Inclusion Criteria:  Patients with body mass index ≥ 30 kg/m2 who are scheduled for general anesthesia  Exclusion Criteria:  Risk of delayed gastric emptying or gastroesophageal reflux (gastroesophageal reflux disease, achalasia, history of stomach surgery, gastrointestinal obstruction, uncontrolled DM) Pregnancy Known or predicted difficult airway