It is standard practice in the United States and many parts of world to perform Gastrointestinal (GI) endoscopy with the patient under deep sedation. Obesity is accepted as a patient specific risk factor for hypoxic events during procedural sedation for GI endoscopic procedures. The Obese population has a higher prevalence of obstructive sleep apnea (OSA) which is characterized by repeated obstruction of the upper airway, and leads to apnea and desaturation. This prospective, randomized study was designed to compare the effectiveness of the high flow nasal cannula and the standard nasal cannula in morbidly obese (BMI > 40) patients receiving deep intravenous sedation during colonoscopies. This study will assess whether use of the high flow nasal cannula (HFNC) leads to less intraoperative desaturation events compared to the current standard of care.