Head Elevation During Pre-oxygenation Can Delay Desaturation Time

This study is a randomized-controlled trial study comparing the association between several degree of head elevation and conventional position during pre-oxygenation to desaturation time in patients undergo endotracheal intubation with general anesthesia

Inclusion Criteria:undergo endotracheal intubation with general anesthesia for elective surgeryaged 18-60 years oldASA physical status 1-2 preoperativelyExclusion Criteria:Patients with difficult airway, cardiopulmonary disease, anemia, grade II obesity, pregnant, history of hypersensitivity to induction agentsPatients did not give consent to follow the study