Effect of Preoperative Stellate Ganglion Block on Early Postoperative Sleep Disturbance in Patients with High Sympathetic Tone Undergoing Laparoscopic Cholecystectomy—A Prospective, Randomized Controlled Study

INTERVENTION: Experimental group:Stellate ganglion block before anesthesia induction, 1% lidocaine 5ml;Control group:False block before anesthesia induction, 5ml of saline ; CONDITION: postoperative sleep disturbance PRIMARY OUTCOME: Incidence of sleep disturbance on the first postoperative day; SECONDARY OUTCOME: Pain score within 24 hours postoperatively;Incidence of PONV;Extubation time and PACU stay duration;QoR‐15 on the first postoperative day; INCLUSION CRITERIA: 1. Age 18‐65 years, male or female; 2. Scheduled for elective laparoscopic cholecystectomy under general anesthesia; 3. Preoperative HRV assessment indicating high sympathetic tone (LF/HF >= 2.5); 4. American Society of Anesthesiologists (ASA) physical status classification I‐III; 5. Alert and oriented, able to cooperate with questionnaire‐based assessments; 6. Willing to participate and provide written informed consent.