RCT: In patients undergoing gastroscopy under intravenous anesthesia, nasal mask oxygenation may reduce the risk of hypoxemia compared to traditional nasal cannula. 27 Jan, 2022 | 09:13h | UTC Comparison of a Nasal Mask and Traditional Nasal Cannula During Intravenous Anesthesia for Gastroscopy Procedures: A Randomized Controlled Trial – Anesthesia & Analgesia