Overview
The goal of this randomized, double-blind, placebo-controlled, 2×2 factorial trial is to evaluate the effect of intraoperative dexmedetomidine combined with either femoral nerve block (FNB) or adductor canal block (ACB) on postoperative sleep quality in patients aged 18-85 years with ASA I-III undergoing elective knee arthroscopy under general anesthesia.
The main questions it aims to answer are:
- Does intraoperative dexmedetomidine infusion (0.5 μg/kg/h) improve postoperative sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI) at 24 h and 48 h after surgery?
- Is there an interaction between the type of nerve block (FNB vs. ACB) and the use of dexmedetomidine on postoperative sleep quality?
Eligibility
Inclusion Criteria:
- Age 18 to 85 years.
- American Society of Anesthesiologists (ASA) physical status I to III.
- Body Mass Index (BMI) between 18 and 30 kg/m² and body weight \> 50 kg.
- Scheduled for elective knee arthroscopy under general anesthesia.
- Complete preoperative workup, confirmed diagnosis, and indication for knee arthroscopy with complete postoperative medical records.
- Normal mental and cognitive status.
- Patient or legally authorized representative has provided written informed consent for anesthesia and study participation.
Exclusion Criteria:
- Refusal to participate in the study.
- Inability to communicate effectively.
- Known allergy or contraindication to any study drug (ropivacaine, dexmedetomidine, propofol, sufentanil, remifentanil, vecuronium, or sevoflurane).
- History of knee trauma or knee surgery; diagnosed with immune system disorders (e.g., rheumatoid arthritis, systemic lupus erythematosus); neuromuscular diseases or psychiatric disorders; restless legs syndrome (RLS); periodic limb movement disorder (PLMD).
- Coagulation disorders or local infection at the puncture site precluding peripheral nerve block.
- Severe hepatic or renal dysfunction.
- Severe cardiopulmonary insufficiency.
- Pregnancy.
- Diagnosis of obstructive sleep apnea (OSA) or requirement for continuous positive airway pressure (CPAP) therapy.
- Regular use of sedative-hypnotic drugs (benzodiazepines, non-benzodiazepine hypnotics, melatonin receptor agonists, etc.) or antidepressants/anxiolytics known to affect sleep architecture (e.g., trazodone, mirtazapine) within the past 1 month.
- Pittsburgh Sleep Quality Index (PSQI) score \> 5.
