A nasal cannula allows insertion of an upper endoscopy probe, a transesophageal echo probe for exams, or the like. Currently, a nasal cannula is used to measure expired carbon dioxide and deliver oxygen to sedated patients undergoing these procedures. Use of a face mask, such as a non-rebreathing face mask, during these procedures allows increased delivery of oxygen in patients with compromised respiratory function. A side port can be cut into the non-rebreathing face mask to allow insertion of the probes into patient's mouths while allowing delivery of a higher oxygen concentration. The facemask has the ability to easily separate from the nasal cannula, providing for continued use of the nasal cannula during, for example, a recovery period from sedation.