Impact of Intraoperative Binaural Beats on remifentanil requirement during remimazolam-based general anesthesia: a randomized controlled trial

Purpose: Binaural beats (BB) may influence anxiety and anesthetic requirements through brainwave entrainment. This study investigated the effect of intraoperative BB on remifentanil requirements during remimazolam-based general anesthesia maintenance
Methods: In a randomized, prospective, single-center study, Seventy-two patients were randomly allocated to two groups: the BB group (B group, n=36) or control group (C group, n=36). The B group listened to BB (4-Hz frequency difference) intraoperatively, while the control group did not. The primary outcome was remifentanil dosage during anesthesia. Secondary outcomes included remimazolam dosage per hour per kg, hemodynamic stability, postoperative pain scores, and EEG spectral analysis. Postoperative pain scores were assessed using the numerical rating scale (NRS), and time-normalized AUC values (AUC per hour) over the first 24 postoperative hours were calculated.
Results: The B group required significantly less remifentanil dosage (8.52 ± 3.39 vs. 11.48 ± 3.68 µg/kg/h, P<0.001). Remimazolam dosage was also lower in the B group (1.01 ± 0.17 vs. 1.11 ± 0.22 mg/kg/h, P=0.031). The incidence of hypotension was lower in the B group (11% vs. 33%, P=0.047). No significant differences were observed in most EEG spectral bands. Time-normalized postoperative pain burden, expressed as NRS AUC per hour, was significantly lower in the BB group both at rest (2.6 ± 1.0 vs. 3.4 ± 1.0, P = 0.001) and during coughing (2.8 ± 1.0 vs. 3.7 ± 1.2, P < 0.001).
Conclusion: Intraoperative BB were associated with reduced remifentanil requirements and improved hemodynamic stability in patients undergoing remimazolam-based general anesthesia. While EEG changes were limited, these findings suggest that binaural beats may serve as a useful adjunct during anesthesia maintenance.