Aim: To determine whether transcutaneous electrical nerve stimulation (TENS) is more efficient than placebo TENS and control groups for pain relief. Design: Randomized, single-blinded, placebo-controlled trial. Setting & participants: A total of 78 adults with postoperative pain, after cholecystectomy, at the University Hospital. They were randomized into active TENS, placebo TENS and control. Intervention: A total of 30-min interventions applied in the first 24 h after the surgery. Outcome: Pain intensity. Results: Pain significantly decreased for both TENS; however, the active TENS was better. A decrease of 2 points or more on the visual analog scale for 53.8% active TENS and 11.5% placebo. Conclusion: There was a greater reduction in pain of important clinical relevance in the active TENS group. Clinical Trial registration: Brazilian Clinical Trial (REBEC): RBR-6cgx2k.
Keywords: acute pain; analgesia; cholecystectomy; postoperative; transcutaneous electrical stimulation; treatment outcome.