Appropriate sizing of the adult facemask and oropharyngeal airway will be determined by the primary anesthesia team. All breaths will be delivered by hand ventilation using the breathing bag of the anesthesia machine. The returned tidal volume will be recorded for each minute of the study period from the pneumotachograph placed inline with the anesthesia circuit at the level of the mask/elbow connector interface as described above. The total time from induction to placement of a breathing tube will be 4-5 minutes and represents an additional minute of "study" time to the standard care. This timing was chosen as the investigators feel that it will provide sufficient information about ventilation volumes without unduly prolonging the anesthetic.