Historically preoxygenation with bag-valve-mask ventilation (BVM) and an oxygen non-rebreather mask has been the standard for preoxygenation. Recently, the use of high flow nasal cannulaes have been used for preoxygenation however it is unclear in the literature if one provides a superior preoxygenation compared to another. In an effort to determine the best preoxygenation modality for airway management, the investigators will conduct a 3 arm interventional crossover designed study to compare preoxygenation using a non-rebreather mask, BVM and HFNC in 150 patients. To determine which modality provides the best preoxygenation, arterial blood gases will be taken after each intervention and compared against each other.