2.1. Study Design, Setting, and Participants

This prospective, observational study was conducted at Kagawa Prefectural Shirotori Hospital from February 2021 to March 2021. Eighty consecutive unsedated patients who underwent screening EGD with EB use were prospectively enrolled. The inclusion criterion was an age of >18 years. The exclusion criteria were refusal to use the EB, a need for emergency endoscopic treatment, the presence of psychiatric disease or psychiatric symptoms, and the presence of severe respiratory disease. All EGD procedures were performed by a single endoscopist (S.F.) in the same room measuring 19.39 m², with a total supply of three air changes per hour, internal recirculation at 23 °C ± 1 °C, and humidity of <60%.