A system configured to deliver pressurized gas to an airway of a subject in accordance with a predetermined therapeutic algorithm. The system includes a pressure generator that generates a pressurized flow of breathable gas and a circuit that communicates the pressurized flow of breathable gas from the pressure generator to the airway of the subject. In order to facilitate the delivery of the pressurized gas to the airway of the subject in accordance with the predetermined therapeutic algorithm, a resistance of the circuit to gas flow is supplemented so that the overall resistance of the circuit is at or near a predetermined level.