Abstract: Described herein is a respiratory apparatus for delivering and detecting gases in a patient. The apparatus includes a first cannula having a distal end adapted to be received at a first depth in a nasal passage of the patient, and a second cannula having a distal end adapted to be received at a second depth in the nasal passage, wherein the distal end of the first cannula can receive a proximal end of the second cannula. The second cannula circumventing any obstruction of the nasal passage. Additionally, the apparatus has a septum which can have a membrane thus facilitating the delivery and detection of gases simultaneously.