An oxygen face mask with capnometer and side port is used in sedated patients undergoing endoscopy or transesophageal echocardiography. The mask can include an elliptical insertion port to maximize access to the oral opening for performing procedures as well as making it easier for awake patients to eat and drink. A reinforcement elliptical band can tent the mask up to enhance oral access. A set of keyhole notches can keep the nasal cannula out of eyes, secures the mask to the face and allows for easy partial/full removal of mask with tactile feedback. An oxygen inflow port may be located laterally, away from the oral opening. The mask can include an attachment pin design that provides easy removal and reapplication when one side of patient's face is turned away from the anesthesiologist. The mask can include carbon dioxide sampling ports to allow for CO2 monitoring from left or right.
