This study is a prospective, single-center, double-blind, randomized controlled trial designed to evaluate the effect of oliceridine versus sufentanil on the incidence of hypoxemia in adult patients undergoing gastrointestinal endoscopy under deep sedation. The trial will compare the rates of hypoxemia (defined as SpO₂ ≤92%) between the two analgesic regimens when combined with propofol. The primary aim is to determine whether oliceridine can reduce the incidence of hypoxemia compared to sufentanil during endoscopic procedures.