Effect of low-dose supplemental esketamine infusion on the intraoperative frontal electroencephalography dynamics and postoperative sleep disturbance during gynecological laparoscopic surgery: a double-blind, randomized clinical trial

Background: Recent studies have shown that intraoperative administration of subanesthetic esketamine not only induced an active prefrontal electroencephalogram (EEG) pattern during sevoflurane anesthesia, but also improve the sleep quality in women after laparoscopic surgery, but the latter regarding the specific mechanism of the EEG frontal power band activity remains unknown. Our research aimed to investigate the impact of low-dose supplemental esketamine infusion on the incidence of postoperative sleep disturbance and the intraoperative frontal EEG characteristics in patients undergoing gynecologic laparoscopic surgery under general anesthesia. Methods: Ninety-eight patients scheduled for gynecological laparoscopic surgery under general anesthesia were randomly assigned to receive either a continuous infusion of 1 mg · kg −1 · h −1 esketamine or an equivalent volume of normal saline for 30 minutes. The primary outcome was the incidence of postoperative sleep disturbance on postoperative day 1, defined as a numeric rating scale (NRS) score of subjective sleep quality ≥6. Secondary outcomes included the changes of frontal EEG patterns and EEG frequency spectrum indices, NRS scores of subjective sleep quality, and the incidence of postoperative sleep disturbance on postoperative days 3 and 7. Results: All 98 patients completed the study. The incidence of postoperative sleep disturbance on postoperative day 1 was significantly lower in the esketamine group compared to the control group (16.3% vs 34.7%; relative risk [RR], 0.47 [95% CI, 0.22-0.99]; P = 0.037). The esketamine group exhibited significantly higher power in the beta wave (mean difference = 1 [0, 3]; P = 0.016), gamma wave (mean difference = 3 [2, 4]; P < 0.001), and peak frequency of the alpha-beta wave (mean difference = 1 [1, 2]; P < 0.001) compared to the control group. Additionally, Ai left and Ai right was significantly higher in the esketamine group at the time of immediately after CO 2 pneumoperitoneum, immediately after cessation of study drug infusion, and at the end of surgery ( P < 0.05 for all). The NRS score of subjective sleep quality on postoperative day 1 was significantly lower in the esketamine group (median difference = −1 [−2,0], P = 0.032). However, no significant differences were observed between the two groups in the NRS scores for subjective sleep quality or the incidence of postoperative sleep disturbance on postoperative days 3 and 7. Conclusions: Supplemental low-dose esketamine significantly reduced the incidence of postoperative sleep disturbance in patients undergoing gynecological laparoscopic surgery, which may be associated with the alternations of the intraoperative frontal four-channel EEG patterns.