Effect of Peripheral Magnetic Stimulation on Acute and Chronic Pain After Surgery: A Systematic Review and Meta-Analysis.

Peripheral magnetic stimulation (PMS) is a potentially promising modality to help manage postoperative pain. We systematically reviewed the effect of PMS on acute and chronic postoperative pain. MEDLINE, Cochrane CENTRAL, EMBASE, ProQuest Dissertations, and clinical trials.gov were searched from inception until May 2021. We included studies of any study design that included patients ≥18 years of age undergoing any type of surgery that administered PMS within the perioperative period and evaluated postoperative pain. Seventeen randomized controlled trials and 1 nonrandomized clinical trial were included into the review. Thirteen out of the 18 studies found a positive effect with PMS on postoperative pain scores. In our meta-analysis, peripheral magnetic stimulation was more efficacious than sham or no intervention within the first 7 postoperative days (mean difference [MD] -1.64 on a 0 to 10 numerical rating score, 95% confidence interval [CI] -2.08 to -1.20, I2 = 77%, 6 studies, 231 patients). This was also true at 1 and 2 months after surgery (MD -1.82, 95% CI -2.48 to -1.17, I2 = 0%, 3 studies, 104 patients; and MD -1.96, 95% CI -3.67 to -.26, I2 = 84%, 3 studies, 104 patients, respectively). A difference was not seen with persistent pain at 6 and 12-months after surgery, acute postoperative opioid consumption, or adverse events between groups. Results are limited by heterogeneity and generally low-quality studies, as well as low or very low quality of evidence. High-quality and adequately blinded trials are needed to definitively confirm the benefits of peripheral magnetic stimulation administered in the perioperative period. PERSPECTIVE: This review evaluates the efficacy and safety of PMS on postoperative pain. The results help elucidate PMS' role in postoperative pain management and identify gaps where more research is required.