The purpose of the study is to evaluate the use of high flow nasal cannula versus standard oxygen therapy for high-risk patients undergoing endoscopy procedures.

Patients with a higher BMI are at greater risk for lower oxygen levels which can delay the endoscopy procedure. This research is being conducted to find out if high risk patients will have a shorter recovery time and improved procedural conditions with a high flow nasal cannula versus standard oxygen therapy.

Inclusion Criteria:

• All patients age 18 years and older who present to Gonda 2 procedural area for Endoscopic ultrasound (EUS) with or without endoscopy (EGD)/biopsy/tissue sampling. with BMI ≥ 35 kg/m2 (BMI within the past 6 months in electronic medical records or at current procedure) who are able to consent will be approached for potential enrollment.

Exclusion Criteria:

• Need for general anesthesia for the procedure instead of the standard monitored anesthesia care.
• Patients undergoing combined procedure: Therapeutic EUS/combined procedures including EUS/ERCP, EUS/colonoscopy
• Patients on home oxygen therapy, or the diagnosis of "severe COPD"
• Patients with existing tracheostomy
• Inpatients undergoing EUS
• Inability to consent
• Cognitive impairment
• Blocked nasal passages
• Trauma/previous surgery to the nasopharynx
• Irregularities of the nose, face, or airway such that HFNC cannot be properly fitted