Low-dose dexmedetomidine improves postoperative sleep and pain in gynecological surgery: a randomized trial.

Background: Postoperative sleep disturbances often lead to a vicious cycle with pain, severely hindering the recovery of patients. Women, due to fluctuations in sex hormones and their unique pain modulation mechanisms, are particularly vulnerable to both postoperative sleep disorders and pain. Dexmedetomidine (DEX) has shown potential in promoting sleep and providing analgesia. Therefore, exploring its application in optimizing postoperative pain management for gynecological patients is of great significance in enhancing recovery outcomes. Objective: This study aimed to assess the impact of adding low-dose dexmedetomidine (DEX) to a sufentanil-based patient-controlled intravenous analgesia (PCIA) regimen on postoperative sleep quality and pain in patients undergoing gynecological surgery. Methods: This single-center, randomized, double-blind, placebo-controlled trial was conducted between 28 September 2025, and 30 November 2025. A total of 130 patients scheduled for elective gynecological surgery were enrolled. Participants were randomly assigned to one of two groups (65 patients per group) using a computer-generated randomization sequence, with allocation concealed via sequentially numbered, opaque sealed envelopes. Patients in the experimental (DS) group received a PCIA) regimen consisting of DEX (0.06 μg/kg/h) combined with sufentanil (0.04 μg/kg/h). The control (S) group received PCIA with sufentanil alone at the same dosage of 0.04 μg/kg/h.The primary outcome was the incidence of sleep disturbance on the first postoperative night, defined as a Pittsburgh Sleep Quality Index (PSQI) global score ≥5. Secondary outcomes included PSQI scores on the first and second postoperative nights, Visual Analogue Scale (VAS) pain scores assessed at 6, 12, 24, and 48 h postoperatively, total postoperative sufentanil consumption, the number of PCA button presses recorded by the infusion pump, and the incidence of adverse events-specifically bradycardia (heart rate <50 bpm), hypotension (mean arterial pressure <60 mmHg), postoperative nausea and vomiting (PONV), and the use of rescue analgesia with intravenous flurbiprofen axetil. Results: For the primary outcome, the incidence of sleep disturbance (PSQI ≥ 5) was significantly lower in the DS group compared to the S group (21.5% vs. 47.7%, P = 0.002). Regarding secondary outcomes, PSQI scores on the first and second postoperative nights were also significantly better in the DS group (P = 0.020 and P = 0.016, respectively). In terms of pain control, VAS pain scores at all time points within 48 h were significantly lower in the DS group (P < 0.05). However, there were no significant differences between the two groups in sufentanil consumption (P = 0.593) or the number of PCA presses (P = 0.092) during the 48-h postoperative period. For adverse events, the DS group had a significantly higher incidence of bradycardia (16.9% vs. 3.1%, P = 0.009), a significantly lower incidence of postoperative nausea and vomiting (PONV) (13.8% vs. 32.3%, P = 0.013), and a lower proportion of patients requiring rescue analgesia (9.2% vs. 26.2%, P = 0.011). No significant difference was observed in the incidence of hypotension between the groups (6.2% vs. 4.6%, P = 0.676). Conclusion: The addition of low-dose DEX (0.06 μg/kg/h) to a sufentanil-based PCIA regimen significantly improved postoperative sleep quality, reduced pain, and decreased the incidence of PONV in gynecological patients, without reducing opioid consumption. The mechanism may be attributed to DEX's mood-stabilizing and direct sleep-promoting effects rather than an opioid-sparing effect. Although the risk of bradycardia increased, there was no rise in hypotension risk. Collectively, our findings support that this low-dose regimen is a safe and effective multimodal analgesic strategy, offering a valuable therapeutic option to simultaneously improve sleep and alleviate pain in female patients during the postoperative period. Clinical Trial Registration: https://www.chictr.org.cn, identifier ChiCTR2500108204.