Transcutaneous electrical nerve stimulation (TENS) versus sham TENS in adult ED patients with abdominal pain: A clinical trial

Objective: There is a growing consensus that the risks of current pharmacologic analgesics warrant consideration of alternative modalities for acute and chronic pain control. The objective of this study was to evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) in adult emergency department (ED) patients presenting with abdominal pain. Methods: We conducted a patient and observer blinded randomized controlled trial comparing TENS to sham TENS. The study was conducted at a large suburban academic ED. Patients with abdominal pain and a verbal numeric pain scale (VNS) of 5 or greater were randomized to TENS or sham TENS applied via 4 skin pads, one in each abdominal quadrant for 30 min. The primary outcome was change in pain scores 30 min after the intervention. Our study had 80% power to detect a between group difference of 1.5 points on the VNS. Results: 81 patients were randomized to TENS (n = 41) or sham TENS (n = 40). Groups were similar in baseline characteristics. The mean (SD) reductions in pain scores were 1.9 (2.1) and 1.7 (2.6) in patients treated with TENS and sham TENS respectively (P = 0.81). Use of rescue medications in patients with treated with TENS and sham TENS was similar (49 vs 55% respectively, P = 0.66). Conclusions: Application of TENS to the abdominal wall did not result in more effective pain relief than sham TENS in adult ED patients with abdominal pain.