Back pain is one of the top 5 most common ED presenting complaints, accounting for approximately 3% of all ED visits. It is estimated that 85% of these patients will leave the ED with a non-specific diagnosis, such as mechanical low back pain, and will recover within 4-6 weeks. Unfortunately, treatment for these patients is limited and often consists of NSAIDs, acetaminophen, and opioids if in significant pain.~TENS is a non-pharmacological option for the treatment of pain. The mechanism of its effect is based on the gate control theory of pain; stimulation of large, myelinated fibers reduces transmission of pain through smaller, nociceptive C-fibers through inhibitory actions of interneurons. It is very safe, with very few reported adverse effects and a short list of contraindications.~In 2015, a Cochrane review examined the benefit of TENS in acute pain, which was defined as less than 12 weeks. Their review demonstrated tentative evidence of benefit in reducing pain, although due to the small sample sizes of the encompassing trials and the inability to blind, definitive conclusions are impossible.~Research question: In patients in the ED triage area,18 years of age or older with acute or acute-on-chronic back pain for less than three weeks, does 30 min of transcutaneous electrical nerve stimulation reduce pain scores as compared to standard care alone?
The effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) to reduce pain scores for patients with acute back pain in an ambulatory emergency department (ED) population will be examined in this dual-center, cluster randomized, controlled, open-label study.