoarthritis pain asks the nurse how a transcutaneous electrical nerve stimulation (TENS) unit relieves pain. Which explanation by the nurse is accurate?
- A"It stimulates large sensory nerve fibers to block pain signals from reaching the brain."
- B"It works by generating heat that increases blood flow to the affected joint."
- C"It triggers the release of stored corticosteroids from surrounding tissue."
- D"It releases numbing medication directly into the joint through the skin."
Show answer & explanationAnswer & explanation
Correct answer: A. "It stimulates large sensory nerve fibers to block pain signals from reaching the brain."
TENS units apply mild electrical stimulation to the skin, activating large-diameter sensory nerve fibers that close the 'gate' in the spinal cord, blocking transmission of pain signals from smaller pain fibers (gate control theory of pain). TENS does not deliver medication, heat, or corticosteroids.
Why the other options are wrong
- B. TENS works via nerve stimulation, not thermal effect.
- C. TENS does not release corticosteroids.
- D. TENS does not deliver medication; it is an electrical stimulation device.
TENS & Gate Control Theory
A TENS unit delivers electrical impulses to stimulate large sensory nerve fibers, which 'close the gate' at the spinal cord and inhibit transmission of pain signals from smaller fibers.
- Based on gate control theory of pain
- Non-pharmacologic pain management method
- Electrodes are placed near or around the painful area
Memory trick: "Big fibers slam the gate shut on pain."