This prospective randomized study aims to compare propofol and remifentanil for sedation during elective diagnostic gastroscopy. The ideal sedative agent for gastroscopy should provide adequate sedation, rapid recovery, patient safety, and high endoscopist satisfaction. Although propofol is widely used for procedural sedation, remifentanil's ultra-short pharmacokinetic profile may offer advantages in short procedures such as gastroscopy. However, comprehensive comparative data evaluating recovery quality, safety, and procedural conditions between these agents remain limited. This study evaluates sedation efficacy, recovery characteristics, complication rates, and endoscopist satisfaction associated with propofol- and remifentanil-based sedation protocols.

Gastroscopy is a commonly performed diagnostic procedure that often requires sedation to improve patient comfort and procedural conditions. The choice of sedative agent plays a critical role in balancing procedural efficacy, patient safety, rapid recovery, and endoscopist satisfaction. Propofol is frequently preferred due to its rapid onset and predictable recovery profile; however, it is associated with dose-dependent respiratory and hemodynamic adverse effects. Remifentanil, an ultra-short-acting opioid, offers rapid titratability and fast recovery, potentially making it an attractive alternative for short-duration procedures such as gastroscopy.

This prospective randomized study was conducted between October 2025 and January 2026 and included 86 adult patients with American Society of Anesthesiologists (ASA) physical status I-III who were scheduled for elective diagnostic gastroscopy. Patients were randomly assigned using block randomization to receive either propofol-based sedation (n=44) or remifentanil-based sedation (n=42). All patients received 2 mg intravenous midazolam as premedication prior to the procedure.

In the propofol group, sedation was maintained using a continuous infusion of propofol at 100-150 mcg/kg/min. In the remifentanil group, patients received a loading dose of 1 mcg/kg followed by a continuous infusion of 0.025-0.1 mcg/kg/min. Sedation depth was standardized and continuously monitored using bispectral index (BIS), targeting values between 60 and 80, in combination with the Ramsay Sedation Scale, targeting scores of 2-3.

The primary outcome measures were recovery time and the incidence of sedation-related complications, including respiratory depression, hypoxia, bradycardia, hypotension, and the need for airway interventions. Secondary outcome measures included procedure duration, patient-reported quality of recovery assessed using the Quality of Recovery-15 (QoR-15) questionnaire (score range 0-75), endoscopist satisfaction measured using a 5-point Likert scale, and time to discharge.

By comparing these two sedation strategies under standardized monitoring and sedation targets, this study aims to provide clinically relevant evidence to guide sedative agent selection for elective gastroscopy, focusing on recovery quality, safety profile, and procedural satisfaction.

Inclusion Criteria:

• Age ≥18 years
• ASA physical status I-III
• Scheduled for elective diagnostic gastroscopy
• Able to provide informed consent

Exclusion Criteria:

• ASA IV-V
• Pregnancy or lactation
• Known allergy to propofol, remifentanil, or midazolam
• Severe cardiopulmonary disease (NYHA III-IV, unstable angina, severe COPD requiring home oxygen)
• Chronic opioid use (>3 months daily use)
• BMI >40 kg/m²
• Obstructive sleep apnea requiring CPAP
• Severe hepatic or renal impairment
• Inability to provide informed consent
• Emergency procedures

Individual participant data will not be shared to protect participant privacy and confidentiality in accordance with local data protection regulations and institutional ethics committee requirements. Summary results will be published in peer-reviewed journals.

Participants are sedated during the procedure and unaware of group assignment. Outcomes assessors (recovery room nurses, independent observers assessing Ramsay scores) are blinded to group allocation. The anesthesiologist administering sedation is necessarily unblinded to allow appropriate drug titration but does not participate in outcome assessment. Endoscopists are blinded to group allocation and BIS values.