Study population
abnormal cognitive function, psychiatric disorders
NEUROLOGICAL DISEASE
Han Chinese patients aged 18–60 years old with an American Society of Anesthesiologists (ASA) physical status of I–II who were scheduled for elective laparoscopic gynecological surgery and signed the informed consent voluntarily were eligible for inclusion in this study. Patients with a history of psychiatric disorders or neurological diseases, alcohol or drug abuse, operation within one month before surgery, use of sedative medicine or antidepressant within one week before surgery, abnormal cognitive function, inability to communicate fluently, body mass index (BMI) ≥ 28 or ≤ 18, contraindications to s-ketamine, and who participated in other trials or who once were recruited were excluded from this study. The withdrawal criteria included: operation time of < 1 h or > 3 h, unexpected intraoperative conversion to laparotomy, incomplete cases data, patients admitting to Intensive Care Unit (ICU) after surgery.