Effect of nasal mask oxygenation on incidence of hypoxemia during gastroscopy with propofol sedation in patients at risk of hypoxemia: a prospective randomized controlled study. - Yan, Wenlong; Yan, Liang; Meng, Wenjun; Cai, Jianyue; Qian, Meiping; Zhang, Yan; Li, Juan; Shu, Shuhua; Kang, Fang (BMC Anesthesiology, 2025)