The use of TENS for the treatment of back pain in the emergency department: A randomized controlled trial.

Objective: Back pain is one of the most common complaints in the emergency department (ED). Since current pharmacological treatments for back pain are often suboptimal, a multimodal approach that includes nonpharmacological modalities has promise to improve pain management. The objective of the current study was to test the hypothesis that transcutaneous electrical nerve stimulation (TENS) would be more effective at relieving back pain than sham TENS.

Methods: We conducted a patient- and observer-blinded, randomized controlled trial that included adult (≥18 years) ED patients with lumbar or thoracic back pain of at least moderate pain severity. Participants were randomly assigned (1:1) to TENS or sham TENS. The primary outcome was absolute reduction in pain severity at 30 min after treatment measured with a verbal numeric scale from 0 to 10 (none to worst). A sample of 80 patients had 80% power to detect a 1.5-point between-group difference in pain severity. The trial was registered with ClinicalTrials.gov (NCT04227067).

Results: We enrolled 80 subjects (40 to the TENS group, 40 to the sham group). Mean (±SD) age was 46 (±16) years, and 51% were female. Mean (±SD) pain scores before and after treatment were 8.4 (±1.6) and 6.8 (±2.4) in patients treated with TENS. Mean (±SD) pain scores before and after treatment were 8.0 (±1.7) and 7.5 (±2.1) in patients treated with sham TENS. The mean (±SD) reduction in pain score was significantly greater in TENS versus sham patients, 1.7 (±2.0) versus 0.5 (±1.0; p = 0.002). Rescue medication was administered to fewer patients treated with TENS than with sham (45% vs. 73%, p = 0.02) and patient satisfaction was higher in the TENS than in the sham group (78% vs. 50%, p = 0.02).

Conclusions: TENS was more effective than sham TENS at reducing pain severity in adult ED patients with back pain.