This study intends to conduct postoperative sleep intervention for elderly patients with sleep disorders undergoing surgery. We hope to explore whether propofol can improve the postoperative sleep quality of elderly patients with sleep disorders, prevent the occurrence of postoperative delirium in elderly patients, relieve patients' pain, promote patients' postoperative rehabilitation, and provide reference for realizing the rapid rehabilitation of elderly patients with sleep disorders through intravenous administration of research drugs, on the premise of improving patient comfort and ensuring patient safety.

The purpose of this multicenter, randomized, controlled clinical study was to evaluate the efficacy and safety of propofol compared with normal saline and dexmedetomidine in the effect of postoperative sleep quality in elderly subjects with sleep disorders. Subjects were randomly assigned to propofol group, dexmedetomidine group or normal saline control group. Propofol group: At 21:00 on the night of tracheal extubation, propofol was administered intravenously. MOAAS/S was used to evaluate subjects 30 seconds after the end of administration.Dexmedetomidine group: treated with dexmedetomidine at 21 PM on the day of tracheal extubation. During administration, patients were evaluated with MOAA/S every 2min. Normal saline control group: 21 on the night of tracheal extubation: Normal saline was injected intravenously at the rate of 0.5ml/(kg.h) beginning at 00. During the administration, patients were evaluated with MOAA/S every 2min. The effect of drugs on sleep improvement was evaluated by subjective scale and objective electrical monitoring.

Inclusion Criteria:

• age ≥ 60 years old
• Chronic insomnia
• Pittsburgh Sleep Quality Index>5 points
• Daytime functional impairment (component Ⅶ ≥2 points in PSQI)
• Patients undergoing elective surgery
• Patients to be admitted to ICU after surgery
• Voluntarily participate in the study and sign the informed consent

Exclusion Criteria:

• Subjects with severe hemodynamic instability
• Subjects with difficult airway
• Patients with other sleep disorders (including sleep apnea syndrome, exercise-related sleep disorders and other types of sleep disorders)
• Subjects requiring sedation, mechanical ventilation, or sleep prior to medication;
• Severe liver dysfunction (Child-Pugh GRADE C)
• Severe renal dysfunction (requiring dialysis before surgery)
• Patients with allergies to study drugs and related ingredients
• Patients with severe dementia, low cognitive function, language impairment, severe hearing or vision impairment, mental disorder, coma and other conditions cannot complete the assessment

The blind group included the principal investigator, and any other participants in the recording, evaluation, analysis, or review of efficacy/safety endpoint data, who were primarily responsible for study operations other than drug administration (e.g., subject screening, efficacy and safety indicator recording, statistical analysis, etc.).