A patient respiratory mask includes a face mask that in use defines an enclosed space, an oxygen reservoir bag in fluid communication with the enclosed space via a one-way intake valve, an out-flow port positioned on the face mask allowing for the exhaust of expired air. A source of oxygen is in fluid communication with the reservoir bag via an oxygen delivery tube, and a nasal cannula is positioned within the enclosed space and is connected to the source of oxygen by a nasal cannula delivery tube that is in fluid communication with the oxygen delivery tube. An in-line flow restrictor is positioned in the nasal cannula delivery tube and allows high-flow oxygen into the reservoir bag, while at the same time limiting oxygen flow into the nasal cannula.
