Emergency department use of cross-channel TENS for acute low back pain: A randomized controlled trial.

Background: Transcutaneous Electrical Nerve Stimulation (TENS) is established for chronic lower back pain but less studied in acute settings. This study evaluated the efficacy of cross-channel TENS for acute lower back pain in the emergency department (ED).

Methods: This single-blinded, randomized controlled trial enrolled ED patients aged 18-59 with acute lower back pain and Emergency Severity Index scores of 4 or 5. Participants were randomized to receive either active or placebo cross-channel TENS. The primary outcome was change in pain scores on a 100 mm visual analog scale (VAS) after 30 min of treatment. A clinically meaningful difference was defined as ≥13 mm. Secondary outcomes included the proportion of patients with clinically significant improvement, patient satisfaction (0-10 scale), and placebo effect assessment. Power analysis was based on a standard deviation of 15 mm, requiring a sample size of 42.

Results: Forty-two subjects completed the study (22 active, 20 placebo). Median pain reduction was 17 mm (IQR 6-29.5) in the active group and 5.5 mm (IQR 1.75-18.25) in the placebo group (difference: 11.5 mm; P = .06). Clinically significant improvement occurred in 68 % of the active group vs. 30 % of the placebo group (P = .03). Median satisfaction was 8 in both groups (P = .81).

Conclusions: Although overall pain reduction was not statistically significant between groups, a higher proportion of patients receiving active TENS achieved clinically meaningful relief. Patient satisfaction was high in both groups. Cross-channel TENS may be a useful adjunct in managing acute lower back pain in lower acuity ED patients. Future studies should explore TENS impact on length of stay and broader ED applications.