Intraoperative 40 Hz gamma frequency auditory stimulation for postoperative sleep disturbance in patients undergoing laparoscopic gynecological surgery: protocol for a randomized controlled trial

Background: Postoperative sleep disturbance (PSD) is a common complication after surgery and is associated with impaired recovery. This protocol describes a randomized controlled trial designed to determine whether intraoperative 40 Hz gamma frequency auditory stimulation reduces the incidence of PSD after laparoscopic gynecological surgery. Methods: This randomized, double-blind, controlled trial will enroll 342 patients scheduled for laparoscopic gynecological surgery under general anesthesia. Patients will be randomly allocated in a 1:1:1 ratio to three parallel groups: control (no headphones), sham stimulation (headphones without auditory output), or active stimulation (headphones delivering 40 Hz auditory stimulation). The primary outcome is the incidence of PSD on the first postoperative night. Secondary outcomes include the incidence of PSD on postoperative nights 2 and 3, daily Athens Insomnia Scale (AIS) scores, anxiety and depression scores (HADS-A/-D), sedative-hypnotic use, pain scores, analgesic consumption, the incidence of postoperative nausea and vomiting (PONV), rescue antiemetic use, duration of post-anesthesia care unit (PACU) stay, length of postoperative hospital stay, quality of postoperative recovery (QoR-15), perioperative adverse events, and patient satisfaction. Discussion: This trial will evaluate whether intraoperative 40 Hz gamma frequency auditory stimulation reduces PSD in patients undergoing laparoscopic gynecological surgery. The findings may provide evidence for a non-invasive perioperative strategy to mitigate sleep disruption and improve postoperative recovery. Clinical trial registration: http://www.chictr.org.cn, identifier [ChiCTR2500110341].