This study aims to evaluate the sedative efficacy and safety of remimazolam combined with oliceridine in elderly patients undergoing painless gastrointestinal endoscopy. Elderly patients often face higher risks of respiratory and hemodynamic depression during clinical sedation. This trial will investigate whether the combination of remimazolam and oliceridine can provide stable sedation, maintain stable vital signs, and reduce the incidence of adverse events such as hypoxemia and postoperative cognitive fluctuation in this vulnerable population.

This is a clinical study conducted at the Baoshan Branch of Renji Hospital, Shanghai Jiao Tong University School of Medicine. The study will strictly adhere to ethical guidelines, and all research activities will be carried out after receiving full approval from the Ethics Committee.

Elderly participants will be enrolled based on predefined inclusion criteria with comprehensive vulnerability assessments. During the gastrointestinal endoscopy procedure, vital signs, particularly oxygen saturation (SpO2) and its duration of depression, will be monitored closely. To address potential educational bias in cognitive assessments, the study will utilize the Mini-Mental State Examination (MMSE) stratified by years of education alongside the Montreal Cognitive Assessment (MoCA) to comprehensively evaluate postoperative cognitive outcomes. Follow-up assessments will be systematically conducted at designated time points (e.g., 1 week, 1 month, 3 months, and 6 months) post-procedure.

Inclusion Criteria:

1. Elderly individuals scheduled to undergo painless gastrointestinal endoscopy.
2. Age between 65 and 80 years.
3. Body mass index (BMI) between 18 and 30 kg/m².
4. American Society of Anesthesiologists (ASA) physical status I-III (ASA III patients eligible only with mild-to-moderate dysfunction of a single organ system, without severe organ failure, and considered able to tolerate the procedure).
5. Fried frailty phenotype score < 3.
6. Mini-Mental State Examination (MMSE) score ≥ 27.
7. Provision of written informed consent by the patient or legal representative.

Exclusion Criteria:

1. Allergy or contraindication to remimazolam, oliceridine, or sufentanil.
2. Liver or renal failure (Child-Pugh class C or eGFR < 30 mL/min).
3. Systemic infection, immunosuppression, coagulation disorder, upper gastrointestinal bleeding, or intestinal obstruction.
4. History of opioid dependence or long-term use of psychotropic drugs.
5. Difficult airway or severe respiratory dysfunction.
6. Cognitive impairment, psychiatric disease, or inability to cooperate with assessment.
7. New York Heart Association (NYHA) functional class III or higher[cite: 3].
8. Fried frailty phenotype score ≥ 3.
9. Use of sedative or analgesic drugs within 24 hours before enrollment.

Due to the inclusion of sensitive clinical and private information of elderly patients, full individual participant data (IPD) cannot be made publicly available as it was not explicitly authorized in the patient informed consent. To protect patient privacy and ensuring data security, the raw IPD will not be shared on public platforms. De-identified data may be available from the corresponding author upon reasonable academic request.