Hypoxia is a common adverse event during sedated hysteroscopy for assisted reproduction, and it is more likely to occur in overweight or obese patients. In sedated gastroscopy, the incidence of hypoxia with remimazolam is lower than that with propofol. The present study is a single-center, randomized, single-blind, controlled clinical trial. Overweight or obese patients undergoing sedated hysteroscopy for diagnosis and treatment, with ASA grade I or II, were selected as subjects and randomly divided into an experimental group and a control group, with 300 subjects in each group. Sedation induction and maintenance are performed using remimazolam or propofol combined with remifentanil, respectively, to compare the incidence of hypoxia during surgery between the two groups of patients.

Inclusion Criteria:

1. Age between 20 and 50 years.
2. Patients undergoing sedated hysteroscopy for assisted reproduction.
3. ASA classification I-II.
4. BMI ≥ 23 kg/㎡.
5. Patients who have signed an informed consent form.

Exclusion Criteria:

1. SpO2 < 95% in patients inhaling air upon entering the room.
2. Diagnosed with chronic obstructive pulmonary disease (COPD) or currently suffering from other acute and chronic lung diseases requiring long-term or intermittent oxygen therapy.
3. Patients with a history of mental and neurological disorders: such as depression, severe central nervous system depression, Parkinson's disease, basal ganglia disease, schizophrenia, epilepsy, Alzheimer's disease, myasthenia gravis, etc.
4. Patients with severe liver dysfunction.
5. Patients with severe renal insufficiency (requiring dialysis before surgery).
6. Severe heart failure (METS < 4).
7. History of drug abuse and/or alcohol abuse within the 2 years preceding the screening period (consuming more than three times the standard alcoholic beverages daily, approximately 10g of alcohol, or equivalent to 50g of Chinese alcohol).
8. Allergies or contraindications to benzodiazepines, flumazenil, opiates and their rescue medications, propofol, eggs, or soy products.
9. Breastfeeding women.
10. Patients whom investigator believe are unsuitable for participating in this trial.