120 consecutive female patients, 18-65 years old, American Society of Anesthesiologists (ASA) physical status I to II, scheduled for hysteroscopic surgery under propofol-based intravenous anesthesia will be recruited in this cohort study. The day before surgery, participants will be assessed the state of preoperative anxiety and depression. On the day of surgery, propofol will be administered by target controlled infusion (TCI) pump. During induction of anesthesia, the level of sedation will be evaluated. The induction dose of propofol, target effect-site concentration(Cet), plasma concentration(Cp) and effect-site concentration (Ce) of propofol will be recorded.

120 consecutive female patients, 18-65 years old, American Society of Anesthesiologists ( ASA) physical status I to II, scheduled for hysteroscopic surgery under propofol-based intravenous anesthesia will be recruited in this prospective cohort study. The day before surgery, participants were asked to complete the modified HADS questionnaire in an isolated calm room, and the score was used to assess the patients' anxiety and depression level in the past 6 months. On the day of surgery, propofol (Fresenius Kabi Austria GmbH, Graz, Austria)was administrated by using an intravenous target controlled infusion (TCI) pump (Alaris PK, Basingstoke, UK) with Schnider kinetic model. The initial effect-site concentration (Ce) was set as 1.0 μg/ml. After the TCI system displayed that Cp and Ce were at equilibrium, the target concentration of propofol was increased by an increment of 0.5 μg/ml until the patients achieved the three desired levels of sedation.The Ce and dose of propofol and the consuming time were recorded.

Inclusion Criteria:

• female
• American Society of Anesthesiologists（ASA） physical status I or II
• Body Mass Index(BMI) 18-25kg/m2
• scheduled for hysteroscopic surgery under propofol-based intravenous anesthesia.

Exclusion Criteria:

• suffering from psychiatric diseases.
• chronic use of anxiolytics, antidepressants, and sedative-hypnotics.
• any sedative premedication.
• a history of alcohol abuse.
• allergy to propofol.
• declining to participate and cooperate.

Female patients, 18-65 years old, American Society of Anesthesiologists （ASA） physical status I or II, scheduled for hysteroscopic surgery under propofol-based intravenous anesthesia in the first affiliated hospital of Sun Yat-sen University in Guangzhou, China will be recruited in this cohort study.

All IPD that underlie results in a publication will be shared.

Starting 6 months after publication.