Evaluating the Effectiveness of Transcutaneous Electrical Nerve Stimulation for Various Outcomes in Emergency Department Settings: A Systematic Review and Meta-Analysis

Pain is a prevalent complaint in emergency departments (EDs) worldwide. Traditional pharmacological methods for pain relief, such as opioids and non-steroidal anti-inflammatory drugs (NSAIDs), have notable side effects and risks. Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological alternative that has shown promise in various clinical settings. This systematic review and meta-analysis aimed to evaluate the effectiveness of TENS for pain management and other outcomes in ED settings. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search was conducted across six major databases: PubMed, Web of Science (WOS), Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL), from inception until June 25, 2024. Randomized clinical trials involving the use of TENS in ED settings were included. Data extraction and quality assessment were performed independently by two reviewers, with conflicts resolved by a third reviewer. The search yielded 3,569 papers, of which 2,889 were screened after removing duplicates. Thirteen full-text articles were reviewed, and seven studies met the inclusion criteria for qualitative synthesis, with five of these suitable for meta-analysis. The studies demonstrated that TENS significantly reduced pain, heart rate, and the requirement for rescue medication in some cases, while also improving patient satisfaction and overall well-being. However, no significant changes were observed in blood pressure. The quality of the included studies varied, with some failing to meet the criteria for blinding and intention-totreat analysis. TENS is an effective non-pharmacological intervention for pain management in ED settings, with additional benefits such as reduced heart rate and increased patient satisfaction. Further high-quality randomized controlled trials are necessary to confirm these findings and better understand the potential of TENS in acute care environments.