Transcutaneous electrical acupoint stimulation to reduce opioid consumption in patients undergoing inguinal hernia repair: protocol for a randomized controlled trial

Background The purpose of this study is to evaluate the efficacy and safety of transcutaneous electrical acupoint stimulation (TEAS) in the postoperative treatment of patients undergoing inguinal hernia repair compared with sham and no treatment group. Methods This study is a protocol for a three-armed, single-blinded, placebo-controlled randomized controlled trial. Ninety participants scheduled for inguinal hernia repair will be randomly assigned to the TEAS group ( n = 30), sham group ( n = 30), and control group ( n = 30). The TEAS group will receive treatment using four portable coin-sized electro-stimulators at both local and distal acupuncture points. The sham group will receive sham treatment with mock electrostimulation. The treatment groups will receive mixed frequency stimulation (alternating at 2 and 100 Hz every 3 s) in continuous mode for 30 min at intervals of 2 h for 24 h postoperatively. The control group will receive postoperative pain control using patient-controlled analgesia (PCA) device. The primary outcome is the total morphine dose received in the postoperative period (mg) using PCA 24 h after surgery. The number of PCA demands (i.e., times the button will be pressed) and delivered bolus doses, score on the Visual Analogue Scale, opioid-related side effects, the requirement for supplemental medications, score on the Hospital Anxiety and Depression Scale (HADS), and blood levels of stress hormones cortisol and prolactin. Discussion The results of this trial will determine whether TEAS with intensified stimulation protocol is a safe and effective option for reducing analgesic consumption and postoperative pain. Trial registration ISRCTN76428396. Registered on 05 October 2020. https://www.isrctn.com/ISRCTN76428396