Preoperative oral spicy stimulation for postoperative pain reduction after spinal surgery: a randomized controlled trial.

Background: Oral spicy stimulation has been shown to decrease pain sensitivity; however, its efficacy for acute postoperative pain remains unclear. This study aimed to evaluate whether preoperative spicy stimulation reduces postoperative pain intensity and analgesic consumption in patients undergoing elective spinal surgery. Methods: This prospective, randomized clinical trial enrolled patients who underwent spinal surgery under general anesthesia at Wuhan Fourth Hospital, China, between November 2023 and November 2024. Patients were randomized to receive oral spicy stimulation held in the mouth for 10 min, a total of nine times preoperatively, or a placebo with identical timing. The primary outcome was the area under the curve (AUC) of rest pain scores during the first 24 h postoperatively, measured using a 0-10 numeric rating scale (NRS). Secondary outcomes included the AUC of movement pain NRS scores within 24 h, the AUC of rest and movement NRS scores within 48 h, supplemental analgesia requirements, and total analgesic consumption expressed as morphine-equivalent doses. Results: Of 106 enrolled patients, 96 were included in the final analysis. Patients receiving oral spicy stimulation had lower 24-h area under the curve (AUC) of rest pain NRS (60.0 [42.0-81.0] vs. 90.0 [64.5-120.0]; MD: -30.0 [95% CI, -45.0 to -15.0]; Conclusion: Preoperative oral spicy intervention was associated with a lower acute postoperative pain burden and reduced postoperative analgesic requirements in patients undergoing spinal surgery. Clinical trial registration: Chictr.org.cn, ChiCTR2300077274.