Given the current Covid-19 pandemic alongside the lack of evidence on aerosolization during upper endoscopy the investigators are conducting a randomized controlled trial seeking to assess both the level of aerosolization that occurs during these procedures along with determining if utilization of an endoscopic patient face-masks reduces the level of aerosolized particles. The protocol includes the use of a commercially available particle counter the investigators are employing for the measurement of aerosols before, during, and after anesthesia assisted upper endoscopic procedures. The investigators are recruiting patients undergoing these procedures with a target of 30 patients undergoing endoscopy without a facemask and 30 patients undergoing endoscopy with one.

Inclusion Criteria:

• All patients undergoing elective upper endoscopic procedures (upper endoscopy, ERCP, endoscopic ultrasound) with monitored anesthesia care at main campus Cleveland Clinic inpatient endoscopy unit.

Exclusion Criteria:

• Any patient requiring endotracheal intubation
• Pregnant patients
• Emergency procedures
• Patients who require use of a facemask before or during the procedure due to medical necessity
• Patients under the age of 18
• Non-English speaking individuals
• Patients unable to provide consent.
• Any procedure done outside the designated procedure room.
• If in the opinion of the anesthesiologist, a subject who was randomized to the control arm requires placement of the procedural mask to augment oxygenation, the subject will be removed from the study

Adverse events were not collected for the study.