Driver BE, et al. - Researchers planned this study to compare the nonrebreather mask with flush rate oxygen to a bag-valve mask with flush rate oxygen (with and without inspiratory assistance) and determine whether the efficacy of bag-valve mask with flush rate oxygen is compromised by a simulated mask leak. The nonrebreather mask with flush rate oxygen was noninferior to the bag-valve mask, with and without inspiratory assistance. Even with flush rate oxygen, bag-valve mask performed poorly with a mask leak. In spontaneously breathing patients with no underlying respiratory pathology, flush rate oxygen with a nonrebreather mask seemed a reasonable default preoxygenation method.