A nasal interface device delivers a high flow rate of a gas having a pressurethat is adjustable to a patient. The deviceincludes a nasal insert that is adapted to deliver pressurized gas to a nasalcavity of the patient, and receive and direct expiredair. The nasal insert has a pressurized breathing gas delivery port and anexpired gas port. An expiratory limb pressure regulator isin fluid communication with the expired gas port.
