BackgroundPostoperative sleep disturbance (PSD) is a common complication after general anesthesia and is associated with delayed recovery and other adverse postoperative outcomes. Perioperative esketamine may improve postoperative sleep, but current evidence remains inconclusive. This systematic review and meta-analysis assessed the efficacy and safety of perioperative esketamine for preventing PSD in adults undergoing surgery under general anesthesia.MethodsPubMed, Embase, the Cochrane Library,