Abstract: Objective: To evaluate the sedative efficacy of topical lidocaine combined with remimazolam-propofol and its effect on
the incidence of intraoperative hypoxemia during painless gastroscopy in high-altitude winter. Methods: Clinical data of patients un⁃
dergoing painless gastroscopy between November 2024 and January 2025 were retrospectively analyzed. Patients were divided into a
propofol-only group and a lidocaine-remimazolam-propofol combination group. Propoful group was given propofol intravenous injec⁃
tion anesthesia, while the combination group received lidocaine throat spray combined with remifentanil-propofol regimen. Intraopera⁃
tive hypoxemia and respiratory depression, minimum and postoperative SpO2, jaw-thrust frequency and duration, recovery time, and
satisfaction scores were compared. Results: No significant differences in baseline characteristics were observed. No hypoxemia or respi⁃
ratory depression occurred in the combination group, whereas both occurred in 4.32% of patients in the propofol group (P<0.05). The
combination group showed significantly higher intraoperative and postoperative SpO2 level, a shorter recovery time, and higher physi⁃
cian and patient satisfaction scores (P<0.05). Conclusion: The combination of topical lidocaine with remimazolam-propofol signifi⁃
cantly reduces the incidence of intraoperative hypoxemia during painless gastroscopy, improves respiratory function, shortens recovery
time, enhances procedural ease and patient satisfaction, and demonstrates favorable safety and clinical value for broader application.

Key words: painless gastroscopy, lidocaine, remimazolam, propofol, hypoxemia, anesthesia regimen