A system and method for delivering a flow of breathing gas to an airway of a patient. The system monitors a characteristic that varies based on variations of the flow of the breathing gas and determines a Target Flow for the gas to be delivered to the patient based on the monitored characteristic. The Target Flow is set to a level sufficient to treat Cheyne-Stokes respiration or a sleep disordered breathing event. The system also alters the Target Flow based on a determination that the patient is experiencing a sleep disordered breathing event. The system further determines a pressure relief component and controls the flow of gas delivered to the patient based on the Target Flow and the pressure relief component.