Effects of noise isolation using noise-canceling headphones during lymphedema liposuction on postoperative pain in patients undergoing general anesthesia: a protocol for a randomized controlled trial.

[BACKGROUND] Operating room noise, generated by medical equipment, poses significant health risks and can lead to hearing impairment, cardiovascular disorders, and anxiety in both patients and staff. Accumulating evidence suggests that auditory processing persists under general anesthesia, with intraoperative noise exposure potentially affecting postoperative outcomes. Recent studies have reported a positive correlation between intraoperative noise levels (≥ 70 dB) and postoperative pain intensity, particularly when using high-noise liposuction devices for lymph liposuction procedures. Non-pharmacological pain management strategies are prioritized to not mask ischemic symptoms in extremities. This study aimed to investigate whether noise-canceling headphones can mitigate postoperative pain by limiting intraoperative noise exposure during lymph liposuction.

[METHODS] This randomized controlled trial will include 90 patients undergoing elective lymph liposuction under general anesthesia. The intervention group will wear noise-canceling headphones throughout surgery, while the control subjects will receive standard care. Primary outcomes include postoperative pain scores (NRS) at 6, 12, and 24 h. Secondary outcomes comprise intraoperative nociceptive threshold index (PTI) monitored via multifunctional electroencephalography (EEG), preoperative/postoperative sleep quality (PSQI), and anxiety levels (HADS). In addition, mediation analysis will be conducted to examine noise exposure duration/intensity as predictors of pain outcomes.

[DISCUSSION] This randomized controlled trial will assess the efficacy and safety of noise-canceling headphones for reducing postoperative pain after lymph liposuction under general anesthesia. Since non-pharmacological interventions play critical roles in multimodal pain management, intraoperative noise reduction may effectively mitigate postoperative pain while avoiding pharmacological masking of ischemic limb symptoms. By integrating real-time neurophysiological monitoring of pain threshold dynamics, this trial explored how auditory environmental factors modulate nociceptive processing during anesthesia. If proven effective, this approach can enhance recovery protocols by minimizing pain-related complications and optimizing perioperative well-being in patients undergoing high-noise surgical procedures.

[TRIAL REGISTRATION] Chinese Clinical Trial Registry ChiCTR2400087400. Registered on July 27, 2024.